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-rw-r--r--notes-merge.c325
1 files changed, 322 insertions, 3 deletions
diff --git a/notes-merge.c b/notes-merge.c
index b9956c3bf3..b1afb7e52c 100644
--- a/notes-merge.c
+++ b/notes-merge.c
@@ -1,9 +1,15 @@
#include "cache.h"
#include "commit.h"
#include "refs.h"
+#include "diff.h"
+#include "diffcore.h"
#include "notes.h"
#include "notes-merge.h"
+struct notes_merge_pair {
+ unsigned char obj[20], base[20], local[20], remote[20];
+};
+
void init_notes_merge_options(struct notes_merge_options *o)
{
memset(o, 0, sizeof(struct notes_merge_options));
@@ -18,6 +24,305 @@ void init_notes_merge_options(struct notes_merge_options *o)
} \
} while (0)
+static int path_to_sha1(const char *path, unsigned char *sha1)
+{
+ char hex_sha1[40];
+ int i = 0;
+ while (*path && i < 40) {
+ if (*path != '/')
+ hex_sha1[i++] = *path;
+ path++;
+ }
+ if (*path || i != 40)
+ return -1;
+ return get_sha1_hex(hex_sha1, sha1);
+}
+
+static int verify_notes_filepair(struct diff_filepair *p, unsigned char *sha1)
+{
+ switch (p->status) {
+ case DIFF_STATUS_MODIFIED:
+ assert(p->one->mode == p->two->mode);
+ assert(!is_null_sha1(p->one->sha1));
+ assert(!is_null_sha1(p->two->sha1));
+ break;
+ case DIFF_STATUS_ADDED:
+ assert(is_null_sha1(p->one->sha1));
+ break;
+ case DIFF_STATUS_DELETED:
+ assert(is_null_sha1(p->two->sha1));
+ break;
+ default:
+ return -1;
+ }
+ assert(!strcmp(p->one->path, p->two->path));
+ return path_to_sha1(p->one->path, sha1);
+}
+
+static struct notes_merge_pair *find_notes_merge_pair_pos(
+ struct notes_merge_pair *list, int len, unsigned char *obj,
+ int insert_new, int *occupied)
+{
+ /*
+ * Both diff_tree_remote() and diff_tree_local() tend to process
+ * merge_pairs in ascending order. Therefore, cache last returned
+ * index, and search sequentially from there until the appropriate
+ * position is found.
+ *
+ * Since inserts only happen from diff_tree_remote() (which mainly
+ * _appends_), we don't care that inserting into the middle of the
+ * list is expensive (using memmove()).
+ */
+ static int last_index;
+ int i = last_index < len ? last_index : len - 1;
+ int prev_cmp = 0, cmp = -1;
+ while (i >= 0 && i < len) {
+ cmp = hashcmp(obj, list[i].obj);
+ if (!cmp) /* obj belongs @ i */
+ break;
+ else if (cmp < 0 && prev_cmp <= 0) /* obj belongs < i */
+ i--;
+ else if (cmp < 0) /* obj belongs between i-1 and i */
+ break;
+ else if (cmp > 0 && prev_cmp >= 0) /* obj belongs > i */
+ i++;
+ else /* if (cmp > 0) */ { /* obj belongs between i and i+1 */
+ i++;
+ break;
+ }
+ prev_cmp = cmp;
+ }
+ if (i < 0)
+ i = 0;
+ /* obj belongs at, or immediately preceding, index i (0 <= i <= len) */
+
+ if (!cmp)
+ *occupied = 1;
+ else {
+ *occupied = 0;
+ if (insert_new && i < len) {
+ memmove(list + i + 1, list + i,
+ (len - i) * sizeof(struct notes_merge_pair));
+ memset(list + i, 0, sizeof(struct notes_merge_pair));
+ }
+ }
+ last_index = i;
+ return list + i;
+}
+
+static unsigned char uninitialized[20] =
+ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff" \
+ "\xff\xff\xff\xff\xff\xff\xff\xff\xff\xff";
+
+static struct notes_merge_pair *diff_tree_remote(struct notes_merge_options *o,
+ const unsigned char *base,
+ const unsigned char *remote,
+ int *num_changes)
+{
+ struct diff_options opt;
+ struct notes_merge_pair *changes;
+ int i, len = 0;
+
+ trace_printf("\tdiff_tree_remote(base = %.7s, remote = %.7s)\n",
+ sha1_to_hex(base), sha1_to_hex(remote));
+
+ diff_setup(&opt);
+ DIFF_OPT_SET(&opt, RECURSIVE);
+ opt.output_format = DIFF_FORMAT_NO_OUTPUT;
+ if (diff_setup_done(&opt) < 0)
+ die("diff_setup_done failed");
+ diff_tree_sha1(base, remote, "", &opt);
+ diffcore_std(&opt);
+
+ changes = xcalloc(diff_queued_diff.nr, sizeof(struct notes_merge_pair));
+
+ for (i = 0; i < diff_queued_diff.nr; i++) {
+ struct diff_filepair *p = diff_queued_diff.queue[i];
+ struct notes_merge_pair *mp;
+ int occupied;
+ unsigned char obj[20];
+
+ if (verify_notes_filepair(p, obj)) {
+ trace_printf("\t\tCannot merge entry '%s' (%c): "
+ "%.7s -> %.7s. Skipping!\n", p->one->path,
+ p->status, sha1_to_hex(p->one->sha1),
+ sha1_to_hex(p->two->sha1));
+ continue;
+ }
+ mp = find_notes_merge_pair_pos(changes, len, obj, 1, &occupied);
+ if (occupied) {
+ /* We've found an addition/deletion pair */
+ assert(!hashcmp(mp->obj, obj));
+ if (is_null_sha1(p->one->sha1)) { /* addition */
+ assert(is_null_sha1(mp->remote));
+ hashcpy(mp->remote, p->two->sha1);
+ } else if (is_null_sha1(p->two->sha1)) { /* deletion */
+ assert(is_null_sha1(mp->base));
+ hashcpy(mp->base, p->one->sha1);
+ } else
+ assert(!"Invalid existing change recorded");
+ } else {
+ hashcpy(mp->obj, obj);
+ hashcpy(mp->base, p->one->sha1);
+ hashcpy(mp->local, uninitialized);
+ hashcpy(mp->remote, p->two->sha1);
+ len++;
+ }
+ trace_printf("\t\tStored remote change for %s: %.7s -> %.7s\n",
+ sha1_to_hex(mp->obj), sha1_to_hex(mp->base),
+ sha1_to_hex(mp->remote));
+ }
+ diff_flush(&opt);
+ diff_tree_release_paths(&opt);
+
+ *num_changes = len;
+ return changes;
+}
+
+static void diff_tree_local(struct notes_merge_options *o,
+ struct notes_merge_pair *changes, int len,
+ const unsigned char *base,
+ const unsigned char *local)
+{
+ struct diff_options opt;
+ int i;
+
+ trace_printf("\tdiff_tree_local(len = %i, base = %.7s, local = %.7s)\n",
+ len, sha1_to_hex(base), sha1_to_hex(local));
+
+ diff_setup(&opt);
+ DIFF_OPT_SET(&opt, RECURSIVE);
+ opt.output_format = DIFF_FORMAT_NO_OUTPUT;
+ if (diff_setup_done(&opt) < 0)
+ die("diff_setup_done failed");
+ diff_tree_sha1(base, local, "", &opt);
+ diffcore_std(&opt);
+
+ for (i = 0; i < diff_queued_diff.nr; i++) {
+ struct diff_filepair *p = diff_queued_diff.queue[i];
+ struct notes_merge_pair *mp;
+ int match;
+ unsigned char obj[20];
+
+ if (verify_notes_filepair(p, obj)) {
+ trace_printf("\t\tCannot merge entry '%s' (%c): "
+ "%.7s -> %.7s. Skipping!\n", p->one->path,
+ p->status, sha1_to_hex(p->one->sha1),
+ sha1_to_hex(p->two->sha1));
+ continue;
+ }
+ mp = find_notes_merge_pair_pos(changes, len, obj, 0, &match);
+ if (!match) {
+ trace_printf("\t\tIgnoring local-only change for %s: "
+ "%.7s -> %.7s\n", sha1_to_hex(obj),
+ sha1_to_hex(p->one->sha1),
+ sha1_to_hex(p->two->sha1));
+ continue;
+ }
+
+ assert(!hashcmp(mp->obj, obj));
+ if (is_null_sha1(p->two->sha1)) { /* deletion */
+ /*
+ * Either this is a true deletion (1), or it is part
+ * of an A/D pair (2), or D/A pair (3):
+ *
+ * (1) mp->local is uninitialized; set it to null_sha1
+ * (2) mp->local is not uninitialized; don't touch it
+ * (3) mp->local is uninitialized; set it to null_sha1
+ * (will be overwritten by following addition)
+ */
+ if (!hashcmp(mp->local, uninitialized))
+ hashclr(mp->local);
+ } else if (is_null_sha1(p->one->sha1)) { /* addition */
+ /*
+ * Either this is a true addition (1), or it is part
+ * of an A/D pair (2), or D/A pair (3):
+ *
+ * (1) mp->local is uninitialized; set to p->two->sha1
+ * (2) mp->local is uninitialized; set to p->two->sha1
+ * (3) mp->local is null_sha1; set to p->two->sha1
+ */
+ assert(is_null_sha1(mp->local) ||
+ !hashcmp(mp->local, uninitialized));
+ hashcpy(mp->local, p->two->sha1);
+ } else { /* modification */
+ /*
+ * This is a true modification. p->one->sha1 shall
+ * match mp->base, and mp->local shall be uninitialized.
+ * Set mp->local to p->two->sha1.
+ */
+ assert(!hashcmp(p->one->sha1, mp->base));
+ assert(!hashcmp(mp->local, uninitialized));
+ hashcpy(mp->local, p->two->sha1);
+ }
+ trace_printf("\t\tStored local change for %s: %.7s -> %.7s\n",
+ sha1_to_hex(mp->obj), sha1_to_hex(mp->base),
+ sha1_to_hex(mp->local));
+ }
+ diff_flush(&opt);
+ diff_tree_release_paths(&opt);
+}
+
+static int merge_changes(struct notes_merge_options *o,
+ struct notes_merge_pair *changes, int *num_changes,
+ struct notes_tree *t)
+{
+ int i, conflicts = 0;
+
+ trace_printf("\tmerge_changes(num_changes = %i)\n", *num_changes);
+ for (i = 0; i < *num_changes; i++) {
+ struct notes_merge_pair *p = changes + i;
+ trace_printf("\t\t%.7s: %.7s -> %.7s/%.7s\n",
+ sha1_to_hex(p->obj), sha1_to_hex(p->base),
+ sha1_to_hex(p->local), sha1_to_hex(p->remote));
+
+ if (!hashcmp(p->base, p->remote)) {
+ /* no remote change; nothing to do */
+ trace_printf("\t\t\tskipping (no remote change)\n");
+ } else if (!hashcmp(p->local, p->remote)) {
+ /* same change in local and remote; nothing to do */
+ trace_printf("\t\t\tskipping (local == remote)\n");
+ } else if (!hashcmp(p->local, uninitialized) ||
+ !hashcmp(p->local, p->base)) {
+ /* no local change; adopt remote change */
+ trace_printf("\t\t\tno local change, adopted remote\n");
+ if (add_note(t, p->obj, p->remote,
+ combine_notes_overwrite))
+ die("BUG: combine_notes_overwrite failed");
+ } else {
+ /* need file-level merge between local and remote */
+ trace_printf("\t\t\tneed content-level merge\n");
+ conflicts += 1; /* TODO */
+ }
+ }
+
+ return conflicts;
+}
+
+static int merge_from_diffs(struct notes_merge_options *o,
+ const unsigned char *base,
+ const unsigned char *local,
+ const unsigned char *remote, struct notes_tree *t)
+{
+ struct notes_merge_pair *changes;
+ int num_changes, conflicts;
+
+ trace_printf("\tmerge_from_diffs(base = %.7s, local = %.7s, "
+ "remote = %.7s)\n", sha1_to_hex(base), sha1_to_hex(local),
+ sha1_to_hex(remote));
+
+ changes = diff_tree_remote(o, base, remote, &num_changes);
+ diff_tree_local(o, changes, num_changes, base, local);
+
+ conflicts = merge_changes(o, changes, &num_changes, t);
+ free(changes);
+
+ OUTPUT(o, 4, "Merge result: %i unmerged notes and a %s notes tree",
+ conflicts, t->dirty ? "dirty" : "clean");
+
+ return conflicts ? -1 : 1;
+}
+
void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
const char *msg, unsigned char *result_sha1)
{
@@ -45,15 +350,17 @@ void create_notes_commit(struct notes_tree *t, struct commit_list *parents,
}
int notes_merge(struct notes_merge_options *o,
+ struct notes_tree *local_tree,
unsigned char *result_sha1)
{
unsigned char local_sha1[20], remote_sha1[20];
struct commit *local, *remote;
struct commit_list *bases = NULL;
- const unsigned char *base_sha1;
+ const unsigned char *base_sha1, *base_tree_sha1;
int result = 0;
assert(o->local_ref && o->remote_ref);
+ assert(!strcmp(o->local_ref, local_tree->ref));
hashclr(result_sha1);
trace_printf("notes_merge(o->local_ref = %s, o->remote_ref = %s)\n",
@@ -107,14 +414,17 @@ int notes_merge(struct notes_merge_options *o,
bases = get_merge_bases(local, remote, 1);
if (!bases) {
base_sha1 = null_sha1;
+ base_tree_sha1 = (unsigned char *)EMPTY_TREE_SHA1_BIN;
OUTPUT(o, 4, "No merge base found; doing history-less merge");
} else if (!bases->next) {
base_sha1 = bases->item->object.sha1;
+ base_tree_sha1 = bases->item->tree->object.sha1;
OUTPUT(o, 4, "One merge base found (%.7s)",
sha1_to_hex(base_sha1));
} else {
/* TODO: How to handle multiple merge-bases? */
base_sha1 = bases->item->object.sha1;
+ base_tree_sha1 = bases->item->tree->object.sha1;
OUTPUT(o, 3, "Multiple merge bases found. Using the first "
"(%.7s)", sha1_to_hex(base_sha1));
}
@@ -136,8 +446,17 @@ int notes_merge(struct notes_merge_options *o,
goto found_result;
}
- /* TODO: */
- result = error("notes_merge() cannot yet handle real merges.");
+ result = merge_from_diffs(o, base_tree_sha1, local->tree->object.sha1,
+ remote->tree->object.sha1, local_tree);
+
+ if (result > 0) { /* successful non-trivial merge */
+ /* Commit result */
+ struct commit_list *parents = NULL;
+ commit_list_insert(remote, &parents); /* LIFO order */
+ commit_list_insert(local, &parents);
+ create_notes_commit(local_tree, parents, o->commit_msg,
+ result_sha1);
+ }
found_result:
free_commit_list(bases);