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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-14 08:37:23 (GMT)
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-14 08:37:23 (GMT)
commit33deb63a36f523c513cf29598d9c05fe78a23cac (patch)
tree298e5d544d67bcc11e95aa6b04f1069a9cd959e6 /merge-tree.c
parent458754a9fe2c2e889e38d1f4f53d5d457eba6faa (diff)
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Add "merge-tree" helper program. Maybe it's retarded, maybe it's helpful.
It only works one directory level at a time, so lookout..
Diffstat (limited to 'merge-tree.c')
-rw-r--r--merge-tree.c128
1 files changed, 128 insertions, 0 deletions
diff --git a/merge-tree.c b/merge-tree.c
new file mode 100644
index 0000000..00ae4e8
--- /dev/null
+++ b/merge-tree.c
@@ -0,0 +1,128 @@
+#include "cache.h"
+
+struct tree_entry {
+ unsigned mode;
+ unsigned char *sha1;
+ char *path;
+ struct tree_entry *next;
+};
+
+static struct tree_entry *read_tree(unsigned char *sha1)
+{
+ char type[20];
+ unsigned long size;
+ void *buf = read_sha1_file(sha1, type, &size);
+ struct tree_entry *ret = NULL, **tp = &ret;
+
+ if (!buf || strcmp(type, "tree"))
+ die("unable to read 'tree' object %s", sha1_to_hex(sha1));
+ while (size) {
+ int len = strlen(buf)+1;
+ struct tree_entry * entry = malloc(sizeof(struct tree_entry));
+ if (size < len + 20 || sscanf(buf, "%o", &entry->mode) != 1)
+ die("corrupt 'tree' object %s", sha1_to_hex(sha1));
+ entry->path = strchr(buf, ' ')+1;
+ entry->sha1 = buf + len;
+ entry->next = NULL;
+ *tp = entry;
+ tp = &entry->next;
+ len += 20;
+ buf += len;
+ size -= len;
+ }
+ return ret;
+}
+
+static void show(const struct tree_entry *a, const char *path)
+{
+ printf("select %o %s %s%c", a->mode, sha1_to_hex(a->sha1), path, 0);
+}
+
+static void merge(const struct tree_entry *a, const struct tree_entry *b, const struct tree_entry *c, const char *path)
+{
+ char hex_a[60], hex_b[60], hex_c[60];
+ strcpy(hex_a, sha1_to_hex(a->sha1));
+ strcpy(hex_b, sha1_to_hex(b->sha1));
+ strcpy(hex_c, sha1_to_hex(c->sha1));
+ printf("merge %o->%o,%o %s->%s,%s %s%c",
+ a->mode, b->mode, c->mode,
+ hex_a, hex_b, hex_c, path, 0);
+}
+
+static int same(const struct tree_entry *a, const struct tree_entry *b)
+{
+ return a->mode == b->mode && !memcmp(a->sha1, b->sha1, 20);
+}
+
+static void merge_entry(const struct tree_entry *src, const struct tree_entry *dst1, const struct tree_entry *dst2)
+{
+ static unsigned char nullsha1[20];
+ static const struct tree_entry none = { 0, nullsha1, "", NULL };
+ const char *path = NULL;
+ const struct tree_entry *a, *b, *c;
+
+ a = &none;
+ b = &none;
+ c = &none;
+ if (src) { a = src; path = src->path; }
+ if (dst1) { b = dst1; path = dst1->path; }
+ if (dst2) { c = dst2; path = dst2->path; }
+ if (same(b, c)) {
+ show(b, path);
+ return;
+ }
+ if (same(a, b)) {
+ show(c, path);
+ return;
+ }
+ if (same(a, c)) {
+ show(b, path);
+ return;
+ }
+ merge(a, b, c, path);
+}
+
+/* For two entries, select the smaller one, clear the bigger one */
+static void smaller(struct tree_entry **ap, struct tree_entry **bp)
+{
+ struct tree_entry *a = *ap, *b = *bp;
+ if (a && b) {
+ int cmp = cache_name_compare(a->path, strlen(a->path), b->path, strlen(b->path));
+ if (cmp) {
+ if (cmp < 0)
+ *bp = NULL;
+ else
+ *ap = NULL;
+ }
+ }
+}
+
+static void merge_tree(struct tree_entry *src, struct tree_entry *dst1, struct tree_entry *dst2)
+{
+ while (src || dst1 || dst2) {
+ struct tree_entry *a, *b, *c;
+ a = src;
+ b = dst1;
+ c = dst2;
+ smaller(&a,&b);
+ smaller(&a,&c);
+ smaller(&b,&c);
+ if (a) src = a->next;
+ if (b) dst1 = b->next;
+ if (c) dst2 = c->next;
+ merge_entry(a,b,c);
+ }
+}
+
+int main(int argc, char **argv)
+{
+ unsigned char src[20], dst1[20], dst2[20];
+
+ if (argc != 4 ||
+ get_sha1_hex(argv[1], src) ||
+ get_sha1_hex(argv[2], dst1) ||
+ get_sha1_hex(argv[3], dst2))
+ usage("merge-tree <src> <dst1> <dst2>");
+ merge_tree(read_tree(src), read_tree(dst1), read_tree(dst2));
+ return 0;
+}