mruby-compiler2-sys 0.4.0

mruby-compiler2 bindings for Rust
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

/*
** pool.c - memory pool
**
** See Copyright Notice in mruby.h
*/

#include "../include/mrc_ccontext.h"

/* configuration section */
/* allocated memory address should be multiple of POOL_ALIGNMENT */
/* or undef it if alignment does not matter */
#ifndef POOL_ALIGNMENT
#if INTPTR_MAX == INT64_MAX
#define POOL_ALIGNMENT 8
#else
#define POOL_ALIGNMENT 4
#endif
#endif
/* page size of memory pool */
#ifndef POOL_PAGE_SIZE
#define POOL_PAGE_SIZE 1024
#endif
/* end of configuration section */

/* Disable MSVC warning "C4200: nonstandard extension used: zero-sized array
 * in struct/union" when in C++ mode */
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable : 4200)
#endif

struct mrc_pool_page {
  struct mrc_pool_page *next;
  size_t offset;
  size_t len;
  void *last;
  char page[];
};

#ifdef _MSC_VER
#pragma warning(pop)
#endif

#ifdef POOL_ALIGNMENT
#  define ALIGN_PADDING(x) ((SIZE_MAX - (x) + 1) & (POOL_ALIGNMENT - 1))
#else
#  define ALIGN_PADDING(x) (0)
#endif

MRC_API mrc_pool*
mrc_pool_open(mrc_ccontext *c)
{
  mrc_pool *pool = (mrc_pool*)mrc_malloc(c, sizeof(mrc_pool));

  if (pool) {
    pool->c = c;
    pool->pages = NULL;
  }
  return pool;
}

MRC_API void
mrc_pool_close(mrc_pool *pool)
{
  struct mrc_pool_page *page;

  if (!pool) return;
  page = pool->pages;
  while (page) {
    struct mrc_pool_page *tmp = page;
    page = page->next;
    mrc_free(pool->c, tmp);
  }
  mrc_free(pool->c, pool);
}

static struct mrc_pool_page*
page_alloc(mrc_pool *pool, size_t len)
{
#if defined(MRC_TARGET_MRUBY)
  mrc_ccontext *c = pool->c;
#endif
  struct mrc_pool_page *page;

  if (len < POOL_PAGE_SIZE)
    len = POOL_PAGE_SIZE;
  page = (struct mrc_pool_page*)mrc_malloc(c, sizeof(struct mrc_pool_page)+len);
  if (page) {
    page->offset = 0;
    page->len = len;
  }

  return page;
}

MRC_API void*
mrc_pool_alloc(mrc_pool *pool, size_t len)
{
  struct mrc_pool_page *page;

  if (!pool) return NULL;
  len += ALIGN_PADDING(len);
  for (page = pool->pages; page; page = page->next) {
    if (page->offset + len <= page->len) {
      size_t n = page->offset;
      page->offset += len;
      page->last = (void*)(page->page+n);
      return page->last;
    }
  }
  page = page_alloc(pool, len);
  if (!page) return NULL;
  page->offset = len;
  page->next = pool->pages;
  pool->pages = page;

  page->last = (void*)page->page;
  return page->last;
}

MRC_API void*
mrc_pool_realloc(mrc_pool *pool, void *p, size_t oldlen, size_t newlen)
{
  if (!pool) return NULL;
  if (newlen < oldlen) return p;
  oldlen += ALIGN_PADDING(oldlen);
  newlen += ALIGN_PADDING(newlen);
  for (struct mrc_pool_page *page = pool->pages; page; page = page->next) {
    if (page->last == p) {
      /* if p is a last allocation from the page */
      size_t beg = (char*)p - page->page;
      /* check beg + oldlen points bottom */
      /* assert(beg + oldlen == page->offset) */
      if (beg + oldlen != page->offset) break;
      if (beg + newlen > page->len) {
        /* new allocation need more space */
        /* abandon this space */
        page->offset = beg;
        break;
      }
      page->offset = beg + newlen;
      return p;
    }
  }
  void *np = mrc_pool_alloc(pool, newlen);
  if (np == NULL) {
    return NULL;
  }
  memcpy(np, p, oldlen);
  return np;
}