git-pickaxe: WIP to refcount origin structure.

The origin structure is allocated for each commit and path while
the code traverse down it is copied into different blame entries.
To avoid leaks, try refcounting them.

This still seems to leak, which I haven't tracked down fully yet.

Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 121 insertions, 21 deletions

diff --git a/builtin-pickaxe.c b/builtin-pickaxe.c
index 663b96dac5..b53c7b0617 100644
--- a/builtin-pickaxe.c
+++ b/builtin-pickaxe.c
@@ -36,6 +36,10 @@ static int max_orig_digits;
 static int max_digits;
 static int max_score_digits;
 
+#ifndef DEBUG
+#define DEBUG 0
+#endif
+
 #define PICKAXE_BLAME_MOVE		01
 #define PICKAXE_BLAME_COPY		02
 #define PICKAXE_BLAME_COPY_HARDER	04
@@ -54,14 +58,30 @@ static unsigned blame_copy_score;
 #define MORE_THAN_ONE_PATH	(1u<<13)
 
 /*
- * One blob in a commit
+ * One blob in a commit that is being suspected
  */
 struct origin {
+	int refcnt;
 	struct commit *commit;
 	unsigned char blob_sha1[20];
 	char path[FLEX_ARRAY];
 };
 
+static inline struct origin *origin_incref(struct origin *o)
+{
+	if (o)
+		o->refcnt++;
+	return o;
+}
+
+static void origin_decref(struct origin *o)
+{
+	if (o && --o->refcnt <= 0) {
+		memset(o, 0, sizeof(*o));
+		free(o);
+	}
+}
+
 struct blame_entry {
 	struct blame_entry *prev;
 	struct blame_entry *next;
@@ -121,6 +141,8 @@ static int cmp_suspect(struct origin *a, struct origin *b)
 	return strcmp(a->path, b->path);
 }
 
+static void sanity_check_refcnt(struct scoreboard *);
+
 static void coalesce(struct scoreboard *sb)
 {
 	struct blame_entry *ent, *next;
@@ -133,11 +155,15 @@ static void coalesce(struct scoreboard *sb)
 			ent->next = next->next;
 			if (ent->next)
 				ent->next->prev = ent;
+			origin_decref(next->suspect);
 			free(next);
 			ent->score = 0;
 			next = ent; /* again */
 		}
 	}
+
+	if (DEBUG) /* sanity */
+		sanity_check_refcnt(sb);
 }
 
 static struct origin *get_origin(struct scoreboard *sb,
@@ -150,10 +176,11 @@ static struct origin *get_origin(struct scoreboard *sb,
 	for (e = sb->ent; e; e = e->next) {
 		if (e->suspect->commit == commit &&
 		    !strcmp(e->suspect->path, path))
-			return e->suspect;
+			return origin_incref(e->suspect);
 	}
 	o = xcalloc(1, sizeof(*o) + strlen(path) + 1);
 	o->commit = commit;
+	o->refcnt = 1;
 	strcpy(o->path, path);
 	return o;
 }
@@ -400,6 +427,8 @@ static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 {
 	struct blame_entry *ent, *prev = NULL;
 
+	origin_incref(e->suspect);
+
 	for (ent = sb->ent; ent && ent->lno < e->lno; ent = ent->next)
 		prev = ent;
 
@@ -420,8 +449,11 @@ static void add_blame_entry(struct scoreboard *sb, struct blame_entry *e)
 static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 {
 	struct blame_entry *p, *n;
+
 	p = dst->prev;
 	n = dst->next;
+	origin_incref(src->suspect);
+	origin_decref(dst->suspect);
 	memcpy(dst, src, sizeof(*src));
 	dst->prev = p;
 	dst->next = n;
@@ -433,7 +465,7 @@ static const char *nth_line(struct scoreboard *sb, int lno)
 	return sb->final_buf + sb->lineno[lno];
 }
 
-static void split_overlap(struct blame_entry split[3],
+static void split_overlap(struct blame_entry *split,
 			  struct blame_entry *e,
 			  int tlno, int plno, int same,
 			  struct origin *parent)
@@ -457,7 +489,7 @@ static void split_overlap(struct blame_entry split[3],
 
 	if (e->s_lno < tlno) {
 		/* there is a pre-chunk part not blamed on parent */
-		split[0].suspect = e->suspect;
+		split[0].suspect = origin_incref(e->suspect);
 		split[0].lno = e->lno;
 		split[0].s_lno = e->s_lno;
 		split[0].num_lines = tlno - e->s_lno;
@@ -471,7 +503,7 @@ static void split_overlap(struct blame_entry split[3],
 
 	if (same < e->s_lno + e->num_lines) {
 		/* there is a post-chunk part not blamed on parent */
-		split[2].suspect = e->suspect;
+		split[2].suspect = origin_incref(e->suspect);
 		split[2].lno = e->lno + (same - e->s_lno);
 		split[2].s_lno = e->s_lno + (same - e->s_lno);
 		split[2].num_lines = e->s_lno + e->num_lines - same;
@@ -483,11 +515,11 @@ static void split_overlap(struct blame_entry split[3],
 
 	if (split[1].num_lines < 1)
 		return;
-	split[1].suspect = parent;
+	split[1].suspect = origin_incref(parent);
 }
 
 static void split_blame(struct scoreboard *sb,
-			struct blame_entry split[3],
+			struct blame_entry *split,
 			struct blame_entry *e)
 {
 	struct blame_entry *new_entry;
@@ -522,7 +554,7 @@ static void split_blame(struct scoreboard *sb,
 		add_blame_entry(sb, new_entry);
 	}
 
-	if (1) { /* sanity */
+	if (DEBUG) { /* sanity */
 		struct blame_entry *ent;
 		int lno = sb->ent->lno, corrupt = 0;
 
@@ -545,6 +577,14 @@ static void split_blame(struct scoreboard *sb,
 	}
 }
 
+static void decref_split(struct blame_entry *split)
+{
+	int i;
+
+	for (i = 0; i < 3; i++)
+		origin_decref(split[i].suspect);
+}
+
 static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 			  int tlno, int plno, int same,
 			  struct origin *parent)
@@ -552,9 +592,9 @@ static void blame_overlap(struct scoreboard *sb, struct blame_entry *e,
 	struct blame_entry split[3];
 
 	split_overlap(split, e, tlno, plno, same, parent);
-	if (!split[1].suspect)
-		return;
-	split_blame(sb, split, e);
+	if (split[1].suspect)
+		split_blame(sb, split, e);
+	decref_split(split);
 }
 
 static int find_last_in_target(struct scoreboard *sb, struct origin *target)
@@ -636,22 +676,28 @@ static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
 }
 
 static void copy_split_if_better(struct scoreboard *sb,
-				 struct blame_entry best_so_far[3],
-				 struct blame_entry this[3])
+				 struct blame_entry *best_so_far,
+				 struct blame_entry *this)
 {
+	int i;
+
 	if (!this[1].suspect)
 		return;
 	if (best_so_far[1].suspect) {
 		if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
 			return;
 	}
+
+	for (i = 0; i < 3; i++)
+		origin_incref(this[i].suspect);
+	decref_split(best_so_far);
 	memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 }
 
 static void find_copy_in_blob(struct scoreboard *sb,
 			      struct blame_entry *ent,
 			      struct origin *parent,
-			      struct blame_entry split[3],
+			      struct blame_entry *split,
 			      mmfile_t *file_p)
 {
 	const char *cp;
@@ -687,6 +733,7 @@ static void find_copy_in_blob(struct scoreboard *sb,
 				      chunk->same + ent->s_lno,
 				      parent);
 			copy_split_if_better(sb, split, this);
+			decref_split(this);
 		}
 		plno = chunk->p_next;
 		tlno = chunk->t_next;
@@ -723,6 +770,7 @@ static int find_move_in_parent(struct scoreboard *sb,
 		if (split[1].suspect &&
 		    blame_move_score < ent_score(sb, &split[1]))
 			split_blame(sb, split, e);
+		decref_split(split);
 	}
 	free(blob_p);
 	return 0;
@@ -806,6 +854,7 @@ static int find_copy_in_parent(struct scoreboard *sb,
 					     this);
 		}
 		free(blob);
+		origin_decref(norigin);
 	}
 	diff_flush(&diff_opts);
 
@@ -814,6 +863,7 @@ static int find_copy_in_parent(struct scoreboard *sb,
 		if (split[1].suspect &&
 		    blame_copy_score < ent_score(sb, &split[1]))
 			split_blame(sb, split, blame_list[j].ent);
+		decref_split(split);
 	}
 	free(blame_list);
 
@@ -843,9 +893,13 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 		if (!hashcmp(porigin->blob_sha1, origin->blob_sha1)) {
 			struct blame_entry *e;
 			for (e = sb->ent; e; e = e->next)
-				if (e->suspect == origin)
+				if (e->suspect == origin) {
+					origin_incref(porigin);
+					origin_decref(e->suspect);
 					e->suspect = porigin;
-			return;
+				}
+			origin_decref(porigin);
+			goto finish;
 		}
 		parent_origin[i] = porigin;
 	}
@@ -857,7 +911,7 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 		if (!porigin)
 			continue;
 		if (pass_blame_to_parent(sb, origin, porigin))
-			return;
+			goto finish;
 	}
 
 	/*
@@ -871,7 +925,7 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 			if (!porigin)
 				continue;
 			if (find_move_in_parent(sb, origin, porigin))
-				return;
+				goto finish;
 		}
 
 	/*
@@ -884,8 +938,12 @@ static void pass_blame(struct scoreboard *sb, struct origin *origin, int opt)
 			struct origin *porigin = parent_origin[i];
 			if (find_copy_in_parent(sb, origin, parent->item,
 						porigin, opt))
-				return;
+				goto finish;
 		}
+
+ finish:
+	for (i = 0; i < MAXPARENT; i++)
+		origin_decref(parent_origin[i]);
 }
 
 static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
@@ -902,6 +960,7 @@ static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
 		if (!suspect)
 			return; /* all done */
 
+		origin_incref(suspect);
 		commit = suspect->commit;
 		parse_commit(commit);
 		if (!(commit->object.flags & UNINTERESTING) &&
@@ -912,7 +971,7 @@ static void assign_blame(struct scoreboard *sb, struct rev_info *revs, int opt)
 		for (ent = sb->ent; ent; ent = ent->next)
 			if (!cmp_suspect(ent->suspect, suspect))
 				ent->guilty = 1;
-
+		origin_decref(suspect);
 		coalesce(sb);
 	}
 }
@@ -1132,7 +1191,9 @@ static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
 			       ent->lno + 1 + cnt);
 		else {
 			if (opt & OUTPUT_SHOW_SCORE)
-				printf(" %*d", max_score_digits, ent->score);
+				printf(" %*d %02d",
+				       max_score_digits, ent->score,
+				       ent->suspect->refcnt);
 			if (opt & OUTPUT_SHOW_NAME)
 				printf(" %-*.*s", longest_file, longest_file,
 				       suspect->path);
@@ -1273,6 +1334,45 @@ static void find_alignment(struct scoreboard *sb, int *option)
 	max_score_digits = lineno_width(largest_score);
 }
 
+static void sanity_check_refcnt(struct scoreboard *sb)
+{
+	int baa = 0;
+	struct blame_entry *ent;
+
+	for (ent = sb->ent; ent; ent = ent->next) {
+		/* first mark the ones that haven't been checked */
+		if (0 < ent->suspect->refcnt)
+			ent->suspect->refcnt = -ent->suspect->refcnt;
+		else if (!ent->suspect->refcnt)
+			baa = 1;
+	}
+	for (ent = sb->ent; ent; ent = ent->next) {
+		/* then pick each and see if they have the the
+		 * correct refcnt
+		 */
+		int found;
+		struct blame_entry *e;
+		struct origin *suspect = ent->suspect;
+
+		if (0 < suspect->refcnt)
+			continue;
+		suspect->refcnt = -suspect->refcnt;
+		for (found = 0, e = sb->ent; e; e = e->next) {
+			if (e->suspect != suspect)
+				continue;
+			found++;
+		}
+		if (suspect->refcnt != found)
+			baa = 1;
+	}
+	if (baa) {
+		int opt = 0160;
+		find_alignment(sb, &opt);
+		output(sb, opt);
+		die("Baa!");
+	}
+}
+
 static int has_path_in_work_tree(const char *path)
 {
 	struct stat st;