diff options
Diffstat (limited to 'xdiff-interface.c')
| -rw-r--r-- | xdiff-interface.c | 239 |
1 files changed, 239 insertions, 0 deletions
diff --git a/xdiff-interface.c b/xdiff-interface.c new file mode 100644 index 0000000000..bba236428a --- /dev/null +++ b/xdiff-interface.c @@ -0,0 +1,239 @@ +#include "cache.h" +#include "xdiff-interface.h" + +static int parse_num(char **cp_p, int *num_p) +{ + char *cp = *cp_p; + int num = 0; + int read_some; + + while ('0' <= *cp && *cp <= '9') + num = num * 10 + *cp++ - '0'; + if (!(read_some = cp - *cp_p)) + return -1; + *cp_p = cp; + *num_p = num; + return 0; +} + +int parse_hunk_header(char *line, int len, + int *ob, int *on, + int *nb, int *nn) +{ + char *cp; + cp = line + 4; + if (parse_num(&cp, ob)) { + bad_line: + return error("malformed diff output: %s", line); + } + if (*cp == ',') { + cp++; + if (parse_num(&cp, on)) + goto bad_line; + } + else + *on = 1; + if (*cp++ != ' ' || *cp++ != '+') + goto bad_line; + if (parse_num(&cp, nb)) + goto bad_line; + if (*cp == ',') { + cp++; + if (parse_num(&cp, nn)) + goto bad_line; + } + else + *nn = 1; + return -!!memcmp(cp, " @@", 3); +} + +static void consume_one(void *priv_, char *s, unsigned long size) +{ + struct xdiff_emit_state *priv = priv_; + char *ep; + while (size) { + unsigned long this_size; + ep = memchr(s, '\n', size); + this_size = (ep == NULL) ? size : (ep - s + 1); + priv->consume(priv, s, this_size); + size -= this_size; + s += this_size; + } +} + +int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf) +{ + struct xdiff_emit_state *priv = priv_; + int i; + + for (i = 0; i < nbuf; i++) { + if (mb[i].ptr[mb[i].size-1] != '\n') { + /* Incomplete line */ + priv->remainder = xrealloc(priv->remainder, + priv->remainder_size + + mb[i].size); + memcpy(priv->remainder + priv->remainder_size, + mb[i].ptr, mb[i].size); + priv->remainder_size += mb[i].size; + continue; + } + + /* we have a complete line */ + if (!priv->remainder) { + consume_one(priv, mb[i].ptr, mb[i].size); + continue; + } + priv->remainder = xrealloc(priv->remainder, + priv->remainder_size + + mb[i].size); + memcpy(priv->remainder + priv->remainder_size, + mb[i].ptr, mb[i].size); + consume_one(priv, priv->remainder, + priv->remainder_size + mb[i].size); + free(priv->remainder); + priv->remainder = NULL; + priv->remainder_size = 0; + } + if (priv->remainder) { + consume_one(priv, priv->remainder, priv->remainder_size); + free(priv->remainder); + priv->remainder = NULL; + priv->remainder_size = 0; + } + return 0; +} + +/* + * Trim down common substring at the end of the buffers, + * but leave at least ctx lines at the end. + */ +static void trim_common_tail(mmfile_t *a, mmfile_t *b, long ctx) +{ + const int blk = 1024; + long trimmed = 0, recovered = 0; + char *ap = a->ptr + a->size; + char *bp = b->ptr + b->size; + long smaller = (a->size < b->size) ? a->size : b->size; + + if (ctx) + return; + + while (blk + trimmed <= smaller && !memcmp(ap - blk, bp - blk, blk)) { + trimmed += blk; + ap -= blk; + bp -= blk; + } + + while (recovered < trimmed) + if (ap[recovered++] == '\n') + break; + a->size -= trimmed - recovered; + b->size -= trimmed - recovered; +} + +int xdi_diff(mmfile_t *mf1, mmfile_t *mf2, xpparam_t const *xpp, xdemitconf_t const *xecfg, xdemitcb_t *xecb) +{ + mmfile_t a = *mf1; + mmfile_t b = *mf2; + + trim_common_tail(&a, &b, xecfg->ctxlen); + + return xdl_diff(&a, &b, xpp, xecfg, xecb); +} + +int read_mmfile(mmfile_t *ptr, const char *filename) +{ + struct stat st; + FILE *f; + size_t sz; + + if (stat(filename, &st)) + return error("Could not stat %s", filename); + if ((f = fopen(filename, "rb")) == NULL) + return error("Could not open %s", filename); + sz = xsize_t(st.st_size); + ptr->ptr = xmalloc(sz); + if (fread(ptr->ptr, sz, 1, f) != 1) + return error("Could not read %s", filename); + fclose(f); + ptr->size = sz; + return 0; +} + +#define FIRST_FEW_BYTES 8000 +int buffer_is_binary(const char *ptr, unsigned long size) +{ + if (FIRST_FEW_BYTES < size) + size = FIRST_FEW_BYTES; + return !!memchr(ptr, 0, size); +} + +struct ff_regs { + int nr; + struct ff_reg { + regex_t re; + int negate; + } *array; +}; + +static long ff_regexp(const char *line, long len, + char *buffer, long buffer_size, void *priv) +{ + char *line_buffer = xstrndup(line, len); /* make NUL terminated */ + struct ff_regs *regs = priv; + regmatch_t pmatch[2]; + int result = 0, i; + + for (i = 0; i < regs->nr; i++) { + struct ff_reg *reg = regs->array + i; + if (reg->negate ^ !!regexec(®->re, + line_buffer, 2, pmatch, 0)) { + free(line_buffer); + return -1; + } + } + i = pmatch[1].rm_so >= 0 ? 1 : 0; + line += pmatch[i].rm_so; + result = pmatch[i].rm_eo - pmatch[i].rm_so; + if (result > buffer_size) + result = buffer_size; + else + while (result > 0 && (isspace(line[result - 1]) || + line[result - 1] == '\n')) + result--; + memcpy(buffer, line, result); + free(line_buffer); + return result; +} + +void xdiff_set_find_func(xdemitconf_t *xecfg, const char *value) +{ + int i; + struct ff_regs *regs; + + xecfg->find_func = ff_regexp; + regs = xecfg->find_func_priv = xmalloc(sizeof(struct ff_regs)); + for (i = 0, regs->nr = 1; value[i]; i++) + if (value[i] == '\n') + regs->nr++; + regs->array = xmalloc(regs->nr * sizeof(struct ff_reg)); + for (i = 0; i < regs->nr; i++) { + struct ff_reg *reg = regs->array + i; + const char *ep = strchr(value, '\n'), *expression; + char *buffer = NULL; + + reg->negate = (*value == '!'); + if (reg->negate && i == regs->nr - 1) + die("Last expression must not be negated: %s", value); + if (*value == '!') + value++; + if (ep) + expression = buffer = xstrndup(value, ep - value); + else + expression = value; + if (regcomp(®->re, expression, 0)) + die("Invalid regexp to look for hunk header: %s", expression); + free(buffer); + value = ep + 1; + } +} |