Ass a "merge-cache" helper program to execute a merge on
authorLinus Torvalds <torvalds@ppc970.osdl.org>
Mon, 18 Apr 2005 02:52:54 +0000 (19:52 -0700)
committerLinus Torvalds <torvalds@ppc970.osdl.org>
Mon, 18 Apr 2005 02:52:54 +0000 (19:52 -0700)
any unmerged files.

This one doesn't actually do the merging, but it makes it
easy to script the programs that do using it.

Makefile
merge-cache.c [new file with mode: 0644]

index 871c0bb..76c4f7c 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ CC=gcc
 
 PROG=   update-cache show-diff init-db write-tree read-tree commit-tree \
        cat-file fsck-cache checkout-cache diff-tree rev-tree show-files \
-       check-files ls-tree merge-base
+       check-files ls-tree merge-base merge-cache
 
 all: $(PROG)
 
@@ -67,6 +67,9 @@ ls-tree: ls-tree.o read-cache.o
 merge-base: merge-base.o read-cache.o
        $(CC) $(CFLAGS) -o merge-base merge-base.o read-cache.o $(LIBS)
 
+merge-cache: merge-cache.o read-cache.o
+       $(CC) $(CFLAGS) -o merge-cache merge-cache.o read-cache.o $(LIBS)
+
 read-cache.o: cache.h
 show-diff.o: cache.h
 
diff --git a/merge-cache.c b/merge-cache.c
new file mode 100644 (file)
index 0000000..3aa391b
--- /dev/null
@@ -0,0 +1,127 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "cache.h"
+
+static const char *pgm = NULL;
+static const char *arguments[5];
+
+static void run_program(void)
+{
+       int pid = fork(), status;
+
+       if (pid < 0)
+               die("unable to fork");
+       if (!pid) {
+               execlp(pgm, arguments[0],
+                           arguments[1],
+                           arguments[2],
+                           arguments[3],
+                           arguments[4],
+                           NULL);
+               die("unable to execute '%s'", pgm);
+       }
+       if (waitpid(pid, &status, 0) < 0 || !WIFEXITED(status) || WEXITSTATUS(status))
+               die("merge program failed");
+}
+
+static char *create_temp_file(int stage, unsigned char *sha1)
+{
+       static char template[4][50];
+       char *path = template[stage];
+       void *buf;
+       char type[100];
+       unsigned long size;
+       int fd;
+
+       buf = read_sha1_file(sha1, type, &size);
+       if (!buf || strcmp(type, "blob"))
+               die("unable to read blob object %s", sha1_to_hex(sha1));
+
+       strcpy(path, ".merge_file_XXXXXX");
+       fd = mkstemp(path);
+       if (fd < 0)
+               die("unable to create temp-file");
+       if (write(fd, buf, size) != size)
+               die("unable to write temp-file");
+       close(fd);
+       return path;
+}
+
+static int merge_entry(int pos, const char *path)
+{
+       int found;
+       
+       if (pos >= active_nr)
+               die("merge-cache: %s not in the cache", path);
+       arguments[0] = pgm;
+       arguments[1] = "";
+       arguments[2] = "";
+       arguments[3] = "";
+       arguments[4] = path;
+       found = 0;
+       do {
+               struct cache_entry *ce = active_cache[pos];
+               int stage = ce_stage(ce);
+
+               if (strcmp(ce->name, path))
+                       break;
+               found++;
+               arguments[stage] = create_temp_file(stage, ce->sha1);
+       } while (++pos < active_nr);
+       if (!found)
+               die("merge-cache: %s not in the cache", path);
+       run_program();
+       return found;
+}
+
+static void merge_file(const char *path)
+{
+       int pos = cache_name_pos(path, strlen(path));
+
+       /*
+        * If it already exists in the cache as stage0, it's
+        * already merged and there is nothing to do.
+        */
+       if (pos < 0)
+               merge_entry(-pos-1, path);
+}
+
+static void merge_all(void)
+{
+       int i;
+       for (i = 0; i < active_nr; i++) {
+               struct cache_entry *ce = active_cache[i];
+               if (!ce_stage(ce))
+                       continue;
+               i += merge_entry(i, ce->name)-1;
+       }
+}
+
+int main(int argc, char **argv)
+{
+       int i, force_file = 0;
+
+       if (argc < 3)
+               usage("merge-cache <merge-program> (-a | <filename>*)");
+
+       read_cache();
+
+       pgm = argv[1];
+       for (i = 2; i < argc; i++) {
+               char *arg = argv[i];
+               if (!force_file && *arg == '-') {
+                       if (!strcmp(arg, "--")) {
+                               force_file = 1;
+                               continue;
+                       }
+                       if (!strcmp(arg, "-a")) {
+                               merge_all();
+                               continue;
+                       }
+                       die("merge-cache: unknown option %s", arg);
+               }
+               merge_file(arg);
+       }
+       return 0;
+}