[PATCH] Split external diff command interface to a separate file.

With this patch, the non-core'ish part of show-diff command that
invokes an external "diff" comand to obtain patches is split
into a separate file.  The next patch will introduce a new
command, diff-tree-helper, which uses this common diff interface
to format diff-tree and diff-cache output into a patch form.

Signed-off-by: Junio C Hamano <junkio@cox.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/Makefile b/Makefile
index 10d041b51f92e4414817ee0c3bd5bda096aa8133..e108b98e63e9f550f4fb1a0f48170643374b4401 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -28,6 +28,9 @@ LIB_OBJS=read-cache.o sha1_file.o usage.o object.o commit.o tree.o blob.o
 LIB_FILE=libgit.a
 LIB_H=cache.h object.h
 
+LIB_H += diff.h
+LIB_OBJS += diff.o
+
 LIBS = $(LIB_FILE)
 LIBS += -lz
 
@@ -67,6 +70,7 @@ checkout-cache.o: $(LIB_H)
 commit.o: $(LIB_H)
 commit-tree.o: $(LIB_H)
 convert-cache.o: $(LIB_H)
+diff.o: $(LIB_H)
 diff-cache.o: $(LIB_H)
 diff-tree.o: $(LIB_H)
 fsck-cache.o: $(LIB_H)

diff --git a/diff.c b/diff.c
new file mode 100644 (file)
index 0000000..dcefe98
--- /dev/null
+++ b/diff.c
@@ -0,0 +1,106 @@
+#include "cache.h"
+#include "diff.h"
+
+static char *diff_cmd = "diff -L 'k/%s' -L 'l/%s' ";
+static char *diff_opts = "-p -u";
+static char *diff_arg_forward  = " - '%s'";
+static char *diff_arg_reverse  = " '%s' -";
+
+void prepare_diff_cmd(void)
+{
+       /*
+        * Default values above are meant to match the
+        * Linux kernel development style.  Examples of
+        * alternative styles you can specify via environment
+        * variables are:
+        *
+        * GIT_DIFF_CMD="diff -L '%s' -L '%s'"
+        * GIT_DIFF_OPTS="-c";
+        */
+       diff_cmd = getenv("GIT_DIFF_CMD") ? : diff_cmd;
+       diff_opts = getenv("GIT_DIFF_OPTS") ? : diff_opts;
+}
+
+/* Help to copy the thing properly quoted for the shell safety.
+ * any single quote is replaced with '\'', and the caller is
+ * expected to enclose the result within a single quote pair.
+ *
+ * E.g.
+ *  original     sq_expand     result
+ *  name     ==> name      ==> 'name'
+ *  a b      ==> a b       ==> 'a b'
+ *  a'b      ==> a'\''b    ==> 'a'\''b'
+ */
+static char *sq_expand(const char *src)
+{
+       static char *buf = NULL;
+       int cnt, c;
+       const char *cp;
+       char *bp;
+
+       /* count bytes needed to store the quoted string. */ 
+       for (cnt = 1, cp = src; *cp; cnt++, cp++)
+               if (*cp == '\'')
+                       cnt += 3;
+
+       if (! (buf = malloc(cnt)))
+           return buf;
+       bp = buf;
+       while ((c = *src++)) {
+               if (c != '\'')
+                       *bp++ = c;
+               else {
+                       bp = strcpy(bp, "'\\''");
+                       bp += 4;
+               }
+       }
+       *bp = 0;
+       return buf;
+}
+
+void show_differences(const char *name, /* filename on the filesystem */
+                     const char *label, /* diff label to use */
+                     void *old_contents, /* contents in core */
+                     unsigned long long old_size, /* size in core */
+                     int reverse /* 0: diff core file
+                                    1: diff file core */)
+{
+       FILE *f;
+       char *name_sq = sq_expand(name);
+       const char *label_sq = (name != label) ? sq_expand(label) : name_sq;
+       char *diff_arg = reverse ? diff_arg_reverse : diff_arg_forward;
+       int cmd_size = strlen(name_sq) + strlen(label_sq) * 2 +
+               strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg);
+       char *cmd = malloc(cmd_size);
+       int next_at;
+
+       fflush(stdout);
+       next_at = snprintf(cmd, cmd_size, diff_cmd, label_sq, label_sq);
+       next_at += snprintf(cmd+next_at, cmd_size-next_at, "%s", diff_opts);
+       next_at += snprintf(cmd+next_at, cmd_size-next_at, diff_arg, name_sq);
+       f = popen(cmd, "w");
+       if (old_size)
+               fwrite(old_contents, old_size, 1, f);
+       pclose(f);
+       if (label_sq != name_sq)
+               free((void*)label_sq); /* constness */
+       free(name_sq);
+       free(cmd);
+}
+
+void show_diff_empty(const unsigned char *sha1,
+                    const char *name,
+                    int reverse)
+{
+       char *old;
+       unsigned long int size;
+       unsigned char type[20];
+
+       old = read_sha1_file(sha1, type, &size);
+       if (! old) {
+               error("unable to read blob object for %s (%s)", name,
+                     sha1_to_hex(sha1));
+               return;
+       }
+       show_differences("/dev/null", name, old, size, reverse);
+}

diff --git a/diff.h b/diff.h
new file mode 100644 (file)
index 0000000..56ca373
--- /dev/null
+++ b/diff.h
@@ -0,0 +1,17 @@
+#ifndef DIFF_H
+#define DIFF_H
+
+extern void prepare_diff_cmd(void);
+
+extern void show_differences(const char *name, /* filename on the filesystem */
+                            const char *label, /* diff label to use */
+                            void *old_contents, /* contents in core */
+                            unsigned long long old_size, /* size in core */
+                            int reverse /* 0: diff core file
+                                           1: diff file core */);
+
+extern void show_diff_empty(const unsigned char *sha1,
+                           const char *name,
+                           int reverse);
+
+#endif /* DIFF_H */

diff --git a/show-diff.c b/show-diff.c
index 2ff0bd4ea636db2ad54e9ff34e1d70ac7a9a98f0..3e798be303ded2218c2d2a2c8ca79c3b4c0fba6f 100644 (file)
--- a/show-diff.c
+++ b/show-diff.c
@@ -4,103 +4,7 @@
  * Copyright (C) Linus Torvalds, 2005
  */
 #include "cache.h"
-
-static char *diff_cmd = "diff -L 'a/%s' -L 'b/%s' ";
-static char *diff_opts = "-p -u";
-static char *diff_arg_forward  = " - '%s'";
-static char *diff_arg_reverse  = " '%s' -";
-
-static void prepare_diff_cmd(void)
-{
-       /*
-        * Default values above are meant to match the
-        * Linux kernel development style.  Examples of
-        * alternative styles you can specify via environment
-        * variables are:
-        *
-        * GIT_DIFF_CMD="diff -L '%s' -L '%s'"
-        * GIT_DIFF_OPTS="-c";
-        */
-       diff_cmd = getenv("GIT_DIFF_CMD") ? : diff_cmd;
-       diff_opts = getenv("GIT_DIFF_OPTS") ? : diff_opts;
-}
-
-/* Help to copy the thing properly quoted for the shell safety.
- * any single quote is replaced with '\'', and the caller is
- * expected to enclose the result within a single quote pair.
- *
- * E.g.
- *  original     sq_expand     result
- *  name     ==> name      ==> 'name'
- *  a b      ==> a b       ==> 'a b'
- *  a'b      ==> a'\''b    ==> 'a'\''b'
- */
-static char *sq_expand(char *src)
-{
-       static char *buf = NULL;
-       int cnt, c;
-       char *cp;
-
-       /* count bytes needed to store the quoted string. */ 
-       for (cnt = 1, cp = src; *cp; cnt++, cp++)
-               if (*cp == '\'')
-                       cnt += 3;
-
-       if (! (buf = malloc(cnt)))
-           return buf;
-       cp = buf;
-       while ((c = *src++)) {
-               if (c != '\'')
-                       *cp++ = c;
-               else {
-                       cp = strcpy(cp, "'\\''");
-                       cp += 4;
-               }
-       }
-       *cp = 0;
-       return buf;
-}
-
-static void show_differences(char *name, char *label, void *old_contents,
-                            unsigned long long old_size, int reverse)
-{
-       FILE *f;
-       char *name_sq = sq_expand(name);
-       char *label_sq = (name != label) ? sq_expand(label) : name_sq;
-       char *diff_arg = reverse ? diff_arg_reverse : diff_arg_forward;
-       int cmd_size = strlen(name_sq) + strlen(label_sq) * 2 +
-               strlen(diff_cmd) + strlen(diff_opts) + strlen(diff_arg);
-       char *cmd = malloc(cmd_size);
-       int next_at;
-
-       fflush(stdout);
-       next_at = snprintf(cmd, cmd_size, diff_cmd, label_sq, label_sq);
-       next_at += snprintf(cmd+next_at, cmd_size-next_at, "%s", diff_opts);
-       next_at += snprintf(cmd+next_at, cmd_size-next_at, diff_arg, name_sq);
-       f = popen(cmd, "w");
-       if (old_size)
-               fwrite(old_contents, old_size, 1, f);
-       pclose(f);
-       if (label_sq != name_sq)
-               free(label_sq);
-       free(name_sq);
-       free(cmd);
-}
-
-static void show_diff_empty(struct cache_entry *ce, int reverse)
-{
-       char *old;
-       unsigned long int size;
-       unsigned char type[20];
-
-       old = read_sha1_file(ce->sha1, type, &size);
-       if (! old) {
-               error("unable to read blob object for %s (%s)", ce->name,
-                     sha1_to_hex(ce->sha1));
-               return;
-       }
-       show_differences("/dev/null", ce->name, old, size, reverse);
-}
+#include "diff.h"
 
 static const char *show_diff_usage = "show-diff [-q] [-s] [-z] [paths...]";
 
@@ -183,7 +87,8 @@ int main(int argc, char **argv)
                        else {
                                printf("%s: %s\n", ce->name, strerror(errno));
                                if (errno == ENOENT)
-                                       show_diff_empty(ce, reverse);
+                                       show_diff_empty(ce->sha1, ce->name,
+                                                       reverse);
                        }
                        continue;
                }