1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653 3654 3655 3656 3657 3658 3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686 3687 3688 3689 3690 3691 3692 3693 3694 3695 3696 3697 3698 3699 3700 3701 3702 3703 3704 3705 3706 3707 3708 3709 3710 3711 3712 3713 3714 3715 3716 3717 3718 3719 3720 3721 3722 3723 3724 3725 3726 3727 3728 3729 3730 3731 3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745 3746 3747 3748 3749 3750 3751 3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798 3799 3800 3801 3802 3803 3804 3805 3806 3807 3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834 3835 3836 3837 3838 3839 3840 3841 3842 3843 3844 3845 3846 3847 3848 3849 3850 3851 3852 3853 3854 3855 3856 3857 3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037 4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050 4051 4052 4053 4054 4055 4056 4057 4058 4059 4060 4061 4062 4063 4064 4065 4066 4067 4068 4069 4070 4071 4072 4073 4074 4075 4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097 4098 4099 4100 4101 4102 4103 4104 4105 4106 4107 4108 4109 4110 4111 4112 4113 4114 4115 4116 4117 4118 4119 4120 4121 4122 4123 4124 4125 4126 4127 4128 4129 4130 4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141 4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170 4171 4172 4173 4174 4175 4176 4177 4178 4179 4180 4181 4182 4183 4184 4185 4186 4187 4188 4189 4190 4191 4192 4193 4194 4195 4196 4197 4198 4199 4200 4201 4202 4203 4204 4205 4206 4207 4208 4209 4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220 4221 4222 4223 4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235 4236 4237 4238 4239 4240 4241 4242 4243 4244 4245 4246 4247 4248 4249 4250 4251 4252 4253 4254 4255 4256 4257 4258 4259 4260 4261 4262 4263
use std::borrow::{Borrow, BorrowMut};
use std::ops::{Deref, DerefMut, RangeBounds};
use std::sync::atomic::Ordering::{Acquire, Relaxed, Release};
use std::sync::atomic::{self, AtomicUsize};
use std::{cmp, fmt, hash, mem, ptr, ptr::NonNull, slice};
use crate::pool::{PoolId, PoolRef};
use crate::{buf::IntoIter, buf::UninitSlice, debug, Buf, BufMut};
/// A reference counted contiguous slice of memory.
///
/// `Bytes` is an efficient container for storing and operating on contiguous
/// slices of memory. It is intended for use primarily in networking code, but
/// could have applications elsewhere as well.
///
/// `Bytes` values facilitate zero-copy network programming by allowing multiple
/// `Bytes` objects to point to the same underlying memory. This is managed by
/// using a reference count to track when the memory is no longer needed and can
/// be freed.
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut mem = Bytes::from(&b"Hello world"[..]);
/// let a = mem.slice(0..5);
///
/// assert_eq!(a, b"Hello");
///
/// let b = mem.split_to(6);
///
/// assert_eq!(mem, b"world");
/// assert_eq!(b, b"Hello ");
/// ```
///
/// # Memory layout
///
/// The `Bytes` struct itself is fairly small, limited to a pointer to the
/// memory and 4 `usize` fields used to track information about which segment of
/// the underlying memory the `Bytes` handle has access to.
///
/// The memory layout looks like this:
///
/// ```text
/// +-------+
/// | Bytes |
/// +-------+
/// / \_____
/// | \
/// v v
/// +-----+------------------------------------+
/// | Arc | | Data | |
/// +-----+------------------------------------+
/// ```
///
/// `Bytes` keeps both a pointer to the shared `Arc` containing the full memory
/// slice and a pointer to the start of the region visible by the handle.
/// `Bytes` also tracks the length of its view into the memory.
///
/// # Sharing
///
/// The memory itself is reference counted, and multiple `Bytes` objects may
/// point to the same region. Each `Bytes` handle point to different sections within
/// the memory region, and `Bytes` handle may or may not have overlapping views
/// into the memory.
///
///
/// ```text
///
/// Arc ptrs +---------+
/// ________________________ / | Bytes 2 |
/// / +---------+
/// / +-----------+ | |
/// |_________/ | Bytes 1 | | |
/// | +-----------+ | |
/// | | | ___/ data | tail
/// | data | tail |/ |
/// v v v v
/// +-----+---------------------------------+-----+
/// | Arc | | | | |
/// +-----+---------------------------------+-----+
/// ```
///
/// # Mutating
///
/// While `Bytes` handles may potentially represent overlapping views of the
/// underlying memory slice and may not be mutated, `BytesMut` handles are
/// guaranteed to be the only handle able to view that slice of memory. As such,
/// `BytesMut` handles are able to mutate the underlying memory. Note that
/// holding a unique view to a region of memory does not mean that there are no
/// other `Bytes` and `BytesMut` handles with disjoint views of the underlying
/// memory.
///
/// # Inline bytes
///
/// As an optimization, when the slice referenced by a `Bytes` handle is small
/// enough [^1]. In this case, a clone is no longer "shallow" and the data will
/// be copied. Converting from a `Vec` will never use inlining. `BytesMut` does
/// not support data inlining and always allocates, but during converion to `Bytes`
/// data from `BytesMut` could be inlined.
///
/// [^1]: Small enough: 31 bytes on 64 bit systems, 15 on 32 bit systems.
///
pub struct Bytes {
inner: Inner,
}
/// A unique reference to a contiguous slice of memory.
///
/// `BytesMut` represents a unique view into a potentially shared memory region.
/// Given the uniqueness guarantee, owners of `BytesMut` handles are able to
/// mutate the memory. It is similar to a `Vec<u8>` but with less copies and
/// allocations.
///
/// For more detail, see [Bytes](struct.Bytes.html).
///
/// # Growth
///
/// One key difference from `Vec<u8>` is that most operations **do not
/// implicitly grow the buffer**. This means that calling `my_bytes.put("hello
/// world");` could panic if `my_bytes` does not have enough capacity. Before
/// writing to the buffer, ensure that there is enough remaining capacity by
/// calling `my_bytes.remaining_mut()`. In general, avoiding calls to `reserve`
/// is preferable.
///
/// The only exception is `extend` which implicitly reserves required capacity.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
///
/// let mut buf = BytesMut::with_capacity(64);
///
/// buf.put_u8(b'h');
/// buf.put_u8(b'e');
/// buf.put("llo");
///
/// assert_eq!(buf, b"hello");
///
/// // Freeze the buffer so that it can be shared
/// let a = buf.freeze();
///
/// // This does not allocate, instead `b` points to the same memory.
/// let b = a.clone();
///
/// assert_eq!(a, b"hello");
/// assert_eq!(b, b"hello");
/// ```
pub struct BytesMut {
inner: Inner,
}
/// A unique reference to a contiguous slice of memory.
///
/// `BytesVec` represents a unique view into a potentially shared memory region.
/// Given the uniqueness guarantee, owners of `BytesVec` handles are able to
/// mutate the memory. It is similar to a `Vec<u8>` but with less copies and
/// allocations. It also always allocates.
///
/// For more detail, see [Bytes](struct.Bytes.html).
///
/// # Growth
///
/// One key difference from `Vec<u8>` is that most operations **do not
/// implicitly grow the buffer**. This means that calling `my_bytes.put("hello
/// world");` could panic if `my_bytes` does not have enough capacity. Before
/// writing to the buffer, ensure that there is enough remaining capacity by
/// calling `my_bytes.remaining_mut()`. In general, avoiding calls to `reserve`
/// is preferable.
///
/// The only exception is `extend` which implicitly reserves required capacity.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
///
/// let mut buf = BytesVec::with_capacity(64);
///
/// buf.put_u8(b'h');
/// buf.put_u8(b'e');
/// buf.put("llo");
///
/// assert_eq!(&buf[..], b"hello");
///
/// // Freeze the buffer so that it can be shared
/// let a = buf.freeze();
///
/// // This does not allocate, instead `b` points to the same memory.
/// let b = a.clone();
///
/// assert_eq!(a, b"hello");
/// assert_eq!(b, b"hello");
/// ```
pub struct BytesVec {
inner: InnerVec,
}
// Both `Bytes` and `BytesMut` are backed by `Inner` and functions are delegated
// to `Inner` functions. The `Bytes` and `BytesMut` shims ensure that functions
// that mutate the underlying buffer are only performed when the data range
// being mutated is only available via a single `BytesMut` handle.
//
// # Data storage modes
//
// The goal of `bytes` is to be as efficient as possible across a wide range of
// potential usage patterns. As such, `bytes` needs to be able to handle buffers
// that are never shared, shared on a single thread, and shared across many
// threads. `bytes` also needs to handle both tiny buffers as well as very large
// buffers. For example, [Cassandra](http://cassandra.apache.org) values have
// been known to be in the hundreds of megabyte, and HTTP header values can be a
// few characters in size.
//
// To achieve high performance in these various situations, `Bytes` and
// `BytesMut` use different strategies for storing the buffer depending on the
// usage pattern.
//
// ## Delayed `Arc` allocation
//
// When a `Bytes` or `BytesMut` is first created, there is only one outstanding
// handle referencing the buffer. Since sharing is not yet required, an `Arc`* is
// not used and the buffer is backed by a `Vec<u8>` directly. Using an
// `Arc<Vec<u8>>` requires two allocations, so if the buffer ends up never being
// shared, that allocation is avoided.
//
// When sharing does become necessary (`clone`, `split_to`, `split_off`), that
// is when the buffer is promoted to being shareable. The `Vec<u8>` is moved
// into an `Arc` and both the original handle and the new handle use the same
// buffer via the `Arc`.
//
// * `Arc` is being used to signify an atomically reference counted cell. We
// don't use the `Arc` implementation provided by `std` and instead use our own.
// This ends up simplifying a number of the `unsafe` code snippets.
//
// ## Inlining small buffers
//
// The `Bytes` / `BytesMut` structs require 4 pointer sized fields. On 64 bit
// systems, this ends up being 32 bytes, which is actually a lot of storage for
// cases where `Bytes` is being used to represent small byte strings, such as
// HTTP header names and values.
//
// To avoid any allocation at all in these cases, `Bytes` will use the struct
// itself for storing the buffer, reserving 1 byte for meta data. This means
// that, on 64 bit systems, 31 byte buffers require no allocation at all.
//
// The byte used for metadata stores a 2 bits flag used to indicate that the
// buffer is stored inline as well as 6 bits for tracking the buffer length (the
// return value of `Bytes::len`).
//
// ## Static buffers
//
// `Bytes` can also represent a static buffer, which is created with
// `Bytes::from_static`. No copying or allocations are required for tracking
// static buffers. The pointer to the `&'static [u8]`, the length, and a flag
// tracking that the `Bytes` instance represents a static buffer is stored in
// the `Bytes` struct.
//
// # Struct layout
//
// Both `Bytes` and `BytesMut` are wrappers around `Inner`, which provides the
// data fields as well as all of the function implementations.
//
// The `Inner` struct is carefully laid out in order to support the
// functionality described above as well as being as small as possible. Size is
// important as growing the size of the `Bytes` struct from 32 bytes to 40 bytes
// added as much as 15% overhead in benchmarks using `Bytes` in an HTTP header
// map structure.
//
// The `Inner` struct contains the following fields:
//
// * `ptr: *mut u8`
// * `len: usize`
// * `cap: usize`
// * `arc: *mut Shared`
//
// ## `ptr: *mut u8`
//
// A pointer to start of the handle's buffer view. When backed by a `Vec<u8>`,
// this is always the `Vec`'s pointer. When backed by an `Arc<Vec<u8>>`, `ptr`
// may have been shifted to point somewhere inside the buffer.
//
// When in "inlined" mode, `ptr` is used as part of the inlined buffer.
//
// ## `len: usize`
//
// The length of the handle's buffer view. When backed by a `Vec<u8>`, this is
// always the `Vec`'s length. The slice represented by `ptr` and `len` should
// (ideally) always be initialized memory.
//
// When in "inlined" mode, `len` is used as part of the inlined buffer.
//
// ## `cap: usize`
//
// The capacity of the handle's buffer view. When backed by a `Vec<u8>`, this is
// always the `Vec`'s capacity. The slice represented by `ptr+len` and `cap-len`
// may or may not be initialized memory.
//
// When in "inlined" mode, `cap` is used as part of the inlined buffer.
//
// ## `arc: *mut Shared`
//
// When `Inner` is in allocated mode (backed by Vec<u8> or Arc<Vec<u8>>), this
// will be the pointer to the `Arc` structure tracking the ref count for the
// underlying buffer. When the pointer is null, then the `Arc` has not been
// allocated yet and `self` is the only outstanding handle for the underlying
// buffer.
//
// The lower two bits of `arc` are used to track the storage mode of `Inner`.
// `0b01` indicates inline storage, `0b10` indicates static storage, and `0b11`
// indicates vector storage, not yet promoted to Arc. Since pointers to
// allocated structures are aligned, the lower two bits of a pointer will always
// be 0. This allows disambiguating between a pointer and the two flags.
//
// When in "inlined" mode, the least significant byte of `arc` is also used to
// store the length of the buffer view (vs. the capacity, which is a constant).
//
// The rest of `arc`'s bytes are used as part of the inline buffer, which means
// that those bytes need to be located next to the `ptr`, `len`, and `cap`
// fields, which make up the rest of the inline buffer. This requires special
// casing the layout of `Inner` depending on if the target platform is big or
// little endian.
//
// On little endian platforms, the `arc` field must be the first field in the
// struct. On big endian platforms, the `arc` field must be the last field in
// the struct. Since a deterministic struct layout is required, `Inner` is
// annotated with `#[repr(C)]`.
//
// # Thread safety
//
// `Bytes::clone()` returns a new `Bytes` handle with no copying. This is done
// by bumping the buffer ref count and returning a new struct pointing to the
// same buffer. However, the `Arc` structure is lazily allocated. This means
// that if `Bytes` is stored itself in an `Arc` (`Arc<Bytes>`), the `clone`
// function can be called concurrently from multiple threads. This is why an
// `AtomicPtr` is used for the `arc` field vs. a `*const`.
//
// Care is taken to ensure that the need for synchronization is minimized. Most
// operations do not require any synchronization.
//
#[cfg(target_endian = "little")]
#[repr(C)]
struct Inner {
// WARNING: Do not access the fields directly unless you know what you are
// doing. Instead, use the fns. See implementation comment above.
arc: NonNull<Shared>,
ptr: *mut u8,
len: usize,
cap: usize,
}
#[cfg(target_endian = "big")]
#[repr(C)]
struct Inner {
// WARNING: Do not access the fields directly unless you know what you are
// doing. Instead, use the fns. See implementation comment above.
ptr: *mut u8,
len: usize,
cap: usize,
arc: NonNull<Shared>,
}
// Thread-safe reference-counted container for the shared storage. This mostly
// the same as `std::sync::Arc` but without the weak counter. The ref counting
// fns are based on the ones found in `std`.
//
// The main reason to use `Shared` instead of `std::sync::Arc` is that it ends
// up making the overall code simpler and easier to reason about. This is due to
// some of the logic around setting `Inner::arc` and other ways the `arc` field
// is used. Using `Arc` ended up requiring a number of funky transmutes and
// other shenanigans to make it work.
struct Shared {
vec: Vec<u8>,
ref_count: AtomicUsize,
pool: PoolRef,
}
struct SharedVec {
cap: usize,
len: u32,
offset: u32,
ref_count: AtomicUsize,
pool: PoolRef,
}
// Buffer storage strategy flags.
const KIND_ARC: usize = 0b00;
const KIND_INLINE: usize = 0b01;
const KIND_STATIC: usize = 0b10;
const KIND_VEC: usize = 0b11;
const KIND_MASK: usize = 0b11;
const KIND_UNMASK: usize = !KIND_MASK;
const MIN_NON_ZERO_CAP: usize = 64;
const SHARED_VEC_SIZE: usize = mem::size_of::<SharedVec>();
// Bit op constants for extracting the inline length value from the `arc` field.
const INLINE_LEN_MASK: usize = 0b1111_1100;
const INLINE_LEN_OFFSET: usize = 2;
// Byte offset from the start of `Inner` to where the inline buffer data
// starts. On little endian platforms, the first byte of the struct is the
// storage flag, so the data is shifted by a byte. On big endian systems, the
// data starts at the beginning of the struct.
#[cfg(target_endian = "little")]
const INLINE_DATA_OFFSET: isize = 2;
#[cfg(target_endian = "big")]
const INLINE_DATA_OFFSET: isize = 0;
// Inline buffer capacity. This is the size of `Inner` minus 1 byte for the
// metadata.
#[cfg(target_pointer_width = "64")]
const INLINE_CAP: usize = 4 * 8 - 2;
#[cfg(target_pointer_width = "32")]
const INLINE_CAP: usize = 4 * 4 - 2;
/*
*
* ===== Bytes =====
*
*/
impl Bytes {
/// Creates a new empty `Bytes`.
///
/// This will not allocate and the returned `Bytes` handle will be empty.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let b = Bytes::new();
/// assert_eq!(&b[..], b"");
/// ```
#[inline]
pub const fn new() -> Bytes {
Bytes {
inner: Inner::empty_inline(),
}
}
/// Creates a new `Bytes` from a static slice.
///
/// The returned `Bytes` will point directly to the static slice. There is
/// no allocating or copying.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let b = Bytes::from_static(b"hello");
/// assert_eq!(&b[..], b"hello");
/// ```
#[inline]
pub const fn from_static(bytes: &'static [u8]) -> Bytes {
Bytes {
inner: Inner::from_static(bytes),
}
}
/// Returns the number of bytes contained in this `Bytes`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let b = Bytes::from(&b"hello"[..]);
/// assert_eq!(b.len(), 5);
/// ```
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Returns true if the `Bytes` has a length of 0.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let b = Bytes::new();
/// assert!(b.is_empty());
/// ```
#[inline]
pub fn is_empty(&self) -> bool {
self.inner.is_empty()
}
/// Return true if the `Bytes` uses inline allocation
///
/// # Examples
/// ```
/// use ntex_bytes::{Bytes, BytesMut};
///
/// assert!(Bytes::from(BytesMut::from(&[0, 0, 0, 0][..])).is_inline());
/// assert!(Bytes::from(Vec::with_capacity(4)).is_inline());
/// assert!(!Bytes::from(&[0; 1024][..]).is_inline());
/// ```
pub fn is_inline(&self) -> bool {
self.inner.is_inline()
}
/// Creates `Bytes` instance from slice, by copying it.
pub fn copy_from_slice(data: &[u8]) -> Self {
Self::copy_from_slice_in(data, PoolId::DEFAULT)
}
/// Creates `Bytes` instance from slice, by copying it.
pub fn copy_from_slice_in<T>(data: &[u8], pool: T) -> Self
where
PoolRef: From<T>,
{
if data.len() <= INLINE_CAP {
Bytes {
inner: Inner::from_slice_inline(data),
}
} else {
Bytes {
inner: Inner::from_slice(data.len(), data, pool.into()),
}
}
}
/// Returns a slice of self for the provided range.
///
/// This will increment the reference count for the underlying memory and
/// return a new `Bytes` handle set to the slice.
///
/// This operation is `O(1)`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let a = Bytes::from(b"hello world");
/// let b = a.slice(2..5);
///
/// assert_eq!(&b[..], b"llo");
/// assert_eq!(&b[..=1], b"ll");
/// assert_eq!(&b[1..=1], b"l");
/// ```
///
/// # Panics
///
/// Requires that `begin <= end` and `end <= self.len()`, otherwise slicing
/// will panic.
pub fn slice(&self, range: impl RangeBounds<usize>) -> Bytes {
self.slice_checked(range)
.expect("Requires that `begin <= end` and `end <= self.len()`")
}
/// Returns a slice of self for the provided range.
///
/// Does nothing if `begin <= end` or `end <= self.len()`
pub fn slice_checked(&self, range: impl RangeBounds<usize>) -> Option<Bytes> {
use std::ops::Bound;
let len = self.len();
let begin = match range.start_bound() {
Bound::Included(&n) => n,
Bound::Excluded(&n) => n + 1,
Bound::Unbounded => 0,
};
let end = match range.end_bound() {
Bound::Included(&n) => n + 1,
Bound::Excluded(&n) => n,
Bound::Unbounded => len,
};
if begin <= end && end <= len {
if end - begin <= INLINE_CAP {
Some(Bytes {
inner: Inner::from_slice_inline(&self[begin..end]),
})
} else {
let mut ret = self.clone();
unsafe {
ret.inner.set_end(end);
ret.inner.set_start(begin);
}
Some(ret)
}
} else {
None
}
}
/// Returns a slice of self that is equivalent to the given `subset`.
///
/// When processing a `Bytes` buffer with other tools, one often gets a
/// `&[u8]` which is in fact a slice of the `Bytes`, i.e. a subset of it.
/// This function turns that `&[u8]` into another `Bytes`, as if one had
/// called `self.slice()` with the offsets that correspond to `subset`.
///
/// This operation is `O(1)`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let bytes = Bytes::from(&b"012345678"[..]);
/// let as_slice = bytes.as_ref();
/// let subset = &as_slice[2..6];
/// let subslice = bytes.slice_ref(&subset);
/// assert_eq!(subslice, b"2345");
/// ```
///
/// # Panics
///
/// Requires that the given `sub` slice is in fact contained within the
/// `Bytes` buffer; otherwise this function will panic.
pub fn slice_ref(&self, subset: &[u8]) -> Bytes {
self.slice_ref_checked(subset)
.expect("Given `sub` slice is not contained within the `Bytes` buffer")
}
/// Returns a slice of self that is equivalent to the given `subset`.
pub fn slice_ref_checked(&self, subset: &[u8]) -> Option<Bytes> {
let bytes_p = self.as_ptr() as usize;
let bytes_len = self.len();
let sub_p = subset.as_ptr() as usize;
let sub_len = subset.len();
if sub_p >= bytes_p && sub_p + sub_len <= bytes_p + bytes_len {
let sub_offset = sub_p - bytes_p;
Some(self.slice(sub_offset..(sub_offset + sub_len)))
} else {
None
}
}
/// Splits the bytes into two at the given index.
///
/// Afterwards `self` contains elements `[0, at)`, and the returned `Bytes`
/// contains elements `[at, len)`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut a = Bytes::from(&b"hello world"[..]);
/// let b = a.split_off(5);
///
/// assert_eq!(a, b"hello");
/// assert_eq!(b, b" world");
/// ```
///
/// # Panics
///
/// Panics if `at > self.len()`.
pub fn split_off(&mut self, at: usize) -> Bytes {
self.split_off_checked(at)
.expect("at value must be <= self.len()`")
}
/// Splits the bytes into two at the given index.
///
/// Does nothing if `at > self.len()`
pub fn split_off_checked(&mut self, at: usize) -> Option<Bytes> {
if at <= self.len() {
if at == self.len() {
Some(Bytes::new())
} else if at == 0 {
Some(mem::replace(self, Bytes::new()))
} else {
Some(Bytes {
inner: self.inner.split_off(at, true),
})
}
} else {
None
}
}
/// Splits the bytes into two at the given index.
///
/// Afterwards `self` contains elements `[at, len)`, and the returned
/// `Bytes` contains elements `[0, at)`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut a = Bytes::from(&b"hello world"[..]);
/// let b = a.split_to(5);
///
/// assert_eq!(a, b" world");
/// assert_eq!(b, b"hello");
/// ```
///
/// # Panics
///
/// Panics if `at > len`.
pub fn split_to(&mut self, at: usize) -> Bytes {
self.split_to_checked(at)
.expect("at value must be <= self.len()`")
}
/// Splits the bytes into two at the given index.
///
/// Does nothing if `at > len`.
pub fn split_to_checked(&mut self, at: usize) -> Option<Bytes> {
if at <= self.len() {
if at == self.len() {
Some(mem::replace(self, Bytes::new()))
} else if at == 0 {
Some(Bytes::new())
} else {
Some(Bytes {
inner: self.inner.split_to(at, true),
})
}
} else {
None
}
}
/// Shortens the buffer, keeping the first `len` bytes and dropping the
/// rest.
///
/// If `len` is greater than the buffer's current length, this has no
/// effect.
///
/// The [`split_off`] method can emulate `truncate`, but this causes the
/// excess bytes to be returned instead of dropped.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut buf = Bytes::from(&b"hello world"[..]);
/// buf.truncate(5);
/// assert_eq!(buf, b"hello"[..]);
/// ```
///
/// [`split_off`]: #method.split_off
#[inline]
pub fn truncate(&mut self, len: usize) {
self.inner.truncate(len, true);
}
/// Shortens the buffer to `len` bytes and dropping the rest.
///
/// This is useful if underlying buffer is larger than cuurrent bytes object.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut buf = Bytes::from(&b"hello world"[..]);
/// buf.trimdown();
/// assert_eq!(buf, b"hello world"[..]);
/// ```
#[inline]
pub fn trimdown(&mut self) {
let kind = self.inner.kind();
// trim down only if buffer is not inline or static and
// buffer's unused space is greater than 64 bytes
if !(kind == KIND_INLINE || kind == KIND_STATIC) {
if self.inner.len() <= INLINE_CAP {
*self = Bytes {
inner: Inner::from_slice_inline(self),
};
} else if self.inner.capacity() - self.inner.len() >= 64 {
*self = Bytes {
inner: Inner::from_slice(self.len(), self, self.inner.pool()),
}
}
}
}
/// Clears the buffer, removing all data.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let mut buf = Bytes::from(&b"hello world"[..]);
/// buf.clear();
/// assert!(buf.is_empty());
/// ```
#[inline]
pub fn clear(&mut self) {
self.inner = Inner::empty_inline();
}
/// Attempts to convert into a `BytesMut` handle.
///
/// This will only succeed if there are no other outstanding references to
/// the underlying chunk of memory. `Bytes` handles that contain inlined
/// bytes will always be convertible to `BytesMut`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::Bytes;
///
/// let a = Bytes::copy_from_slice(&b"Mary had a little lamb, little lamb, little lamb..."[..]);
///
/// // Create a shallow clone
/// let b = a.clone();
///
/// // This will fail because `b` shares a reference with `a`
/// let a = a.try_mut().unwrap_err();
///
/// drop(b);
///
/// // This will succeed
/// let mut a = a.try_mut().unwrap();
///
/// a[0] = b'b';
///
/// assert_eq!(&a[..4], b"bary");
/// ```
pub fn try_mut(self) -> Result<BytesMut, Bytes> {
if self.inner.is_mut_safe() {
Ok(BytesMut { inner: self.inner })
} else {
Err(self)
}
}
/// Returns an iterator over the bytes contained by the buffer.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{Buf, Bytes};
///
/// let buf = Bytes::from(&b"abc"[..]);
/// let mut iter = buf.iter();
///
/// assert_eq!(iter.next().map(|b| *b), Some(b'a'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'b'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'c'));
/// assert_eq!(iter.next(), None);
/// ```
pub fn iter(&'_ self) -> std::slice::Iter<'_, u8> {
self.chunk().iter()
}
}
impl Buf for Bytes {
#[inline]
fn remaining(&self) -> usize {
self.len()
}
#[inline]
fn chunk(&self) -> &[u8] {
self.inner.as_ref()
}
#[inline]
fn advance(&mut self, cnt: usize) {
assert!(
cnt <= self.inner.as_ref().len(),
"cannot advance past `remaining`"
);
unsafe {
self.inner.set_start(cnt);
}
}
}
impl bytes::buf::Buf for Bytes {
#[inline]
fn remaining(&self) -> usize {
self.len()
}
#[inline]
fn chunk(&self) -> &[u8] {
self.inner.as_ref()
}
#[inline]
fn advance(&mut self, cnt: usize) {
assert!(
cnt <= self.inner.as_ref().len(),
"cannot advance past `remaining`"
);
unsafe {
self.inner.set_start(cnt);
}
}
}
impl Clone for Bytes {
fn clone(&self) -> Bytes {
Bytes {
inner: unsafe { self.inner.shallow_clone() },
}
}
}
impl AsRef<[u8]> for Bytes {
#[inline]
fn as_ref(&self) -> &[u8] {
self.inner.as_ref()
}
}
impl Deref for Bytes {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
self.inner.as_ref()
}
}
impl From<&Bytes> for Bytes {
fn from(src: &Bytes) -> Bytes {
src.clone()
}
}
impl From<BytesMut> for Bytes {
fn from(src: BytesMut) -> Bytes {
src.freeze()
}
}
impl From<Vec<u8>> for Bytes {
/// Convert a `Vec` into a `Bytes`
///
/// This constructor may be used to avoid the inlining optimization used by
/// `with_capacity`. A `Bytes` constructed this way will always store its
/// data on the heap.
fn from(src: Vec<u8>) -> Bytes {
if src.is_empty() {
Bytes::new()
} else if src.len() <= INLINE_CAP {
Bytes {
inner: Inner::from_slice_inline(&src),
}
} else {
BytesMut::from(src).freeze()
}
}
}
impl From<String> for Bytes {
fn from(src: String) -> Bytes {
if src.is_empty() {
Bytes::new()
} else if src.bytes().len() <= INLINE_CAP {
Bytes {
inner: Inner::from_slice_inline(src.as_bytes()),
}
} else {
BytesMut::from(src).freeze()
}
}
}
impl From<&'static [u8]> for Bytes {
fn from(src: &'static [u8]) -> Bytes {
Bytes::from_static(src)
}
}
impl From<&'static str> for Bytes {
fn from(src: &'static str) -> Bytes {
Bytes::from_static(src.as_bytes())
}
}
impl<'a, const N: usize> From<&'a [u8; N]> for Bytes {
fn from(src: &'a [u8; N]) -> Bytes {
Bytes::copy_from_slice(src)
}
}
impl FromIterator<u8> for Bytes {
fn from_iter<T: IntoIterator<Item = u8>>(into_iter: T) -> Self {
BytesMut::from_iter(into_iter).freeze()
}
}
impl<'a> FromIterator<&'a u8> for Bytes {
fn from_iter<T: IntoIterator<Item = &'a u8>>(into_iter: T) -> Self {
BytesMut::from_iter(into_iter).freeze()
}
}
impl Eq for Bytes {}
impl PartialEq for Bytes {
fn eq(&self, other: &Bytes) -> bool {
self.inner.as_ref() == other.inner.as_ref()
}
}
impl PartialOrd for Bytes {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
Some(self.cmp(other))
}
}
impl Ord for Bytes {
fn cmp(&self, other: &Bytes) -> cmp::Ordering {
self.inner.as_ref().cmp(other.inner.as_ref())
}
}
impl Default for Bytes {
#[inline]
fn default() -> Bytes {
Bytes::new()
}
}
impl fmt::Debug for Bytes {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&debug::BsDebug(self.inner.as_ref()), fmt)
}
}
impl hash::Hash for Bytes {
fn hash<H>(&self, state: &mut H)
where
H: hash::Hasher,
{
let s: &[u8] = self.as_ref();
s.hash(state);
}
}
impl Borrow<[u8]> for Bytes {
fn borrow(&self) -> &[u8] {
self.as_ref()
}
}
impl IntoIterator for Bytes {
type Item = u8;
type IntoIter = IntoIter<Bytes>;
fn into_iter(self) -> Self::IntoIter {
IntoIter::new(self)
}
}
impl<'a> IntoIterator for &'a Bytes {
type Item = &'a u8;
type IntoIter = std::slice::Iter<'a, u8>;
fn into_iter(self) -> Self::IntoIter {
self.as_ref().iter()
}
}
/*
*
* ===== BytesMut =====
*
*/
impl BytesMut {
/// Creates a new `BytesMut` with the specified capacity.
///
/// The returned `BytesMut` will be able to hold at least `capacity` bytes
/// without reallocating. If `capacity` is under `4 * size_of::<usize>() - 1`,
/// then `BytesMut` will not allocate.
///
/// It is important to note that this function does not specify the length
/// of the returned `BytesMut`, but only the capacity.
///
/// # Panics
///
/// Panics if `capacity` greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
///
/// let mut bytes = BytesMut::with_capacity(64);
///
/// // `bytes` contains no data, even though there is capacity
/// assert_eq!(bytes.len(), 0);
///
/// bytes.put(&b"hello world"[..]);
///
/// assert_eq!(&bytes[..], b"hello world");
/// ```
#[inline]
pub fn with_capacity(capacity: usize) -> BytesMut {
Self::with_capacity_in(capacity, PoolId::DEFAULT.pool_ref())
}
/// Creates a new `BytesMut` with the specified capacity and in specified memory pool.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut, PoolId};
///
/// let mut bytes = BytesMut::with_capacity_in(64, PoolId::P1);
///
/// // `bytes` contains no data, even though there is capacity
/// assert_eq!(bytes.len(), 0);
///
/// bytes.put(&b"hello world"[..]);
///
/// assert_eq!(&bytes[..], b"hello world");
/// assert!(PoolId::P1.pool_ref().allocated() > 0);
/// ```
#[inline]
pub fn with_capacity_in<T>(capacity: usize, pool: T) -> BytesMut
where
PoolRef: From<T>,
{
BytesMut {
inner: Inner::with_capacity(capacity, pool.into()),
}
}
/// Creates a new `BytesMut` from slice, by copying it.
pub fn copy_from_slice<T: AsRef<[u8]>>(src: T) -> Self {
Self::copy_from_slice_in(src, PoolId::DEFAULT)
}
/// Creates a new `BytesMut` from slice, by copying it.
pub fn copy_from_slice_in<T, U>(src: T, pool: U) -> Self
where
T: AsRef<[u8]>,
PoolRef: From<U>,
{
let s = src.as_ref();
BytesMut {
inner: Inner::from_slice(s.len(), s, pool.into()),
}
}
#[inline]
/// Convert a `Vec` into a `BytesMut`
pub fn from_vec<T>(src: Vec<u8>, pool: T) -> BytesMut
where
PoolRef: From<T>,
{
BytesMut {
inner: Inner::from_vec(src, pool.into()),
}
}
/// Creates a new `BytesMut` with default capacity.
///
/// Resulting object has length 0 and unspecified capacity.
/// This function does not allocate.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
///
/// let mut bytes = BytesMut::new();
///
/// assert_eq!(0, bytes.len());
///
/// bytes.reserve(2);
/// bytes.put_slice(b"xy");
///
/// assert_eq!(&b"xy"[..], &bytes[..]);
/// ```
#[inline]
pub fn new() -> BytesMut {
BytesMut::with_capacity(MIN_NON_ZERO_CAP)
}
/// Returns the number of bytes contained in this `BytesMut`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let b = BytesMut::from(&b"hello"[..]);
/// assert_eq!(b.len(), 5);
/// ```
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Returns true if the `BytesMut` has a length of 0.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let b = BytesMut::with_capacity(64);
/// assert!(b.is_empty());
/// ```
#[inline]
pub fn is_empty(&self) -> bool {
self.inner.is_empty()
}
/// Returns the number of bytes the `BytesMut` can hold without reallocating.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let b = BytesMut::with_capacity(64);
/// assert_eq!(b.capacity(), 64);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
/// Converts `self` into an immutable `Bytes`.
///
/// The conversion is zero cost and is used to indicate that the slice
/// referenced by the handle will no longer be mutated. Once the conversion
/// is done, the handle can be cloned and shared across threads.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
/// use std::thread;
///
/// let mut b = BytesMut::with_capacity(64);
/// b.put("hello world");
/// let b1 = b.freeze();
/// let b2 = b1.clone();
///
/// let th = thread::spawn(move || {
/// assert_eq!(b1, b"hello world");
/// });
///
/// assert_eq!(b2, b"hello world");
/// th.join().unwrap();
/// ```
#[inline]
pub fn freeze(self) -> Bytes {
if self.inner.len() <= INLINE_CAP {
Bytes {
inner: Inner::from_slice_inline(self.inner.as_ref()),
}
} else {
Bytes { inner: self.inner }
}
}
/// Splits the bytes into two at the given index.
///
/// Afterwards `self` contains elements `[0, at)`, and the returned
/// `BytesMut` contains elements `[at, capacity)`.
///
/// This is an `O(1)` operation that just increases the reference count
/// and sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut a = BytesMut::from(&b"hello world"[..]);
/// let mut b = a.split_off(5);
///
/// a[0] = b'j';
/// b[0] = b'!';
///
/// assert_eq!(&a[..], b"jello");
/// assert_eq!(&b[..], b"!world");
/// ```
///
/// # Panics
///
/// Panics if `at > capacity`.
pub fn split_off(&mut self, at: usize) -> BytesMut {
BytesMut {
inner: self.inner.split_off(at, false),
}
}
/// Removes the bytes from the current view, returning them in a new
/// `BytesMut` handle.
///
/// Afterwards, `self` will be empty, but will retain any additional
/// capacity that it had before the operation. This is identical to
/// `self.split_to(self.len())`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
///
/// let mut buf = BytesMut::with_capacity(1024);
/// buf.put(&b"hello world"[..]);
///
/// let other = buf.split();
///
/// assert!(buf.is_empty());
/// assert_eq!(1013, buf.capacity());
///
/// assert_eq!(other, b"hello world"[..]);
/// ```
pub fn split(&mut self) -> BytesMut {
self.split_to(self.len())
}
/// Splits the buffer into two at the given index.
///
/// Afterwards `self` contains elements `[at, len)`, and the returned `BytesMut`
/// contains elements `[0, at)`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut a = BytesMut::from(&b"hello world"[..]);
/// let mut b = a.split_to(5);
///
/// a[0] = b'!';
/// b[0] = b'j';
///
/// assert_eq!(&a[..], b"!world");
/// assert_eq!(&b[..], b"jello");
/// ```
///
/// # Panics
///
/// Panics if `at > len`.
pub fn split_to(&mut self, at: usize) -> BytesMut {
self.split_to_checked(at)
.expect("at value must be <= self.len()`")
}
/// Splits the bytes into two at the given index.
///
/// Does nothing if `at > len`.
pub fn split_to_checked(&mut self, at: usize) -> Option<BytesMut> {
if at <= self.len() {
Some(BytesMut {
inner: self.inner.split_to(at, false),
})
} else {
None
}
}
/// Shortens the buffer, keeping the first `len` bytes and dropping the
/// rest.
///
/// If `len` is greater than the buffer's current length, this has no
/// effect.
///
/// The [`split_off`] method can emulate `truncate`, but this causes the
/// excess bytes to be returned instead of dropped.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut buf = BytesMut::from(&b"hello world"[..]);
/// buf.truncate(5);
/// assert_eq!(buf, b"hello"[..]);
/// ```
///
/// [`split_off`]: #method.split_off
pub fn truncate(&mut self, len: usize) {
self.inner.truncate(len, false);
}
/// Clears the buffer, removing all data.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut buf = BytesMut::from(&b"hello world"[..]);
/// buf.clear();
/// assert!(buf.is_empty());
/// ```
pub fn clear(&mut self) {
self.truncate(0);
}
/// Resizes the buffer so that `len` is equal to `new_len`.
///
/// If `new_len` is greater than `len`, the buffer is extended by the
/// difference with each additional byte set to `value`. If `new_len` is
/// less than `len`, the buffer is simply truncated.
///
/// # Panics
///
/// Panics if `new_len` greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut buf = BytesMut::new();
///
/// buf.resize(3, 0x1);
/// assert_eq!(&buf[..], &[0x1, 0x1, 0x1]);
///
/// buf.resize(2, 0x2);
/// assert_eq!(&buf[..], &[0x1, 0x1]);
///
/// buf.resize(4, 0x3);
/// assert_eq!(&buf[..], &[0x1, 0x1, 0x3, 0x3]);
/// ```
#[inline]
pub fn resize(&mut self, new_len: usize, value: u8) {
self.inner.resize(new_len, value);
}
/// Sets the length of the buffer.
///
/// This will explicitly set the size of the buffer without actually
/// modifying the data, so it is up to the caller to ensure that the data
/// has been initialized.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut b = BytesMut::from(&b"hello world"[..]);
///
/// unsafe {
/// b.set_len(5);
/// }
///
/// assert_eq!(&b[..], b"hello");
///
/// unsafe {
/// b.set_len(11);
/// }
///
/// assert_eq!(&b[..], b"hello world");
/// ```
///
/// # Panics
///
/// This method will panic if `len` is out of bounds for the underlying
/// slice or if it comes after the `end` of the configured window.
#[inline]
#[allow(clippy::missing_safety_doc)]
pub unsafe fn set_len(&mut self, len: usize) {
self.inner.set_len(len)
}
/// Reserves capacity for at least `additional` more bytes to be inserted
/// into the given `BytesMut`.
///
/// More than `additional` bytes may be reserved in order to avoid frequent
/// reallocations. A call to `reserve` may result in an allocation.
///
/// Before allocating new buffer space, the function will attempt to reclaim
/// space in the existing buffer. If the current handle references a small
/// view in the original buffer and all other handles have been dropped,
/// and the requested capacity is less than or equal to the existing
/// buffer's capacity, then the current view will be copied to the front of
/// the buffer and the handle will take ownership of the full buffer.
///
/// # Panics
///
/// Panics if new capacity is greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// In the following example, a new buffer is allocated.
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut buf = BytesMut::from(&b"hello"[..]);
/// buf.reserve(64);
/// assert!(buf.capacity() >= 69);
/// ```
///
/// In the following example, the existing buffer is reclaimed.
///
/// ```
/// use ntex_bytes::{BytesMut, BufMut};
///
/// let mut buf = BytesMut::with_capacity(128);
/// buf.put(&[0; 64][..]);
///
/// let ptr = buf.as_ptr();
/// let other = buf.split();
///
/// assert!(buf.is_empty());
/// assert_eq!(buf.capacity(), 64);
///
/// drop(other);
/// buf.reserve(128);
///
/// assert_eq!(buf.capacity(), 128);
/// assert_eq!(buf.as_ptr(), ptr);
/// ```
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
#[inline]
pub fn reserve(&mut self, additional: usize) {
let len = self.len();
let rem = self.capacity() - len;
if additional <= rem {
// The handle can already store at least `additional` more bytes, so
// there is no further work needed to be done.
return;
}
self.inner.reserve_inner(additional);
}
/// Appends given bytes to this object.
///
/// If this `BytesMut` object has not enough capacity, it is resized first.
/// So unlike `put_slice` operation, `extend_from_slice` does not panic.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesMut;
///
/// let mut buf = BytesMut::with_capacity(0);
/// buf.extend_from_slice(b"aaabbb");
/// buf.extend_from_slice(b"cccddd");
///
/// assert_eq!(b"aaabbbcccddd", &buf[..]);
/// ```
#[inline]
pub fn extend_from_slice(&mut self, extend: &[u8]) {
self.put_slice(extend);
}
/// Returns an iterator over the bytes contained by the buffer.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{Buf, BytesMut};
///
/// let buf = BytesMut::from(&b"abc"[..]);
/// let mut iter = buf.iter();
///
/// assert_eq!(iter.next().map(|b| *b), Some(b'a'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'b'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'c'));
/// assert_eq!(iter.next(), None);
/// ```
#[inline]
pub fn iter(&'_ self) -> std::slice::Iter<'_, u8> {
self.chunk().iter()
}
#[cfg(feature = "mpool")]
pub(crate) fn move_to_pool(&mut self, pool: PoolRef) {
self.inner.move_to_pool(pool);
}
}
impl Buf for BytesMut {
#[inline]
fn remaining(&self) -> usize {
self.len()
}
#[inline]
fn chunk(&self) -> &[u8] {
self.inner.as_ref()
}
#[inline]
fn advance(&mut self, cnt: usize) {
assert!(
cnt <= self.inner.as_ref().len(),
"cannot advance past `remaining`"
);
unsafe {
self.inner.set_start(cnt);
}
}
}
impl BufMut for BytesMut {
#[inline]
fn remaining_mut(&self) -> usize {
self.capacity() - self.len()
}
#[inline]
unsafe fn advance_mut(&mut self, cnt: usize) {
let new_len = self.len() + cnt;
// This call will panic if `cnt` is too big
self.inner.set_len(new_len);
}
#[inline]
fn chunk_mut(&mut self) -> &mut UninitSlice {
let len = self.len();
unsafe {
// This will never panic as `len` can never become invalid
let ptr = &mut self.inner.as_raw()[len..];
UninitSlice::from_raw_parts_mut(ptr.as_mut_ptr(), self.capacity() - len)
}
}
#[inline]
fn put_slice(&mut self, src: &[u8]) {
let len = src.len();
self.reserve(len);
unsafe {
ptr::copy_nonoverlapping(src.as_ptr(), self.chunk_mut().as_mut_ptr(), len);
self.advance_mut(len);
}
}
#[inline]
fn put_u8(&mut self, n: u8) {
self.reserve(1);
self.inner.put_u8(n);
}
#[inline]
fn put_i8(&mut self, n: i8) {
self.reserve(1);
self.put_u8(n as u8);
}
}
impl bytes::buf::Buf for BytesMut {
#[inline]
fn remaining(&self) -> usize {
self.len()
}
#[inline]
fn chunk(&self) -> &[u8] {
self.inner.as_ref()
}
#[inline]
fn advance(&mut self, cnt: usize) {
Buf::advance(self, cnt)
}
}
unsafe impl bytes::buf::BufMut for BytesMut {
#[inline]
fn remaining_mut(&self) -> usize {
BufMut::remaining_mut(self)
}
#[inline]
unsafe fn advance_mut(&mut self, cnt: usize) {
BufMut::advance_mut(self, cnt)
}
#[inline]
fn chunk_mut(&mut self) -> &mut bytes::buf::UninitSlice {
let len = self.len();
unsafe {
// This will never panic as `len` can never become invalid
let ptr = &mut self.inner.as_raw()[len..];
bytes::buf::UninitSlice::from_raw_parts_mut(
ptr.as_mut_ptr(),
self.capacity() - len,
)
}
}
#[inline]
fn put_slice(&mut self, src: &[u8]) {
BufMut::put_slice(self, src)
}
#[inline]
fn put_u8(&mut self, n: u8) {
BufMut::put_u8(self, n)
}
#[inline]
fn put_i8(&mut self, n: i8) {
BufMut::put_i8(self, n)
}
}
impl AsRef<[u8]> for BytesMut {
#[inline]
fn as_ref(&self) -> &[u8] {
self.inner.as_ref()
}
}
impl AsMut<[u8]> for BytesMut {
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
self.inner.as_mut()
}
}
impl Deref for BytesMut {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
self.as_ref()
}
}
impl DerefMut for BytesMut {
#[inline]
fn deref_mut(&mut self) -> &mut [u8] {
self.inner.as_mut()
}
}
impl From<Vec<u8>> for BytesMut {
#[inline]
/// Convert a `Vec` into a `BytesMut`
///
/// This constructor may be used to avoid the inlining optimization used by
/// `with_capacity`. A `BytesMut` constructed this way will always store
/// its data on the heap.
fn from(src: Vec<u8>) -> BytesMut {
BytesMut::from_vec(src, PoolId::DEFAULT.pool_ref())
}
}
impl From<String> for BytesMut {
#[inline]
fn from(src: String) -> BytesMut {
BytesMut::from_vec(src.into_bytes(), PoolId::DEFAULT.pool_ref())
}
}
impl<'a> From<&'a [u8]> for BytesMut {
fn from(src: &'a [u8]) -> BytesMut {
if src.is_empty() {
BytesMut::new()
} else {
BytesMut::copy_from_slice_in(src, PoolId::DEFAULT.pool_ref())
}
}
}
impl<const N: usize> From<[u8; N]> for BytesMut {
fn from(src: [u8; N]) -> BytesMut {
BytesMut::copy_from_slice_in(src, PoolId::DEFAULT.pool_ref())
}
}
impl<'a, const N: usize> From<&'a [u8; N]> for BytesMut {
fn from(src: &'a [u8; N]) -> BytesMut {
BytesMut::copy_from_slice_in(src, PoolId::DEFAULT.pool_ref())
}
}
impl<'a> From<&'a str> for BytesMut {
#[inline]
fn from(src: &'a str) -> BytesMut {
BytesMut::from(src.as_bytes())
}
}
impl From<Bytes> for BytesMut {
#[inline]
fn from(src: Bytes) -> BytesMut {
src.try_mut()
.unwrap_or_else(|src| BytesMut::copy_from_slice_in(&src[..], src.inner.pool()))
}
}
impl Eq for BytesMut {}
impl PartialEq for BytesMut {
#[inline]
fn eq(&self, other: &BytesMut) -> bool {
self.inner.as_ref() == other.inner.as_ref()
}
}
impl Default for BytesMut {
#[inline]
fn default() -> BytesMut {
BytesMut::new()
}
}
impl Borrow<[u8]> for BytesMut {
#[inline]
fn borrow(&self) -> &[u8] {
self.as_ref()
}
}
impl BorrowMut<[u8]> for BytesMut {
#[inline]
fn borrow_mut(&mut self) -> &mut [u8] {
self.as_mut()
}
}
impl fmt::Debug for BytesMut {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&debug::BsDebug(self.inner.as_ref()), fmt)
}
}
impl fmt::Write for BytesMut {
#[inline]
fn write_str(&mut self, s: &str) -> fmt::Result {
if self.remaining_mut() >= s.len() {
self.put_slice(s.as_bytes());
Ok(())
} else {
Err(fmt::Error)
}
}
#[inline]
fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> fmt::Result {
fmt::write(self, args)
}
}
impl Clone for BytesMut {
#[inline]
fn clone(&self) -> BytesMut {
BytesMut::from(&self[..])
}
}
impl IntoIterator for BytesMut {
type Item = u8;
type IntoIter = IntoIter<BytesMut>;
fn into_iter(self) -> Self::IntoIter {
IntoIter::new(self)
}
}
impl<'a> IntoIterator for &'a BytesMut {
type Item = &'a u8;
type IntoIter = std::slice::Iter<'a, u8>;
fn into_iter(self) -> Self::IntoIter {
self.as_ref().iter()
}
}
impl FromIterator<u8> for BytesMut {
fn from_iter<T: IntoIterator<Item = u8>>(into_iter: T) -> Self {
let iter = into_iter.into_iter();
let (min, maybe_max) = iter.size_hint();
let mut out = BytesMut::with_capacity(maybe_max.unwrap_or(min));
for i in iter {
out.reserve(1);
out.put_u8(i);
}
out
}
}
impl<'a> FromIterator<&'a u8> for BytesMut {
fn from_iter<T: IntoIterator<Item = &'a u8>>(into_iter: T) -> Self {
into_iter.into_iter().copied().collect::<BytesMut>()
}
}
impl Extend<u8> for BytesMut {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = u8>,
{
let iter = iter.into_iter();
let (lower, _) = iter.size_hint();
self.reserve(lower);
for b in iter {
self.put_u8(b);
}
}
}
impl<'a> Extend<&'a u8> for BytesMut {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = &'a u8>,
{
self.extend(iter.into_iter().copied())
}
}
/*
*
* ===== BytesVec =====
*
*/
impl BytesVec {
/// Creates a new `BytesVec` with the specified capacity.
///
/// The returned `BytesVec` will be able to hold at least `capacity` bytes
/// without reallocating.
///
/// It is important to note that this function does not specify the length
/// of the returned `BytesVec`, but only the capacity.
///
/// # Panics
///
/// Panics if `capacity` greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
///
/// let mut bytes = BytesVec::with_capacity(64);
///
/// // `bytes` contains no data, even though there is capacity
/// assert_eq!(bytes.len(), 0);
///
/// bytes.put(&b"hello world"[..]);
///
/// assert_eq!(&bytes[..], b"hello world");
/// ```
#[inline]
pub fn with_capacity(capacity: usize) -> BytesVec {
Self::with_capacity_in(capacity, PoolId::DEFAULT.pool_ref())
}
/// Creates a new `BytesVec` with the specified capacity and in specified memory pool.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut, PoolId};
///
/// let mut bytes = BytesVec::with_capacity_in(64, PoolId::P1);
///
/// // `bytes` contains no data, even though there is capacity
/// assert_eq!(bytes.len(), 0);
///
/// bytes.put(&b"hello world"[..]);
///
/// assert_eq!(&bytes[..], b"hello world");
/// assert!(PoolId::P1.pool_ref().allocated() > 0);
/// ```
#[inline]
pub fn with_capacity_in<T>(capacity: usize, pool: T) -> BytesVec
where
PoolRef: From<T>,
{
BytesVec {
inner: InnerVec::with_capacity(capacity, pool.into()),
}
}
/// Creates a new `BytesVec` from slice, by copying it.
pub fn copy_from_slice<T: AsRef<[u8]>>(src: T) -> Self {
Self::copy_from_slice_in(src, PoolId::DEFAULT)
}
/// Creates a new `BytesVec` from slice, by copying it.
pub fn copy_from_slice_in<T, U>(src: T, pool: U) -> Self
where
T: AsRef<[u8]>,
PoolRef: From<U>,
{
let s = src.as_ref();
BytesVec {
inner: InnerVec::from_slice(s.len(), s, pool.into()),
}
}
/// Creates a new `BytesVec` with default capacity.
///
/// Resulting object has length 0 and unspecified capacity.
/// This function does not allocate.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
///
/// let mut bytes = BytesVec::new();
///
/// assert_eq!(0, bytes.len());
///
/// bytes.reserve(2);
/// bytes.put_slice(b"xy");
///
/// assert_eq!(&b"xy"[..], &bytes[..]);
/// ```
#[inline]
pub fn new() -> BytesVec {
BytesVec::with_capacity(MIN_NON_ZERO_CAP)
}
/// Returns the number of bytes contained in this `BytesVec`.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let b = BytesVec::copy_from_slice(&b"hello"[..]);
/// assert_eq!(b.len(), 5);
/// ```
#[inline]
pub fn len(&self) -> usize {
self.inner.len()
}
/// Returns true if the `BytesVec` has a length of 0.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let b = BytesVec::with_capacity(64);
/// assert!(b.is_empty());
/// ```
#[inline]
pub fn is_empty(&self) -> bool {
self.inner.len() == 0
}
/// Returns the number of bytes the `BytesVec` can hold without reallocating.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let b = BytesVec::with_capacity(64);
/// assert_eq!(b.capacity(), 64);
/// ```
#[inline]
pub fn capacity(&self) -> usize {
self.inner.capacity()
}
/// Converts `self` into an immutable `Bytes`.
///
/// The conversion is zero cost and is used to indicate that the slice
/// referenced by the handle will no longer be mutated. Once the conversion
/// is done, the handle can be cloned and shared across threads.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
/// use std::thread;
///
/// let mut b = BytesVec::with_capacity(64);
/// b.put("hello world");
/// let b1 = b.freeze();
/// let b2 = b1.clone();
///
/// let th = thread::spawn(move || {
/// assert_eq!(b1, b"hello world");
/// });
///
/// assert_eq!(b2, b"hello world");
/// th.join().unwrap();
/// ```
#[inline]
pub fn freeze(self) -> Bytes {
Bytes {
inner: self.inner.into_inner(),
}
}
/// Removes the bytes from the current view, returning them in a new
/// `Bytes` instance.
///
/// Afterwards, `self` will be empty, but will retain any additional
/// capacity that it had before the operation. This is identical to
/// `self.split_to(self.len())`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
///
/// let mut buf = BytesVec::with_capacity(1024);
/// buf.put(&b"hello world"[..]);
///
/// let other = buf.split();
///
/// assert!(buf.is_empty());
/// assert_eq!(1013, buf.capacity());
///
/// assert_eq!(other, b"hello world"[..]);
/// ```
pub fn split(&mut self) -> BytesMut {
self.split_to(self.len())
}
/// Splits the buffer into two at the given index.
///
/// Afterwards `self` contains elements `[at, len)`, and the returned `Bytes`
/// contains elements `[0, at)`.
///
/// This is an `O(1)` operation that just increases the reference count and
/// sets a few indices.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut a = BytesVec::copy_from_slice(&b"hello world"[..]);
/// let mut b = a.split_to(5);
///
/// a[0] = b'!';
///
/// assert_eq!(&a[..], b"!world");
/// assert_eq!(&b[..], b"hello");
/// ```
///
/// # Panics
///
/// Panics if `at > len`.
pub fn split_to(&mut self, at: usize) -> BytesMut {
self.split_to_checked(at)
.expect("at value must be <= self.len()`")
}
/// Splits the bytes into two at the given index.
///
/// Does nothing if `at > len`.
pub fn split_to_checked(&mut self, at: usize) -> Option<BytesMut> {
if at <= self.len() {
Some(BytesMut {
inner: self.inner.split_to(at, false),
})
} else {
None
}
}
/// Shortens the buffer, keeping the first `len` bytes and dropping the
/// rest.
///
/// If `len` is greater than the buffer's current length, this has no
/// effect.
///
/// The [`split_off`] method can emulate `truncate`, but this causes the
/// excess bytes to be returned instead of dropped.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut buf = BytesVec::copy_from_slice(&b"hello world"[..]);
/// buf.truncate(5);
/// assert_eq!(buf, b"hello"[..]);
/// ```
///
/// [`split_off`]: #method.split_off
pub fn truncate(&mut self, len: usize) {
self.inner.truncate(len);
}
/// Clears the buffer, removing all data.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut buf = BytesVec::copy_from_slice(&b"hello world"[..]);
/// buf.clear();
/// assert!(buf.is_empty());
/// ```
pub fn clear(&mut self) {
self.truncate(0);
}
/// Resizes the buffer so that `len` is equal to `new_len`.
///
/// If `new_len` is greater than `len`, the buffer is extended by the
/// difference with each additional byte set to `value`. If `new_len` is
/// less than `len`, the buffer is simply truncated.
///
/// # Panics
///
/// Panics if `new_len` greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut buf = BytesVec::new();
///
/// buf.resize(3, 0x1);
/// assert_eq!(&buf[..], &[0x1, 0x1, 0x1]);
///
/// buf.resize(2, 0x2);
/// assert_eq!(&buf[..], &[0x1, 0x1]);
///
/// buf.resize(4, 0x3);
/// assert_eq!(&buf[..], &[0x1, 0x1, 0x3, 0x3]);
/// ```
#[inline]
pub fn resize(&mut self, new_len: usize, value: u8) {
self.inner.resize(new_len, value);
}
/// Sets the length of the buffer.
///
/// This will explicitly set the size of the buffer without actually
/// modifying the data, so it is up to the caller to ensure that the data
/// has been initialized.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut b = BytesVec::copy_from_slice(&b"hello world"[..]);
///
/// unsafe {
/// b.set_len(5);
/// }
///
/// assert_eq!(&b[..], b"hello");
///
/// unsafe {
/// b.set_len(11);
/// }
///
/// assert_eq!(&b[..], b"hello world");
/// ```
///
/// # Panics
///
/// This method will panic if `len` is out of bounds for the underlying
/// slice or if it comes after the `end` of the configured window.
#[inline]
#[allow(clippy::missing_safety_doc)]
pub unsafe fn set_len(&mut self, len: usize) {
self.inner.set_len(len)
}
/// Reserves capacity for at least `additional` more bytes to be inserted
/// into the given `BytesVec`.
///
/// More than `additional` bytes may be reserved in order to avoid frequent
/// reallocations. A call to `reserve` may result in an allocation.
///
/// Before allocating new buffer space, the function will attempt to reclaim
/// space in the existing buffer. If the current handle references a small
/// view in the original buffer and all other handles have been dropped,
/// and the requested capacity is less than or equal to the existing
/// buffer's capacity, then the current view will be copied to the front of
/// the buffer and the handle will take ownership of the full buffer.
///
/// # Panics
///
/// Panics if new capacity is greater than 60bit for 64bit systems
/// and 28bit for 32bit systems
///
/// # Examples
///
/// In the following example, a new buffer is allocated.
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut buf = BytesVec::copy_from_slice(&b"hello"[..]);
/// buf.reserve(64);
/// assert!(buf.capacity() >= 69);
/// ```
///
/// In the following example, the existing buffer is reclaimed.
///
/// ```
/// use ntex_bytes::{BytesVec, BufMut};
///
/// let mut buf = BytesVec::with_capacity(128);
/// buf.put(&[0; 64][..]);
///
/// let ptr = buf.as_ptr();
/// let other = buf.split();
///
/// assert!(buf.is_empty());
/// assert_eq!(buf.capacity(), 64);
///
/// drop(other);
/// buf.reserve(128);
///
/// assert_eq!(buf.capacity(), 128);
/// assert_eq!(buf.as_ptr(), ptr);
/// ```
///
/// # Panics
///
/// Panics if the new capacity overflows `usize`.
#[inline]
pub fn reserve(&mut self, additional: usize) {
let len = self.len();
let rem = self.capacity() - len;
if additional <= rem {
// The handle can already store at least `additional` more bytes, so
// there is no further work needed to be done.
return;
}
self.inner.reserve_inner(additional);
}
/// Appends given bytes to this object.
///
/// If this `BytesVec` object has not enough capacity, it is resized first.
/// So unlike `put_slice` operation, `extend_from_slice` does not panic.
///
/// # Examples
///
/// ```
/// use ntex_bytes::BytesVec;
///
/// let mut buf = BytesVec::with_capacity(0);
/// buf.extend_from_slice(b"aaabbb");
/// buf.extend_from_slice(b"cccddd");
///
/// assert_eq!(b"aaabbbcccddd", &buf[..]);
/// ```
#[inline]
pub fn extend_from_slice(&mut self, extend: &[u8]) {
self.put_slice(extend);
}
/// Run provided function with `BytesMut` instance that contains current data.
#[inline]
pub fn with_bytes_mut<F, R>(&mut self, f: F) -> R
where
F: FnOnce(&mut BytesMut) -> R,
{
self.inner.with_bytes_mut(f)
}
/// Returns an iterator over the bytes contained by the buffer.
///
/// # Examples
///
/// ```
/// use ntex_bytes::{Buf, BytesVec};
///
/// let buf = BytesVec::copy_from_slice(&b"abc"[..]);
/// let mut iter = buf.iter();
///
/// assert_eq!(iter.next().map(|b| *b), Some(b'a'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'b'));
/// assert_eq!(iter.next().map(|b| *b), Some(b'c'));
/// assert_eq!(iter.next(), None);
/// ```
#[inline]
pub fn iter(&'_ self) -> std::slice::Iter<'_, u8> {
self.chunk().iter()
}
#[cfg(feature = "mpool")]
pub(crate) fn move_to_pool(&mut self, pool: PoolRef) {
self.inner.move_to_pool(pool);
}
}
impl Buf for BytesVec {
#[inline]
fn remaining(&self) -> usize {
self.len()
}
#[inline]
fn chunk(&self) -> &[u8] {
self.inner.as_ref()
}
#[inline]
fn advance(&mut self, cnt: usize) {
assert!(
cnt <= self.inner.as_ref().len(),
"cannot advance past `remaining`"
);
unsafe {
self.inner.set_start(cnt as u32);
}
}
}
impl BufMut for BytesVec {
#[inline]
fn remaining_mut(&self) -> usize {
self.capacity() - self.len()
}
#[inline]
unsafe fn advance_mut(&mut self, cnt: usize) {
let new_len = self.len() + cnt;
// This call will panic if `cnt` is too big
self.inner.set_len(new_len);
}
#[inline]
fn chunk_mut(&mut self) -> &mut UninitSlice {
let len = self.len();
unsafe {
// This will never panic as `len` can never become invalid
let ptr = &mut self.inner.as_raw()[len..];
UninitSlice::from_raw_parts_mut(ptr.as_mut_ptr(), self.capacity() - len)
}
}
#[inline]
fn put_slice(&mut self, src: &[u8]) {
let len = src.len();
self.reserve(len);
unsafe {
ptr::copy_nonoverlapping(src.as_ptr(), self.chunk_mut().as_mut_ptr(), len);
self.advance_mut(len);
}
}
#[inline]
fn put_u8(&mut self, n: u8) {
self.reserve(1);
self.inner.put_u8(n);
}
#[inline]
fn put_i8(&mut self, n: i8) {
self.reserve(1);
self.put_u8(n as u8);
}
}
impl AsRef<[u8]> for BytesVec {
#[inline]
fn as_ref(&self) -> &[u8] {
self.inner.as_ref()
}
}
impl AsMut<[u8]> for BytesVec {
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
self.inner.as_mut()
}
}
impl Deref for BytesVec {
type Target = [u8];
#[inline]
fn deref(&self) -> &[u8] {
self.as_ref()
}
}
impl DerefMut for BytesVec {
#[inline]
fn deref_mut(&mut self) -> &mut [u8] {
self.inner.as_mut()
}
}
impl Eq for BytesVec {}
impl PartialEq for BytesVec {
#[inline]
fn eq(&self, other: &BytesVec) -> bool {
self.inner.as_ref() == other.inner.as_ref()
}
}
impl Default for BytesVec {
#[inline]
fn default() -> BytesVec {
BytesVec::new()
}
}
impl Borrow<[u8]> for BytesVec {
#[inline]
fn borrow(&self) -> &[u8] {
self.as_ref()
}
}
impl BorrowMut<[u8]> for BytesVec {
#[inline]
fn borrow_mut(&mut self) -> &mut [u8] {
self.as_mut()
}
}
impl fmt::Debug for BytesVec {
fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
fmt::Debug::fmt(&debug::BsDebug(self.inner.as_ref()), fmt)
}
}
impl fmt::Write for BytesVec {
#[inline]
fn write_str(&mut self, s: &str) -> fmt::Result {
if self.remaining_mut() >= s.len() {
self.put_slice(s.as_bytes());
Ok(())
} else {
Err(fmt::Error)
}
}
#[inline]
fn write_fmt(&mut self, args: fmt::Arguments<'_>) -> fmt::Result {
fmt::write(self, args)
}
}
impl IntoIterator for BytesVec {
type Item = u8;
type IntoIter = IntoIter<BytesVec>;
fn into_iter(self) -> Self::IntoIter {
IntoIter::new(self)
}
}
impl<'a> IntoIterator for &'a BytesVec {
type Item = &'a u8;
type IntoIter = std::slice::Iter<'a, u8>;
fn into_iter(self) -> Self::IntoIter {
self.as_ref().iter()
}
}
impl FromIterator<u8> for BytesVec {
fn from_iter<T: IntoIterator<Item = u8>>(into_iter: T) -> Self {
let iter = into_iter.into_iter();
let (min, maybe_max) = iter.size_hint();
let mut out = BytesVec::with_capacity(maybe_max.unwrap_or(min));
for i in iter {
out.reserve(1);
out.put_u8(i);
}
out
}
}
impl<'a> FromIterator<&'a u8> for BytesVec {
fn from_iter<T: IntoIterator<Item = &'a u8>>(into_iter: T) -> Self {
into_iter.into_iter().copied().collect::<BytesVec>()
}
}
impl Extend<u8> for BytesVec {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = u8>,
{
let iter = iter.into_iter();
let (lower, _) = iter.size_hint();
self.reserve(lower);
for b in iter {
self.put_u8(b);
}
}
}
impl<'a> Extend<&'a u8> for BytesVec {
fn extend<T>(&mut self, iter: T)
where
T: IntoIterator<Item = &'a u8>,
{
self.extend(iter.into_iter().copied())
}
}
struct InnerVec(NonNull<SharedVec>);
impl InnerVec {
#[inline]
fn with_capacity(capacity: usize, pool: PoolRef) -> InnerVec {
Self::from_slice(capacity, &[], pool)
}
#[inline]
fn from_slice(cap: usize, src: &[u8], pool: PoolRef) -> InnerVec {
// vec must be aligned to SharedVec instead of u8
let vec_cap = if cap % SHARED_VEC_SIZE != 0 {
(cap / SHARED_VEC_SIZE) + 2
} else {
(cap / SHARED_VEC_SIZE) + 1
};
let mut vec = Vec::<SharedVec>::with_capacity(vec_cap);
unsafe {
// Store data in vec
let len = src.len() as u32;
let cap = vec.capacity() * SHARED_VEC_SIZE;
let shared_ptr = vec.as_mut_ptr();
mem::forget(vec);
pool.acquire(cap);
let ptr = shared_ptr.add(1) as *mut u8;
if !src.is_empty() {
ptr::copy_nonoverlapping(src.as_ptr(), ptr, src.len());
}
ptr::write(
shared_ptr,
SharedVec {
len,
cap,
pool,
ref_count: AtomicUsize::new(1),
offset: SHARED_VEC_SIZE as u32,
},
);
InnerVec(NonNull::new_unchecked(shared_ptr))
}
}
#[cfg(feature = "mpool")]
#[inline]
fn move_to_pool(&mut self, pool: PoolRef) {
unsafe {
let inner = self.as_inner();
if pool != inner.pool {
pool.acquire(inner.cap);
let pool = mem::replace(&mut inner.pool, pool);
pool.release(inner.cap);
}
}
}
/// Return a slice for the handle's view into the shared buffer
#[inline]
fn as_ref(&self) -> &[u8] {
unsafe { slice::from_raw_parts(self.as_ptr(), self.len()) }
}
/// Return a mutable slice for the handle's view into the shared buffer
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
unsafe { slice::from_raw_parts_mut(self.as_ptr(), self.len()) }
}
/// Return a mutable slice for the handle's view into the shared buffer
/// including potentially uninitialized bytes.
#[inline]
unsafe fn as_raw(&mut self) -> &mut [u8] {
slice::from_raw_parts_mut(self.as_ptr(), self.capacity())
}
/// Return a raw pointer to data
#[inline]
unsafe fn as_ptr(&self) -> *mut u8 {
(self.0.as_ptr() as *mut u8).add((*self.0.as_ptr()).offset as usize)
}
#[inline]
unsafe fn as_inner(&mut self) -> &mut SharedVec {
self.0.as_mut()
}
/// Insert a byte into the next slot and advance the len by 1.
#[inline]
fn put_u8(&mut self, n: u8) {
unsafe {
let inner = self.as_inner();
let len = inner.len as usize;
assert!(len < (inner.cap - inner.offset as usize));
inner.len += 1;
*self.as_ptr().add(len) = n;
}
}
#[inline]
fn len(&self) -> usize {
unsafe { (*self.0.as_ptr()).len as usize }
}
/// slice.
#[inline]
unsafe fn set_len(&mut self, len: usize) {
let inner = self.as_inner();
assert!(len <= (inner.cap - inner.offset as usize) && len < u32::MAX as usize);
inner.len = len as u32;
}
#[inline]
fn capacity(&self) -> usize {
unsafe { (*self.0.as_ptr()).cap - (*self.0.as_ptr()).offset as usize }
}
fn into_inner(mut self) -> Inner {
unsafe {
let ptr = self.as_ptr();
if self.len() <= INLINE_CAP {
Inner::from_ptr_inline(ptr, self.len())
} else {
let inner = self.as_inner();
let inner = Inner {
ptr,
len: inner.len as usize,
cap: inner.cap - inner.offset as usize,
arc: NonNull::new_unchecked(
(self.0.as_ptr() as usize ^ KIND_VEC) as *mut Shared,
),
};
mem::forget(self);
inner
}
}
}
fn with_bytes_mut<F, R>(&mut self, f: F) -> R
where
F: FnOnce(&mut BytesMut) -> R,
{
unsafe {
// create Inner for BytesMut
let ptr = self.as_ptr();
let inner = self.as_inner();
let inner = Inner {
ptr,
len: inner.len as usize,
cap: inner.cap - inner.offset as usize,
arc: NonNull::new_unchecked(
(self.0.as_ptr() as usize ^ KIND_VEC) as *mut Shared,
),
};
// run function
let mut buf = BytesMut { inner };
let result = f(&mut buf);
// convert BytesMut back to InnerVec
let kind = buf.inner.kind();
let new_inner =
// only KIND_VEC could be converted to self, otherwise we have to copy data
if kind == KIND_INLINE || kind == KIND_STATIC || kind == KIND_ARC {
InnerVec::from_slice(
buf.inner.capacity(),
buf.inner.as_ref(),
buf.inner.pool(),
)
} else if kind == KIND_VEC {
let ptr = buf.inner.shared_vec();
let offset = buf.inner.ptr as usize - ptr as usize;
// we cannot use shared vec if BytesMut points to inside of vec
if buf.inner.cap < (*ptr).cap - offset {
InnerVec::from_slice(
buf.inner.capacity(),
buf.inner.as_ref(),
buf.inner.pool(),
)
} else {
// BytesMut owns rest of the vec, so re-use
(*ptr).len = buf.len() as u32;
(*ptr).offset = offset as u32;
let inner = InnerVec(NonNull::new_unchecked(ptr));
mem::forget(buf); // reuse bytes
inner
}
} else {
panic!()
};
// drop old inner, we cannot drop because BytesMut used it
let old = mem::replace(self, new_inner);
mem::forget(old);
result
}
}
fn split_to(&mut self, at: usize, create_inline: bool) -> Inner {
unsafe {
let ptr = self.as_ptr();
let other = if create_inline && at <= INLINE_CAP {
Inner::from_ptr_inline(ptr, at)
} else {
let inner = self.as_inner();
let old_size = inner.ref_count.fetch_add(1, Relaxed);
if old_size == usize::MAX {
abort();
}
Inner {
ptr,
len: at,
cap: at,
arc: NonNull::new_unchecked(
(self.0.as_ptr() as usize ^ KIND_VEC) as *mut Shared,
),
}
};
self.set_start(at as u32);
other
}
}
fn truncate(&mut self, len: usize) {
unsafe {
if len <= self.len() {
self.set_len(len);
}
}
}
fn resize(&mut self, new_len: usize, value: u8) {
let len = self.len();
if new_len > len {
let additional = new_len - len;
self.reserve(additional);
unsafe {
let dst = self.as_raw()[len..].as_mut_ptr();
ptr::write_bytes(dst, value, additional);
self.set_len(new_len);
}
} else {
self.truncate(new_len);
}
}
#[inline]
fn reserve(&mut self, additional: usize) {
let len = self.len();
let rem = self.capacity() - len;
if additional <= rem {
// The handle can already store at least `additional` more bytes, so
// there is no further work needed to be done.
return;
}
self.reserve_inner(additional)
}
#[inline]
// In separate function to allow the short-circuits in `reserve` to
// be inline-able. Significant helps performance.
fn reserve_inner(&mut self, additional: usize) {
let len = self.len();
// Reserving involves abandoning the currently shared buffer and
// allocating a new vector with the requested capacity.
let new_cap = len + additional;
unsafe {
let inner = self.as_inner();
let vec_cap = inner.cap - SHARED_VEC_SIZE;
// try to reclaim the buffer. This is possible if the current
// handle is the only outstanding handle pointing to the buffer.
if inner.is_unique() && vec_cap >= new_cap {
let offset = inner.offset;
inner.offset = SHARED_VEC_SIZE as u32;
// The capacity is sufficient, reclaim the buffer
let src = (self.0.as_ptr() as *mut u8).add(offset as usize);
let dst = (self.0.as_ptr() as *mut u8).add(SHARED_VEC_SIZE);
ptr::copy(src, dst, len);
} else {
// Create a new vector storage
let pool = inner.pool;
*self = InnerVec::from_slice(new_cap, self.as_ref(), pool);
}
}
}
unsafe fn set_start(&mut self, start: u32) {
// Setting the start to 0 is a no-op, so return early if this is the
// case.
if start == 0 {
return;
}
let inner = self.as_inner();
assert!(start <= inner.cap as u32);
// Updating the start of the view is setting `offset` to point to the
// new start and updating the `len` field to reflect the new length
// of the view.
inner.offset += start;
if inner.len >= start {
inner.len -= start;
} else {
inner.len = 0;
}
}
}
impl Drop for InnerVec {
fn drop(&mut self) {
release_shared_vec(self.0.as_ptr());
}
}
/*
*
* ===== Inner =====
*
*/
impl Inner {
#[inline]
const fn from_static(bytes: &'static [u8]) -> Inner {
let ptr = bytes.as_ptr() as *mut u8;
Inner {
// `arc` won't ever store a pointer. Instead, use it to
// track the fact that the `Bytes` handle is backed by a
// static buffer.
arc: unsafe { NonNull::new_unchecked(KIND_STATIC as *mut Shared) },
ptr,
len: bytes.len(),
cap: bytes.len(),
}
}
#[inline]
const fn empty_inline() -> Inner {
Inner {
arc: unsafe { NonNull::new_unchecked(KIND_INLINE as *mut Shared) },
ptr: 0 as *mut u8,
len: 0,
cap: 0,
}
}
#[inline]
fn from_vec(mut vec: Vec<u8>, pool: PoolRef) -> Inner {
let len = vec.len();
let cap = vec.capacity();
let ptr = vec.as_mut_ptr();
pool.acquire(cap);
// Store data in arc
let shared = Box::into_raw(Box::new(Shared {
vec,
pool,
ref_count: AtomicUsize::new(1),
}));
// The pointer should be aligned, so this assert should always succeed.
debug_assert!(0 == (shared as usize & KIND_MASK));
// Create new arc, so atomic operations can be avoided.
Inner {
ptr,
len,
cap,
arc: unsafe { NonNull::new_unchecked(shared) },
}
}
#[inline]
fn with_capacity(capacity: usize, pool: PoolRef) -> Inner {
Inner::from_slice(capacity, &[], pool)
}
#[inline]
fn from_slice(cap: usize, src: &[u8], pool: PoolRef) -> Inner {
// vec must be aligned to SharedVec instead of u8
let mut vec_cap = (cap / SHARED_VEC_SIZE) + 1;
if cap % SHARED_VEC_SIZE != 0 {
vec_cap += 1;
}
let mut vec = Vec::<SharedVec>::with_capacity(vec_cap);
// Store data in vec
let len = src.len();
let full_cap = vec.capacity() * SHARED_VEC_SIZE;
let cap = full_cap - SHARED_VEC_SIZE;
vec.push(SharedVec {
pool,
cap: full_cap,
ref_count: AtomicUsize::new(1),
len: 0,
offset: 0,
});
pool.acquire(full_cap);
let shared_ptr = vec.as_mut_ptr();
mem::forget(vec);
let (ptr, arc) = unsafe {
let ptr = shared_ptr.add(1) as *mut u8;
ptr::copy_nonoverlapping(src.as_ptr(), ptr, src.len());
let arc =
NonNull::new_unchecked((shared_ptr as usize ^ KIND_VEC) as *mut Shared);
(ptr, arc)
};
// Create new arc, so atomic operations can be avoided.
Inner { len, cap, ptr, arc }
}
#[inline]
fn from_slice_inline(src: &[u8]) -> Inner {
unsafe { Inner::from_ptr_inline(src.as_ptr(), src.len()) }
}
#[inline]
unsafe fn from_ptr_inline(src: *const u8, len: usize) -> Inner {
let mut inner = Inner {
arc: NonNull::new_unchecked(KIND_INLINE as *mut Shared),
ptr: ptr::null_mut(),
len: 0,
cap: 0,
};
let dst = inner.inline_ptr();
ptr::copy(src, dst, len);
inner.set_inline_len(len);
inner
}
#[inline]
fn pool(&self) -> PoolRef {
let kind = self.kind();
if kind == KIND_VEC {
unsafe { (*self.shared_vec()).pool }
} else if kind == KIND_ARC {
unsafe { (*self.arc.as_ptr()).pool }
} else {
PoolId::DEFAULT.pool_ref()
}
}
#[cfg(feature = "mpool")]
#[inline]
fn move_to_pool(&mut self, pool: PoolRef) {
let kind = self.kind();
if kind == KIND_VEC {
let vec = self.shared_vec();
unsafe {
let cap = (*vec).cap;
pool.acquire(cap);
let pool = mem::replace(&mut (*vec).pool, pool);
pool.release(cap);
}
} else if kind == KIND_ARC {
let arc = self.arc.as_ptr();
unsafe {
let cap = (*arc).vec.capacity();
pool.acquire(cap);
let pool = mem::replace(&mut (*arc).pool, pool);
pool.release(cap);
}
}
}
/// Return a slice for the handle's view into the shared buffer
#[inline]
fn as_ref(&self) -> &[u8] {
unsafe {
if self.is_inline() {
slice::from_raw_parts(self.inline_ptr_ro(), self.inline_len())
} else {
slice::from_raw_parts(self.ptr, self.len)
}
}
}
/// Return a mutable slice for the handle's view into the shared buffer
#[inline]
fn as_mut(&mut self) -> &mut [u8] {
debug_assert!(!self.is_static());
unsafe {
if self.is_inline() {
slice::from_raw_parts_mut(self.inline_ptr(), self.inline_len())
} else {
slice::from_raw_parts_mut(self.ptr, self.len)
}
}
}
/// Return a mutable slice for the handle's view into the shared buffer
/// including potentially uninitialized bytes.
#[inline]
unsafe fn as_raw(&mut self) -> &mut [u8] {
debug_assert!(!self.is_static());
if self.is_inline() {
slice::from_raw_parts_mut(self.inline_ptr(), INLINE_CAP)
} else {
slice::from_raw_parts_mut(self.ptr, self.cap)
}
}
/// Return a raw pointer to data
#[inline]
unsafe fn as_ptr(&mut self) -> *mut u8 {
if self.is_inline() {
self.inline_ptr()
} else {
self.ptr
}
}
/// Insert a byte into the next slot and advance the len by 1.
#[inline]
fn put_u8(&mut self, n: u8) {
if self.is_inline() {
let len = self.inline_len();
assert!(len < INLINE_CAP);
unsafe {
*self.inline_ptr().add(len) = n;
}
self.set_inline_len(len + 1);
} else {
assert!(self.len < self.cap);
unsafe {
*self.ptr.add(self.len) = n;
}
self.len += 1;
}
}
#[inline]
fn len(&self) -> usize {
if self.is_inline() {
self.inline_len()
} else {
self.len
}
}
/// Pointer to the start of the inline buffer
#[inline]
unsafe fn inline_ptr(&mut self) -> *mut u8 {
(self as *mut Inner as *mut u8).offset(INLINE_DATA_OFFSET)
}
/// Pointer to the start of the inline buffer
#[inline]
unsafe fn inline_ptr_ro(&self) -> *const u8 {
(self as *const Inner as *const u8).offset(INLINE_DATA_OFFSET)
}
#[inline]
fn inline_len(&self) -> usize {
// This is undefind behavior due to a data race, but experimental
// evidence shows that it works in practice (discussion:
// https://internals.rust-lang.org/t/bit-wise-reasoning-for-atomic-accesses/8853).
(self.arc.as_ptr() as usize & INLINE_LEN_MASK) >> INLINE_LEN_OFFSET
}
/// Set the length of the inline buffer. This is done by writing to the
/// least significant byte of the `arc` field.
#[inline]
fn set_inline_len(&mut self, len: usize) {
debug_assert!(len <= INLINE_CAP);
self.arc = unsafe {
NonNull::new_unchecked(
((self.arc.as_ptr() as usize & !INLINE_LEN_MASK)
| (len << INLINE_LEN_OFFSET)) as _,
)
};
}
/// slice.
#[inline]
unsafe fn set_len(&mut self, len: usize) {
if self.is_inline() {
assert!(len <= INLINE_CAP);
self.set_inline_len(len);
} else {
assert!(len <= self.cap);
self.len = len;
}
}
#[inline]
fn is_empty(&self) -> bool {
self.len() == 0
}
#[inline]
fn capacity(&self) -> usize {
if self.is_inline() {
INLINE_CAP
} else {
self.cap
}
}
fn split_off(&mut self, at: usize, create_inline: bool) -> Inner {
let other = unsafe {
if create_inline && self.len() - at <= INLINE_CAP {
Inner::from_ptr_inline(self.as_ptr().add(at), self.len() - at)
} else {
let mut other = self.shallow_clone();
other.set_start(at);
other
}
};
unsafe {
if create_inline && at <= INLINE_CAP {
*self = Inner::from_ptr_inline(self.as_ptr(), at);
} else {
self.set_end(at);
}
}
other
}
fn split_to(&mut self, at: usize, create_inline: bool) -> Inner {
let other = unsafe {
if create_inline && at <= INLINE_CAP {
Inner::from_ptr_inline(self.as_ptr(), at)
} else {
let mut other = self.shallow_clone();
other.set_end(at);
other
}
};
unsafe {
if create_inline && self.len() - at <= INLINE_CAP {
*self = Inner::from_ptr_inline(self.as_ptr().add(at), self.len() - at);
} else {
self.set_start(at);
}
}
other
}
fn truncate(&mut self, len: usize, create_inline: bool) {
unsafe {
if len <= self.len() {
if create_inline && len < INLINE_CAP {
*self = Inner::from_ptr_inline(self.as_ptr(), len);
} else {
self.set_len(len);
}
}
}
}
fn resize(&mut self, new_len: usize, value: u8) {
let len = self.len();
if new_len > len {
let additional = new_len - len;
self.reserve(additional);
unsafe {
let dst = self.as_raw()[len..].as_mut_ptr();
ptr::write_bytes(dst, value, additional);
self.set_len(new_len);
}
} else {
self.truncate(new_len, false);
}
}
unsafe fn set_start(&mut self, start: usize) {
// Setting the start to 0 is a no-op, so return early if this is the
// case.
if start == 0 {
return;
}
let kind = self.kind();
// Always check `inline` first, because if the handle is using inline
// data storage, all of the `Inner` struct fields will be gibberish.
if kind == KIND_INLINE {
assert!(start <= INLINE_CAP);
let len = self.inline_len();
if len <= start {
self.set_inline_len(0);
} else {
// `set_start` is essentially shifting data off the front of the
// view. Inlined buffers only track the length of the slice.
// So, to update the start, the data at the new starting point
// is copied to the beginning of the buffer.
let new_len = len - start;
let dst = self.inline_ptr();
let src = (dst as *const u8).add(start);
ptr::copy(src, dst, new_len);
self.set_inline_len(new_len);
}
} else {
assert!(start <= self.cap);
// Updating the start of the view is setting `ptr` to point to the
// new start and updating the `len` field to reflect the new length
// of the view.
self.ptr = self.ptr.add(start);
if self.len >= start {
self.len -= start;
} else {
self.len = 0;
}
self.cap -= start;
}
}
unsafe fn set_end(&mut self, end: usize) {
// Always check `inline` first, because if the handle is using inline
// data storage, all of the `Inner` struct fields will be gibberish.
if self.is_inline() {
assert!(end <= INLINE_CAP);
let new_len = cmp::min(self.inline_len(), end);
self.set_inline_len(new_len);
} else {
assert!(end <= self.cap);
self.cap = end;
self.len = cmp::min(self.len, end);
}
}
/// Checks if it is safe to mutate the memory
fn is_mut_safe(&self) -> bool {
let kind = self.kind();
// Always check `inline` first, because if the handle is using inline
// data storage, all of the `Inner` struct fields will be gibberish.
if kind == KIND_INLINE {
// Inlined buffers can always be mutated as the data is never shared
// across handles.
true
} else if kind == KIND_STATIC {
false
} else if kind == KIND_VEC {
// Otherwise, the underlying buffer is potentially shared with other
// handles, so the ref_count needs to be checked.
unsafe { (*self.shared_vec()).is_unique() }
} else {
// Otherwise, the underlying buffer is potentially shared with other
// handles, so the ref_count needs to be checked.
unsafe { (*self.arc.as_ptr()).is_unique() }
}
}
/// Increments the ref count. This should only be done if it is known that
/// it can be done safely. As such, this fn is not public, instead other
/// fns will use this one while maintaining the guarantees.
/// Parameter `mut_self` should only be set to `true` if caller holds
/// `&mut self` reference.
///
/// "Safely" is defined as not exposing two `BytesMut` values that point to
/// the same byte window.
///
/// This function is thread safe.
unsafe fn shallow_clone(&self) -> Inner {
// Always check `inline` first, because if the handle is using inline
// data storage, all of the `Inner` struct fields will be gibberish.
//
// Additionally, if kind is STATIC, then Arc is *never* changed, making
// it safe and faster to check for it now before an atomic acquire.
if self.is_inline_or_static() {
// In this case, a shallow_clone still involves copying the data.
let mut inner: mem::MaybeUninit<Inner> = mem::MaybeUninit::uninit();
ptr::copy_nonoverlapping(self, inner.as_mut_ptr(), 1);
inner.assume_init()
} else {
self.shallow_clone_sync()
}
}
#[cold]
unsafe fn shallow_clone_sync(&self) -> Inner {
// The function requires `&self`, this means that `shallow_clone`
// could be called concurrently.
//
// The first step is to load the value of `arc`. This will determine
// how to proceed. The `Acquire` ordering synchronizes with the
// `compare_and_swap` that comes later in this function. The goal is
// to ensure that if `arc` is currently set to point to a `Shared`,
// that the current thread acquires the associated memory.
let arc: *mut Shared = self.arc.as_ptr();
let kind = arc as usize & KIND_MASK;
if kind == KIND_ARC {
let old_size = (*arc).ref_count.fetch_add(1, Relaxed);
if old_size == usize::MAX {
abort();
}
Inner {
arc: NonNull::new_unchecked(arc),
..*self
}
} else {
assert!(kind == KIND_VEC);
let vec_arc = (arc as usize & KIND_UNMASK) as *mut SharedVec;
let old_size = (*vec_arc).ref_count.fetch_add(1, Relaxed);
if old_size == usize::MAX {
abort();
}
Inner {
arc: NonNull::new_unchecked(arc),
..*self
}
}
}
#[inline]
fn reserve(&mut self, additional: usize) {
let len = self.len();
let rem = self.capacity() - len;
if additional <= rem {
// The handle can already store at least `additional` more bytes, so
// there is no further work needed to be done.
return;
}
self.reserve_inner(additional)
}
#[inline]
// In separate function to allow the short-circuits in `reserve` to
// be inline-able. Significant helps performance.
fn reserve_inner(&mut self, additional: usize) {
let len = self.len();
let kind = self.kind();
// Always check `inline` first, because if the handle is using inline
// data storage, all of the `Inner` struct fields will be gibberish.
if kind == KIND_INLINE {
let new_cap = len + additional;
// Promote to a vector
*self = Inner::from_slice(new_cap, self.as_ref(), PoolId::DEFAULT.pool_ref());
return;
}
// Reserving involves abandoning the currently shared buffer and
// allocating a new vector with the requested capacity.
let new_cap = len + additional;
if kind == KIND_VEC {
let vec = self.shared_vec();
unsafe {
let vec_cap = (*vec).cap - SHARED_VEC_SIZE;
// First, try to reclaim the buffer. This is possible if the current
// handle is the only outstanding handle pointing to the buffer.
if (*vec).is_unique() && vec_cap >= new_cap {
// The capacity is sufficient, reclaim the buffer
let ptr = (vec as *mut u8).add(SHARED_VEC_SIZE);
ptr::copy(self.ptr, ptr, len);
self.ptr = ptr;
self.cap = vec_cap;
} else {
// Create a new vector storage
*self = Inner::from_slice(new_cap, self.as_ref(), (*vec).pool);
}
}
} else {
debug_assert!(kind == KIND_ARC);
let arc = self.arc.as_ptr();
unsafe {
// First, try to reclaim the buffer. This is possible if the current
// handle is the only outstanding handle pointing to the buffer.
if (*arc).is_unique() {
// This is the only handle to the buffer. It can be reclaimed.
// However, before doing the work of copying data, check to make
// sure that the vector has enough capacity.
let v = &mut (*arc).vec;
if v.capacity() >= new_cap {
// The capacity is sufficient, reclaim the buffer
let ptr = v.as_mut_ptr();
ptr::copy(self.ptr, ptr, len);
self.ptr = ptr;
self.cap = v.capacity();
return;
}
}
// Create a new vector storage
*self = Inner::from_slice(new_cap, self.as_ref(), (*arc).pool);
}
}
}
/// Returns true if the buffer is stored inline
#[inline]
fn is_inline(&self) -> bool {
self.kind() == KIND_INLINE
}
#[inline]
fn is_inline_or_static(&self) -> bool {
// The value returned by `kind` isn't itself safe, but the value could
// inform what operations to take, and unsafely do something without
// synchronization.
//
// KIND_INLINE and KIND_STATIC will *never* change, so branches on that
// information is safe.
let kind = self.kind();
kind == KIND_INLINE || kind == KIND_STATIC
}
/// Used for `debug_assert` statements
#[inline]
fn is_static(&self) -> bool {
matches!(self.kind(), KIND_STATIC)
}
#[inline]
fn shared_vec(&self) -> *mut SharedVec {
((self.arc.as_ptr() as usize) & KIND_UNMASK) as *mut SharedVec
}
#[inline]
fn kind(&self) -> usize {
// This function is going to probably raise some eyebrows. The function
// returns true if the buffer is stored inline. This is done by checking
// the least significant bit in the `arc` field.
//
// Now, you may notice that `arc` is an `AtomicPtr` and this is
// accessing it as a normal field without performing an atomic load...
//
// Again, the function only cares about the least significant bit, and
// this bit is set when `Inner` is created and never changed after that.
// All platforms have atomic "word" operations and won't randomly flip
// bits, so even without any explicit atomic operations, reading the
// flag will be correct.
//
// This is undefined behavior due to a data race, but experimental
// evidence shows that it works in practice (discussion:
// https://internals.rust-lang.org/t/bit-wise-reasoning-for-atomic-accesses/8853).
//
// This function is very critical performance wise as it is called for
// every operation. Performing an atomic load would mess with the
// compiler's ability to optimize. Simple benchmarks show up to a 10%
// slowdown using a `Relaxed` atomic load on x86.
#[cfg(target_endian = "little")]
#[inline]
fn imp(arc: *mut Shared) -> usize {
(arc as usize) & KIND_MASK
}
#[cfg(target_endian = "big")]
#[inline]
fn imp(arc: *mut Shared) -> usize {
unsafe {
let p: *const usize = arc as *const usize;
*p & KIND_MASK
}
}
imp(self.arc.as_ptr())
}
}
impl Drop for Inner {
fn drop(&mut self) {
let kind = self.kind();
if kind == KIND_VEC {
release_shared_vec(self.shared_vec());
} else if kind == KIND_ARC {
release_shared(self.arc.as_ptr());
}
}
}
fn release_shared(ptr: *mut Shared) {
// `Shared` storage... follow the drop steps from Arc.
unsafe {
if (*ptr).ref_count.fetch_sub(1, Release) != 1 {
return;
}
// This fence is needed to prevent reordering of use of the data and
// deletion of the data. Because it is marked `Release`, the decreasing
// of the reference count synchronizes with this `Acquire` fence. This
// means that use of the data happens before decreasing the reference
// count, which happens before this fence, which happens before the
// deletion of the data.
//
// As explained in the [Boost documentation][1],
//
// > It is important to enforce any possible access to the object in one
// > thread (through an existing reference) to *happen before* deleting
// > the object in a different thread. This is achieved by a "release"
// > operation after dropping a reference (any access to the object
// > through this reference must obviously happened before), and an
// > "acquire" operation before deleting the object.
//
// [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
atomic::fence(Acquire);
// Drop the data
let arc = Box::from_raw(ptr);
arc.pool.release(arc.vec.capacity());
}
}
fn release_shared_vec(ptr: *mut SharedVec) {
// `Shared` storage... follow the drop steps from Arc.
unsafe {
if (*ptr).ref_count.fetch_sub(1, Release) != 1 {
return;
}
// This fence is needed to prevent reordering of use of the data and
// deletion of the data. Because it is marked `Release`, the decreasing
// of the reference count synchronizes with this `Acquire` fence. This
// means that use of the data happens before decreasing the reference
// count, which happens before this fence, which happens before the
// deletion of the data.
//
// As explained in the [Boost documentation][1],
//
// > It is important to enforce any possible access to the object in one
// > thread (through an existing reference) to *happen before* deleting
// > the object in a different thread. This is achieved by a "release"
// > operation after dropping a reference (any access to the object
// > through this reference must obviously happened before), and an
// > "acquire" operation before deleting the object.
//
// [1]: (www.boost.org/doc/libs/1_55_0/doc/html/atomic/usage_examples.html)
atomic::fence(Acquire);
// Drop the data
let cap = (*ptr).cap;
(*ptr).pool.release(cap);
ptr::drop_in_place(ptr);
Vec::<u8>::from_raw_parts(ptr as *mut u8, 0, cap);
}
}
impl Shared {
fn is_unique(&self) -> bool {
// The goal is to check if the current handle is the only handle
// that currently has access to the buffer. This is done by
// checking if the `ref_count` is currently 1.
//
// The `Acquire` ordering synchronizes with the `Release` as
// part of the `fetch_sub` in `release_shared`. The `fetch_sub`
// operation guarantees that any mutations done in other threads
// are ordered before the `ref_count` is decremented. As such,
// this `Acquire` will guarantee that those mutations are
// visible to the current thread.
self.ref_count.load(Acquire) == 1
}
}
impl SharedVec {
fn is_unique(&self) -> bool {
// This is same as Shared::is_unique() but for KIND_VEC
self.ref_count.load(Acquire) == 1
}
}
unsafe impl Send for Inner {}
unsafe impl Sync for Inner {}
/*
*
* ===== PartialEq / PartialOrd =====
*
*/
impl PartialEq<[u8]> for BytesMut {
fn eq(&self, other: &[u8]) -> bool {
&**self == other
}
}
impl<const N: usize> PartialEq<[u8; N]> for BytesMut {
fn eq(&self, other: &[u8; N]) -> bool {
&**self == other
}
}
impl PartialEq<BytesMut> for [u8] {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl<const N: usize> PartialEq<BytesMut> for [u8; N] {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl<'a, const N: usize> PartialEq<BytesMut> for &'a [u8; N] {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl PartialEq<str> for BytesMut {
fn eq(&self, other: &str) -> bool {
&**self == other.as_bytes()
}
}
impl PartialEq<BytesMut> for str {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl PartialEq<Vec<u8>> for BytesMut {
fn eq(&self, other: &Vec<u8>) -> bool {
*self == other[..]
}
}
impl PartialEq<BytesMut> for Vec<u8> {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl PartialEq<String> for BytesMut {
fn eq(&self, other: &String) -> bool {
*self == other[..]
}
}
impl PartialEq<BytesMut> for String {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl<'a, T: ?Sized> PartialEq<&'a T> for BytesMut
where
BytesMut: PartialEq<T>,
{
fn eq(&self, other: &&'a T) -> bool {
*self == **other
}
}
impl PartialEq<BytesMut> for &[u8] {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl PartialEq<BytesMut> for &str {
fn eq(&self, other: &BytesMut) -> bool {
*other == *self
}
}
impl PartialEq<[u8]> for Bytes {
fn eq(&self, other: &[u8]) -> bool {
self.inner.as_ref() == other
}
}
impl<const N: usize> PartialEq<[u8; N]> for Bytes {
fn eq(&self, other: &[u8; N]) -> bool {
self.inner.as_ref() == other.as_ref()
}
}
impl PartialOrd<[u8]> for Bytes {
fn partial_cmp(&self, other: &[u8]) -> Option<cmp::Ordering> {
self.inner.as_ref().partial_cmp(other)
}
}
impl<const N: usize> PartialOrd<[u8; N]> for Bytes {
fn partial_cmp(&self, other: &[u8; N]) -> Option<cmp::Ordering> {
self.inner.as_ref().partial_cmp(other.as_ref())
}
}
impl PartialEq<Bytes> for [u8] {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl<const N: usize> PartialEq<Bytes> for [u8; N] {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl<'a, const N: usize> PartialEq<Bytes> for &'a [u8; N] {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for [u8] {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl<const N: usize> PartialOrd<Bytes> for [u8; N] {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl PartialEq<str> for Bytes {
fn eq(&self, other: &str) -> bool {
self.inner.as_ref() == other.as_bytes()
}
}
impl PartialOrd<str> for Bytes {
fn partial_cmp(&self, other: &str) -> Option<cmp::Ordering> {
self.inner.as_ref().partial_cmp(other.as_bytes())
}
}
impl PartialEq<Bytes> for str {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for str {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl PartialEq<Vec<u8>> for Bytes {
fn eq(&self, other: &Vec<u8>) -> bool {
*self == other[..]
}
}
impl PartialOrd<Vec<u8>> for Bytes {
fn partial_cmp(&self, other: &Vec<u8>) -> Option<cmp::Ordering> {
self.inner.as_ref().partial_cmp(&other[..])
}
}
impl PartialEq<Bytes> for Vec<u8> {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for Vec<u8> {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl PartialEq<String> for Bytes {
fn eq(&self, other: &String) -> bool {
*self == other[..]
}
}
impl PartialOrd<String> for Bytes {
fn partial_cmp(&self, other: &String) -> Option<cmp::Ordering> {
self.inner.as_ref().partial_cmp(other.as_bytes())
}
}
impl PartialEq<Bytes> for String {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for String {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl PartialEq<Bytes> for &[u8] {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for &[u8] {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl PartialEq<Bytes> for &str {
fn eq(&self, other: &Bytes) -> bool {
*other == *self
}
}
impl PartialOrd<Bytes> for &str {
fn partial_cmp(&self, other: &Bytes) -> Option<cmp::Ordering> {
other.partial_cmp(self)
}
}
impl<'a, T: ?Sized> PartialEq<&'a T> for Bytes
where
Bytes: PartialEq<T>,
{
fn eq(&self, other: &&'a T) -> bool {
*self == **other
}
}
impl From<BytesVec> for Bytes {
fn from(b: BytesVec) -> Self {
b.freeze()
}
}
impl<'a, T: ?Sized> PartialOrd<&'a T> for Bytes
where
Bytes: PartialOrd<T>,
{
fn partial_cmp(&self, other: &&'a T) -> Option<cmp::Ordering> {
self.partial_cmp(&**other)
}
}
impl PartialEq<BytesMut> for Bytes {
fn eq(&self, other: &BytesMut) -> bool {
other[..] == self[..]
}
}
impl PartialEq<BytesVec> for Bytes {
fn eq(&self, other: &BytesVec) -> bool {
other[..] == self[..]
}
}
impl PartialEq<Bytes> for BytesVec {
fn eq(&self, other: &Bytes) -> bool {
other[..] == self[..]
}
}
impl PartialEq<Bytes> for BytesMut {
fn eq(&self, other: &Bytes) -> bool {
other[..] == self[..]
}
}
impl PartialEq<BytesMut> for BytesVec {
fn eq(&self, other: &BytesMut) -> bool {
other[..] == self[..]
}
}
impl PartialEq<BytesVec> for BytesMut {
fn eq(&self, other: &BytesVec) -> bool {
other[..] == self[..]
}
}
impl PartialEq<[u8]> for BytesVec {
fn eq(&self, other: &[u8]) -> bool {
&**self == other
}
}
impl<const N: usize> PartialEq<[u8; N]> for BytesVec {
fn eq(&self, other: &[u8; N]) -> bool {
&**self == other
}
}
impl PartialEq<BytesVec> for [u8] {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl<const N: usize> PartialEq<BytesVec> for [u8; N] {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl<'a, const N: usize> PartialEq<BytesVec> for &'a [u8; N] {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl PartialEq<str> for BytesVec {
fn eq(&self, other: &str) -> bool {
&**self == other.as_bytes()
}
}
impl PartialEq<BytesVec> for str {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl PartialEq<Vec<u8>> for BytesVec {
fn eq(&self, other: &Vec<u8>) -> bool {
*self == other[..]
}
}
impl PartialEq<BytesVec> for Vec<u8> {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl PartialEq<String> for BytesVec {
fn eq(&self, other: &String) -> bool {
*self == other[..]
}
}
impl PartialEq<BytesVec> for String {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl<'a, T: ?Sized> PartialEq<&'a T> for BytesVec
where
BytesVec: PartialEq<T>,
{
fn eq(&self, other: &&'a T) -> bool {
*self == **other
}
}
impl PartialEq<BytesVec> for &[u8] {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
impl PartialEq<BytesVec> for &str {
fn eq(&self, other: &BytesVec) -> bool {
*other == *self
}
}
// While there is `std::process:abort`, it's only available in Rust 1.17, and
// our minimum supported version is currently 1.15. So, this acts as an abort
// by triggering a double panic, which always aborts in Rust.
struct Abort;
impl Drop for Abort {
fn drop(&mut self) {
panic!();
}
}
#[inline(never)]
#[cold]
fn abort() {
let _a = Abort;
panic!();
}
#[cfg(test)]
mod tests {
use std::collections::HashMap;
use super::*;
const LONG: &[u8] = b"mary had a little lamb, little lamb, little lamb, little lamb, little lamb, little lamb \
mary had a little lamb, little lamb, little lamb, little lamb, little lamb, little lamb \
mary had a little lamb, little lamb, little lamb, little lamb, little lamb, little lamb";
#[test]
fn trimdown() {
let mut b = Bytes::from(LONG.to_vec());
assert_eq!(b.inner.capacity(), 263);
unsafe { b.inner.set_len(68) };
assert_eq!(b.len(), 68);
assert_eq!(b.inner.capacity(), 263);
b.trimdown();
assert_eq!(b.inner.capacity(), 96);
unsafe { b.inner.set_len(16) };
b.trimdown();
assert!(b.is_inline());
}
#[test]
#[allow(
clippy::len_zero,
clippy::nonminimal_bool,
clippy::unnecessary_fallible_conversions
)]
fn bytes() {
let mut b = Bytes::from(LONG.to_vec());
b.clear();
assert!(b.is_inline());
assert!(b.is_empty());
assert!(b.len() == 0);
let b = Bytes::from(&Bytes::from(LONG));
assert_eq!(b, LONG);
let b = Bytes::from(BytesMut::from(LONG));
assert_eq!(b, LONG);
let mut b: Bytes = BytesMut::try_from(b).unwrap().freeze();
assert_eq!(b, LONG);
assert!(!(b > b));
assert_eq!(<Bytes as Buf>::remaining(&b), LONG.len());
assert_eq!(<Bytes as Buf>::chunk(&b), LONG);
<Bytes as Buf>::advance(&mut b, 10);
assert_eq!(Buf::chunk(&b), &LONG[10..]);
let mut h: HashMap<Bytes, usize> = HashMap::default();
h.insert(b.clone(), 1);
assert_eq!(h.get(&b), Some(&1));
let mut b = BytesMut::try_from(LONG).unwrap();
assert_eq!(b, LONG);
assert_eq!(<BytesMut as Buf>::remaining(&b), LONG.len());
assert_eq!(<BytesMut as BufMut>::remaining_mut(&b), 25);
assert_eq!(<BytesMut as Buf>::chunk(&b), LONG);
<BytesMut as Buf>::advance(&mut b, 10);
assert_eq!(<BytesMut as Buf>::chunk(&b), &LONG[10..]);
let mut b = BytesMut::with_capacity(12);
<BytesMut as BufMut>::put_i8(&mut b, 1);
assert_eq!(b, b"\x01".as_ref());
<BytesMut as BufMut>::put_u8(&mut b, 2);
assert_eq!(b, b"\x01\x02".as_ref());
<BytesMut as BufMut>::put_slice(&mut b, b"12345");
assert_eq!(b, b"\x01\x0212345".as_ref());
<BytesMut as BufMut>::chunk_mut(&mut b).write_byte(0, b'1');
unsafe { <BytesMut as BufMut>::advance_mut(&mut b, 1) };
assert_eq!(b, b"\x01\x02123451".as_ref());
}
#[test]
#[allow(clippy::unnecessary_fallible_conversions)]
fn bytes_vec() {
let bv = BytesVec::copy_from_slice(LONG);
// SharedVec size is 32
assert_eq!(bv.capacity(), mem::size_of::<SharedVec>() * 9);
assert_eq!(bv.len(), 263);
assert_eq!(bv.as_ref().len(), 263);
assert_eq!(bv.as_ref(), LONG);
let mut bv = BytesVec::copy_from_slice(&b"hello"[..]);
assert_eq!(bv.capacity(), mem::size_of::<SharedVec>());
assert_eq!(bv.len(), 5);
assert_eq!(bv.as_ref().len(), 5);
assert_eq!(bv.as_ref()[0], b"h"[0]);
bv.put_u8(b" "[0]);
assert_eq!(bv.as_ref(), &b"hello "[..]);
bv.put("world");
assert_eq!(bv, "hello world");
let b = Bytes::from(bv);
assert_eq!(b, "hello world");
let mut b = BytesMut::try_from(b).unwrap();
b.put(".");
assert_eq!(b, "hello world.");
}
}