Andrew's git / gitweb.git / strbuf.c
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strbuf.con commit doc: make clear --assume-unchanged's user contract (ccadb25)
   1#include "cache.h"
   2#include "refs.h"
   3
   4int starts_with(const char *str, const char *prefix)
   5{
   6        for (; ; str++, prefix++)
   7                if (!*prefix)
   8                        return 1;
   9                else if (*str != *prefix)
  10                        return 0;
  11}
  12
  13int prefixcmp(const char *str, const char *prefix)
  14{
  15        for (; ; str++, prefix++)
  16                if (!*prefix)
  17                        return 0;
  18                else if (*str != *prefix)
  19                        return (unsigned char)*prefix - (unsigned char)*str;
  20}
  21
  22int ends_with(const char *str, const char *suffix)
  23{
  24        int len = strlen(str), suflen = strlen(suffix);
  25        if (len < suflen)
  26                return 0;
  27        else
  28                return !strcmp(str + len - suflen, suffix);
  29}
  30
  31int suffixcmp(const char *str, const char *suffix)
  32{
  33        int len = strlen(str), suflen = strlen(suffix);
  34        if (len < suflen)
  35                return -1;
  36        else
  37                return strcmp(str + len - suflen, suffix);
  38}
  39
  40/*
  41 * Used as the default ->buf value, so that people can always assume
  42 * buf is non NULL and ->buf is NUL terminated even for a freshly
  43 * initialized strbuf.
  44 */
  45char strbuf_slopbuf[1];
  46
  47void strbuf_init(struct strbuf *sb, size_t hint)
  48{
  49        sb->alloc = sb->len = 0;
  50        sb->buf = strbuf_slopbuf;
  51        if (hint)
  52                strbuf_grow(sb, hint);
  53}
  54
  55void strbuf_release(struct strbuf *sb)
  56{
  57        if (sb->alloc) {
  58                free(sb->buf);
  59                strbuf_init(sb, 0);
  60        }
  61}
  62
  63char *strbuf_detach(struct strbuf *sb, size_t *sz)
  64{
  65        char *res;
  66        strbuf_grow(sb, 0);
  67        res = sb->buf;
  68        if (sz)
  69                *sz = sb->len;
  70        strbuf_init(sb, 0);
  71        return res;
  72}
  73
  74void strbuf_attach(struct strbuf *sb, void *buf, size_t len, size_t alloc)
  75{
  76        strbuf_release(sb);
  77        sb->buf   = buf;
  78        sb->len   = len;
  79        sb->alloc = alloc;
  80        strbuf_grow(sb, 0);
  81        sb->buf[sb->len] = '\0';
  82}
  83
  84void strbuf_grow(struct strbuf *sb, size_t extra)
  85{
  86        int new_buf = !sb->alloc;
  87        if (unsigned_add_overflows(extra, 1) ||
  88            unsigned_add_overflows(sb->len, extra + 1))
  89                die("you want to use way too much memory");
  90        if (new_buf)
  91                sb->buf = NULL;
  92        ALLOC_GROW(sb->buf, sb->len + extra + 1, sb->alloc);
  93        if (new_buf)
  94                sb->buf[0] = '\0';
  95}
  96
  97void strbuf_trim(struct strbuf *sb)
  98{
  99        char *b = sb->buf;
 100        while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 101                sb->len--;
 102        while (sb->len > 0 && isspace(*b)) {
 103                b++;
 104                sb->len--;
 105        }
 106        memmove(sb->buf, b, sb->len);
 107        sb->buf[sb->len] = '\0';
 108}
 109void strbuf_rtrim(struct strbuf *sb)
 110{
 111        while (sb->len > 0 && isspace((unsigned char)sb->buf[sb->len - 1]))
 112                sb->len--;
 113        sb->buf[sb->len] = '\0';
 114}
 115
 116void strbuf_ltrim(struct strbuf *sb)
 117{
 118        char *b = sb->buf;
 119        while (sb->len > 0 && isspace(*b)) {
 120                b++;
 121                sb->len--;
 122        }
 123        memmove(sb->buf, b, sb->len);
 124        sb->buf[sb->len] = '\0';
 125}
 126
 127struct strbuf **strbuf_split_buf(const char *str, size_t slen,
 128                                 int terminator, int max)
 129{
 130        struct strbuf **ret = NULL;
 131        size_t nr = 0, alloc = 0;
 132        struct strbuf *t;
 133
 134        while (slen) {
 135                int len = slen;
 136                if (max <= 0 || nr + 1 < max) {
 137                        const char *end = memchr(str, terminator, slen);
 138                        if (end)
 139                                len = end - str + 1;
 140                }
 141                t = xmalloc(sizeof(struct strbuf));
 142                strbuf_init(t, len);
 143                strbuf_add(t, str, len);
 144                ALLOC_GROW(ret, nr + 2, alloc);
 145                ret[nr++] = t;
 146                str += len;
 147                slen -= len;
 148        }
 149        ALLOC_GROW(ret, nr + 1, alloc); /* In case string was empty */
 150        ret[nr] = NULL;
 151        return ret;
 152}
 153
 154void strbuf_list_free(struct strbuf **sbs)
 155{
 156        struct strbuf **s = sbs;
 157
 158        while (*s) {
 159                strbuf_release(*s);
 160                free(*s++);
 161        }
 162        free(sbs);
 163}
 164
 165int strbuf_cmp(const struct strbuf *a, const struct strbuf *b)
 166{
 167        int len = a->len < b->len ? a->len: b->len;
 168        int cmp = memcmp(a->buf, b->buf, len);
 169        if (cmp)
 170                return cmp;
 171        return a->len < b->len ? -1: a->len != b->len;
 172}
 173
 174void strbuf_splice(struct strbuf *sb, size_t pos, size_t len,
 175                                   const void *data, size_t dlen)
 176{
 177        if (unsigned_add_overflows(pos, len))
 178                die("you want to use way too much memory");
 179        if (pos > sb->len)
 180                die("`pos' is too far after the end of the buffer");
 181        if (pos + len > sb->len)
 182                die("`pos + len' is too far after the end of the buffer");
 183
 184        if (dlen >= len)
 185                strbuf_grow(sb, dlen - len);
 186        memmove(sb->buf + pos + dlen,
 187                        sb->buf + pos + len,
 188                        sb->len - pos - len);
 189        memcpy(sb->buf + pos, data, dlen);
 190        strbuf_setlen(sb, sb->len + dlen - len);
 191}
 192
 193void strbuf_insert(struct strbuf *sb, size_t pos, const void *data, size_t len)
 194{
 195        strbuf_splice(sb, pos, 0, data, len);
 196}
 197
 198void strbuf_remove(struct strbuf *sb, size_t pos, size_t len)
 199{
 200        strbuf_splice(sb, pos, len, NULL, 0);
 201}
 202
 203void strbuf_add(struct strbuf *sb, const void *data, size_t len)
 204{
 205        strbuf_grow(sb, len);
 206        memcpy(sb->buf + sb->len, data, len);
 207        strbuf_setlen(sb, sb->len + len);
 208}
 209
 210void strbuf_adddup(struct strbuf *sb, size_t pos, size_t len)
 211{
 212        strbuf_grow(sb, len);
 213        memcpy(sb->buf + sb->len, sb->buf + pos, len);
 214        strbuf_setlen(sb, sb->len + len);
 215}
 216
 217void strbuf_addf(struct strbuf *sb, const char *fmt, ...)
 218{
 219        va_list ap;
 220        va_start(ap, fmt);
 221        strbuf_vaddf(sb, fmt, ap);
 222        va_end(ap);
 223}
 224
 225static void add_lines(struct strbuf *out,
 226                        const char *prefix1,
 227                        const char *prefix2,
 228                        const char *buf, size_t size)
 229{
 230        while (size) {
 231                const char *prefix;
 232                const char *next = memchr(buf, '\n', size);
 233                next = next ? (next + 1) : (buf + size);
 234
 235                prefix = (prefix2 && buf[0] == '\n') ? prefix2 : prefix1;
 236                strbuf_addstr(out, prefix);
 237                strbuf_add(out, buf, next - buf);
 238                size -= next - buf;
 239                buf = next;
 240        }
 241        strbuf_complete_line(out);
 242}
 243
 244void strbuf_add_commented_lines(struct strbuf *out, const char *buf, size_t size)
 245{
 246        static char prefix1[3];
 247        static char prefix2[2];
 248
 249        if (prefix1[0] != comment_line_char) {
 250                sprintf(prefix1, "%c ", comment_line_char);
 251                sprintf(prefix2, "%c", comment_line_char);
 252        }
 253        add_lines(out, prefix1, prefix2, buf, size);
 254}
 255
 256void strbuf_commented_addf(struct strbuf *sb, const char *fmt, ...)
 257{
 258        va_list params;
 259        struct strbuf buf = STRBUF_INIT;
 260        int incomplete_line = sb->len && sb->buf[sb->len - 1] != '\n';
 261
 262        va_start(params, fmt);
 263        strbuf_vaddf(&buf, fmt, params);
 264        va_end(params);
 265
 266        strbuf_add_commented_lines(sb, buf.buf, buf.len);
 267        if (incomplete_line)
 268                sb->buf[--sb->len] = '\0';
 269
 270        strbuf_release(&buf);
 271}
 272
 273void strbuf_vaddf(struct strbuf *sb, const char *fmt, va_list ap)
 274{
 275        int len;
 276        va_list cp;
 277
 278        if (!strbuf_avail(sb))
 279                strbuf_grow(sb, 64);
 280        va_copy(cp, ap);
 281        len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, cp);
 282        va_end(cp);
 283        if (len < 0)
 284                die("BUG: your vsnprintf is broken (returned %d)", len);
 285        if (len > strbuf_avail(sb)) {
 286                strbuf_grow(sb, len);
 287                len = vsnprintf(sb->buf + sb->len, sb->alloc - sb->len, fmt, ap);
 288                if (len > strbuf_avail(sb))
 289                        die("BUG: your vsnprintf is broken (insatiable)");
 290        }
 291        strbuf_setlen(sb, sb->len + len);
 292}
 293
 294void strbuf_expand(struct strbuf *sb, const char *format, expand_fn_t fn,
 295                   void *context)
 296{
 297        for (;;) {
 298                const char *percent;
 299                size_t consumed;
 300
 301                percent = strchrnul(format, '%');
 302                strbuf_add(sb, format, percent - format);
 303                if (!*percent)
 304                        break;
 305                format = percent + 1;
 306
 307                if (*format == '%') {
 308                        strbuf_addch(sb, '%');
 309                        format++;
 310                        continue;
 311                }
 312
 313                consumed = fn(sb, format, context);
 314                if (consumed)
 315                        format += consumed;
 316                else
 317                        strbuf_addch(sb, '%');
 318        }
 319}
 320
 321size_t strbuf_expand_dict_cb(struct strbuf *sb, const char *placeholder,
 322                void *context)
 323{
 324        struct strbuf_expand_dict_entry *e = context;
 325        size_t len;
 326
 327        for (; e->placeholder && (len = strlen(e->placeholder)); e++) {
 328                if (!strncmp(placeholder, e->placeholder, len)) {
 329                        if (e->value)
 330                                strbuf_addstr(sb, e->value);
 331                        return len;
 332                }
 333        }
 334        return 0;
 335}
 336
 337void strbuf_addbuf_percentquote(struct strbuf *dst, const struct strbuf *src)
 338{
 339        int i, len = src->len;
 340
 341        for (i = 0; i < len; i++) {
 342                if (src->buf[i] == '%')
 343                        strbuf_addch(dst, '%');
 344                strbuf_addch(dst, src->buf[i]);
 345        }
 346}
 347
 348size_t strbuf_fread(struct strbuf *sb, size_t size, FILE *f)
 349{
 350        size_t res;
 351        size_t oldalloc = sb->alloc;
 352
 353        strbuf_grow(sb, size);
 354        res = fread(sb->buf + sb->len, 1, size, f);
 355        if (res > 0)
 356                strbuf_setlen(sb, sb->len + res);
 357        else if (oldalloc == 0)
 358                strbuf_release(sb);
 359        return res;
 360}
 361
 362ssize_t strbuf_read(struct strbuf *sb, int fd, size_t hint)
 363{
 364        size_t oldlen = sb->len;
 365        size_t oldalloc = sb->alloc;
 366
 367        strbuf_grow(sb, hint ? hint : 8192);
 368        for (;;) {
 369                ssize_t cnt;
 370
 371                cnt = xread(fd, sb->buf + sb->len, sb->alloc - sb->len - 1);
 372                if (cnt < 0) {
 373                        if (oldalloc == 0)
 374                                strbuf_release(sb);
 375                        else
 376                                strbuf_setlen(sb, oldlen);
 377                        return -1;
 378                }
 379                if (!cnt)
 380                        break;
 381                sb->len += cnt;
 382                strbuf_grow(sb, 8192);
 383        }
 384
 385        sb->buf[sb->len] = '\0';
 386        return sb->len - oldlen;
 387}
 388
 389#define STRBUF_MAXLINK (2*PATH_MAX)
 390
 391int strbuf_readlink(struct strbuf *sb, const char *path, size_t hint)
 392{
 393        size_t oldalloc = sb->alloc;
 394
 395        if (hint < 32)
 396                hint = 32;
 397
 398        while (hint < STRBUF_MAXLINK) {
 399                int len;
 400
 401                strbuf_grow(sb, hint);
 402                len = readlink(path, sb->buf, hint);
 403                if (len < 0) {
 404                        if (errno != ERANGE)
 405                                break;
 406                } else if (len < hint) {
 407                        strbuf_setlen(sb, len);
 408                        return 0;
 409                }
 410
 411                /* .. the buffer was too small - try again */
 412                hint *= 2;
 413        }
 414        if (oldalloc == 0)
 415                strbuf_release(sb);
 416        return -1;
 417}
 418
 419int strbuf_getwholeline(struct strbuf *sb, FILE *fp, int term)
 420{
 421        int ch;
 422
 423        if (feof(fp))
 424                return EOF;
 425
 426        strbuf_reset(sb);
 427        while ((ch = fgetc(fp)) != EOF) {
 428                strbuf_grow(sb, 1);
 429                sb->buf[sb->len++] = ch;
 430                if (ch == term)
 431                        break;
 432        }
 433        if (ch == EOF && sb->len == 0)
 434                return EOF;
 435
 436        sb->buf[sb->len] = '\0';
 437        return 0;
 438}
 439
 440int strbuf_getline(struct strbuf *sb, FILE *fp, int term)
 441{
 442        if (strbuf_getwholeline(sb, fp, term))
 443                return EOF;
 444        if (sb->buf[sb->len-1] == term)
 445                strbuf_setlen(sb, sb->len-1);
 446        return 0;
 447}
 448
 449int strbuf_getwholeline_fd(struct strbuf *sb, int fd, int term)
 450{
 451        strbuf_reset(sb);
 452
 453        while (1) {
 454                char ch;
 455                ssize_t len = xread(fd, &ch, 1);
 456                if (len <= 0)
 457                        return EOF;
 458                strbuf_addch(sb, ch);
 459                if (ch == term)
 460                        break;
 461        }
 462        return 0;
 463}
 464
 465int strbuf_read_file(struct strbuf *sb, const char *path, size_t hint)
 466{
 467        int fd, len;
 468
 469        fd = open(path, O_RDONLY);
 470        if (fd < 0)
 471                return -1;
 472        len = strbuf_read(sb, fd, hint);
 473        close(fd);
 474        if (len < 0)
 475                return -1;
 476
 477        return len;
 478}
 479
 480void strbuf_add_lines(struct strbuf *out, const char *prefix,
 481                      const char *buf, size_t size)
 482{
 483        add_lines(out, prefix, NULL, buf, size);
 484}
 485
 486void strbuf_addstr_xml_quoted(struct strbuf *buf, const char *s)
 487{
 488        while (*s) {
 489                size_t len = strcspn(s, "\"<>&");
 490                strbuf_add(buf, s, len);
 491                s += len;
 492                switch (*s) {
 493                case '"':
 494                        strbuf_addstr(buf, "&quot;");
 495                        break;
 496                case '<':
 497                        strbuf_addstr(buf, "&lt;");
 498                        break;
 499                case '>':
 500                        strbuf_addstr(buf, "&gt;");
 501                        break;
 502                case '&':
 503                        strbuf_addstr(buf, "&amp;");
 504                        break;
 505                case 0:
 506                        return;
 507                }
 508                s++;
 509        }
 510}
 511
 512static int is_rfc3986_reserved(char ch)
 513{
 514        switch (ch) {
 515                case '!': case '*': case '\'': case '(': case ')': case ';':
 516                case ':': case '@': case '&': case '=': case '+': case '$':
 517                case ',': case '/': case '?': case '#': case '[': case ']':
 518                        return 1;
 519        }
 520        return 0;
 521}
 522
 523static int is_rfc3986_unreserved(char ch)
 524{
 525        return isalnum(ch) ||
 526                ch == '-' || ch == '_' || ch == '.' || ch == '~';
 527}
 528
 529static void strbuf_add_urlencode(struct strbuf *sb, const char *s, size_t len,
 530                                 int reserved)
 531{
 532        strbuf_grow(sb, len);
 533        while (len--) {
 534                char ch = *s++;
 535                if (is_rfc3986_unreserved(ch) ||
 536                    (!reserved && is_rfc3986_reserved(ch)))
 537                        strbuf_addch(sb, ch);
 538                else
 539                        strbuf_addf(sb, "%%%02x", ch);
 540        }
 541}
 542
 543void strbuf_addstr_urlencode(struct strbuf *sb, const char *s,
 544                             int reserved)
 545{
 546        strbuf_add_urlencode(sb, s, strlen(s), reserved);
 547}
 548
 549void strbuf_humanise_bytes(struct strbuf *buf, off_t bytes)
 550{
 551        if (bytes > 1 << 30) {
 552                strbuf_addf(buf, "%u.%2.2u GiB",
 553                            (int)(bytes >> 30),
 554                            (int)(bytes & ((1 << 30) - 1)) / 10737419);
 555        } else if (bytes > 1 << 20) {
 556                int x = bytes + 5243;  /* for rounding */
 557                strbuf_addf(buf, "%u.%2.2u MiB",
 558                            x >> 20, ((x & ((1 << 20) - 1)) * 100) >> 20);
 559        } else if (bytes > 1 << 10) {
 560                int x = bytes + 5;  /* for rounding */
 561                strbuf_addf(buf, "%u.%2.2u KiB",
 562                            x >> 10, ((x & ((1 << 10) - 1)) * 100) >> 10);
 563        } else {
 564                strbuf_addf(buf, "%u bytes", (int)bytes);
 565        }
 566}
 567
 568int printf_ln(const char *fmt, ...)
 569{
 570        int ret;
 571        va_list ap;
 572        va_start(ap, fmt);
 573        ret = vprintf(fmt, ap);
 574        va_end(ap);
 575        if (ret < 0 || putchar('\n') == EOF)
 576                return -1;
 577        return ret + 1;
 578}
 579
 580int fprintf_ln(FILE *fp, const char *fmt, ...)
 581{
 582        int ret;
 583        va_list ap;
 584        va_start(ap, fmt);
 585        ret = vfprintf(fp, fmt, ap);
 586        va_end(ap);
 587        if (ret < 0 || putc('\n', fp) == EOF)
 588                return -1;
 589        return ret + 1;
 590}