strbuf.c

   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  */
   8 char strbuf_slopbuf[1];
   9
  10 void 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
  18 void strbuf_release(struct strbuf *sb)
  19 {
  20         if (sb->alloc) {
  21                 free(sb->buf);
  22                 strbuf_init(sb, 0);
  23         }
  24 }
  25
  26 char *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
  35 void 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
  45 void 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
  54 void 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
  61 int 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
  73 void 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
  92 void 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
  97 void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
  98 {
  99         strbuf_splice(sb, pos, len, NULL, 0);
 100 }
 101
 102 void 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
 109 void 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
 132 size_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
 144 ssize_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
 167 int 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
 189 int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 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, hint);
 197         close(fd);
 198         if (len < 0)
 199                 return -1;
 200
 201         return len;
 202 }