convert.con commit Merge branch 'js/i18n-scripts-2' (a536a9d)
   1#include "cache.h"
   2#include "attr.h"
   3#include "run-command.h"
   4#include "quote.h"
   5
   6/*
   7 * convert.c - convert a file when checking it out and checking it in.
   8 *
   9 * This should use the pathname to decide on whether it wants to do some
  10 * more interesting conversions (automatic gzip/unzip, general format
  11 * conversions etc etc), but by default it just does automatic CRLF<->LF
  12 * translation when the "text" attribute or "auto_crlf" option is set.
  13 */
  14
  15enum crlf_action {
  16        CRLF_GUESS = -1,
  17        CRLF_BINARY = 0,
  18        CRLF_TEXT,
  19        CRLF_INPUT,
  20        CRLF_CRLF,
  21        CRLF_AUTO
  22};
  23
  24struct text_stat {
  25        /* NUL, CR, LF and CRLF counts */
  26        unsigned nul, cr, lf, crlf;
  27
  28        /* These are just approximations! */
  29        unsigned printable, nonprintable;
  30};
  31
  32static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats)
  33{
  34        unsigned long i;
  35
  36        memset(stats, 0, sizeof(*stats));
  37
  38        for (i = 0; i < size; i++) {
  39                unsigned char c = buf[i];
  40                if (c == '\r') {
  41                        stats->cr++;
  42                        if (i+1 < size && buf[i+1] == '\n')
  43                                stats->crlf++;
  44                        continue;
  45                }
  46                if (c == '\n') {
  47                        stats->lf++;
  48                        continue;
  49                }
  50                if (c == 127)
  51                        /* DEL */
  52                        stats->nonprintable++;
  53                else if (c < 32) {
  54                        switch (c) {
  55                                /* BS, HT, ESC and FF */
  56                        case '\b': case '\t': case '\033': case '\014':
  57                                stats->printable++;
  58                                break;
  59                        case 0:
  60                                stats->nul++;
  61                                /* fall through */
  62                        default:
  63                                stats->nonprintable++;
  64                        }
  65                }
  66                else
  67                        stats->printable++;
  68        }
  69
  70        /* If file ends with EOF then don't count this EOF as non-printable. */
  71        if (size >= 1 && buf[size-1] == '\032')
  72                stats->nonprintable--;
  73}
  74
  75/*
  76 * The same heuristics as diff.c::mmfile_is_binary()
  77 */
  78static int is_binary(unsigned long size, struct text_stat *stats)
  79{
  80
  81        if (stats->nul)
  82                return 1;
  83        if ((stats->printable >> 7) < stats->nonprintable)
  84                return 1;
  85        /*
  86         * Other heuristics? Average line length might be relevant,
  87         * as might LF vs CR vs CRLF counts..
  88         *
  89         * NOTE! It might be normal to have a low ratio of CRLF to LF
  90         * (somebody starts with a LF-only file and edits it with an editor
  91         * that adds CRLF only to lines that are added..). But do  we
  92         * want to support CR-only? Probably not.
  93         */
  94        return 0;
  95}
  96
  97static enum eol output_eol(enum crlf_action crlf_action)
  98{
  99        switch (crlf_action) {
 100        case CRLF_BINARY:
 101                return EOL_UNSET;
 102        case CRLF_CRLF:
 103                return EOL_CRLF;
 104        case CRLF_INPUT:
 105                return EOL_LF;
 106        case CRLF_GUESS:
 107                if (!auto_crlf)
 108                        return EOL_UNSET;
 109                /* fall through */
 110        case CRLF_TEXT:
 111        case CRLF_AUTO:
 112                if (auto_crlf == AUTO_CRLF_TRUE)
 113                        return EOL_CRLF;
 114                else if (auto_crlf == AUTO_CRLF_INPUT)
 115                        return EOL_LF;
 116                else if (core_eol == EOL_UNSET)
 117                        return EOL_NATIVE;
 118        }
 119        return core_eol;
 120}
 121
 122static void check_safe_crlf(const char *path, enum crlf_action crlf_action,
 123                            struct text_stat *stats, enum safe_crlf checksafe)
 124{
 125        if (!checksafe)
 126                return;
 127
 128        if (output_eol(crlf_action) == EOL_LF) {
 129                /*
 130                 * CRLFs would not be restored by checkout:
 131                 * check if we'd remove CRLFs
 132                 */
 133                if (stats->crlf) {
 134                        if (checksafe == SAFE_CRLF_WARN)
 135                                warning("CRLF will be replaced by LF in %s.\nThe file will have its original line endings in your working directory.", path);
 136                        else /* i.e. SAFE_CRLF_FAIL */
 137                                die("CRLF would be replaced by LF in %s.", path);
 138                }
 139        } else if (output_eol(crlf_action) == EOL_CRLF) {
 140                /*
 141                 * CRLFs would be added by checkout:
 142                 * check if we have "naked" LFs
 143                 */
 144                if (stats->lf != stats->crlf) {
 145                        if (checksafe == SAFE_CRLF_WARN)
 146                                warning("LF will be replaced by CRLF in %s.\nThe file will have its original line endings in your working directory.", path);
 147                        else /* i.e. SAFE_CRLF_FAIL */
 148                                die("LF would be replaced by CRLF in %s", path);
 149                }
 150        }
 151}
 152
 153static int has_cr_in_index(const char *path)
 154{
 155        int pos, len;
 156        unsigned long sz;
 157        enum object_type type;
 158        void *data;
 159        int has_cr;
 160        struct index_state *istate = &the_index;
 161
 162        len = strlen(path);
 163        pos = index_name_pos(istate, path, len);
 164        if (pos < 0) {
 165                /*
 166                 * We might be in the middle of a merge, in which
 167                 * case we would read stage #2 (ours).
 168                 */
 169                int i;
 170                for (i = -pos - 1;
 171                     (pos < 0 && i < istate->cache_nr &&
 172                      !strcmp(istate->cache[i]->name, path));
 173                     i++)
 174                        if (ce_stage(istate->cache[i]) == 2)
 175                                pos = i;
 176        }
 177        if (pos < 0)
 178                return 0;
 179        data = read_sha1_file(istate->cache[pos]->sha1, &type, &sz);
 180        if (!data || type != OBJ_BLOB) {
 181                free(data);
 182                return 0;
 183        }
 184
 185        has_cr = memchr(data, '\r', sz) != NULL;
 186        free(data);
 187        return has_cr;
 188}
 189
 190static int crlf_to_git(const char *path, const char *src, size_t len,
 191                       struct strbuf *buf,
 192                       enum crlf_action crlf_action, enum safe_crlf checksafe)
 193{
 194        struct text_stat stats;
 195        char *dst;
 196
 197        if (crlf_action == CRLF_BINARY ||
 198            (crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE) || !len)
 199                return 0;
 200
 201        gather_stats(src, len, &stats);
 202
 203        if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
 204                /*
 205                 * We're currently not going to even try to convert stuff
 206                 * that has bare CR characters. Does anybody do that crazy
 207                 * stuff?
 208                 */
 209                if (stats.cr != stats.crlf)
 210                        return 0;
 211
 212                /*
 213                 * And add some heuristics for binary vs text, of course...
 214                 */
 215                if (is_binary(len, &stats))
 216                        return 0;
 217
 218                if (crlf_action == CRLF_GUESS) {
 219                        /*
 220                         * If the file in the index has any CR in it, do not convert.
 221                         * This is the new safer autocrlf handling.
 222                         */
 223                        if (has_cr_in_index(path))
 224                                return 0;
 225                }
 226        }
 227
 228        check_safe_crlf(path, crlf_action, &stats, checksafe);
 229
 230        /* Optimization: No CR? Nothing to convert, regardless. */
 231        if (!stats.cr)
 232                return 0;
 233
 234        /* only grow if not in place */
 235        if (strbuf_avail(buf) + buf->len < len)
 236                strbuf_grow(buf, len - buf->len);
 237        dst = buf->buf;
 238        if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
 239                /*
 240                 * If we guessed, we already know we rejected a file with
 241                 * lone CR, and we can strip a CR without looking at what
 242                 * follow it.
 243                 */
 244                do {
 245                        unsigned char c = *src++;
 246                        if (c != '\r')
 247                                *dst++ = c;
 248                } while (--len);
 249        } else {
 250                do {
 251                        unsigned char c = *src++;
 252                        if (! (c == '\r' && (1 < len && *src == '\n')))
 253                                *dst++ = c;
 254                } while (--len);
 255        }
 256        strbuf_setlen(buf, dst - buf->buf);
 257        return 1;
 258}
 259
 260static int crlf_to_worktree(const char *path, const char *src, size_t len,
 261                            struct strbuf *buf, enum crlf_action crlf_action)
 262{
 263        char *to_free = NULL;
 264        struct text_stat stats;
 265
 266        if (!len || output_eol(crlf_action) != EOL_CRLF)
 267                return 0;
 268
 269        gather_stats(src, len, &stats);
 270
 271        /* No LF? Nothing to convert, regardless. */
 272        if (!stats.lf)
 273                return 0;
 274
 275        /* Was it already in CRLF format? */
 276        if (stats.lf == stats.crlf)
 277                return 0;
 278
 279        if (crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS) {
 280                if (crlf_action == CRLF_GUESS) {
 281                        /* If we have any CR or CRLF line endings, we do not touch it */
 282                        /* This is the new safer autocrlf-handling */
 283                        if (stats.cr > 0 || stats.crlf > 0)
 284                                return 0;
 285                }
 286
 287                /* If we have any bare CR characters, we're not going to touch it */
 288                if (stats.cr != stats.crlf)
 289                        return 0;
 290
 291                if (is_binary(len, &stats))
 292                        return 0;
 293        }
 294
 295        /* are we "faking" in place editing ? */
 296        if (src == buf->buf)
 297                to_free = strbuf_detach(buf, NULL);
 298
 299        strbuf_grow(buf, len + stats.lf - stats.crlf);
 300        for (;;) {
 301                const char *nl = memchr(src, '\n', len);
 302                if (!nl)
 303                        break;
 304                if (nl > src && nl[-1] == '\r') {
 305                        strbuf_add(buf, src, nl + 1 - src);
 306                } else {
 307                        strbuf_add(buf, src, nl - src);
 308                        strbuf_addstr(buf, "\r\n");
 309                }
 310                len -= nl + 1 - src;
 311                src  = nl + 1;
 312        }
 313        strbuf_add(buf, src, len);
 314
 315        free(to_free);
 316        return 1;
 317}
 318
 319struct filter_params {
 320        const char *src;
 321        unsigned long size;
 322        const char *cmd;
 323        const char *path;
 324};
 325
 326static int filter_buffer(int in, int out, void *data)
 327{
 328        /*
 329         * Spawn cmd and feed the buffer contents through its stdin.
 330         */
 331        struct child_process child_process;
 332        struct filter_params *params = (struct filter_params *)data;
 333        int write_err, status;
 334        const char *argv[] = { NULL, NULL };
 335
 336        /* apply % substitution to cmd */
 337        struct strbuf cmd = STRBUF_INIT;
 338        struct strbuf path = STRBUF_INIT;
 339        struct strbuf_expand_dict_entry dict[] = {
 340                { "f", NULL, },
 341                { NULL, NULL, },
 342        };
 343
 344        /* quote the path to preserve spaces, etc. */
 345        sq_quote_buf(&path, params->path);
 346        dict[0].value = path.buf;
 347
 348        /* expand all %f with the quoted path */
 349        strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict);
 350        strbuf_release(&path);
 351
 352        argv[0] = cmd.buf;
 353
 354        memset(&child_process, 0, sizeof(child_process));
 355        child_process.argv = argv;
 356        child_process.use_shell = 1;
 357        child_process.in = -1;
 358        child_process.out = out;
 359
 360        if (start_command(&child_process))
 361                return error("cannot fork to run external filter %s", params->cmd);
 362
 363        write_err = (write_in_full(child_process.in, params->src, params->size) < 0);
 364        if (close(child_process.in))
 365                write_err = 1;
 366        if (write_err)
 367                error("cannot feed the input to external filter %s", params->cmd);
 368
 369        status = finish_command(&child_process);
 370        if (status)
 371                error("external filter %s failed %d", params->cmd, status);
 372
 373        strbuf_release(&cmd);
 374        return (write_err || status);
 375}
 376
 377static int apply_filter(const char *path, const char *src, size_t len,
 378                        struct strbuf *dst, const char *cmd)
 379{
 380        /*
 381         * Create a pipeline to have the command filter the buffer's
 382         * contents.
 383         *
 384         * (child --> cmd) --> us
 385         */
 386        int ret = 1;
 387        struct strbuf nbuf = STRBUF_INIT;
 388        struct async async;
 389        struct filter_params params;
 390
 391        if (!cmd)
 392                return 0;
 393
 394        memset(&async, 0, sizeof(async));
 395        async.proc = filter_buffer;
 396        async.data = &params;
 397        async.out = -1;
 398        params.src = src;
 399        params.size = len;
 400        params.cmd = cmd;
 401        params.path = path;
 402
 403        fflush(NULL);
 404        if (start_async(&async))
 405                return 0;       /* error was already reported */
 406
 407        if (strbuf_read(&nbuf, async.out, len) < 0) {
 408                error("read from external filter %s failed", cmd);
 409                ret = 0;
 410        }
 411        if (close(async.out)) {
 412                error("read from external filter %s failed", cmd);
 413                ret = 0;
 414        }
 415        if (finish_async(&async)) {
 416                error("external filter %s failed", cmd);
 417                ret = 0;
 418        }
 419
 420        if (ret) {
 421                strbuf_swap(dst, &nbuf);
 422        }
 423        strbuf_release(&nbuf);
 424        return ret;
 425}
 426
 427static struct convert_driver {
 428        const char *name;
 429        struct convert_driver *next;
 430        const char *smudge;
 431        const char *clean;
 432} *user_convert, **user_convert_tail;
 433
 434static int read_convert_config(const char *var, const char *value, void *cb)
 435{
 436        const char *ep, *name;
 437        int namelen;
 438        struct convert_driver *drv;
 439
 440        /*
 441         * External conversion drivers are configured using
 442         * "filter.<name>.variable".
 443         */
 444        if (prefixcmp(var, "filter.") || (ep = strrchr(var, '.')) == var + 6)
 445                return 0;
 446        name = var + 7;
 447        namelen = ep - name;
 448        for (drv = user_convert; drv; drv = drv->next)
 449                if (!strncmp(drv->name, name, namelen) && !drv->name[namelen])
 450                        break;
 451        if (!drv) {
 452                drv = xcalloc(1, sizeof(struct convert_driver));
 453                drv->name = xmemdupz(name, namelen);
 454                *user_convert_tail = drv;
 455                user_convert_tail = &(drv->next);
 456        }
 457
 458        ep++;
 459
 460        /*
 461         * filter.<name>.smudge and filter.<name>.clean specifies
 462         * the command line:
 463         *
 464         *      command-line
 465         *
 466         * The command-line will not be interpolated in any way.
 467         */
 468
 469        if (!strcmp("smudge", ep))
 470                return git_config_string(&drv->smudge, var, value);
 471
 472        if (!strcmp("clean", ep))
 473                return git_config_string(&drv->clean, var, value);
 474
 475        return 0;
 476}
 477
 478static int count_ident(const char *cp, unsigned long size)
 479{
 480        /*
 481         * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$"
 482         */
 483        int cnt = 0;
 484        char ch;
 485
 486        while (size) {
 487                ch = *cp++;
 488                size--;
 489                if (ch != '$')
 490                        continue;
 491                if (size < 3)
 492                        break;
 493                if (memcmp("Id", cp, 2))
 494                        continue;
 495                ch = cp[2];
 496                cp += 3;
 497                size -= 3;
 498                if (ch == '$')
 499                        cnt++; /* $Id$ */
 500                if (ch != ':')
 501                        continue;
 502
 503                /*
 504                 * "$Id: ... "; scan up to the closing dollar sign and discard.
 505                 */
 506                while (size) {
 507                        ch = *cp++;
 508                        size--;
 509                        if (ch == '$') {
 510                                cnt++;
 511                                break;
 512                        }
 513                        if (ch == '\n')
 514                                break;
 515                }
 516        }
 517        return cnt;
 518}
 519
 520static int ident_to_git(const char *path, const char *src, size_t len,
 521                        struct strbuf *buf, int ident)
 522{
 523        char *dst, *dollar;
 524
 525        if (!ident || !count_ident(src, len))
 526                return 0;
 527
 528        /* only grow if not in place */
 529        if (strbuf_avail(buf) + buf->len < len)
 530                strbuf_grow(buf, len - buf->len);
 531        dst = buf->buf;
 532        for (;;) {
 533                dollar = memchr(src, '$', len);
 534                if (!dollar)
 535                        break;
 536                memmove(dst, src, dollar + 1 - src);
 537                dst += dollar + 1 - src;
 538                len -= dollar + 1 - src;
 539                src  = dollar + 1;
 540
 541                if (len > 3 && !memcmp(src, "Id:", 3)) {
 542                        dollar = memchr(src + 3, '$', len - 3);
 543                        if (!dollar)
 544                                break;
 545                        if (memchr(src + 3, '\n', dollar - src - 3)) {
 546                                /* Line break before the next dollar. */
 547                                continue;
 548                        }
 549
 550                        memcpy(dst, "Id$", 3);
 551                        dst += 3;
 552                        len -= dollar + 1 - src;
 553                        src  = dollar + 1;
 554                }
 555        }
 556        memmove(dst, src, len);
 557        strbuf_setlen(buf, dst + len - buf->buf);
 558        return 1;
 559}
 560
 561static int ident_to_worktree(const char *path, const char *src, size_t len,
 562                             struct strbuf *buf, int ident)
 563{
 564        unsigned char sha1[20];
 565        char *to_free = NULL, *dollar, *spc;
 566        int cnt;
 567
 568        if (!ident)
 569                return 0;
 570
 571        cnt = count_ident(src, len);
 572        if (!cnt)
 573                return 0;
 574
 575        /* are we "faking" in place editing ? */
 576        if (src == buf->buf)
 577                to_free = strbuf_detach(buf, NULL);
 578        hash_sha1_file(src, len, "blob", sha1);
 579
 580        strbuf_grow(buf, len + cnt * 43);
 581        for (;;) {
 582                /* step 1: run to the next '$' */
 583                dollar = memchr(src, '$', len);
 584                if (!dollar)
 585                        break;
 586                strbuf_add(buf, src, dollar + 1 - src);
 587                len -= dollar + 1 - src;
 588                src  = dollar + 1;
 589
 590                /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */
 591                if (len < 3 || memcmp("Id", src, 2))
 592                        continue;
 593
 594                /* step 3: skip over Id$ or Id:xxxxx$ */
 595                if (src[2] == '$') {
 596                        src += 3;
 597                        len -= 3;
 598                } else if (src[2] == ':') {
 599                        /*
 600                         * It's possible that an expanded Id has crept its way into the
 601                         * repository, we cope with that by stripping the expansion out.
 602                         * This is probably not a good idea, since it will cause changes
 603                         * on checkout, which won't go away by stash, but let's keep it
 604                         * for git-style ids.
 605                         */
 606                        dollar = memchr(src + 3, '$', len - 3);
 607                        if (!dollar) {
 608                                /* incomplete keyword, no more '$', so just quit the loop */
 609                                break;
 610                        }
 611
 612                        if (memchr(src + 3, '\n', dollar - src - 3)) {
 613                                /* Line break before the next dollar. */
 614                                continue;
 615                        }
 616
 617                        spc = memchr(src + 4, ' ', dollar - src - 4);
 618                        if (spc && spc < dollar-1) {
 619                                /* There are spaces in unexpected places.
 620                                 * This is probably an id from some other
 621                                 * versioning system. Keep it for now.
 622                                 */
 623                                continue;
 624                        }
 625
 626                        len -= dollar + 1 - src;
 627                        src  = dollar + 1;
 628                } else {
 629                        /* it wasn't a "Id$" or "Id:xxxx$" */
 630                        continue;
 631                }
 632
 633                /* step 4: substitute */
 634                strbuf_addstr(buf, "Id: ");
 635                strbuf_add(buf, sha1_to_hex(sha1), 40);
 636                strbuf_addstr(buf, " $");
 637        }
 638        strbuf_add(buf, src, len);
 639
 640        free(to_free);
 641        return 1;
 642}
 643
 644static int git_path_check_crlf(const char *path, struct git_attr_check *check)
 645{
 646        const char *value = check->value;
 647
 648        if (ATTR_TRUE(value))
 649                return CRLF_TEXT;
 650        else if (ATTR_FALSE(value))
 651                return CRLF_BINARY;
 652        else if (ATTR_UNSET(value))
 653                ;
 654        else if (!strcmp(value, "input"))
 655                return CRLF_INPUT;
 656        else if (!strcmp(value, "auto"))
 657                return CRLF_AUTO;
 658        return CRLF_GUESS;
 659}
 660
 661static int git_path_check_eol(const char *path, struct git_attr_check *check)
 662{
 663        const char *value = check->value;
 664
 665        if (ATTR_UNSET(value))
 666                ;
 667        else if (!strcmp(value, "lf"))
 668                return EOL_LF;
 669        else if (!strcmp(value, "crlf"))
 670                return EOL_CRLF;
 671        return EOL_UNSET;
 672}
 673
 674static struct convert_driver *git_path_check_convert(const char *path,
 675                                             struct git_attr_check *check)
 676{
 677        const char *value = check->value;
 678        struct convert_driver *drv;
 679
 680        if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value))
 681                return NULL;
 682        for (drv = user_convert; drv; drv = drv->next)
 683                if (!strcmp(value, drv->name))
 684                        return drv;
 685        return NULL;
 686}
 687
 688static int git_path_check_ident(const char *path, struct git_attr_check *check)
 689{
 690        const char *value = check->value;
 691
 692        return !!ATTR_TRUE(value);
 693}
 694
 695static enum crlf_action input_crlf_action(enum crlf_action text_attr, enum eol eol_attr)
 696{
 697        if (text_attr == CRLF_BINARY)
 698                return CRLF_BINARY;
 699        if (eol_attr == EOL_LF)
 700                return CRLF_INPUT;
 701        if (eol_attr == EOL_CRLF)
 702                return CRLF_CRLF;
 703        return text_attr;
 704}
 705
 706struct conv_attrs {
 707        struct convert_driver *drv;
 708        enum crlf_action crlf_action;
 709        enum eol eol_attr;
 710        int ident;
 711};
 712
 713static const char *conv_attr_name[] = {
 714        "crlf", "ident", "filter", "eol", "text",
 715};
 716#define NUM_CONV_ATTRS ARRAY_SIZE(conv_attr_name)
 717
 718static void convert_attrs(struct conv_attrs *ca, const char *path)
 719{
 720        int i;
 721        static struct git_attr_check ccheck[NUM_CONV_ATTRS];
 722
 723        if (!ccheck[0].attr) {
 724                for (i = 0; i < NUM_CONV_ATTRS; i++)
 725                        ccheck[i].attr = git_attr(conv_attr_name[i]);
 726                user_convert_tail = &user_convert;
 727                git_config(read_convert_config, NULL);
 728        }
 729
 730        if (!git_check_attr(path, NUM_CONV_ATTRS, ccheck)) {
 731                ca->crlf_action = git_path_check_crlf(path, ccheck + 4);
 732                if (ca->crlf_action == CRLF_GUESS)
 733                        ca->crlf_action = git_path_check_crlf(path, ccheck + 0);
 734                ca->ident = git_path_check_ident(path, ccheck + 1);
 735                ca->drv = git_path_check_convert(path, ccheck + 2);
 736                ca->eol_attr = git_path_check_eol(path, ccheck + 3);
 737        } else {
 738                ca->drv = NULL;
 739                ca->crlf_action = CRLF_GUESS;
 740                ca->eol_attr = EOL_UNSET;
 741                ca->ident = 0;
 742        }
 743}
 744
 745int convert_to_git(const char *path, const char *src, size_t len,
 746                   struct strbuf *dst, enum safe_crlf checksafe)
 747{
 748        int ret = 0;
 749        const char *filter = NULL;
 750        struct conv_attrs ca;
 751
 752        convert_attrs(&ca, path);
 753        if (ca.drv)
 754                filter = ca.drv->clean;
 755
 756        ret |= apply_filter(path, src, len, dst, filter);
 757        if (ret) {
 758                src = dst->buf;
 759                len = dst->len;
 760        }
 761        ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
 762        ret |= crlf_to_git(path, src, len, dst, ca.crlf_action, checksafe);
 763        if (ret) {
 764                src = dst->buf;
 765                len = dst->len;
 766        }
 767        return ret | ident_to_git(path, src, len, dst, ca.ident);
 768}
 769
 770static int convert_to_working_tree_internal(const char *path, const char *src,
 771                                            size_t len, struct strbuf *dst,
 772                                            int normalizing)
 773{
 774        int ret = 0;
 775        const char *filter = NULL;
 776        struct conv_attrs ca;
 777
 778        convert_attrs(&ca, path);
 779        if (ca.drv)
 780                filter = ca.drv->smudge;
 781
 782        ret |= ident_to_worktree(path, src, len, dst, ca.ident);
 783        if (ret) {
 784                src = dst->buf;
 785                len = dst->len;
 786        }
 787        /*
 788         * CRLF conversion can be skipped if normalizing, unless there
 789         * is a smudge filter.  The filter might expect CRLFs.
 790         */
 791        if (filter || !normalizing) {
 792                ca.crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
 793                ret |= crlf_to_worktree(path, src, len, dst, ca.crlf_action);
 794                if (ret) {
 795                        src = dst->buf;
 796                        len = dst->len;
 797                }
 798        }
 799        return ret | apply_filter(path, src, len, dst, filter);
 800}
 801
 802int convert_to_working_tree(const char *path, const char *src, size_t len, struct strbuf *dst)
 803{
 804        return convert_to_working_tree_internal(path, src, len, dst, 0);
 805}
 806
 807int renormalize_buffer(const char *path, const char *src, size_t len, struct strbuf *dst)
 808{
 809        int ret = convert_to_working_tree_internal(path, src, len, dst, 1);
 810        if (ret) {
 811                src = dst->buf;
 812                len = dst->len;
 813        }
 814        return ret | convert_to_git(path, src, len, dst, 0);
 815}
 816
 817/*****************************************************************
 818 *
 819 * Streaming converison support
 820 *
 821 *****************************************************************/
 822
 823typedef int (*filter_fn)(struct stream_filter *,
 824                         const char *input, size_t *isize_p,
 825                         char *output, size_t *osize_p);
 826typedef void (*free_fn)(struct stream_filter *);
 827
 828struct stream_filter_vtbl {
 829        filter_fn filter;
 830        free_fn free;
 831};
 832
 833struct stream_filter {
 834        struct stream_filter_vtbl *vtbl;
 835};
 836
 837static int null_filter_fn(struct stream_filter *filter,
 838                          const char *input, size_t *isize_p,
 839                          char *output, size_t *osize_p)
 840{
 841        size_t count;
 842
 843        if (!input)
 844                return 0; /* we do not keep any states */
 845        count = *isize_p;
 846        if (*osize_p < count)
 847                count = *osize_p;
 848        if (count) {
 849                memmove(output, input, count);
 850                *isize_p -= count;
 851                *osize_p -= count;
 852        }
 853        return 0;
 854}
 855
 856static void null_free_fn(struct stream_filter *filter)
 857{
 858        ; /* nothing -- null instances are shared */
 859}
 860
 861static struct stream_filter_vtbl null_vtbl = {
 862        null_filter_fn,
 863        null_free_fn,
 864};
 865
 866static struct stream_filter null_filter_singleton = {
 867        &null_vtbl,
 868};
 869
 870int is_null_stream_filter(struct stream_filter *filter)
 871{
 872        return filter == &null_filter_singleton;
 873}
 874
 875
 876/*
 877 * LF-to-CRLF filter
 878 */
 879static int lf_to_crlf_filter_fn(struct stream_filter *filter,
 880                                const char *input, size_t *isize_p,
 881                                char *output, size_t *osize_p)
 882{
 883        size_t count;
 884
 885        if (!input)
 886                return 0; /* we do not keep any states */
 887        count = *isize_p;
 888        if (count) {
 889                size_t i, o;
 890                for (i = o = 0; o < *osize_p && i < count; i++) {
 891                        char ch = input[i];
 892                        if (ch == '\n') {
 893                                if (o + 1 < *osize_p)
 894                                        output[o++] = '\r';
 895                                else
 896                                        break;
 897                        }
 898                        output[o++] = ch;
 899                }
 900
 901                *osize_p -= o;
 902                *isize_p -= i;
 903        }
 904        return 0;
 905}
 906
 907static struct stream_filter_vtbl lf_to_crlf_vtbl = {
 908        lf_to_crlf_filter_fn,
 909        null_free_fn,
 910};
 911
 912static struct stream_filter lf_to_crlf_filter_singleton = {
 913        &lf_to_crlf_vtbl,
 914};
 915
 916
 917/*
 918 * Cascade filter
 919 */
 920#define FILTER_BUFFER 1024
 921struct cascade_filter {
 922        struct stream_filter filter;
 923        struct stream_filter *one;
 924        struct stream_filter *two;
 925        char buf[FILTER_BUFFER];
 926        int end, ptr;
 927};
 928
 929static int cascade_filter_fn(struct stream_filter *filter,
 930                             const char *input, size_t *isize_p,
 931                             char *output, size_t *osize_p)
 932{
 933        struct cascade_filter *cas = (struct cascade_filter *) filter;
 934        size_t filled = 0;
 935        size_t sz = *osize_p;
 936        size_t to_feed, remaining;
 937
 938        /*
 939         * input -- (one) --> buf -- (two) --> output
 940         */
 941        while (filled < sz) {
 942                remaining = sz - filled;
 943
 944                /* do we already have something to feed two with? */
 945                if (cas->ptr < cas->end) {
 946                        to_feed = cas->end - cas->ptr;
 947                        if (stream_filter(cas->two,
 948                                          cas->buf + cas->ptr, &to_feed,
 949                                          output + filled, &remaining))
 950                                return -1;
 951                        cas->ptr += (cas->end - cas->ptr) - to_feed;
 952                        filled = sz - remaining;
 953                        continue;
 954                }
 955
 956                /* feed one from upstream and have it emit into our buffer */
 957                to_feed = input ? *isize_p : 0;
 958                if (input && !to_feed)
 959                        break;
 960                remaining = sizeof(cas->buf);
 961                if (stream_filter(cas->one,
 962                                  input, &to_feed,
 963                                  cas->buf, &remaining))
 964                        return -1;
 965                cas->end = sizeof(cas->buf) - remaining;
 966                cas->ptr = 0;
 967                if (input) {
 968                        size_t fed = *isize_p - to_feed;
 969                        *isize_p -= fed;
 970                        input += fed;
 971                }
 972
 973                /* do we know that we drained one completely? */
 974                if (input || cas->end)
 975                        continue;
 976
 977                /* tell two to drain; we have nothing more to give it */
 978                to_feed = 0;
 979                remaining = sz - filled;
 980                if (stream_filter(cas->two,
 981                                  NULL, &to_feed,
 982                                  output + filled, &remaining))
 983                        return -1;
 984                if (remaining == (sz - filled))
 985                        break; /* completely drained two */
 986                filled = sz - remaining;
 987        }
 988        *osize_p -= filled;
 989        return 0;
 990}
 991
 992static void cascade_free_fn(struct stream_filter *filter)
 993{
 994        struct cascade_filter *cas = (struct cascade_filter *)filter;
 995        free_stream_filter(cas->one);
 996        free_stream_filter(cas->two);
 997        free(filter);
 998}
 999
1000static struct stream_filter_vtbl cascade_vtbl = {
1001        cascade_filter_fn,
1002        cascade_free_fn,
1003};
1004
1005static struct stream_filter *cascade_filter(struct stream_filter *one,
1006                                            struct stream_filter *two)
1007{
1008        struct cascade_filter *cascade;
1009
1010        if (!one || is_null_stream_filter(one))
1011                return two;
1012        if (!two || is_null_stream_filter(two))
1013                return one;
1014
1015        cascade = xmalloc(sizeof(*cascade));
1016        cascade->one = one;
1017        cascade->two = two;
1018        cascade->end = cascade->ptr = 0;
1019        cascade->filter.vtbl = &cascade_vtbl;
1020        return (struct stream_filter *)cascade;
1021}
1022
1023/*
1024 * ident filter
1025 */
1026#define IDENT_DRAINING (-1)
1027#define IDENT_SKIPPING (-2)
1028struct ident_filter {
1029        struct stream_filter filter;
1030        struct strbuf left;
1031        int state;
1032        char ident[45]; /* ": x40 $" */
1033};
1034
1035static int is_foreign_ident(const char *str)
1036{
1037        int i;
1038
1039        if (prefixcmp(str, "$Id: "))
1040                return 0;
1041        for (i = 5; str[i]; i++) {
1042                if (isspace(str[i]) && str[i+1] != '$')
1043                        return 1;
1044        }
1045        return 0;
1046}
1047
1048static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p)
1049{
1050        size_t to_drain = ident->left.len;
1051
1052        if (*osize_p < to_drain)
1053                to_drain = *osize_p;
1054        if (to_drain) {
1055                memcpy(*output_p, ident->left.buf, to_drain);
1056                strbuf_remove(&ident->left, 0, to_drain);
1057                *output_p += to_drain;
1058                *osize_p -= to_drain;
1059        }
1060        if (!ident->left.len)
1061                ident->state = 0;
1062}
1063
1064static int ident_filter_fn(struct stream_filter *filter,
1065                           const char *input, size_t *isize_p,
1066                           char *output, size_t *osize_p)
1067{
1068        struct ident_filter *ident = (struct ident_filter *)filter;
1069        static const char head[] = "$Id";
1070
1071        if (!input) {
1072                /* drain upon eof */
1073                switch (ident->state) {
1074                default:
1075                        strbuf_add(&ident->left, head, ident->state);
1076                case IDENT_SKIPPING:
1077                        /* fallthru */
1078                case IDENT_DRAINING:
1079                        ident_drain(ident, &output, osize_p);
1080                }
1081                return 0;
1082        }
1083
1084        while (*isize_p || (ident->state == IDENT_DRAINING)) {
1085                int ch;
1086
1087                if (ident->state == IDENT_DRAINING) {
1088                        ident_drain(ident, &output, osize_p);
1089                        if (!*osize_p)
1090                                break;
1091                        continue;
1092                }
1093
1094                ch = *(input++);
1095                (*isize_p)--;
1096
1097                if (ident->state == IDENT_SKIPPING) {
1098                        /*
1099                         * Skipping until '$' or LF, but keeping them
1100                         * in case it is a foreign ident.
1101                         */
1102                        strbuf_addch(&ident->left, ch);
1103                        if (ch != '\n' && ch != '$')
1104                                continue;
1105                        if (ch == '$' && !is_foreign_ident(ident->left.buf)) {
1106                                strbuf_setlen(&ident->left, sizeof(head) - 1);
1107                                strbuf_addstr(&ident->left, ident->ident);
1108                        }
1109                        ident->state = IDENT_DRAINING;
1110                        continue;
1111                }
1112
1113                if (ident->state < sizeof(head) &&
1114                    head[ident->state] == ch) {
1115                        ident->state++;
1116                        continue;
1117                }
1118
1119                if (ident->state)
1120                        strbuf_add(&ident->left, head, ident->state);
1121                if (ident->state == sizeof(head) - 1) {
1122                        if (ch != ':' && ch != '$') {
1123                                strbuf_addch(&ident->left, ch);
1124                                ident->state = 0;
1125                                continue;
1126                        }
1127
1128                        if (ch == ':') {
1129                                strbuf_addch(&ident->left, ch);
1130                                ident->state = IDENT_SKIPPING;
1131                        } else {
1132                                strbuf_addstr(&ident->left, ident->ident);
1133                                ident->state = IDENT_DRAINING;
1134                        }
1135                        continue;
1136                }
1137
1138                strbuf_addch(&ident->left, ch);
1139                ident->state = IDENT_DRAINING;
1140        }
1141        return 0;
1142}
1143
1144static void ident_free_fn(struct stream_filter *filter)
1145{
1146        struct ident_filter *ident = (struct ident_filter *)filter;
1147        strbuf_release(&ident->left);
1148        free(filter);
1149}
1150
1151static struct stream_filter_vtbl ident_vtbl = {
1152        ident_filter_fn,
1153        ident_free_fn,
1154};
1155
1156static struct stream_filter *ident_filter(const unsigned char *sha1)
1157{
1158        struct ident_filter *ident = xmalloc(sizeof(*ident));
1159
1160        sprintf(ident->ident, ": %s $", sha1_to_hex(sha1));
1161        strbuf_init(&ident->left, 0);
1162        ident->filter.vtbl = &ident_vtbl;
1163        ident->state = 0;
1164        return (struct stream_filter *)ident;
1165}
1166
1167/*
1168 * Return an appropriately constructed filter for the path, or NULL if
1169 * the contents cannot be filtered without reading the whole thing
1170 * in-core.
1171 *
1172 * Note that you would be crazy to set CRLF, smuge/clean or ident to a
1173 * large binary blob you would want us not to slurp into the memory!
1174 */
1175struct stream_filter *get_stream_filter(const char *path, const unsigned char *sha1)
1176{
1177        struct conv_attrs ca;
1178        enum crlf_action crlf_action;
1179        struct stream_filter *filter = NULL;
1180
1181        convert_attrs(&ca, path);
1182
1183        if (ca.drv && (ca.drv->smudge || ca.drv->clean))
1184                return filter;
1185
1186        if (ca.ident)
1187                filter = ident_filter(sha1);
1188
1189        crlf_action = input_crlf_action(ca.crlf_action, ca.eol_attr);
1190
1191        if ((crlf_action == CRLF_BINARY) || (crlf_action == CRLF_INPUT) ||
1192            (crlf_action == CRLF_GUESS && auto_crlf == AUTO_CRLF_FALSE))
1193                filter = cascade_filter(filter, &null_filter_singleton);
1194
1195        else if (output_eol(crlf_action) == EOL_CRLF &&
1196                 !(crlf_action == CRLF_AUTO || crlf_action == CRLF_GUESS))
1197                filter = cascade_filter(filter, &lf_to_crlf_filter_singleton);
1198
1199        return filter;
1200}
1201
1202void free_stream_filter(struct stream_filter *filter)
1203{
1204        filter->vtbl->free(filter);
1205}
1206
1207int stream_filter(struct stream_filter *filter,
1208                  const char *input, size_t *isize_p,
1209                  char *output, size_t *osize_p)
1210{
1211        return filter->vtbl->filter(filter, input, isize_p, output, osize_p);
1212}