git/notes-merge.c

#include "cache.h"
#include "commit.h"
#include "refs.h"
#include "diff.h"
#include "diffcore.h"
#include "xdiff-interface.h"
#include "ll-merge.h"
#include "dir.h"
#include "notes.h"
#include "notes-merge.h"
#include "strbuf.h"
#include "notes-utils.h"

struct notes_merge_pair {
	struct object_id obj, base, local, remote;
};

void init_notes_merge_options(struct notes_merge_options *o)
{
	memset(o, 0, sizeof(struct notes_merge_options));
	strbuf_init(&(o->commit_msg), 0);
	o->verbosity = NOTES_MERGE_VERBOSITY_DEFAULT;
}

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_oid(&p->one->oid));
		assert(!is_null_oid(&p->two->oid));
		break;
	case DIFF_STATUS_ADDED:
		assert(is_null_oid(&p->one->oid));
		break;
	case DIFF_STATUS_DELETED:
		assert(is_null_oid(&p->two->oid));
		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.hash);
		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 struct object_id uninitialized = {
	"\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;
	diff_setup_done(&opt);
	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, oid_to_hex(&p->one->oid),
			       oid_to_hex(&p->two->oid));
			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.hash, obj));
			if (is_null_oid(&p->one->oid)) { /* addition */