liba 0.1.15

An algorithm library based on C/C++
Documentation 
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

#include "a.h"
#include "a/crc.h"

struct crc64
{
    a_u64 table[0x100];
    a_u64 (*eval)(a_u64 const table[0x100], void const *pdata, a_size nbyte, a_u64 value);
};

static JSClassID liba_crc64_class_id;

static void liba_crc64_finalizer(JSRuntime *rt, JSValue val)
{
    js_free_rt(rt, JS_GetOpaque(val, liba_crc64_class_id));
}

static JSClassDef liba_crc64_class = {"crc64", .finalizer = liba_crc64_finalizer};

static JSValue liba_crc64_ctor(JSContext *ctx, JSValueConst new_target, int argc, JSValueConst *argv)
{
    JSValue proto, clazz = JS_UNDEFINED;
    struct crc64 *const self = (struct crc64 *)js_mallocz(ctx, sizeof(struct crc64));
    if (!self) { return JS_EXCEPTION; }
    a_i64 poly = 0;
    if (JS_ToInt64Ext(ctx, &poly, argv[0])) { goto fail; }
    int reversed = 0;
    if (argc > 1)
    {
        reversed = JS_ToBool(ctx, argv[1]);
        if (reversed < 0) { goto fail; }
    }
    if (reversed)
    {
        a_crc64l_init(self->table, (a_u64)poly);
        self->eval = a_crc64l;
    }
    else
    {
        a_crc64m_init(self->table, (a_u64)poly);
        self->eval = a_crc64m;
    }
    proto = JS_GetPropertyStr(ctx, new_target, "prototype");
    if (JS_IsException(proto)) { goto fail; }
    clazz = JS_NewObjectProtoClass(ctx, proto, liba_crc64_class_id);
    JS_FreeValue(ctx, proto);
    if (JS_IsException(clazz)) { goto fail; }
    JS_SetOpaque(clazz, self);
    return clazz;
fail:
    js_free(ctx, self);
    JS_FreeValue(ctx, clazz);
    return JS_UNDEFINED;
}

static JSValue liba_crc64_gen(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
{
    struct crc64 *const self = (struct crc64 *)JS_GetOpaque2(ctx, this_val, liba_crc64_class_id);
    if (!self) { return JS_EXCEPTION; }
    a_i64 poly = 0;
    if (JS_ToInt64Ext(ctx, &poly, argv[0])) { return JS_EXCEPTION; }
    int reversed = 0;
    if (argc > 1)
    {
        reversed = JS_ToBool(ctx, argv[1]);
        if (reversed < 0) { return JS_EXCEPTION; }
    }
    if (reversed)
    {
        a_crc64l_init(self->table, (a_u64)poly);
        self->eval = a_crc64l;
    }
    else
    {
        a_crc64m_init(self->table, (a_u64)poly);
        self->eval = a_crc64m;
    }
    return JS_UNDEFINED;
}

static JSValue liba_crc64_eval(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
{
    struct crc64 *const self = (struct crc64 *)JS_GetOpaque2(ctx, this_val, liba_crc64_class_id);
    if (!self) { return JS_EXCEPTION; }
    a_u64 value = 0;
    if (argc > 1)
    {
        a_i64 x = 0;
        if (JS_ToInt64Ext(ctx, &x, argv[1])) { return JS_EXCEPTION; }
        value = (a_u64)x;
    }
    size_t n = 0;
    if (JS_IsArray(ctx, argv[0]))
    {
        a_byte *p = JS_GetArrayBuffer(ctx, &n, argv[0]);
        if (p) { value = self->eval(self->table, p, n, value); }
    }
    else
    {
        char const *const p = JS_ToCStringLen(ctx, &n, argv[0]);
        value = self->eval(self->table, p, n, value);
        JS_FreeCString(ctx, p);
    }
    return JS_NewBigUint64(ctx, value);
}

static JSValue liba_crc64_pack(JSContext *ctx, JSValueConst this_val, int argc, JSValueConst *argv)
{
    JSValue val = JS_UNDEFINED;
    struct crc64 *const self = (struct crc64 *)JS_GetOpaque2(ctx, this_val, liba_crc64_class_id);
    if (!self) { return JS_EXCEPTION; }
    a_u64 value = 0;
    if (argc > 1)
    {
        a_i64 x = 0;
        if (JS_ToInt64Ext(ctx, &x, argv[1])) { return JS_EXCEPTION; }
        value = (a_u64)x;
    }
    size_t n = 0;
    char const *const s = JS_ToCStringLen(ctx, &n, argv[0]);
    value = self->eval(self->table, s, n, value);
    a_byte *p = (a_byte *)js_malloc(ctx, n + 8);
    if (p) { a_copy(p, s, n); }
    else { goto fail; }
    self->eval == a_crc64m
        ? a_u64_setb(p + n, value)
        : a_u64_setl(p + n, value);
    val = js_array_u8_new(ctx, p, (uint32_t)n + 8);
fail:
    JS_FreeCString(ctx, s);
    js_free(ctx, p);
    return val;
}

enum
{
    self_table,
};

static JSValue liba_crc64_get(JSContext *ctx, JSValueConst this_val, int magic)
{
    struct crc64 *const self = (struct crc64 *)JS_GetOpaque2(ctx, this_val, liba_crc64_class_id);
    if (!self) { return JS_EXCEPTION; }
    if (magic == self_table)
    {
        return js_array_u64_new(ctx, self->table, 0x100);
    }
    return JS_UNDEFINED;
}

static JSCFunctionListEntry const liba_crc64_proto[] = {
    JS_PROP_STRING_DEF("[Symbol.toStringTag]", "a.crc64", 0),
    JS_CGETSET_MAGIC_DEF("table", liba_crc64_get, NULL, self_table),
    JS_CFUNC_DEF("gen", 2, liba_crc64_gen),
    JS_CFUNC_DEF("eval", 2, liba_crc64_eval),
    JS_CFUNC_DEF("pack", 2, liba_crc64_pack),
};

int js_liba_crc64_init(JSContext *ctx, JSModuleDef *m)
{
    JS_NewClassID(&liba_crc64_class_id);
    JS_NewClass(JS_GetRuntime(ctx), liba_crc64_class_id, &liba_crc64_class);

    JSValue const proto = JS_NewObject(ctx);
    JS_SetPropertyFunctionList(ctx, proto, liba_crc64_proto, A_LEN(liba_crc64_proto));

    JSValue const clazz = JS_NewCFunction2(ctx, liba_crc64_ctor, "crc64", 2, JS_CFUNC_constructor, 0);
    JS_SetConstructor(ctx, clazz, proto);
    JS_SetClassProto(ctx, liba_crc64_class_id, proto);

    return JS_SetModuleExport(ctx, m, "crc64", clazz);
}