summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-09 20:00:54 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-09 20:00:54 (GMT)
commit9174026cfe69d73ef80b27890615f8b2ef5c265a (patch)
treed4a96ba891017d0d26c15e509b4e6515e40d75ee
parent79517a067a293ddf19867e363f0d9237c7ef8e22 (diff)
downloadgit-9174026cfe69d73ef80b27890615f8b2ef5c265a.zip
git-9174026cfe69d73ef80b27890615f8b2ef5c265a.tar.gz
git-9174026cfe69d73ef80b27890615f8b2ef5c265a.tar.bz2
Add "diff-tree" program to show which files have changed between two trees.
Very useful for creating diffs efficiently, and in general to see what has changed in the namespace.
-rw-r--r--Makefile5
-rw-r--r--diff-tree.c109
2 files changed, 113 insertions, 1 deletions
diff --git a/Makefile b/Makefile
index 42479f0..d09390c 100644
--- a/Makefile
+++ b/Makefile
@@ -2,7 +2,7 @@ CFLAGS=-g -O3 -Wall
CC=gcc
PROG= update-cache show-diff init-db write-tree read-tree commit-tree \
- cat-file fsck-cache checkout-cache
+ cat-file fsck-cache checkout-cache diff-tree
all: $(PROG)
@@ -37,6 +37,9 @@ fsck-cache: fsck-cache.o read-cache.o
checkout-cache: checkout-cache.o read-cache.o
$(CC) $(CFLAGS) -o checkout-cache checkout-cache.o read-cache.o $(LIBS)
+diff-tree: diff-tree.o read-cache.o
+ $(CC) $(CFLAGS) -o diff-tree diff-tree.o read-cache.o $(LIBS)
+
read-cache.o: cache.h
show-diff.o: cache.h
diff --git a/diff-tree.c b/diff-tree.c
new file mode 100644
index 0000000..2f04d1e
--- /dev/null
+++ b/diff-tree.c
@@ -0,0 +1,109 @@
+#include "cache.h"
+
+struct tree_entry;
+
+static struct tree_entry *update_tree_entry(void **bufp, unsigned long *sizep)
+{
+ void *buf = *bufp;
+ unsigned long size = *sizep;
+ int len = strlen(buf) + 1 + 20;
+
+ if (size < len)
+ usage("corrupt tree file");
+ *bufp = buf + len;
+ *sizep = size - len;
+ return buf;
+}
+
+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)
+ usage("corrupt tree file");
+ *pathp = path+1;
+ return sha1;
+}
+
+static void show_file(const char *prefix, void *tree, unsigned long size)
+{
+ unsigned mode;
+ const char *path;
+ const unsigned char *sha1 = extract(tree, size, &path, &mode);
+ printf("%s%o %s %s%c", prefix, mode, sha1_to_hex(sha1), path, 0);
+}
+
+static int compare_tree_entry(void *tree1, unsigned long size1, void *tree2, unsigned long size2)
+{
+ unsigned mode1, mode2;
+ const char *path1, *path2;
+ const unsigned char *sha1, *sha2;
+ int cmp;
+
+ sha1 = extract(tree1, size1, &path1, &mode1);
+ sha2 = extract(tree2, size2, &path2, &mode2);
+
+ cmp = cache_name_compare(path1, strlen(path1), path2, strlen(path2));
+ if (cmp < 0) {
+ show_file("-", tree1, size1);
+ return -1;
+ }
+ if (cmp > 0) {
+ show_file("+", tree2, size2);
+ return 1;
+ }
+ if (!memcmp(sha1, sha2, 20) && mode1 == mode2)
+ return 0;
+ show_file("<", tree1, size1);
+ show_file(">", tree2, size2);
+ return 0;
+}
+
+static int diff_tree(void *tree1, unsigned long size1, void *tree2, unsigned long size2)
+{
+ while (size1 | size2) {
+ if (!size1) {
+ show_file("+", tree2, size2);
+ update_tree_entry(&tree2, &size2);
+ continue;
+ }
+ if (!size2) {
+ show_file("-", tree1, size1);
+ update_tree_entry(&tree1, &size1);
+ continue;
+ }
+ switch (compare_tree_entry(tree1, size1, tree2, size2)) {
+ case -1:
+ update_tree_entry(&tree1, &size1);
+ continue;
+ case 0:
+ update_tree_entry(&tree1, &size1);
+ /* Fallthrough */
+ case 1:
+ update_tree_entry(&tree2, &size2);
+ continue;
+ }
+ usage("diff-tree: internal error");
+ }
+ return 0;
+}
+
+int main(int argc, char **argv)
+{
+ unsigned char old[20], new[20];
+ void *tree1, *tree2;
+ unsigned long size1, size2;
+ char type[20];
+
+ if (argc != 3 || get_sha1_hex(argv[1], old) || get_sha1_hex(argv[2], new))
+ usage("diff-tree <tree sha1> <tree sha1>");
+ tree1 = read_sha1_file(old, type, &size1);
+ if (!tree1 || strcmp(type, "tree"))
+ usage("unable to read source tree");
+ tree2 = read_sha1_file(new, type, &size2);
+ if (!tree2 || strcmp(type, "tree"))
+ usage("unable to read destination tree");
+ return diff_tree(tree1, size1, tree2, size2);
+}