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authorLinus Torvalds <torvalds@linux-foundation.org>2010-02-22 16:42:18 (GMT)
committerJunio C Hamano <gitster@pobox.com>2010-02-22 22:29:41 (GMT)
commit81b50f3ce40bfdd66e5d967bf82be001039a9a98 (patch)
tree7e86bb81e83c9fad73dcbdaa0ef33038137b4274 /builtin/merge-tree.c
parent241b9254e1c8ff071d8054f8b6fbe1883b389d69 (diff)
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Move 'builtin-*' into a 'builtin/' subdirectory
This shrinks the top-level directory a bit, and makes it much more pleasant to use auto-completion on the thing. Instead of [torvalds@nehalem git]$ em buil<tab> Display all 180 possibilities? (y or n) [torvalds@nehalem git]$ em builtin-sh builtin-shortlog.c builtin-show-branch.c builtin-show-ref.c builtin-shortlog.o builtin-show-branch.o builtin-show-ref.o [torvalds@nehalem git]$ em builtin-shor<tab> builtin-shortlog.c builtin-shortlog.o [torvalds@nehalem git]$ em builtin-shortlog.c you get [torvalds@nehalem git]$ em buil<tab> [type] builtin/ builtin.h [torvalds@nehalem git]$ em builtin [auto-completes to] [torvalds@nehalem git]$ em builtin/sh<tab> [type] shortlog.c shortlog.o show-branch.c show-branch.o show-ref.c show-ref.o [torvalds@nehalem git]$ em builtin/sho [auto-completes to] [torvalds@nehalem git]$ em builtin/shor<tab> [type] shortlog.c shortlog.o [torvalds@nehalem git]$ em builtin/shortlog.c which doesn't seem all that different, but not having that annoying break in "Display all 180 possibilities?" is quite a relief. NOTE! If you do this in a clean tree (no object files etc), or using an editor that has auto-completion rules that ignores '*.o' files, you won't see that annoying 'Display all 180 possibilities?' message - it will just show the choices instead. I think bash has some cut-off around 100 choices or something. So the reason I see this is that I'm using an odd editory, and thus don't have the rules to cut down on auto-completion. But you can simulate that by using 'ls' instead, or something similar. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
Diffstat (limited to 'builtin/merge-tree.c')
-rw-r--r--builtin/merge-tree.c358
1 files changed, 358 insertions, 0 deletions
diff --git a/builtin/merge-tree.c b/builtin/merge-tree.c
new file mode 100644
index 0000000..a4a4f2c
--- /dev/null
+++ b/builtin/merge-tree.c
@@ -0,0 +1,358 @@
+#include "cache.h"
+#include "tree-walk.h"
+#include "xdiff-interface.h"
+#include "blob.h"
+#include "exec_cmd.h"
+
+static const char merge_tree_usage[] = "git merge-tree <base-tree> <branch1> <branch2>";
+static int resolve_directories = 1;
+
+struct merge_list {
+ struct merge_list *next;
+ struct merge_list *link; /* other stages for this object */
+
+ unsigned int stage : 2,
+ flags : 30;
+ unsigned int mode;
+ const char *path;
+ struct blob *blob;
+};
+
+static struct merge_list *merge_result, **merge_result_end = &merge_result;
+
+static void add_merge_entry(struct merge_list *entry)
+{
+ *merge_result_end = entry;
+ merge_result_end = &entry->next;
+}
+
+static void merge_trees(struct tree_desc t[3], const char *base);
+
+static const char *explanation(struct merge_list *entry)
+{
+ switch (entry->stage) {
+ case 0:
+ return "merged";
+ case 3:
+ return "added in remote";
+ case 2:
+ if (entry->link)
+ return "added in both";
+ return "added in local";
+ }
+
+ /* Existed in base */
+ entry = entry->link;
+ if (!entry)
+ return "removed in both";
+
+ if (entry->link)
+ return "changed in both";
+
+ if (entry->stage == 3)
+ return "removed in local";
+ return "removed in remote";
+}
+
+extern void *merge_file(const char *, struct blob *, struct blob *, struct blob *, unsigned long *);
+
+static void *result(struct merge_list *entry, unsigned long *size)
+{
+ enum object_type type;
+ struct blob *base, *our, *their;
+
+ if (!entry->stage)
+ return read_sha1_file(entry->blob->object.sha1, &type, size);
+ base = NULL;
+ if (entry->stage == 1) {
+ base = entry->blob;
+ entry = entry->link;
+ }
+ our = NULL;
+ if (entry && entry->stage == 2) {
+ our = entry->blob;
+ entry = entry->link;
+ }
+ their = NULL;
+ if (entry)
+ their = entry->blob;
+ return merge_file(entry->path, base, our, their, size);
+}
+
+static void *origin(struct merge_list *entry, unsigned long *size)
+{
+ enum object_type type;
+ while (entry) {
+ if (entry->stage == 2)
+ return read_sha1_file(entry->blob->object.sha1, &type, size);
+ entry = entry->link;
+ }
+ return NULL;
+}
+
+static int show_outf(void *priv_, mmbuffer_t *mb, int nbuf)
+{
+ int i;
+ for (i = 0; i < nbuf; i++)
+ printf("%.*s", (int) mb[i].size, mb[i].ptr);
+ return 0;
+}
+
+static void show_diff(struct merge_list *entry)
+{
+ unsigned long size;
+ mmfile_t src, dst;
+ xpparam_t xpp;
+ xdemitconf_t xecfg;
+ xdemitcb_t ecb;
+
+ xpp.flags = XDF_NEED_MINIMAL;
+ memset(&xecfg, 0, sizeof(xecfg));
+ xecfg.ctxlen = 3;
+ ecb.outf = show_outf;
+ ecb.priv = NULL;
+
+ src.ptr = origin(entry, &size);
+ if (!src.ptr)
+ size = 0;
+ src.size = size;
+ dst.ptr = result(entry, &size);
+ if (!dst.ptr)
+ size = 0;
+ dst.size = size;
+ xdi_diff(&src, &dst, &xpp, &xecfg, &ecb);
+ free(src.ptr);
+ free(dst.ptr);
+}
+
+static void show_result_list(struct merge_list *entry)
+{
+ printf("%s\n", explanation(entry));
+ do {
+ struct merge_list *link = entry->link;
+ static const char *desc[4] = { "result", "base", "our", "their" };
+ printf(" %-6s %o %s %s\n", desc[entry->stage], entry->mode, sha1_to_hex(entry->blob->object.sha1), entry->path);
+ entry = link;
+ } while (entry);
+}
+
+static void show_result(void)
+{
+ struct merge_list *walk;
+
+ walk = merge_result;
+ while (walk) {
+ show_result_list(walk);
+ show_diff(walk);
+ walk = walk->next;
+ }
+}
+
+/* An empty entry never compares same, not even to another empty entry */
+static int same_entry(struct name_entry *a, struct name_entry *b)
+{
+ return a->sha1 &&
+ b->sha1 &&
+ !hashcmp(a->sha1, b->sha1) &&
+ a->mode == b->mode;
+}
+
+static struct merge_list *create_entry(unsigned stage, unsigned mode, const unsigned char *sha1, const char *path)
+{
+ struct merge_list *res = xcalloc(1, sizeof(*res));
+
+ res->stage = stage;
+ res->path = path;
+ res->mode = mode;
+ res->blob = lookup_blob(sha1);
+ return res;
+}
+
+static char *traverse_path(const struct traverse_info *info, const struct name_entry *n)
+{
+ char *path = xmalloc(traverse_path_len(info, n) + 1);
+ return make_traverse_path(path, info, n);
+}
+
+static void resolve(const struct traverse_info *info, struct name_entry *branch1, struct name_entry *result)
+{
+ struct merge_list *orig, *final;
+ const char *path;
+
+ /* If it's already branch1, don't bother showing it */
+ if (!branch1)
+ return;
+
+ path = traverse_path(info, result);
+ orig = create_entry(2, branch1->mode, branch1->sha1, path);
+ final = create_entry(0, result->mode, result->sha1, path);
+
+ final->link = orig;
+
+ add_merge_entry(final);
+}
+
+static int unresolved_directory(const struct traverse_info *info, struct name_entry n[3])
+{
+ char *newbase;
+ struct name_entry *p;
+ struct tree_desc t[3];
+ void *buf0, *buf1, *buf2;
+
+ if (!resolve_directories)
+ return 0;
+ p = n;
+ if (!p->mode) {
+ p++;
+ if (!p->mode)
+ p++;
+ }
+ if (!S_ISDIR(p->mode))
+ return 0;
+ newbase = traverse_path(info, p);
+ buf0 = fill_tree_descriptor(t+0, n[0].sha1);
+ buf1 = fill_tree_descriptor(t+1, n[1].sha1);
+ buf2 = fill_tree_descriptor(t+2, n[2].sha1);
+ merge_trees(t, newbase);
+
+ free(buf0);
+ free(buf1);
+ free(buf2);
+ free(newbase);
+ return 1;
+}
+
+
+static struct merge_list *link_entry(unsigned stage, const struct traverse_info *info, struct name_entry *n, struct merge_list *entry)
+{
+ const char *path;
+ struct merge_list *link;
+
+ if (!n->mode)
+ return entry;
+ if (entry)
+ path = entry->path;
+ else
+ path = traverse_path(info, n);
+ link = create_entry(stage, n->mode, n->sha1, path);
+ link->link = entry;
+ return link;
+}
+
+static void unresolved(const struct traverse_info *info, struct name_entry n[3])
+{
+ struct merge_list *entry = NULL;
+
+ if (unresolved_directory(info, n))
+ return;
+
+ /*
+ * Do them in reverse order so that the resulting link
+ * list has the stages in order - link_entry adds new
+ * links at the front.
+ */
+ entry = link_entry(3, info, n + 2, entry);
+ entry = link_entry(2, info, n + 1, entry);
+ entry = link_entry(1, info, n + 0, entry);
+
+ add_merge_entry(entry);
+}
+
+/*
+ * Merge two trees together (t[1] and t[2]), using a common base (t[0])
+ * as the origin.
+ *
+ * This walks the (sorted) trees in lock-step, checking every possible
+ * name. Note that directories automatically sort differently from other
+ * files (see "base_name_compare"), so you'll never see file/directory
+ * conflicts, because they won't ever compare the same.
+ *
+ * IOW, if a directory changes to a filename, it will automatically be
+ * seen as the directory going away, and the filename being created.
+ *
+ * Think of this as a three-way diff.
+ *
+ * The output will be either:
+ * - successful merge
+ * "0 mode sha1 filename"
+ * NOTE NOTE NOTE! FIXME! We really really need to walk the index
+ * in parallel with this too!
+ *
+ * - conflict:
+ * "1 mode sha1 filename"
+ * "2 mode sha1 filename"
+ * "3 mode sha1 filename"
+ * where not all of the 1/2/3 lines may exist, of course.
+ *
+ * The successful merge rules are the same as for the three-way merge
+ * in git-read-tree.
+ */
+static int threeway_callback(int n, unsigned long mask, unsigned long dirmask, struct name_entry *entry, struct traverse_info *info)
+{
+ /* Same in both? */
+ if (same_entry(entry+1, entry+2)) {
+ if (entry[0].sha1) {
+ resolve(info, NULL, entry+1);
+ return mask;
+ }
+ }
+
+ if (same_entry(entry+0, entry+1)) {
+ if (entry[2].sha1 && !S_ISDIR(entry[2].mode)) {
+ resolve(info, entry+1, entry+2);
+ return mask;
+ }
+ }
+
+ if (same_entry(entry+0, entry+2)) {
+ if (entry[1].sha1 && !S_ISDIR(entry[1].mode)) {
+ resolve(info, NULL, entry+1);
+ return mask;
+ }
+ }
+
+ unresolved(info, entry);
+ return mask;
+}
+
+static void merge_trees(struct tree_desc t[3], const char *base)
+{
+ struct traverse_info info;
+
+ setup_traverse_info(&info, base);
+ info.fn = threeway_callback;
+ traverse_trees(3, t, &info);
+}
+
+static void *get_tree_descriptor(struct tree_desc *desc, const char *rev)
+{
+ unsigned char sha1[20];
+ void *buf;
+
+ if (get_sha1(rev, sha1))
+ die("unknown rev %s", rev);
+ buf = fill_tree_descriptor(desc, sha1);
+ if (!buf)
+ die("%s is not a tree", rev);
+ return buf;
+}
+
+int cmd_merge_tree(int argc, const char **argv, const char *prefix)
+{
+ struct tree_desc t[3];
+ void *buf1, *buf2, *buf3;
+
+ if (argc != 4)
+ usage(merge_tree_usage);
+
+ buf1 = get_tree_descriptor(t+0, argv[1]);
+ buf2 = get_tree_descriptor(t+1, argv[2]);
+ buf3 = get_tree_descriptor(t+2, argv[3]);
+ merge_trees(t, "");
+ free(buf1);
+ free(buf2);
+ free(buf3);
+
+ show_result();
+ return 0;
+}