strbuf.con commit strbuf change: be sure ->buf is never ever NULL. (b315c5c)
   1#include "cache.h"
   2
   3/*
   4 * Used as the default ->buf value, so that people can always assume
   5 * buf is non NULL and ->buf is NUL terminated even for a freshly
   6 * initialized strbuf.
   7 */
   8char strbuf_slopbuf[1];
   9
  10void strbuf_init(struct strbuf *sb, size_t hint)
  11{
  12        sb->alloc = sb->len = 0;
  13        sb->buf = strbuf_slopbuf;
  14        if (hint)
  15                strbuf_grow(sb, hint);
  16}
  17
  18void strbuf_release(struct strbuf *sb)
  19{
  20        if (sb->alloc) {
  21                free(sb->buf);
  22                strbuf_init(sb, 0);
  23        }
  24}
  25
  26char *strbuf_detach(struct strbuf *sb, size_t *sz)
  27{
  28        char *res = sb->alloc ? sb->buf : NULL;
  29        if (sz)
  30                *sz = sb->len;
  31        strbuf_init(sb, 0);
  32        return res;
  33}
  34
  35void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  36{
  37        strbuf_release(sb);
  38        sb->buf   = buf;
  39        sb->len   = len;
  40        sb->alloc = alloc;
  41        strbuf_grow(sb, 0);
  42        sb->buf[sb->len] = '\0';
  43}
  44
  45void strbuf_grow(struct strbuf *sb, size_t extra)
  46{
  47        if (sb->len + extra + 1 <= sb->len)
  48                die("you want to use way too much memory");
  49        if (!sb->alloc)
  50                sb->buf = NULL;
  51        ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  52}
  53
  54void strbuf_rtrim(struct strbuf *sb)
  55{
  56        while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
  57                sb->len--;
  58        sb->buf[sb->len] = '\0';
  59}
  60
  61int strbuf_cmp(struct strbuf *a, struct strbuf *b)
  62{
  63        int cmp;
  64        if (a->len < b->len) {
  65                cmp = memcmp(a->buf, b->buf, a->len);
  66                return cmp ? cmp : -1;
  67        } else {
  68                cmp = memcmp(a->buf, b->buf, b->len);
  69                return cmp ? cmp : a->len != b->len;
  70        }
  71}
  72
  73void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
  74                                   const void *data, size_t dlen)
  75{
  76        if (pos + len < pos)
  77                die("you want to use way too much memory");
  78        if (pos > sb->len)
  79                die("`pos' is too far after the end of the buffer");
  80        if (pos + len > sb->len)
  81                die("`pos + len' is too far after the end of the buffer");
  82
  83        if (dlen >= len)
  84                strbuf_grow(sb, dlen - len);
  85        memmove(sb->buf + pos + dlen,
  86                        sb->buf + pos + len,
  87                        sb->len - pos - len);
  88        memcpy(sb->buf + pos, data, dlen);
  89        strbuf_setlen(sb, sb->len + dlen - len);
  90}
  91
  92void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
  93{
  94        strbuf_splice(sb, pos, 0, data, len);
  95}
  96
  97void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
  98{
  99        strbuf_splice(sb, pos, len, NULL, 0);
 100}
 101
 102void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 103{
 104        strbuf_grow(sb, len);
 105        memcpy(sb->buf + sb->len, data, len);
 106        strbuf_setlen(sb, sb->len + len);
 107}
 108
 109void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 110{
 111        int len;
 112        va_list ap;
 113
 114        va_start(ap, fmt);
 115        len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 116        va_end(ap);
 117        if (len < 0) {
 118                len = 0;
 119        }
 120        if (len > strbuf_avail(sb)) {
 121                strbuf_grow(sb, len);
 122                va_start(ap, fmt);
 123                len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 124                va_end(ap);
 125                if (len > strbuf_avail(sb)) {
 126                        die("this should not happen, your snprintf is broken");
 127                }
 128        }
 129        strbuf_setlen(sb, sb->len + len);
 130}
 131
 132size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 133{
 134        size_t res;
 135
 136        strbuf_grow(sb, size);
 137        res = fread(sb->buf + sb->len, 1, size, f);
 138        if (res > 0) {
 139                strbuf_setlen(sb, sb->len + res);
 140        }
 141        return res;
 142}
 143
 144ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 145{
 146        size_t oldlen = sb->len;
 147
 148        strbuf_grow(sb, hint ? hint : 8192);
 149        for (;;) {
 150                ssize_t cnt;
 151
 152                cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 153                if (cnt < 0) {
 154                        strbuf_setlen(sb, oldlen);
 155                        return -1;
 156                }
 157                if (!cnt)
 158                        break;
 159                sb->len += cnt;
 160                strbuf_grow(sb, 8192);
 161        }
 162
 163        sb->buf[sb->len] = '\0';
 164        return sb->len - oldlen;
 165}
 166
 167int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
 168{
 169        int ch;
 170
 171        strbuf_grow(sb, 0);
 172        if (feof(fp))
 173                return EOF;
 174
 175        strbuf_reset(sb);
 176        while ((ch = fgetc(fp)) != EOF) {
 177                if (ch == term)
 178                        break;
 179                strbuf_grow(sb, 1);
 180                sb->buf[sb->len++] = ch;
 181        }
 182        if (ch == EOF && sb->len == 0)
 183                return EOF;
 184
 185        sb->buf[sb->len] = '\0';
 186        return 0;
 187}
 188
 189int strbuf_read_file(struct strbuf *sb, const char *path)
 190{
 191        int fd, len;
 192
 193        fd = open(path, O_RDONLY);
 194        if (fd < 0)
 195                return -1;
 196        len = strbuf_read(sb, fd, 0);
 197        close(fd);
 198        if (len < 0)
 199                return -1;
 200
 201        return len;
 202}