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-rw-r--r--xdiff-interface.c239
1 files changed, 239 insertions, 0 deletions
diff --git a/xdiff-interface.c b/xdiff-interface.c
new file mode 100644
index 0000000000..61dc5c5470
--- /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 ? sz : 1);
+ if (sz && 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(&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);
+ free(buffer);
+ value = ep + 1;
+ }
+}