combine-diff: refactor built-in xdiff interface.

This refactors the line-by-line callback mechanism used in
combine-diff so that other programs can reuse it more easily.

Signed-off-by: Junio C Hamano <junkio@cox.net>

diff --git a/Makefile b/Makefile
index 145099a..7030370 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -208,7 +208,7 @@ LIB_OBJS = \
        quote.o read-cache.o refs.o run-command.o \
        server-info.o setup.o sha1_file.o sha1_name.o strbuf.o \
        tag.o tree.o usage.o config.o environment.o ctype.o copy.o \
-       fetch-clone.o revision.o pager.o tree-walk.o \
+       fetch-clone.o revision.o pager.o tree-walk.o xdiff-interface.o \
        $(DIFF_OBJS)
 
 GITLIBS = $(LIB_FILE) $(XDIFF_LIB)

diff --git a/combine-diff.c b/combine-diff.c
index 11f5143..e17afd1 100644 (file)
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -4,7 +4,7 @@
 #include "diff.h"
 #include "diffcore.h"
 #include "quote.h"
-#include "xdiff/xdiff.h"
+#include "xdiff-interface.h"
 
 static int uninteresting(struct diff_filepair *p)
 {
@@ -195,8 +195,8 @@ static void append_lost(struct sline *sline, int n, const char *line, int len)
 }
 
 struct combine_diff_state {
-       char *remainder;
-       unsigned long remainder_size;
+       struct xdiff_emit_state xm;
+
        unsigned int lno, ob, on, nb, nn;
        unsigned long nmask;
        int num_parent;
@@ -205,10 +205,9 @@ struct combine_diff_state {
        struct sline *lost_bucket;
 };
 
-static void consume_line(struct combine_diff_state *state,
-                        char *line,
-                        unsigned long len)
+static void consume_line(void *state_, char *line, unsigned long len)
 {
+       struct combine_diff_state *state = state_;
        if (5 < len && !memcmp("@@ -", line, 4)) {
                if (parse_hunk_header(line, len,
                                      &state->ob, &state->on,
@@ -249,41 +248,6 @@ static void consume_line(struct combine_diff_state *state,
        }
 }
 
-static int combine_diff_outf(void *priv_, mmbuffer_t *mb, int nbuf)
-{
-       struct combine_diff_state *priv = priv_;
-       int i;
-       for (i = 0; i < nbuf; i++) {
-               if (mb[i].ptr[mb[i].size-1] != '\n') {
-                       /* Incomplete line */
-                       priv->remainder = realloc(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_line(priv, mb[i].ptr, mb[i].size);
-                       continue;
-               }
-               priv->remainder = realloc(priv->remainder,
-                                         priv->remainder_size +
-                                         mb[i].size);
-               memcpy(priv->remainder + priv->remainder_size,
-                      mb[i].ptr, mb[i].size);
-               consume_line(priv, priv->remainder,
-                            priv->remainder_size + mb[i].size);
-               free(priv->remainder);
-               priv->remainder = NULL;
-               priv->remainder_size = 0;
-       }
-       return 0;
-}
-
 static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
                         struct sline *sline, int cnt, int n, int num_parent)
 {
@@ -304,9 +268,10 @@ static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
        xpp.flags = XDF_NEED_MINIMAL;
        xecfg.ctxlen = 0;
        xecfg.flags = 0;
-       ecb.outf = combine_diff_outf;
+       ecb.outf = xdiff_outf;
        ecb.priv = &state;
        memset(&state, 0, sizeof(state));
+       state.xm.consume = consume_line;
        state.nmask = nmask;
        state.sline = sline;
        state.lno = 1;
@@ -314,9 +279,6 @@ static void combine_diff(const unsigned char *parent, mmfile_t *result_file,
        state.n = n;
 
        xdl_diff(&parent_file, result_file, &xpp, &xecfg, &ecb);
-       if (state.remainder && state.remainder_size)
-               consume_line(&state, state.remainder, state.remainder_size);
-       free(state.remainder);
        free(parent_file.ptr);
 
        /* Assign line numbers for this parent.

diff --git a/xdiff-interface.c b/xdiff-interface.c
new file mode 100644 (file)
index 0000000..0a66ded
--- /dev/null
+++ b/xdiff-interface.c
@@ -0,0 +1,58 @@
+#include "cache.h"
+#include "xdiff-interface.h"
+
+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 = realloc(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 = realloc(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;
+}

diff --git a/xdiff-interface.h b/xdiff-interface.h
new file mode 100644 (file)
index 0000000..e2f0d66
--- /dev/null
+++ b/xdiff-interface.h
@@ -0,0 +1,18 @@
+#ifndef XDIFF_INTERFACE_H
+#define XDIFF_INTERFACE_H
+
+#include "xdiff/xdiff.h"
+
+struct xdiff_emit_state;
+
+typedef void (*xdiff_emit_consume_fn)(void *, char *, unsigned long);
+
+struct xdiff_emit_state {
+       xdiff_emit_consume_fn consume;
+       char *remainder;
+       unsigned long remainder_size;
+};
+
+int xdiff_outf(void *priv_, mmbuffer_t *mb, int nbuf);
+
+#endif