New "diff-cache" implementation.

This one is about a million times simpler, and much more likely to be
correct too.

Instead of trying to match up a tree object against the index, we just
read in the tree object side-by-side into the index, and just walk the
resulting index file. This was what all the read-tree cleanups were
all getting to.

diff --git a/cache.h b/cache.h
index 69dc877655032fa39b7e608f3ddd9c3564a01490..bf30ac4741d2eeeb483079f566182505898082f3 100644 (file)
--- a/cache.h
+++ b/cache.h
@@ -99,7 +99,9 @@ extern int read_cache(void);
 extern int write_cache(int newfd, struct cache_entry **cache, int entries);
 extern int cache_name_pos(const char *name, int namelen);
 extern int add_cache_entry(struct cache_entry *ce, int ok_to_add);
+extern int remove_entry_at(int pos);
 extern int remove_file_from_cache(char *path);
+extern int same_name(struct cache_entry *a, struct cache_entry *b);
 extern int cache_match_stat(struct cache_entry *ce, struct stat *st);
 
 #define MTIME_CHANGED  0x0001

diff --git a/diff-cache.c b/diff-cache.c
index 5e1d1a6e6d83291964dca82e6969e576f6a839ec..b407d753e520fa0b1523d770d98b3015af197275 100644 (file)
--- a/diff-cache.c
+++ b/diff-cache.c
@@ -1,220 +1,90 @@
 #include "cache.h"
 
 static int cached_only = 0;
-static int recursive = 0;
 static int line_termination = '\n';
 
-static int diff_cache(void *tree, unsigned long size, struct cache_entry **ac, int entries, const char *base);
-
-static void update_tree_entry(void **bufp, unsigned long *sizep)
-{
-       void *buf = *bufp;
-       unsigned long size = *sizep;
-       int len = strlen(buf) + 1 + 20;
-
-       if (size < len)
-               die("corrupt tree file 1 (%s)", size);
-       *bufp = buf + len;
-       *sizep = size - len;
-}
-
-static const unsigned char *extract(void *tree, unsigned long size, const char **pathp, unsigned int *modep)
-{
-       int len = strlen(tree)+1;
-       const unsigned char *sha1 = tree + len;
-       const char *path = strchr(tree, ' ');
-
-       if (!path || size < len + 20 || sscanf(tree, "%o", modep) != 1)
-               die("corrupt tree file 2 (%d)", size);
-       *pathp = path+1;
-       return sha1;
-}
-
-static char *malloc_base(const char *base, const char *path, int pathlen)
-{
-       int baselen = strlen(base);
-       char *newbase = malloc(baselen + pathlen + 2);
-       memcpy(newbase, base, baselen);
-       memcpy(newbase + baselen, path, pathlen);
-       memcpy(newbase + baselen + pathlen, "/", 2);
-       return newbase;
-}
-
-static void show_file(const char *prefix, const char *path, unsigned int mode, const unsigned char *sha1, const char *base);
-
-/* A whole sub-tree went away or appeared */
-static void show_tree(const char *prefix, void *tree, unsigned long size, const char *base)
-{
-       while (size) {
-               const char *path;
-               unsigned int mode;
-               const unsigned char *sha1 = extract(tree, size, &path, &mode);
-               
-               show_file(prefix, path, mode, sha1, base);
-               update_tree_entry(&tree, &size);
-       }
-}
-
 /* A file entry went away or appeared */
-static void show_file(const char *prefix, const char *path, unsigned int mode, const unsigned char *sha1, const char *base)
+static void show_file(const char *prefix, struct cache_entry *ce)
 {
-       if (recursive && S_ISDIR(mode)) {
-               char type[20];
-               unsigned long size;
-               char *newbase = malloc_base(base, path, strlen(path));
-               void *tree;
-
-               tree = read_sha1_file(sha1, type, &size);
-               if (!tree || strcmp(type, "tree"))
-                       die("corrupt tree sha %s", sha1_to_hex(sha1));
-
-               show_tree(prefix, tree, size, newbase);
-               
-               free(tree);
-               free(newbase);
-               return;
-       }
-
-       printf("%s%o\t%s\t%s\t%s%s%c", prefix, mode,
-              S_ISDIR(mode) ? "tree" : "blob",
-              sha1_to_hex(sha1), base, path,
-              line_termination);
+       printf("%s%o\t%s\t%s\t%s%c", prefix, ntohl(ce->ce_mode), "blob",
+              sha1_to_hex(ce->sha1), ce->name, line_termination);
 }
 
-static int compare_tree_entry(const char *path1, unsigned int mode1, const unsigned char *sha1,
-                             struct cache_entry **ac, int *entries, const char *base)
+static int show_modified(struct cache_entry *old, struct cache_entry *new)
 {
-       int baselen = strlen(base);
-       struct cache_entry *ce = *ac;
-       const char *path2 = ce->name + baselen;
-       unsigned int mode2 = ntohl(ce->ce_mode);
-       const unsigned char *sha2 = ce->sha1;
-       int cmp, pathlen1, pathlen2;
-       char old_sha1_hex[50];
-
-       pathlen1 = strlen(path1);
-       pathlen2 = strlen(path2);
-       cmp = cache_name_compare(path1, pathlen1, path2, pathlen2);
-       if (cmp < 0) {
-               if (S_ISDIR(mode1)) {
-                       char type[20];
-                       unsigned long size;
-                       void *tree = read_sha1_file(sha1, type, &size);
-                       char *newbase = malloc(baselen + 2 + pathlen1);
-
-                       memcpy(newbase, base, baselen);
-                       memcpy(newbase + baselen, path1, pathlen1);
-                       memcpy(newbase + baselen + pathlen1, "/", 2);
-                       if (!tree || strcmp(type, "tree"))
-                               die("unable to read tree object %s", sha1_to_hex(sha1));
-                       *entries = diff_cache(tree, size, ac, *entries, newbase);
-                       free(newbase);
-                       free(tree);
-                       return -1;
-               }
-               show_file("-", path1, mode1, sha1, base);
-               return -1;
-       }
+       unsigned int mode = ntohl(new->ce_mode), oldmode;
+       unsigned char *sha1 = new->sha1;
+       unsigned char old_sha1_hex[60];
 
        if (!cached_only) {
                static unsigned char no_sha1[20];
-               int fd, changed;
+               int changed;
                struct stat st;
-               fd = open(ce->name, O_RDONLY);
-               if (fd < 0 || fstat(fd, &st) < 0) {
-                       show_file("-", path1, mode1, sha1, base);
+               if (stat(new->name, &st) < 0) {
+                       show_file("-", old);
                        return -1;
                }
-               changed = cache_match_stat(ce, &st);
-               close(fd);
+               changed = cache_match_stat(new, &st);
                if (changed) {
-                       mode2 = st.st_mode;
-                       sha2 = no_sha1;
+                       mode = st.st_mode;
+                       sha1 = no_sha1;
                }
        }
 
-       if (cmp > 0) {
-               show_file("+", path2, mode2, sha2, base);
-               return 1;
-       }
-       if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
+       oldmode = ntohl(old->ce_mode);
+       if (mode == oldmode && !memcmp(sha1, old->sha1, 20))
                return 0;
 
-       /*
-        * If the filemode has changed to/from a directory from/to a regular
-        * file, we need to consider it a remove and an add.
-        */
-       if (S_ISDIR(mode1) || S_ISDIR(mode2)) {
-               show_file("-", path1, mode1, sha1, base);
-               show_file("+", path2, mode2, sha2, base);
-               return 0;
-       }
-
-       strcpy(old_sha1_hex, sha1_to_hex(sha1));
-       printf("*%o->%o\t%s\t%s->%s\t%s%s%c", mode1, mode2,
-              S_ISDIR(mode1) ? "tree" : "blob",
-              old_sha1_hex, sha1_to_hex(sha2), base, path1,
-              line_termination);
+       strcpy(old_sha1_hex, sha1_to_hex(old->sha1));
+       printf("*%o->%o\t%s\t%s->%s\t%s%c", oldmode, mode,
+              "blob",
+              old_sha1_hex, sha1_to_hex(sha1),
+              old->name, line_termination);
        return 0;
 }
 
-static int diff_cache(void *tree, unsigned long size, struct cache_entry **ac, int entries, const char *base)
+static int diff_cache(struct cache_entry **ac, int entries)
 {
-       int baselen = strlen(base);
-
-       for (;;) {
-               struct cache_entry *ce;
-               unsigned int mode;
-               const char *path;
-               const unsigned char *sha1;
-               int left;
-
-               /*
-                * No entries in the cache (with this base)?
-                * Output the tree contents.
-                */
-               if (!entries || ce_namelen(ce = *ac) < baselen || memcmp(ce->name, base, baselen)) {
-                       if (!size)
-                               return entries;
-                       sha1 = extract(tree, size, &path, &mode);
-                       show_file("-", path, mode, sha1, base);
-                       update_tree_entry(&tree, &size);
-                       continue;
-               }
+       while (entries) {
+               struct cache_entry *ce = *ac;
 
-               /*
-                * No entries in the tree? Output the cache contents
-                */
-               if (!size) {
-                       show_file("+", ce->name, ntohl(ce->ce_mode), ce->sha1, "");
+               /* No matching 0-stage (current) entry? Show it as deleted */
+               if (ce_stage(ce)) {
+                       show_file("-", ce);
                        ac++;
                        entries--;
                        continue;
                }
-
-               sha1 = extract(tree, size, &path, &mode);
-               left = entries;
-               switch (compare_tree_entry(path, mode, sha1, ac, &left, base)) {
-               case -1:
-                       update_tree_entry(&tree, &size);
-                       if (left < entries) {
-                               ac += (entries - left);
-                               entries = left;
-                       }
-                       continue;
-               case 0:
-                       update_tree_entry(&tree, &size);
-                       /* Fallthrough */
-               case 1:
+               /* No matching 1-stage (tree) entry? Show the current one as added */
+               if (entries == 1 || !same_name(ce, ac[1])) {
+                       show_file("-", ce);
                        ac++;
                        entries--;
                        continue;
                }
-               die("diff-cache: internal error");
+               show_modified(ac[1], ce);
+               ac += 2;
+               entries -= 2;
+               continue;
        }
        return 0;
 }
 
+static void remove_merge_entries(void)
+{
+       int i;
+       for (i = 0; i < active_nr; i++) {
+               struct cache_entry *ce = active_cache[i];
+               if (!ce_stage(ce))
+                       break;
+               printf("%s: unmerged\n", ce->name);
+               while (remove_entry_at(i)) {
+                       if (!ce_stage(active_cache[i]))
+                               break;
+               }
+       }
+}
+
 static char *diff_cache_usage = "diff-cache [-r] [-z] [--cached] <tree sha1>";
 
 int main(int argc, char **argv)
@@ -229,7 +99,7 @@ int main(int argc, char **argv)
                argv++;
                argc--;
                if (!strcmp(arg, "-r")) {
-                       recursive = 1;
+                       /* We accept the -r flag just to look like diff-tree */
                        continue;
                }
                if (!strcmp(arg, "-z")) {
@@ -246,9 +116,13 @@ int main(int argc, char **argv)
        if (argc != 2 || get_sha1_hex(argv[1], tree_sha1))
                usage(diff_cache_usage);
 
+       remove_merge_entries();
+
        tree = read_tree_with_tree_or_commit_sha1(tree_sha1, &size, 0);
        if (!tree)
                die("bad tree object %s", argv[1]);
+       if (read_tree(tree, size, 1))
+               die("unable to read tree object %s", argv[1]);
 
-       return diff_cache(tree, size, active_cache, active_nr, "");
+       return diff_cache(active_cache, active_nr);
 }

diff --git a/read-cache.c b/read-cache.c
index 4b668be47d378d3127230974613db5e0db19d806..f67aceb6b12f6d9cadf6a80bb1d33cf1bcd7f619 100644 (file)
--- a/read-cache.c
+++ b/read-cache.c
@@ -87,7 +87,7 @@ int cache_name_pos(const char *name, int namelen)
 }
 
 /* Remove entry, return true if there are more entries to go.. */
-static int remove_entry_at(int pos)
+int remove_entry_at(int pos)
 {
        active_nr--;
        if (pos >= active_nr)
@@ -106,7 +106,7 @@ int remove_file_from_cache(char *path)
        return 0;
 }
 
-static int same_name(struct cache_entry *a, struct cache_entry *b)
+int same_name(struct cache_entry *a, struct cache_entry *b)
 {
        int len = ce_namelen(a);
        return ce_namelen(b) == len && !memcmp(a->name, b->name, len);