diff options
Diffstat (limited to 'convert.c')
| -rw-r--r-- | convert.c | 1984 |
1 files changed, 1984 insertions, 0 deletions
diff --git a/convert.c b/convert.c new file mode 100644 index 0000000..5ead3ce --- /dev/null +++ b/convert.c @@ -0,0 +1,1984 @@ +#include "cache.h" +#include "config.h" +#include "object-store.h" +#include "attr.h" +#include "run-command.h" +#include "quote.h" +#include "sigchain.h" +#include "pkt-line.h" +#include "sub-process.h" +#include "utf8.h" +#include "ll-merge.h" + +/* + * convert.c - convert a file when checking it out and checking it in. + * + * This should use the pathname to decide on whether it wants to do some + * more interesting conversions (automatic gzip/unzip, general format + * conversions etc etc), but by default it just does automatic CRLF<->LF + * translation when the "text" attribute or "auto_crlf" option is set. + */ + +/* Stat bits: When BIN is set, the txt bits are unset */ +#define CONVERT_STAT_BITS_TXT_LF 0x1 +#define CONVERT_STAT_BITS_TXT_CRLF 0x2 +#define CONVERT_STAT_BITS_BIN 0x4 + +enum crlf_action { + CRLF_UNDEFINED, + CRLF_BINARY, + CRLF_TEXT, + CRLF_TEXT_INPUT, + CRLF_TEXT_CRLF, + CRLF_AUTO, + CRLF_AUTO_INPUT, + CRLF_AUTO_CRLF +}; + +struct text_stat { + /* NUL, CR, LF and CRLF counts */ + unsigned nul, lonecr, lonelf, crlf; + + /* These are just approximations! */ + unsigned printable, nonprintable; +}; + +static void gather_stats(const char *buf, unsigned long size, struct text_stat *stats) +{ + unsigned long i; + + memset(stats, 0, sizeof(*stats)); + + for (i = 0; i < size; i++) { + unsigned char c = buf[i]; + if (c == '\r') { + if (i+1 < size && buf[i+1] == '\n') { + stats->crlf++; + i++; + } else + stats->lonecr++; + continue; + } + if (c == '\n') { + stats->lonelf++; + continue; + } + if (c == 127) + /* DEL */ + stats->nonprintable++; + else if (c < 32) { + switch (c) { + /* BS, HT, ESC and FF */ + case '\b': case '\t': case '\033': case '\014': + stats->printable++; + break; + case 0: + stats->nul++; + /* fall through */ + default: + stats->nonprintable++; + } + } + else + stats->printable++; + } + + /* If file ends with EOF then don't count this EOF as non-printable. */ + if (size >= 1 && buf[size-1] == '\032') + stats->nonprintable--; +} + +/* + * The same heuristics as diff.c::mmfile_is_binary() + * We treat files with bare CR as binary + */ +static int convert_is_binary(const struct text_stat *stats) +{ + if (stats->lonecr) + return 1; + if (stats->nul) + return 1; + if ((stats->printable >> 7) < stats->nonprintable) + return 1; + return 0; +} + +static unsigned int gather_convert_stats(const char *data, unsigned long size) +{ + struct text_stat stats; + int ret = 0; + if (!data || !size) + return 0; + gather_stats(data, size, &stats); + if (convert_is_binary(&stats)) + ret |= CONVERT_STAT_BITS_BIN; + if (stats.crlf) + ret |= CONVERT_STAT_BITS_TXT_CRLF; + if (stats.lonelf) + ret |= CONVERT_STAT_BITS_TXT_LF; + + return ret; +} + +static const char *gather_convert_stats_ascii(const char *data, unsigned long size) +{ + unsigned int convert_stats = gather_convert_stats(data, size); + + if (convert_stats & CONVERT_STAT_BITS_BIN) + return "-text"; + switch (convert_stats) { + case CONVERT_STAT_BITS_TXT_LF: + return "lf"; + case CONVERT_STAT_BITS_TXT_CRLF: + return "crlf"; + case CONVERT_STAT_BITS_TXT_LF | CONVERT_STAT_BITS_TXT_CRLF: + return "mixed"; + default: + return "none"; + } +} + +const char *get_cached_convert_stats_ascii(const struct index_state *istate, + const char *path) +{ + const char *ret; + unsigned long sz; + void *data = read_blob_data_from_index(istate, path, &sz); + ret = gather_convert_stats_ascii(data, sz); + free(data); + return ret; +} + +const char *get_wt_convert_stats_ascii(const char *path) +{ + const char *ret = ""; + struct strbuf sb = STRBUF_INIT; + if (strbuf_read_file(&sb, path, 0) >= 0) + ret = gather_convert_stats_ascii(sb.buf, sb.len); + strbuf_release(&sb); + return ret; +} + +static int text_eol_is_crlf(void) +{ + if (auto_crlf == AUTO_CRLF_TRUE) + return 1; + else if (auto_crlf == AUTO_CRLF_INPUT) + return 0; + if (core_eol == EOL_CRLF) + return 1; + if (core_eol == EOL_UNSET && EOL_NATIVE == EOL_CRLF) + return 1; + return 0; +} + +static enum eol output_eol(enum crlf_action crlf_action) +{ + switch (crlf_action) { + case CRLF_BINARY: + return EOL_UNSET; + case CRLF_TEXT_CRLF: + return EOL_CRLF; + case CRLF_TEXT_INPUT: + return EOL_LF; + case CRLF_UNDEFINED: + case CRLF_AUTO_CRLF: + return EOL_CRLF; + case CRLF_AUTO_INPUT: + return EOL_LF; + case CRLF_TEXT: + case CRLF_AUTO: + /* fall through */ + return text_eol_is_crlf() ? EOL_CRLF : EOL_LF; + } + warning(_("illegal crlf_action %d"), (int)crlf_action); + return core_eol; +} + +static void check_global_conv_flags_eol(const char *path, enum crlf_action crlf_action, + struct text_stat *old_stats, struct text_stat *new_stats, + int conv_flags) +{ + if (old_stats->crlf && !new_stats->crlf ) { + /* + * CRLFs would not be restored by checkout + */ + if (conv_flags & CONV_EOL_RNDTRP_DIE) + die(_("CRLF would be replaced by LF in %s"), path); + else if (conv_flags & CONV_EOL_RNDTRP_WARN) + warning(_("CRLF will be replaced by LF in %s.\n" + "The file will have its original line" + " endings in your working directory"), path); + } else if (old_stats->lonelf && !new_stats->lonelf ) { + /* + * CRLFs would be added by checkout + */ + if (conv_flags & CONV_EOL_RNDTRP_DIE) + die(_("LF would be replaced by CRLF in %s"), path); + else if (conv_flags & CONV_EOL_RNDTRP_WARN) + warning(_("LF will be replaced by CRLF in %s.\n" + "The file will have its original line" + " endings in your working directory"), path); + } +} + +static int has_crlf_in_index(const struct index_state *istate, const char *path) +{ + unsigned long sz; + void *data; + const char *crp; + int has_crlf = 0; + + data = read_blob_data_from_index(istate, path, &sz); + if (!data) + return 0; + + crp = memchr(data, '\r', sz); + if (crp) { + unsigned int ret_stats; + ret_stats = gather_convert_stats(data, sz); + if (!(ret_stats & CONVERT_STAT_BITS_BIN) && + (ret_stats & CONVERT_STAT_BITS_TXT_CRLF)) + has_crlf = 1; + } + free(data); + return has_crlf; +} + +static int will_convert_lf_to_crlf(struct text_stat *stats, + enum crlf_action crlf_action) +{ + if (output_eol(crlf_action) != EOL_CRLF) + return 0; + /* No "naked" LF? Nothing to convert, regardless. */ + if (!stats->lonelf) + return 0; + + if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) { + /* If we have any CR or CRLF line endings, we do not touch it */ + /* This is the new safer autocrlf-handling */ + if (stats->lonecr || stats->crlf) + return 0; + + if (convert_is_binary(stats)) + return 0; + } + return 1; + +} + +static int validate_encoding(const char *path, const char *enc, + const char *data, size_t len, int die_on_error) +{ + const char *stripped; + + /* We only check for UTF here as UTF?? can be an alias for UTF-?? */ + if (skip_iprefix(enc, "UTF", &stripped)) { + skip_prefix(stripped, "-", &stripped); + + /* + * Check for detectable errors in UTF encodings + */ + if (has_prohibited_utf_bom(enc, data, len)) { + const char *error_msg = _( + "BOM is prohibited in '%s' if encoded as %s"); + /* + * This advice is shown for UTF-??BE and UTF-??LE encodings. + * We cut off the last two characters of the encoding name + * to generate the encoding name suitable for BOMs. + */ + const char *advise_msg = _( + "The file '%s' contains a byte order " + "mark (BOM). Please use UTF-%.*s as " + "working-tree-encoding."); + int stripped_len = strlen(stripped) - strlen("BE"); + advise(advise_msg, path, stripped_len, stripped); + if (die_on_error) + die(error_msg, path, enc); + else { + return error(error_msg, path, enc); + } + + } else if (is_missing_required_utf_bom(enc, data, len)) { + const char *error_msg = _( + "BOM is required in '%s' if encoded as %s"); + const char *advise_msg = _( + "The file '%s' is missing a byte order " + "mark (BOM). Please use UTF-%sBE or UTF-%sLE " + "(depending on the byte order) as " + "working-tree-encoding."); + advise(advise_msg, path, stripped, stripped); + if (die_on_error) + die(error_msg, path, enc); + else { + return error(error_msg, path, enc); + } + } + + } + return 0; +} + +static void trace_encoding(const char *context, const char *path, + const char *encoding, const char *buf, size_t len) +{ + static struct trace_key coe = TRACE_KEY_INIT(WORKING_TREE_ENCODING); + struct strbuf trace = STRBUF_INIT; + int i; + + strbuf_addf(&trace, "%s (%s, considered %s):\n", context, path, encoding); + for (i = 0; i < len && buf; ++i) { + strbuf_addf( + &trace, "| \033[2m%2i:\033[0m %2x \033[2m%c\033[0m%c", + i, + (unsigned char) buf[i], + (buf[i] > 32 && buf[i] < 127 ? buf[i] : ' '), + ((i+1) % 8 && (i+1) < len ? ' ' : '\n') + ); + } + strbuf_addchars(&trace, '\n', 1); + + trace_strbuf(&coe, &trace); + strbuf_release(&trace); +} + +static int check_roundtrip(const char *enc_name) +{ + /* + * check_roundtrip_encoding contains a string of comma and/or + * space separated encodings (eg. "UTF-16, ASCII, CP1125"). + * Search for the given encoding in that string. + */ + const char *found = strcasestr(check_roundtrip_encoding, enc_name); + const char *next; + int len; + if (!found) + return 0; + next = found + strlen(enc_name); + len = strlen(check_roundtrip_encoding); + return (found && ( + /* + * check that the found encoding is at the + * beginning of check_roundtrip_encoding or + * that it is prefixed with a space or comma + */ + found == check_roundtrip_encoding || ( + (isspace(found[-1]) || found[-1] == ',') + ) + ) && ( + /* + * check that the found encoding is at the + * end of check_roundtrip_encoding or + * that it is suffixed with a space or comma + */ + next == check_roundtrip_encoding + len || ( + next < check_roundtrip_encoding + len && + (isspace(next[0]) || next[0] == ',') + ) + )); +} + +static const char *default_encoding = "UTF-8"; + +static int encode_to_git(const char *path, const char *src, size_t src_len, + struct strbuf *buf, const char *enc, int conv_flags) +{ + char *dst; + size_t dst_len; + int die_on_error = conv_flags & CONV_WRITE_OBJECT; + + /* + * No encoding is specified or there is nothing to encode. + * Tell the caller that the content was not modified. + */ + if (!enc || (src && !src_len)) + return 0; + + /* + * Looks like we got called from "would_convert_to_git()". + * This means Git wants to know if it would encode (= modify!) + * the content. Let's answer with "yes", since an encoding was + * specified. + */ + if (!buf && !src) + return 1; + + if (validate_encoding(path, enc, src, src_len, die_on_error)) + return 0; + + trace_encoding("source", path, enc, src, src_len); + dst = reencode_string_len(src, src_len, default_encoding, enc, + &dst_len); + if (!dst) { + /* + * We could add the blob "as-is" to Git. However, on checkout + * we would try to re-encode to the original encoding. This + * would fail and we would leave the user with a messed-up + * working tree. Let's try to avoid this by screaming loud. + */ + const char* msg = _("failed to encode '%s' from %s to %s"); + if (die_on_error) + die(msg, path, enc, default_encoding); + else { + error(msg, path, enc, default_encoding); + return 0; + } + } + trace_encoding("destination", path, default_encoding, dst, dst_len); + + /* + * UTF supports lossless conversion round tripping [1] and conversions + * between UTF and other encodings are mostly round trip safe as + * Unicode aims to be a superset of all other character encodings. + * However, certain encodings (e.g. SHIFT-JIS) are known to have round + * trip issues [2]. Check the round trip conversion for all encodings + * listed in core.checkRoundtripEncoding. + * + * The round trip check is only performed if content is written to Git. + * This ensures that no information is lost during conversion to/from + * the internal UTF-8 representation. + * + * Please note, the code below is not tested because I was not able to + * generate a faulty round trip without an iconv error. Iconv errors + * are already caught above. + * + * [1] http://unicode.org/faq/utf_bom.html#gen2 + * [2] https://support.microsoft.com/en-us/help/170559/prb-conversion-problem-between-shift-jis-and-unicode + */ + if (die_on_error && check_roundtrip(enc)) { + char *re_src; + size_t re_src_len; + + re_src = reencode_string_len(dst, dst_len, + enc, default_encoding, + &re_src_len); + + trace_printf("Checking roundtrip encoding for %s...\n", enc); + trace_encoding("reencoded source", path, enc, + re_src, re_src_len); + + if (!re_src || src_len != re_src_len || + memcmp(src, re_src, src_len)) { + const char* msg = _("encoding '%s' from %s to %s and " + "back is not the same"); + die(msg, path, enc, default_encoding); + } + + free(re_src); + } + + strbuf_attach(buf, dst, dst_len, dst_len + 1); + return 1; +} + +static int encode_to_worktree(const char *path, const char *src, size_t src_len, + struct strbuf *buf, const char *enc) +{ + char *dst; + size_t dst_len; + + /* + * No encoding is specified or there is nothing to encode. + * Tell the caller that the content was not modified. + */ + if (!enc || (src && !src_len)) + return 0; + + dst = reencode_string_len(src, src_len, enc, default_encoding, + &dst_len); + if (!dst) { + error(_("failed to encode '%s' from %s to %s"), + path, default_encoding, enc); + return 0; + } + + strbuf_attach(buf, dst, dst_len, dst_len + 1); + return 1; +} + +static int crlf_to_git(const struct index_state *istate, + const char *path, const char *src, size_t len, + struct strbuf *buf, + enum crlf_action crlf_action, int conv_flags) +{ + struct text_stat stats; + char *dst; + int convert_crlf_into_lf; + + if (crlf_action == CRLF_BINARY || + (src && !len)) + return 0; + + /* + * If we are doing a dry-run and have no source buffer, there is + * nothing to analyze; we must assume we would convert. + */ + if (!buf && !src) + return 1; + + gather_stats(src, len, &stats); + /* Optimization: No CRLF? Nothing to convert, regardless. */ + convert_crlf_into_lf = !!stats.crlf; + + if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) { + if (convert_is_binary(&stats)) + return 0; + /* + * If the file in the index has any CR in it, do not + * convert. This is the new safer autocrlf handling, + * unless we want to renormalize in a merge or + * cherry-pick. + */ + if ((!(conv_flags & CONV_EOL_RENORMALIZE)) && + has_crlf_in_index(istate, path)) + convert_crlf_into_lf = 0; + } + if (((conv_flags & CONV_EOL_RNDTRP_WARN) || + ((conv_flags & CONV_EOL_RNDTRP_DIE) && len))) { + struct text_stat new_stats; + memcpy(&new_stats, &stats, sizeof(new_stats)); + /* simulate "git add" */ + if (convert_crlf_into_lf) { + new_stats.lonelf += new_stats.crlf; + new_stats.crlf = 0; + } + /* simulate "git checkout" */ + if (will_convert_lf_to_crlf(&new_stats, crlf_action)) { + new_stats.crlf += new_stats.lonelf; + new_stats.lonelf = 0; + } + check_global_conv_flags_eol(path, crlf_action, &stats, &new_stats, conv_flags); + } + if (!convert_crlf_into_lf) + return 0; + + /* + * At this point all of our source analysis is done, and we are sure we + * would convert. If we are in dry-run mode, we can give an answer. + */ + if (!buf) + return 1; + + /* only grow if not in place */ + if (strbuf_avail(buf) + buf->len < len) + strbuf_grow(buf, len - buf->len); + dst = buf->buf; + if (crlf_action == CRLF_AUTO || crlf_action == CRLF_AUTO_INPUT || crlf_action == CRLF_AUTO_CRLF) { + /* + * If we guessed, we already know we rejected a file with + * lone CR, and we can strip a CR without looking at what + * follow it. + */ + do { + unsigned char c = *src++; + if (c != '\r') + *dst++ = c; + } while (--len); + } else { + do { + unsigned char c = *src++; + if (! (c == '\r' && (1 < len && *src == '\n'))) + *dst++ = c; + } while (--len); + } + strbuf_setlen(buf, dst - buf->buf); + return 1; +} + +static int crlf_to_worktree(const char *src, size_t len, + struct strbuf *buf, enum crlf_action crlf_action) +{ + char *to_free = NULL; + struct text_stat stats; + + if (!len || output_eol(crlf_action) != EOL_CRLF) + return 0; + + gather_stats(src, len, &stats); + if (!will_convert_lf_to_crlf(&stats, crlf_action)) + return 0; + + /* are we "faking" in place editing ? */ + if (src == buf->buf) + to_free = strbuf_detach(buf, NULL); + + strbuf_grow(buf, len + stats.lonelf); + for (;;) { + const char *nl = memchr(src, '\n', len); + if (!nl) + break; + if (nl > src && nl[-1] == '\r') { + strbuf_add(buf, src, nl + 1 - src); + } else { + strbuf_add(buf, src, nl - src); + strbuf_addstr(buf, "\r\n"); + } + len -= nl + 1 - src; + src = nl + 1; + } + strbuf_add(buf, src, len); + + free(to_free); + return 1; +} + +struct filter_params { + const char *src; + unsigned long size; + int fd; + const char *cmd; + const char *path; +}; + +static int filter_buffer_or_fd(int in, int out, void *data) +{ + /* + * Spawn cmd and feed the buffer contents through its stdin. + */ + struct child_process child_process = CHILD_PROCESS_INIT; + struct filter_params *params = (struct filter_params *)data; + int write_err, status; + const char *argv[] = { NULL, NULL }; + + /* apply % substitution to cmd */ + struct strbuf cmd = STRBUF_INIT; + struct strbuf path = STRBUF_INIT; + struct strbuf_expand_dict_entry dict[] = { + { "f", NULL, }, + { NULL, NULL, }, + }; + + /* quote the path to preserve spaces, etc. */ + sq_quote_buf(&path, params->path); + dict[0].value = path.buf; + + /* expand all %f with the quoted path */ + strbuf_expand(&cmd, params->cmd, strbuf_expand_dict_cb, &dict); + strbuf_release(&path); + + argv[0] = cmd.buf; + + child_process.argv = argv; + child_process.use_shell = 1; + child_process.in = -1; + child_process.out = out; + + if (start_command(&child_process)) { + strbuf_release(&cmd); + return error(_("cannot fork to run external filter '%s'"), + params->cmd); + } + + sigchain_push(SIGPIPE, SIG_IGN); + + if (params->src) { + write_err = (write_in_full(child_process.in, + params->src, params->size) < 0); + if (errno == EPIPE) + write_err = 0; + } else { + write_err = copy_fd(params->fd, child_process.in); + if (write_err == COPY_WRITE_ERROR && errno == EPIPE) + write_err = 0; + } + + if (close(child_process.in)) + write_err = 1; + if (write_err) + error(_("cannot feed the input to external filter '%s'"), + params->cmd); + + sigchain_pop(SIGPIPE); + + status = finish_command(&child_process); + if (status) + error(_("external filter '%s' failed %d"), params->cmd, status); + + strbuf_release(&cmd); + return (write_err || status); +} + +static int apply_single_file_filter(const char *path, const char *src, size_t len, int fd, + struct strbuf *dst, const char *cmd) +{ + /* + * Create a pipeline to have the command filter the buffer's + * contents. + * + * (child --> cmd) --> us + */ + int err = 0; + struct strbuf nbuf = STRBUF_INIT; + struct async async; + struct filter_params params; + + memset(&async, 0, sizeof(async)); + async.proc = filter_buffer_or_fd; + async.data = ¶ms; + async.out = -1; + params.src = src; + params.size = len; + params.fd = fd; + params.cmd = cmd; + params.path = path; + + fflush(NULL); + if (start_async(&async)) + return 0; /* error was already reported */ + + if (strbuf_read(&nbuf, async.out, 0) < 0) { + err = error(_("read from external filter '%s' failed"), cmd); + } + if (close(async.out)) { + err = error(_("read from external filter '%s' failed"), cmd); + } + if (finish_async(&async)) { + err = error(_("external filter '%s' failed"), cmd); + } + + if (!err) { + strbuf_swap(dst, &nbuf); + } + strbuf_release(&nbuf); + return !err; +} + +#define CAP_CLEAN (1u<<0) +#define CAP_SMUDGE (1u<<1) +#define CAP_DELAY (1u<<2) + +struct cmd2process { + struct subprocess_entry subprocess; /* must be the first member! */ + unsigned int supported_capabilities; +}; + +static int subprocess_map_initialized; +static struct hashmap subprocess_map; + +static int start_multi_file_filter_fn(struct subprocess_entry *subprocess) +{ + static int versions[] = {2, 0}; + static struct subprocess_capability capabilities[] = { + { "clean", CAP_CLEAN }, + { "smudge", CAP_SMUDGE }, + { "delay", CAP_DELAY }, + { NULL, 0 } + }; + struct cmd2process *entry = (struct cmd2process *)subprocess; + return subprocess_handshake(subprocess, "git-filter", versions, NULL, + capabilities, + &entry->supported_capabilities); +} + +static void handle_filter_error(const struct strbuf *filter_status, + struct cmd2process *entry, + const unsigned int wanted_capability) +{ + if (!strcmp(filter_status->buf, "error")) + ; /* The filter signaled a problem with the file. */ + else if (!strcmp(filter_status->buf, "abort") && wanted_capability) { + /* + * The filter signaled a permanent problem. Don't try to filter + * files with the same command for the lifetime of the current + * Git process. + */ + entry->supported_capabilities &= ~wanted_capability; + } else { + /* + * Something went wrong with the protocol filter. + * Force shutdown and restart if another blob requires filtering. + */ + error(_("external filter '%s' failed"), entry->subprocess.cmd); + subprocess_stop(&subprocess_map, &entry->subprocess); + free(entry); + } +} + +static int apply_multi_file_filter(const char *path, const char *src, size_t len, + int fd, struct strbuf *dst, const char *cmd, + const unsigned int wanted_capability, + struct delayed_checkout *dco) +{ + int err; + int can_delay = 0; + struct cmd2process *entry; + struct child_process *process; + struct strbuf nbuf = STRBUF_INIT; + struct strbuf filter_status = STRBUF_INIT; + const char *filter_type; + + if (!subprocess_map_initialized) { + subprocess_map_initialized = 1; + hashmap_init(&subprocess_map, cmd2process_cmp, NULL, 0); + entry = NULL; + } else { + entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd); + } + + fflush(NULL); + + if (!entry) { + entry = xmalloc(sizeof(*entry)); + entry->supported_capabilities = 0; + + if (subprocess_start(&subprocess_map, &entry->subprocess, cmd, start_multi_file_filter_fn)) { + free(entry); + return 0; + } + } + process = &entry->subprocess.process; + + if (!(entry->supported_capabilities & wanted_capability)) + return 0; + + if (wanted_capability & CAP_CLEAN) + filter_type = "clean"; + else if (wanted_capability & CAP_SMUDGE) + filter_type = "smudge"; + else + die(_("unexpected filter type")); + + sigchain_push(SIGPIPE, SIG_IGN); + + assert(strlen(filter_type) < LARGE_PACKET_DATA_MAX - strlen("command=\n")); + err = packet_write_fmt_gently(process->in, "command=%s\n", filter_type); + if (err) + goto done; + + err = strlen(path) > LARGE_PACKET_DATA_MAX - strlen("pathname=\n"); + if (err) { + error(_("path name too long for external filter")); + goto done; + } + + err = packet_write_fmt_gently(process->in, "pathname=%s\n", path); + if (err) + goto done; + + if ((entry->supported_capabilities & CAP_DELAY) && + dco && dco->state == CE_CAN_DELAY) { + can_delay = 1; + err = packet_write_fmt_gently(process->in, "can-delay=1\n"); + if (err) + goto done; + } + + err = packet_flush_gently(process->in); + if (err) + goto done; + + if (fd >= 0) + err = write_packetized_from_fd(fd, process->in); + else + err = write_packetized_from_buf(src, len, process->in); + if (err) + goto done; + + err = subprocess_read_status(process->out, &filter_status); + if (err) + goto done; + + if (can_delay && !strcmp(filter_status.buf, "delayed")) { + string_list_insert(&dco->filters, cmd); + string_list_insert(&dco->paths, path); + } else { + /* The filter got the blob and wants to send us a response. */ + err = strcmp(filter_status.buf, "success"); + if (err) + goto done; + + err = read_packetized_to_strbuf(process->out, &nbuf) < 0; + if (err) + goto done; + + err = subprocess_read_status(process->out, &filter_status); + if (err) + goto done; + + err = strcmp(filter_status.buf, "success"); + } + +done: + sigchain_pop(SIGPIPE); + + if (err) + handle_filter_error(&filter_status, entry, wanted_capability); + else + strbuf_swap(dst, &nbuf); + strbuf_release(&nbuf); + return !err; +} + + +int async_query_available_blobs(const char *cmd, struct string_list *available_paths) +{ + int err; + char *line; + struct cmd2process *entry; + struct child_process *process; + struct strbuf filter_status = STRBUF_INIT; + + assert(subprocess_map_initialized); + entry = (struct cmd2process *)subprocess_find_entry(&subprocess_map, cmd); + if (!entry) { + error(_("external filter '%s' is not available anymore although " + "not all paths have been filtered"), cmd); + return 0; + } + process = &entry->subprocess.process; + sigchain_push(SIGPIPE, SIG_IGN); + + err = packet_write_fmt_gently( + process->in, "command=list_available_blobs\n"); + if (err) + goto done; + + err = packet_flush_gently(process->in); + if (err) + goto done; + + while ((line = packet_read_line(process->out, NULL))) { + const char *path; + if (skip_prefix(line, "pathname=", &path)) + string_list_insert(available_paths, xstrdup(path)); + else + ; /* ignore unknown keys */ + } + + err = subprocess_read_status(process->out, &filter_status); + if (err) + goto done; + + err = strcmp(filter_status.buf, "success"); + +done: + sigchain_pop(SIGPIPE); + + if (err) + handle_filter_error(&filter_status, entry, 0); + return !err; +} + +static struct convert_driver { + const char *name; + struct convert_driver *next; + const char *smudge; + const char *clean; + const char *process; + int required; +} *user_convert, **user_convert_tail; + +static int apply_filter(const char *path, const char *src, size_t len, + int fd, struct strbuf *dst, struct convert_driver *drv, + const unsigned int wanted_capability, + struct delayed_checkout *dco) +{ + const char *cmd = NULL; + + if (!drv) + return 0; + + if (!dst) + return 1; + + if ((wanted_capability & CAP_CLEAN) && !drv->process && drv->clean) + cmd = drv->clean; + else if ((wanted_capability & CAP_SMUDGE) && !drv->process && drv->smudge) + cmd = drv->smudge; + + if (cmd && *cmd) + return apply_single_file_filter(path, src, len, fd, dst, cmd); + else if (drv->process && *drv->process) + return apply_multi_file_filter(path, src, len, fd, dst, + drv->process, wanted_capability, dco); + + return 0; +} + +static int read_convert_config(const char *var, const char *value, void *cb) +{ + const char *key, *name; + int namelen; + struct convert_driver *drv; + + /* + * External conversion drivers are configured using + * "filter.<name>.variable". + */ + if (parse_config_key(var, "filter", &name, &namelen, &key) < 0 || !name) + return 0; + for (drv = user_convert; drv; drv = drv->next) + if (!strncmp(drv->name, name, namelen) && !drv->name[namelen]) + break; + if (!drv) { + drv = xcalloc(1, sizeof(struct convert_driver)); + drv->name = xmemdupz(name, namelen); + *user_convert_tail = drv; + user_convert_tail = &(drv->next); + } + + /* + * filter.<name>.smudge and filter.<name>.clean specifies + * the command line: + * + * command-line + * + * The command-line will not be interpolated in any way. + */ + + if (!strcmp("smudge", key)) + return git_config_string(&drv->smudge, var, value); + + if (!strcmp("clean", key)) + return git_config_string(&drv->clean, var, value); + + if (!strcmp("process", key)) + return git_config_string(&drv->process, var, value); + + if (!strcmp("required", key)) { + drv->required = git_config_bool(var, value); + return 0; + } + + return 0; +} + +static int count_ident(const char *cp, unsigned long size) +{ + /* + * "$Id: 0000000000000000000000000000000000000000 $" <=> "$Id$" + */ + int cnt = 0; + char ch; + + while (size) { + ch = *cp++; + size--; + if (ch != '$') + continue; + if (size < 3) + break; + if (memcmp("Id", cp, 2)) + continue; + ch = cp[2]; + cp += 3; + size -= 3; + if (ch == '$') + cnt++; /* $Id$ */ + if (ch != ':') + continue; + + /* + * "$Id: ... "; scan up to the closing dollar sign and discard. + */ + while (size) { + ch = *cp++; + size--; + if (ch == '$') { + cnt++; + break; + } + if (ch == '\n') + break; + } + } + return cnt; +} + +static int ident_to_git(const char *src, size_t len, + struct strbuf *buf, int ident) +{ + char *dst, *dollar; + + if (!ident || (src && !count_ident(src, len))) + return 0; + + if (!buf) + return 1; + + /* only grow if not in place */ + if (strbuf_avail(buf) + buf->len < len) + strbuf_grow(buf, len - buf->len); + dst = buf->buf; + for (;;) { + dollar = memchr(src, '$', len); + if (!dollar) + break; + memmove(dst, src, dollar + 1 - src); + dst += dollar + 1 - src; + len -= dollar + 1 - src; + src = dollar + 1; + + if (len > 3 && !memcmp(src, "Id:", 3)) { + dollar = memchr(src + 3, '$', len - 3); + if (!dollar) + break; + if (memchr(src + 3, '\n', dollar - src - 3)) { + /* Line break before the next dollar. */ + continue; + } + + memcpy(dst, "Id$", 3); + dst += 3; + len -= dollar + 1 - src; + src = dollar + 1; + } + } + memmove(dst, src, len); + strbuf_setlen(buf, dst + len - buf->buf); + return 1; +} + +static int ident_to_worktree(const char *src, size_t len, + struct strbuf *buf, int ident) +{ + struct object_id oid; + char *to_free = NULL, *dollar, *spc; + int cnt; + + if (!ident) + return 0; + + cnt = count_ident(src, len); + if (!cnt) + return 0; + + /* are we "faking" in place editing ? */ + if (src == buf->buf) + to_free = strbuf_detach(buf, NULL); + hash_object_file(the_hash_algo, src, len, "blob", &oid); + + strbuf_grow(buf, len + cnt * (the_hash_algo->hexsz + 3)); + for (;;) { + /* step 1: run to the next '$' */ + dollar = memchr(src, '$', len); + if (!dollar) + break; + strbuf_add(buf, src, dollar + 1 - src); + len -= dollar + 1 - src; + src = dollar + 1; + + /* step 2: does it looks like a bit like Id:xxx$ or Id$ ? */ + if (len < 3 || memcmp("Id", src, 2)) + continue; + + /* step 3: skip over Id$ or Id:xxxxx$ */ + if (src[2] == '$') { + src += 3; + len -= 3; + } else if (src[2] == ':') { + /* + * It's possible that an expanded Id has crept its way into the + * repository, we cope with that by stripping the expansion out. + * This is probably not a good idea, since it will cause changes + * on checkout, which won't go away by stash, but let's keep it + * for git-style ids. + */ + dollar = memchr(src + 3, '$', len - 3); + if (!dollar) { + /* incomplete keyword, no more '$', so just quit the loop */ + break; + } + + if (memchr(src + 3, '\n', dollar - src - 3)) { + /* Line break before the next dollar. */ + continue; + } + + spc = memchr(src + 4, ' ', dollar - src - 4); + if (spc && spc < dollar-1) { + /* There are spaces in unexpected places. + * This is probably an id from some other + * versioning system. Keep it for now. + */ + continue; + } + + len -= dollar + 1 - src; + src = dollar + 1; + } else { + /* it wasn't a "Id$" or "Id:xxxx$" */ + continue; + } + + /* step 4: substitute */ + strbuf_addstr(buf, "Id: "); + strbuf_addstr(buf, oid_to_hex(&oid)); + strbuf_addstr(buf, " $"); + } + strbuf_add(buf, src, len); + + free(to_free); + return 1; +} + +static const char *git_path_check_encoding(struct attr_check_item *check) +{ + const char *value = check->value; + + if (ATTR_UNSET(value) || !strlen(value)) + return NULL; + + if (ATTR_TRUE(value) || ATTR_FALSE(value)) { + die(_("true/false are no valid working-tree-encodings")); + } + + /* Don't encode to the default encoding */ + if (same_encoding(value, default_encoding)) + return NULL; + + return value; +} + +static enum crlf_action git_path_check_crlf(struct attr_check_item *check) +{ + const char *value = check->value; + + if (ATTR_TRUE(value)) + return CRLF_TEXT; + else if (ATTR_FALSE(value)) + return CRLF_BINARY; + else if (ATTR_UNSET(value)) + ; + else if (!strcmp(value, "input")) + return CRLF_TEXT_INPUT; + else if (!strcmp(value, "auto")) + return CRLF_AUTO; + return CRLF_UNDEFINED; +} + +static enum eol git_path_check_eol(struct attr_check_item *check) +{ + const char *value = check->value; + + if (ATTR_UNSET(value)) + ; + else if (!strcmp(value, "lf")) + return EOL_LF; + else if (!strcmp(value, "crlf")) + return EOL_CRLF; + return EOL_UNSET; +} + +static struct convert_driver *git_path_check_convert(struct attr_check_item *check) +{ + const char *value = check->value; + struct convert_driver *drv; + + if (ATTR_TRUE(value) || ATTR_FALSE(value) || ATTR_UNSET(value)) + return NULL; + for (drv = user_convert; drv; drv = drv->next) + if (!strcmp(value, drv->name)) + return drv; + return NULL; +} + +static int git_path_check_ident(struct attr_check_item *check) +{ + const char *value = check->value; + + return !!ATTR_TRUE(value); +} + +struct conv_attrs { + struct convert_driver *drv; + enum crlf_action attr_action; /* What attr says */ + enum crlf_action crlf_action; /* When no attr is set, use core.autocrlf */ + int ident; + const char *working_tree_encoding; /* Supported encoding or default encoding if NULL */ +}; + +static struct attr_check *check; + +static void convert_attrs(const struct index_state *istate, + struct conv_attrs *ca, const char *path) +{ + struct attr_check_item *ccheck = NULL; + + if (!check) { + check = attr_check_initl("crlf", "ident", "filter", + "eol", "text", "working-tree-encoding", + NULL); + user_convert_tail = &user_convert; + git_config(read_convert_config, NULL); + } + + git_check_attr(istate, path, check); + ccheck = check->items; + ca->crlf_action = git_path_check_crlf(ccheck + 4); + if (ca->crlf_action == CRLF_UNDEFINED) + ca->crlf_action = git_path_check_crlf(ccheck + 0); + ca->ident = git_path_check_ident(ccheck + 1); + ca->drv = git_path_check_convert(ccheck + 2); + if (ca->crlf_action != CRLF_BINARY) { + enum eol eol_attr = git_path_check_eol(ccheck + 3); + if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_LF) + ca->crlf_action = CRLF_AUTO_INPUT; + else if (ca->crlf_action == CRLF_AUTO && eol_attr == EOL_CRLF) + ca->crlf_action = CRLF_AUTO_CRLF; + else if (eol_attr == EOL_LF) + ca->crlf_action = CRLF_TEXT_INPUT; + else if (eol_attr == EOL_CRLF) + ca->crlf_action = CRLF_TEXT_CRLF; + } + ca->working_tree_encoding = git_path_check_encoding(ccheck + 5); + + /* Save attr and make a decision for action */ + ca->attr_action = ca->crlf_action; + if (ca->crlf_action == CRLF_TEXT) + ca->crlf_action = text_eol_is_crlf() ? CRLF_TEXT_CRLF : CRLF_TEXT_INPUT; + if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_FALSE) + ca->crlf_action = CRLF_BINARY; + if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_TRUE) + ca->crlf_action = CRLF_AUTO_CRLF; + if (ca->crlf_action == CRLF_UNDEFINED && auto_crlf == AUTO_CRLF_INPUT) + ca->crlf_action = CRLF_AUTO_INPUT; +} + +void reset_parsed_attributes(void) +{ + struct convert_driver *drv, *next; + + attr_check_free(check); + check = NULL; + reset_merge_attributes(); + + for (drv = user_convert; drv; drv = next) { + next = drv->next; + free((void *)drv->name); + free(drv); + } + user_convert = NULL; + user_convert_tail = NULL; +} + +int would_convert_to_git_filter_fd(const struct index_state *istate, const char *path) +{ + struct conv_attrs ca; + + convert_attrs(istate, &ca, path); + if (!ca.drv) + return 0; + + /* + * Apply a filter to an fd only if the filter is required to succeed. + * We must die if the filter fails, because the original data before + * filtering is not available. + */ + if (!ca.drv->required) + return 0; + + return apply_filter(path, NULL, 0, -1, NULL, ca.drv, CAP_CLEAN, NULL); +} + +const char *get_convert_attr_ascii(const struct index_state *istate, const char *path) +{ + struct conv_attrs ca; + + convert_attrs(istate, &ca, path); + switch (ca.attr_action) { + case CRLF_UNDEFINED: + return ""; + case CRLF_BINARY: + return "-text"; + case CRLF_TEXT: + return "text"; + case CRLF_TEXT_INPUT: + return "text eol=lf"; + case CRLF_TEXT_CRLF: + return "text eol=crlf"; + case CRLF_AUTO: + return "text=auto"; + case CRLF_AUTO_CRLF: + return "text=auto eol=crlf"; + case CRLF_AUTO_INPUT: + return "text=auto eol=lf"; + } + return ""; +} + +int convert_to_git(const struct index_state *istate, + const char *path, const char *src, size_t len, + struct strbuf *dst, int conv_flags) +{ + int ret = 0; + struct conv_attrs ca; + + convert_attrs(istate, &ca, path); + + ret |= apply_filter(path, src, len, -1, dst, ca.drv, CAP_CLEAN, NULL); + if (!ret && ca.drv && ca.drv->required) + die(_("%s: clean filter '%s' failed"), path, ca.drv->name); + + if (ret && dst) { + src = dst->buf; + len = dst->len; + } + + ret |= encode_to_git(path, src, len, dst, ca.working_tree_encoding, conv_flags); + if (ret && dst) { + src = dst->buf; + len = dst->len; + } + + if (!(conv_flags & CONV_EOL_KEEP_CRLF)) { + ret |= crlf_to_git(istate, path, src, len, dst, ca.crlf_action, conv_flags); + if (ret && dst) { + src = dst->buf; + len = dst->len; + } + } + return ret | ident_to_git(src, len, dst, ca.ident); +} + +void convert_to_git_filter_fd(const struct index_state *istate, + const char *path, int fd, struct strbuf *dst, + int conv_flags) +{ + struct conv_attrs ca; + convert_attrs(istate, &ca, path); + + assert(ca.drv); + assert(ca.drv->clean || ca.drv->process); + + if (!apply_filter(path, NULL, 0, fd, dst, ca.drv, CAP_CLEAN, NULL)) + die(_("%s: clean filter '%s' failed"), path, ca.drv->name); + + encode_to_git(path, dst->buf, dst->len, dst, ca.working_tree_encoding, conv_flags); + crlf_to_git(istate, path, dst->buf, dst->len, dst, ca.crlf_action, conv_flags); + ident_to_git(dst->buf, dst->len, dst, ca.ident); +} + +static int convert_to_working_tree_internal(const struct index_state *istate, + const char *path, const char *src, + size_t len, struct strbuf *dst, + int normalizing, struct delayed_checkout *dco) +{ + int ret = 0, ret_filter = 0; + struct conv_attrs ca; + + convert_attrs(istate, &ca, path); + + ret |= ident_to_worktree(src, len, dst, ca.ident); + if (ret) { + src = dst->buf; + len = dst->len; + } + /* + * CRLF conversion can be skipped if normalizing, unless there + * is a smudge or process filter (even if the process filter doesn't + * support smudge). The filters might expect CRLFs. + */ + if ((ca.drv && (ca.drv->smudge || ca.drv->process)) || !normalizing) { + ret |= crlf_to_worktree(src, len, dst, ca.crlf_action); + if (ret) { + src = dst->buf; + len = dst->len; + } + } + + ret |= encode_to_worktree(path, src, len, dst, ca.working_tree_encoding); + if (ret) { + src = dst->buf; + len = dst->len; + } + + ret_filter = apply_filter( + path, src, len, -1, dst, ca.drv, CAP_SMUDGE, dco); + if (!ret_filter && ca.drv && ca.drv->required) + die(_("%s: smudge filter %s failed"), path, ca.drv->name); + + return ret | ret_filter; +} + +int async_convert_to_working_tree(const struct index_state *istate, + const char *path, const char *src, + size_t len, struct strbuf *dst, + void *dco) +{ + return convert_to_working_tree_internal(istate, path, src, len, dst, 0, dco); +} + +int convert_to_working_tree(const struct index_state *istate, + const char *path, const char *src, + size_t len, struct strbuf *dst) +{ + return convert_to_working_tree_internal(istate, path, src, len, dst, 0, NULL); +} + +int renormalize_buffer(const struct index_state *istate, const char *path, + const char *src, size_t len, struct strbuf *dst) +{ + int ret = convert_to_working_tree_internal(istate, path, src, len, dst, 1, NULL); + if (ret) { + src = dst->buf; + len = dst->len; + } + return ret | convert_to_git(istate, path, src, len, dst, CONV_EOL_RENORMALIZE); +} + +/***************************************************************** + * + * Streaming conversion support + * + *****************************************************************/ + +typedef int (*filter_fn)(struct stream_filter *, + const char *input, size_t *isize_p, + char *output, size_t *osize_p); +typedef void (*free_fn)(struct stream_filter *); + +struct stream_filter_vtbl { + filter_fn filter; + free_fn free; +}; + +struct stream_filter { + struct stream_filter_vtbl *vtbl; +}; + +static int null_filter_fn(struct stream_filter *filter, + const char *input, size_t *isize_p, + char *output, size_t *osize_p) +{ + size_t count; + + if (!input) + return 0; /* we do not keep any states */ + count = *isize_p; + if (*osize_p < count) + count = *osize_p; + if (count) { + memmove(output, input, count); + *isize_p -= count; + *osize_p -= count; + } + return 0; +} + +static void null_free_fn(struct stream_filter *filter) +{ + ; /* nothing -- null instances are shared */ +} + +static struct stream_filter_vtbl null_vtbl = { + null_filter_fn, + null_free_fn, +}; + +static struct stream_filter null_filter_singleton = { + &null_vtbl, +}; + +int is_null_stream_filter(struct stream_filter *filter) +{ + return filter == &null_filter_singleton; +} + + +/* + * LF-to-CRLF filter + */ + +struct lf_to_crlf_filter { + struct stream_filter filter; + unsigned has_held:1; + char held; +}; + +static int lf_to_crlf_filter_fn(struct stream_filter *filter, + const char *input, size_t *isize_p, + char *output, size_t *osize_p) +{ + size_t count, o = 0; + struct lf_to_crlf_filter *lf_to_crlf = (struct lf_to_crlf_filter *)filter; + + /* + * We may be holding onto the CR to see if it is followed by a + * LF, in which case we would need to go to the main loop. + * Otherwise, just emit it to the output stream. + */ + if (lf_to_crlf->has_held && (lf_to_crlf->held != '\r' || !input)) { + output[o++] = lf_to_crlf->held; + lf_to_crlf->has_held = 0; + } + + /* We are told to drain */ + if (!input) { + *osize_p -= o; + return 0; + } + + count = *isize_p; + if (count || lf_to_crlf->has_held) { + size_t i; + int was_cr = 0; + + if (lf_to_crlf->has_held) { + was_cr = 1; + lf_to_crlf->has_held = 0; + } + + for (i = 0; o < *osize_p && i < count; i++) { + char ch = input[i]; + + if (ch == '\n') { + output[o++] = '\r'; + } else if (was_cr) { + /* + * Previous round saw CR and it is not followed + * by a LF; emit the CR before processing the + * current character. + */ + output[o++] = '\r'; + } + + /* + * We may have consumed the last output slot, + * in which case we need to break out of this + * loop; hold the current character before + * returning. + */ + if (*osize_p <= o) { + lf_to_crlf->has_held = 1; + lf_to_crlf->held = ch; + continue; /* break but increment i */ + } + + if (ch == '\r') { + was_cr = 1; + continue; + } + + was_cr = 0; + output[o++] = ch; + } + + *osize_p -= o; + *isize_p -= i; + + if (!lf_to_crlf->has_held && was_cr) { + lf_to_crlf->has_held = 1; + lf_to_crlf->held = '\r'; + } + } + return 0; +} + +static void lf_to_crlf_free_fn(struct stream_filter *filter) +{ + free(filter); +} + +static struct stream_filter_vtbl lf_to_crlf_vtbl = { + lf_to_crlf_filter_fn, + lf_to_crlf_free_fn, +}; + +static struct stream_filter *lf_to_crlf_filter(void) +{ + struct lf_to_crlf_filter *lf_to_crlf = xcalloc(1, sizeof(*lf_to_crlf)); + + lf_to_crlf->filter.vtbl = &lf_to_crlf_vtbl; + return (struct stream_filter *)lf_to_crlf; +} + +/* + * Cascade filter + */ +#define FILTER_BUFFER 1024 +struct cascade_filter { + struct stream_filter filter; + struct stream_filter *one; + struct stream_filter *two; + char buf[FILTER_BUFFER]; + int end, ptr; +}; + +static int cascade_filter_fn(struct stream_filter *filter, + const char *input, size_t *isize_p, + char *output, size_t *osize_p) +{ + struct cascade_filter *cas = (struct cascade_filter *) filter; + size_t filled = 0; + size_t sz = *osize_p; + size_t to_feed, remaining; + + /* + * input -- (one) --> buf -- (two) --> output + */ + while (filled < sz) { + remaining = sz - filled; + + /* do we already have something to feed two with? */ + if (cas->ptr < cas->end) { + to_feed = cas->end - cas->ptr; + if (stream_filter(cas->two, + cas->buf + cas->ptr, &to_feed, + output + filled, &remaining)) + return -1; + cas->ptr += (cas->end - cas->ptr) - to_feed; + filled = sz - remaining; + continue; + } + + /* feed one from upstream and have it emit into our buffer */ + to_feed = input ? *isize_p : 0; + if (input && !to_feed) + break; + remaining = sizeof(cas->buf); + if (stream_filter(cas->one, + input, &to_feed, + cas->buf, &remaining)) + return -1; + cas->end = sizeof(cas->buf) - remaining; + cas->ptr = 0; + if (input) { + size_t fed = *isize_p - to_feed; + *isize_p -= fed; + input += fed; + } + + /* do we know that we drained one completely? */ + if (input || cas->end) + continue; + + /* tell two to drain; we have nothing more to give it */ + to_feed = 0; + remaining = sz - filled; + if (stream_filter(cas->two, + NULL, &to_feed, + output + filled, &remaining)) + return -1; + if (remaining == (sz - filled)) + break; /* completely drained two */ + filled = sz - remaining; + } + *osize_p -= filled; + return 0; +} + +static void cascade_free_fn(struct stream_filter *filter) +{ + struct cascade_filter *cas = (struct cascade_filter *)filter; + free_stream_filter(cas->one); + free_stream_filter(cas->two); + free(filter); +} + +static struct stream_filter_vtbl cascade_vtbl = { + cascade_filter_fn, + cascade_free_fn, +}; + +static struct stream_filter *cascade_filter(struct stream_filter *one, + struct stream_filter *two) +{ + struct cascade_filter *cascade; + + if (!one || is_null_stream_filter(one)) + return two; + if (!two || is_null_stream_filter(two)) + return one; + + cascade = xmalloc(sizeof(*cascade)); + cascade->one = one; + cascade->two = two; + cascade->end = cascade->ptr = 0; + cascade->filter.vtbl = &cascade_vtbl; + return (struct stream_filter *)cascade; +} + +/* + * ident filter + */ +#define IDENT_DRAINING (-1) +#define IDENT_SKIPPING (-2) +struct ident_filter { + struct stream_filter filter; + struct strbuf left; + int state; + char ident[GIT_MAX_HEXSZ + 5]; /* ": x40 $" */ +}; + +static int is_foreign_ident(const char *str) +{ + int i; + + if (!skip_prefix(str, "$Id: ", &str)) + return 0; + for (i = 0; str[i]; i++) { + if (isspace(str[i]) && str[i+1] != '$') + return 1; + } + return 0; +} + +static void ident_drain(struct ident_filter *ident, char **output_p, size_t *osize_p) +{ + size_t to_drain = ident->left.len; + + if (*osize_p < to_drain) + to_drain = *osize_p; + if (to_drain) { + memcpy(*output_p, ident->left.buf, to_drain); + strbuf_remove(&ident->left, 0, to_drain); + *output_p += to_drain; + *osize_p -= to_drain; + } + if (!ident->left.len) + ident->state = 0; +} + +static int ident_filter_fn(struct stream_filter *filter, + const char *input, size_t *isize_p, + char *output, size_t *osize_p) +{ + struct ident_filter *ident = (struct ident_filter *)filter; + static const char head[] = "$Id"; + + if (!input) { + /* drain upon eof */ + switch (ident->state) { + default: + strbuf_add(&ident->left, head, ident->state); + /* fallthrough */ + case IDENT_SKIPPING: + /* fallthrough */ + case IDENT_DRAINING: + ident_drain(ident, &output, osize_p); + } + return 0; + } + + while (*isize_p || (ident->state == IDENT_DRAINING)) { + int ch; + + if (ident->state == IDENT_DRAINING) { + ident_drain(ident, &output, osize_p); + if (!*osize_p) + break; + continue; + } + + ch = *(input++); + (*isize_p)--; + + if (ident->state == IDENT_SKIPPING) { + /* + * Skipping until '$' or LF, but keeping them + * in case it is a foreign ident. + */ + strbuf_addch(&ident->left, ch); + if (ch != '\n' && ch != '$') + continue; + if (ch == '$' && !is_foreign_ident(ident->left.buf)) { + strbuf_setlen(&ident->left, sizeof(head) - 1); + strbuf_addstr(&ident->left, ident->ident); + } + ident->state = IDENT_DRAINING; + continue; + } + + if (ident->state < sizeof(head) && + head[ident->state] == ch) { + ident->state++; + continue; + } + + if (ident->state) + strbuf_add(&ident->left, head, ident->state); + if (ident->state == sizeof(head) - 1) { + if (ch != ':' && ch != '$') { + strbuf_addch(&ident->left, ch); + ident->state = 0; + continue; + } + + if (ch == ':') { + strbuf_addch(&ident->left, ch); + ident->state = IDENT_SKIPPING; + } else { + strbuf_addstr(&ident->left, ident->ident); + ident->state = IDENT_DRAINING; + } + continue; + } + + strbuf_addch(&ident->left, ch); + ident->state = IDENT_DRAINING; + } + return 0; +} + +static void ident_free_fn(struct stream_filter *filter) +{ + struct ident_filter *ident = (struct ident_filter *)filter; + strbuf_release(&ident->left); + free(filter); +} + +static struct stream_filter_vtbl ident_vtbl = { + ident_filter_fn, + ident_free_fn, +}; + +static struct stream_filter *ident_filter(const struct object_id *oid) +{ + struct ident_filter *ident = xmalloc(sizeof(*ident)); + + xsnprintf(ident->ident, sizeof(ident->ident), + ": %s $", oid_to_hex(oid)); + strbuf_init(&ident->left, 0); + ident->filter.vtbl = &ident_vtbl; + ident->state = 0; + return (struct stream_filter *)ident; +} + +/* + * Return an appropriately constructed filter for the path, or NULL if + * the contents cannot be filtered without reading the whole thing + * in-core. + * + * Note that you would be crazy to set CRLF, smudge/clean or ident to a + * large binary blob you would want us not to slurp into the memory! + */ +struct stream_filter *get_stream_filter(const struct index_state *istate, + const char *path, + const struct object_id *oid) +{ + struct conv_attrs ca; + struct stream_filter *filter = NULL; + + convert_attrs(istate, &ca, path); + if (ca.drv && (ca.drv->process || ca.drv->smudge || ca.drv->clean)) + return NULL; + + if (ca.working_tree_encoding) + return NULL; + + if (ca.crlf_action == CRLF_AUTO || ca.crlf_action == CRLF_AUTO_CRLF) + return NULL; + + if (ca.ident) + filter = ident_filter(oid); + + if (output_eol(ca.crlf_action) == EOL_CRLF) + filter = cascade_filter(filter, lf_to_crlf_filter()); + else + filter = cascade_filter(filter, &null_filter_singleton); + + return filter; +} + +void free_stream_filter(struct stream_filter *filter) +{ + filter->vtbl->free(filter); +} + +int stream_filter(struct stream_filter *filter, + const char *input, size_t *isize_p, + char *output, size_t *osize_p) +{ + return filter->vtbl->filter(filter, input, isize_p, output, osize_p); +} |