1 files changed, 181 insertions, 204 deletions

diff --git a/diffcore-rename.c b/diffcore-rename.c
index f40ab78bd..34e83dac8 100644
--- a/diffcore-rename.c
+++ b/diffcore-rename.c
@@ -6,29 +6,92 @@
 #include "diffcore.h"
 #include "delta.h"
 
-struct diff_rename_pool {
-	struct diff_filespec **s;
-	int nr, alloc;
-};
+/* Table of rename/copy destinations */
+
+static struct diff_rename_dst {
+	struct diff_filespec *two;
+	struct diff_filepair *pair;
+} *rename_dst;
+static int rename_dst_nr, rename_dst_alloc;
 
-static void diff_rename_pool_clear(struct diff_rename_pool *pool)
+static struct diff_rename_dst *locate_rename_dst(struct diff_filespec *two,
+						 int insert_ok)
 {
-	pool->s = NULL; pool->nr = pool->alloc = 0;
+	int first, last;
+
+	first = 0;
+	last = rename_dst_nr;
+	while (last > first) {
+		int next = (last + first) >> 1;
+		struct diff_rename_dst *dst = &(rename_dst[next]);
+		int cmp = strcmp(two->path, dst->two->path);
+		if (!cmp)
+			return dst;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+	/* not found */
+	if (!insert_ok)
+		return NULL;
+	/* insert to make it at "first" */
+	if (rename_dst_alloc <= rename_dst_nr) {
+		rename_dst_alloc = alloc_nr(rename_dst_alloc);
+		rename_dst = xrealloc(rename_dst,
+				      rename_dst_alloc * sizeof(*rename_dst));
+	}
+	rename_dst_nr++;
+	if (first < rename_dst_nr)
+		memmove(rename_dst + first + 1, rename_dst + first,
+			(rename_dst_nr - first - 1) * sizeof(*rename_dst));
+	rename_dst[first].two = two;
+	rename_dst[first].pair = NULL;
+	return &(rename_dst[first]);
 }
 
-static void diff_rename_pool_add(struct diff_rename_pool *pool,
-				 struct diff_filespec *s)
-{
-	if (S_ISDIR(s->mode))
-		return;  /* no trees, please */
+static struct diff_rename_src {
+	struct diff_filespec *one;
+	unsigned src_used : 1;
+} *rename_src;
+static int rename_src_nr, rename_src_alloc;
 
-	if (pool->alloc <= pool->nr) {
-		pool->alloc = alloc_nr(pool->alloc);
-		pool->s = xrealloc(pool->s,
-				   sizeof(*(pool->s)) * pool->alloc);
+static struct diff_rename_src *locate_rename_src(struct diff_filespec *one,
+						 int insert_ok)
+{
+	int first, last;
+
+	first = 0;
+	last = rename_src_nr;
+	while (last > first) {
+		int next = (last + first) >> 1;
+		struct diff_rename_src *src = &(rename_src[next]);
+		int cmp = strcmp(one->path, src->one->path);
+		if (!cmp)
+			return src;
+		if (cmp < 0) {
+			last = next;
+			continue;
+		}
+		first = next+1;
+	}
+	/* not found */
+	if (!insert_ok)
+		return NULL;
+	/* insert to make it at "first" */
+	if (rename_src_alloc <= rename_src_nr) {
+		rename_src_alloc = alloc_nr(rename_src_alloc);
+		rename_src = xrealloc(rename_src,
+				      rename_src_alloc * sizeof(*rename_src));
 	}
-	pool->s[pool->nr] = s;
-	pool->nr++;
+	rename_src_nr++;
+	if (first < rename_src_nr)
+		memmove(rename_src + first + 1, rename_src + first,
+			(rename_src_nr - first - 1) * sizeof(*rename_src));
+	rename_src[first].one = one;
+	rename_src[first].src_used = 0;
+	return &(rename_src[first]);
 }
 
 static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst)
@@ -46,8 +109,8 @@ static int is_exact_match(struct diff_filespec *src, struct diff_filespec *dst)
 }
 
 struct diff_score {
-	struct diff_filespec *src;
-	struct diff_filespec *dst;
+	int src; /* index in rename_src */
+	int dst; /* index in rename_dst */
 	int score;
 	int rank;
 };
@@ -113,92 +176,28 @@ static int estimate_similarity(struct diff_filespec *src,
 	return score;
 }
 
-static void record_rename_pair(struct diff_queue_struct *outq,
-			       struct diff_filespec *src,
-			       struct diff_filespec *dst,
-			       int rank,
-			       int score)
+static void record_rename_pair(struct diff_queue_struct *renq,
+			       int dst_index, int src_index, int score)
 {
-	/*
-	 * These ranks are used to sort the final output, because there
-	 * are certain dependencies:
-	 *
-	 *  1. rename/copy that depends on deleted ones.
-	 *  2. deletions in the original.
-	 *  3. rename/copy that depends on the pre-edit image of kept files.
-	 *  4. additions, modifications and no-modifications in the original.
-	 *  5. rename/copy that depends on the post-edit image of kept files
-	 *     (note that we currently do not detect such rename/copy).
-	 *
-	 * The downstream diffcore transformers are free to reorder
-	 * the entries as long as they keep file pairs that has the
-	 * same p->one->path in earlier rename_rank to appear before
-	 * later ones.
-	 *
-	 * To the final output routine, and in the diff-raw format
-	 * output, a rename/copy that is based on a path that has a
-	 * later entry that shares the same p->one->path and is not a
-	 * deletion is a copy.  Otherwise it is a rename.
-	 */
+	struct diff_filespec *one, *two, *src, *dst;
+	struct diff_filepair *dp;
 
-	struct diff_filepair *dp = diff_queue(outq, src, dst);
-	dp->rename_rank = rank * 2 + 1;
-	dp->score = score;
-	dst->xfrm_flags |= RENAME_DST_MATCHED;
-}
+	if (rename_dst[dst_index].pair)
+		die("internal error: dst already matched.");
 
-#if 0
-static void debug_filespec(struct diff_filespec *s, int x, const char *one)
-{
-	fprintf(stderr, "queue[%d] %s (%s) %s %06o %s\n",
-		x, one,
-		s->path,
-		DIFF_FILE_VALID(s) ? "valid" : "invalid",
-		s->mode,
-		s->sha1_valid ? sha1_to_hex(s->sha1) : "");
-	fprintf(stderr, "queue[%d] %s size %lu flags %d\n",
-		x, one,
-		s->size, s->xfrm_flags);
-}
+	src = rename_src[src_index].one;
+	one = alloc_filespec(src->path);
+	fill_filespec(one, src->sha1, src->mode);
 
-static void debug_filepair(const struct diff_filepair *p, int i)
-{
-	debug_filespec(p->one, i, "one");
-	debug_filespec(p->two, i, "two");
-	fprintf(stderr, "pair rank %d, orig order %d, score %d\n",
-		p->rename_rank, p->orig_order, p->score);
-}
+	dst = rename_dst[dst_index].two;
+	two = alloc_filespec(dst->path);
+	fill_filespec(two, dst->sha1, dst->mode);
 
-static void debug_queue(const char *msg, struct diff_queue_struct *q)
-{
-	int i;
-	if (msg)
-		fprintf(stderr, "%s\n", msg);
-	fprintf(stderr, "q->nr = %d\n", q->nr);
-	for (i = 0; i < q->nr; i++) {
-		struct diff_filepair *p = q->queue[i];
-		debug_filepair(p, i);
-	}
-}
-#else
-#define debug_queue(a,b) do { ; /*nothing*/ } while(0)
-#endif
+	dp = diff_queue(renq, one, two);
+	dp->score = score;
 
-/*
- * We sort the outstanding diff entries according to the rank (see
- * comment at the beginning of record_rename_pair) and tiebreak with
- * the order in the original input.
- */
-static int rank_compare(const void *a_, const void *b_)
-{
-	const struct diff_filepair *a = *(const struct diff_filepair **)a_;
-	const struct diff_filepair *b = *(const struct diff_filepair **)b_;
-	int a_rank = a->rename_rank;
-	int b_rank = b->rename_rank;
-
-	if (a_rank != b_rank)
-		return a_rank - b_rank;
-	return a->orig_order - b->orig_order;
+	rename_src[src_index].src_used = 1;
+	rename_dst[dst_index].pair = dp;
 }
 
 /*
@@ -232,24 +231,15 @@ int diff_scoreopt_parse(const char *opt)
 void diffcore_rename(int detect_rename, int minimum_score)
 {
 	struct diff_queue_struct *q = &diff_queued_diff;
-	struct diff_queue_struct outq;
-	struct diff_rename_pool created, deleted, stay;
-	struct diff_rename_pool *(srcs[2]);
+	struct diff_queue_struct renq, outq;
 	struct diff_score *mx;
-	int h, i, j;
-	int num_create, num_src, dst_cnt, src_cnt;
+	int i, j;
+	int num_create, num_src, dst_cnt;
 
 	if (!minimum_score)
 		minimum_score = DEFAULT_MINIMUM_SCORE;
-	outq.queue = NULL;
-	outq.nr = outq.alloc = 0;
-
-	diff_rename_pool_clear(&created);
-	diff_rename_pool_clear(&deleted);
-	diff_rename_pool_clear(&stay);
-
-	srcs[0] = &deleted;
-	srcs[1] = &stay;
+	renq.queue = NULL;
+	renq.nr = renq.alloc = 0;
 
 	for (i = 0; i < q->nr; i++) {
 		struct diff_filepair *p = q->queue[i];
@@ -257,76 +247,70 @@ void diffcore_rename(int detect_rename, int minimum_score)
 			if (!DIFF_FILE_VALID(p->two))
 				continue; /* unmerged */
 			else
-				diff_rename_pool_add(&created, p->two);
+				locate_rename_dst(p->two, 1);
 		else if (!DIFF_FILE_VALID(p->two))
-			diff_rename_pool_add(&deleted, p->one);
+			locate_rename_src(p->one, 1);
 		else if (1 < detect_rename) /* find copy, too */
-			diff_rename_pool_add(&stay, p->one);
+			locate_rename_src(p->one, 1);
 	}
-	if (created.nr == 0)
+	if (rename_dst_nr == 0)
 		goto cleanup; /* nothing to do */
 
 	/* We really want to cull the candidates list early
 	 * with cheap tests in order to avoid doing deltas.
 	 */
-	for (i = 0; i < created.nr; i++) {
-		for (h = 0; h < sizeof(srcs)/sizeof(srcs[0]); h++) {
-			struct diff_rename_pool *p = srcs[h];
-			for (j = 0; j < p->nr; j++) {
-				if (!is_exact_match(p->s[j], created.s[i]))
-					continue;
-				record_rename_pair(&outq,
-						   p->s[j], created.s[i], h,
-						   MAX_SCORE);
-				break; /* we are done with this entry */
-			}
+	for (i = 0; i < rename_dst_nr; i++) {
+		struct diff_filespec *two = rename_dst[i].two;
+		for (j = 0; j < rename_src_nr; j++) {
+			struct diff_filespec *one = rename_src[j].one;
+			if (!is_exact_match(one, two))
+				continue;
+			record_rename_pair(&renq, i, j, MAX_SCORE);
+			break; /* we are done with this entry */
 		}
 	}
-	debug_queue("done detecting exact", &outq);
+	diff_debug_queue("done detecting exact", &renq);
 
 	/* Have we run out the created file pool?  If so we can avoid
 	 * doing the delta matrix altogether.
 	 */
-	if (outq.nr == created.nr)
+	if (renq.nr == rename_dst_nr)
 		goto flush_rest;
 
-	num_create = (created.nr - outq.nr);
-	num_src = deleted.nr + stay.nr;
+	num_create = (rename_dst_nr - renq.nr);
+	num_src = rename_src_nr;
 	mx = xmalloc(sizeof(*mx) * num_create * num_src);
-	for (dst_cnt = i = 0; i < created.nr; i++) {
+	for (dst_cnt = i = 0; i < rename_dst_nr; i++) {
 		int base = dst_cnt * num_src;
-		if (created.s[i]->xfrm_flags & RENAME_DST_MATCHED)
+		struct diff_filespec *two = rename_dst[i].two;
+		if (rename_dst[i].pair)
 			continue; /* dealt with exact match already. */
-		for (src_cnt = h = 0; h < sizeof(srcs)/sizeof(srcs[0]); h++) {
-			struct diff_rename_pool *p = srcs[h];
-			for (j = 0; j < p->nr; j++, src_cnt++) {
-				struct diff_score *m = &mx[base + src_cnt];
-				m->src = p->s[j];
-				m->dst = created.s[i];
-				m->score = estimate_similarity(m->src, m->dst,
-							       minimum_score);
-				m->rank = h;
-			}
+		for (j = 0; j < rename_src_nr; j++) {
+			struct diff_filespec *one = rename_src[j].one;
+			struct diff_score *m = &mx[base+j];
+			m->src = j;
+			m->dst = i;
+			m->score = estimate_similarity(one, two,
+						       minimum_score);
 		}
 		dst_cnt++;
 	}
 	/* cost matrix sorted by most to least similar pair */
 	qsort(mx, num_create * num_src, sizeof(*mx), score_compare);
 	for (i = 0; i < num_create * num_src; i++) {
-		if (mx[i].dst->xfrm_flags & RENAME_DST_MATCHED)
-			continue; /* alreayd done, either exact or fuzzy. */
+		struct diff_rename_dst *dst = &rename_dst[mx[i].dst];
+		if (dst->pair)
+			continue; /* already done, either exact or fuzzy. */
 		if (mx[i].score < minimum_score)
 			break; /* there is not any more diffs applicable. */
-		record_rename_pair(&outq,
-				  mx[i].src, mx[i].dst, mx[i].rank,
-				  mx[i].score);
+		record_rename_pair(&renq, mx[i].dst, mx[i].src, mx[i].score);
 	}
 	free(mx);
-	debug_queue("done detecting fuzzy", &outq);
+	diff_debug_queue("done detecting fuzzy", &renq);
 
  flush_rest:
 	/* At this point, we have found some renames and copies and they
-	 * are kept in outq.  The original list is still in *q.
+	 * are kept in renq.  The original list is still in *q.
 	 *
 	 * Scan the original list and move them into the outq; we will sort
 	 * outq and swap it into the queue supplied to pass that to
@@ -335,68 +319,61 @@ void diffcore_rename(int detect_rename, int minimum_score)
 	 * See comments at the top of record_rename_pair for numbers used
 	 * to assign rename_rank.
 	 */
+	outq.queue = NULL;
+	outq.nr = outq.alloc = 0;
 	for (i = 0; i < q->nr; i++) {
-		struct diff_filepair *dp, *p = q->queue[i];
-		if (!DIFF_FILE_VALID(p->one)) {
-			/* creation or unmerged entries */
-			dp = diff_queue(&outq, p->one, p->two);
-			dp->rename_rank = 4;
-		}
-		else if (!DIFF_FILE_VALID(p->two)) {
-			/* deletion */
-			dp = diff_queue(&outq, p->one, p->two);
-			dp->rename_rank = 2;
+		struct diff_filepair *p = q->queue[i];
+		struct diff_rename_src *src = locate_rename_src(p->one, 0);
+		struct diff_rename_dst *dst = locate_rename_dst(p->two, 0);
+		struct diff_filepair *pair_to_free = NULL;
+
+		if (dst) {
+			/* creation */
+			if (dst->pair) {
+				/* renq has rename/copy already to produce
+				 * this file, so we do not emit the creation
+				 * record in the output.
+				 */
+				diff_q(&outq, dst->pair);
+				pair_to_free = p;
+			}
+			else
+				/* no matching rename/copy source, so record
+				 * this as a creation.
+				 */
+				diff_q(&outq, p);
 		}
+		else if (!diff_unmodified_pair(p))
+			/* all the other cases need to be recorded as is */
+			diff_q(&outq, p);
 		else {
-			/* modification, or stay as is */
-			dp = diff_queue(&outq, p->one, p->two);
-			dp->rename_rank = 4;
-		}
-		free(p);
-	}
-	debug_queue("done copying original", &outq);
-
-	/* Sort outq */
-	qsort(outq.queue, outq.nr, sizeof(outq.queue[0]), rank_compare);
-
-	debug_queue("done sorting", &outq);
-
-	free(q->queue);
-	q->nr = q->alloc = 0;
-	q->queue = NULL;
-
-	/* Copy it out to q, removing duplicates. */
-	for (i = 0; i < outq.nr; i++) {
-		struct diff_filepair *p = outq.queue[i];
-		if (!DIFF_FILE_VALID(p->one)) {
-			/* created or unmerged */
-			if (p->two->xfrm_flags & RENAME_DST_MATCHED)
-				; /* rename/copy created it already */
+			/* unmodified pair needs to be recorded only if
+			 * it is used as the source of rename/copy
+			 */
+			if (src && src->src_used)
+				diff_q(&outq, p);
 			else
-				diff_queue(q, p->one, p->two);
-		}
-		else if (!DIFF_FILE_VALID(p->two)) {
-			/* deleted */
-			diff_queue(q, p->one, p->two);
+				pair_to_free = p;
 		}
-		else if (strcmp(p->one->path, p->two->path)) {
-			/* rename or copy */
-			struct diff_filepair *dp =
-				diff_queue(q, p->one, p->two);
-			dp->score = p->score;
+		if (pair_to_free) {
+			diff_free_filespec_data(pair_to_free->one);
+			diff_free_filespec_data(pair_to_free->two);
+			free(pair_to_free);
 		}
-		else
-			/* otherwise it is a modified (or "stay") entry */
-			diff_queue(q, p->one, p->two);
-		free(p);
 	}
+	diff_debug_queue("done copying original", &outq);
 
-	free(outq.queue);
-	debug_queue("done collapsing", q);
+	free(renq.queue);
+	free(q->queue);
+	*q = outq;
+	diff_debug_queue("done collapsing", q);
 
  cleanup:
-	free(created.s);
-	free(deleted.s);
-	free(stay.s);
+	free(rename_dst);
+	rename_dst = NULL;
+	rename_dst_nr = rename_dst_alloc = 0;
+	free(rename_src);
+	rename_src = NULL;
+	rename_src_nr = rename_src_alloc = 0;
 	return;
 }