diff-delta.c: Rationalize culling of hash buckets

diff --git a/xdiff-interface.c b/xdiff-interface.c
index 10816e95a07c23dda7554c102c306d7e9beca606..be866d12d38f6f1328f5fae8c7108176d4ecba70 100644 (file)
--- a/xdiff-interface.c
+++ b/xdiff-interface.c
@@ -122,4 +122,81 @@ int read_mmfile(mmfile_t *ptr, const char *filename)
        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(&reg->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(&reg->re, expression, 0))
+                       die("Invalid regexp to look for hunk header: %s", expression);
+               if (buffer)
+                       free(buffer);
+               value = ep + 1;
+       }
+}