Merge branch 'jc/pickaxe' into next

* jc/pickaxe:
  git-pickaxe: introduce heuristics to avoid "trivial" chunks
  git-pickaxe: improve "best match" heuristics
  git-pickaxe: fix nth_line()
  git-pickaxe: pagenate output by default.

builtin-pickaxe.c

@@ -34,13 +34,21 @@ static int longest_file;
 static int longest_author;
 static int max_orig_digits;
 static int max_digits;
-
-#define DEBUG 0
+static int max_score_digits;
 
 #define PICKAXE_BLAME_MOVE		01
 #define PICKAXE_BLAME_COPY		02
 #define PICKAXE_BLAME_COPY_HARDER	04
 
+/*
+ * blame for a blame_entry with score lower than these thresholds
+ * is not passed to the parent using move/copy logic.
+ */
+static unsigned blame_move_score;
+static unsigned blame_copy_score;
+#define BLAME_DEFAULT_MOVE_SCORE	20
+#define BLAME_DEFAULT_COPY_SCORE	40
+
 /* bits #0..7 in revision.h, #8..11 used for merge_bases() in commit.c */
 #define METAINFO_SHOWN		(1u<<12)
 #define MORE_THAN_ONE_PATH	(1u<<13)
@@ -78,6 +86,11 @@ struct blame_entry {
 	 * suspect's file; internally all line numbers are 0 based.
 	 */
 	int s_lno;
+
+	/* how significant this entry is -- cached to avoid
+	 * scanning the lines over and over
+	 */
+	unsigned score;
 };
 
 struct scoreboard {
@@ -215,9 +228,6 @@ static void process_u_diff(void *state_, char *line, unsigned long len)
 	struct chunk *chunk;
 	int off1, off2, len1, len2, num;
 
-	if (DEBUG)
-		fprintf(stderr, "%.*s", (int) len, line);
-
 	num = state->ret->num;
 	if (len < 4 || line[0] != '@' || line[1] != '@') {
 		if (state->hunk_in_pre_context && line[0] == ' ')
@@ -295,10 +305,6 @@ static struct patch *get_patch(struct origin *parent, struct origin *origin)
 	char *blob_p, *blob_o;
 	struct patch *patch;
 
-	if (DEBUG) fprintf(stderr, "get patch %.8s %.8s\n",
-			   sha1_to_hex(parent->commit->object.sha1),
-			   sha1_to_hex(origin->commit->object.sha1));
-
 	blob_p = read_sha1_file(parent->blob_sha1, type,
 				(unsigned long *) &file_p.size);
 	blob_o = read_sha1_file(origin->blob_sha1, type,
@@ -352,6 +358,7 @@ static void dup_entry(struct blame_entry *dst, struct blame_entry *src)
 	memcpy(dst, src, sizeof(*src));
 	dst->prev = p;
 	dst->next = n;
+	dst->score = 0;
 }
 
 static const char *nth_line(struct scoreboard *sb, int lno)
@@ -448,7 +455,7 @@ static void split_blame(struct scoreboard *sb,
 		add_blame_entry(sb, new_entry);
 	}
 
-	if (DEBUG) {
+	if (1) { /* sanity */
 		struct blame_entry *ent;
 		int lno = 0, corrupt = 0;
 
@@ -530,12 +537,6 @@ static int pass_blame_to_parent(struct scoreboard *sb,
 	for (i = 0; i < patch->num; i++) {
 		struct chunk *chunk = &patch->chunks[i];
 
-		if (DEBUG)
-			fprintf(stderr,
-				"plno = %d, tlno = %d, "
-				"same as parent up to %d, resync %d and %d\n",
-				plno, tlno,
-				chunk->same, chunk->p_next, chunk->t_next);
 		blame_chunk(sb, tlno, plno, chunk->same, target, parent);
 		plno = chunk->p_next;
 		tlno = chunk->t_next;
@@ -547,14 +548,37 @@ static int pass_blame_to_parent(struct scoreboard *sb,
 	return 0;
 }
 
-static void copy_split_if_better(struct blame_entry best_so_far[3],
+static unsigned ent_score(struct scoreboard *sb, struct blame_entry *e)
+{
+	unsigned score;
+	const char *cp, *ep;
+
+	if (e->score)
+		return e->score;
+
+	score = 0;
+	cp = nth_line(sb, e->lno);
+	ep = nth_line(sb, e->lno + e->num_lines);
+	while (cp < ep) {
+		unsigned ch = *((unsigned char *)cp);
+		if (isalnum(ch))
+			score++;
+		cp++;
+	}
+	e->score = score;
+	return score;
+}
+
+static void copy_split_if_better(struct scoreboard *sb,
+				 struct blame_entry best_so_far[3],
 				 struct blame_entry this[3])
 {
 	if (!this[1].suspect)
 		return;
-	if (best_so_far[1].suspect &&
-	    (this[1].num_lines < best_so_far[1].num_lines))
-		return;
+	if (best_so_far[1].suspect) {
+		if (ent_score(sb, &this[1]) < ent_score(sb, &best_so_far[1]))
+			return;
+	}
 	memcpy(best_so_far, this, sizeof(struct blame_entry [3]));
 }
 
@@ -596,7 +620,7 @@ static void find_copy_in_blob(struct scoreboard *sb,
 				      tlno + ent->s_lno, plno,
 				      chunk->same + ent->s_lno,
 				      parent);
-			copy_split_if_better(split, this);
+			copy_split_if_better(sb, split, this);
 		}
 		plno = chunk->p_next;
 		tlno = chunk->t_next;
@@ -630,7 +654,8 @@ static int find_move_in_parent(struct scoreboard *sb,
 		if (ent->suspect != target || ent->guilty)
 			continue;
 		find_copy_in_blob(sb, ent, parent, split, &file_p);
-		if (split[1].suspect)
+		if (split[1].suspect &&
+		    blame_move_score < ent_score(sb, &split[1]))
 			split_blame(sb, split, ent);
 	}
 	free(blob_p);
@@ -699,9 +724,10 @@ static int find_copy_in_parent(struct scoreboard *sb,
 				continue;
 			}
 			find_copy_in_blob(sb, ent, norigin, this, &file_p);
-			copy_split_if_better(split, this);
+			copy_split_if_better(sb, split, this);
 		}
-		if (split[1].suspect)
+		if (split[1].suspect &&
+		    blame_copy_score < ent_score(sb, &split[1]))
 			split_blame(sb, split, ent);
 	}
 	diff_flush(&diff_opts);
@@ -944,6 +970,7 @@ static void get_commit_info(struct commit *commit,
 #define OUTPUT_PORCELAIN	010
 #define OUTPUT_SHOW_NAME	020
 #define OUTPUT_SHOW_NUMBER	040
+#define OUTPUT_SHOW_SCORE      0100
 
 static void emit_porcelain(struct scoreboard *sb, struct blame_entry *ent)
 {
@@ -1016,6 +1043,8 @@ static void emit_other(struct scoreboard *sb, struct blame_entry *ent, int opt)
 					   show_raw_time),
 			       ent->lno + 1 + cnt);
 		else {
+			if (opt & OUTPUT_SHOW_SCORE)
+				printf(" %*d", max_score_digits, ent->score);
 			if (opt & OUTPUT_SHOW_NAME)
 				printf(" %-*.*s", longest_file, longest_file,
 				       suspect->path);
@@ -1060,8 +1089,9 @@ static void output(struct scoreboard *sb, int option)
 	for (ent = sb->ent; ent; ent = ent->next) {
 		if (option & OUTPUT_PORCELAIN)
 			emit_porcelain(sb, ent);
-		else
+		else {
 			emit_other(sb, ent, option);
+		}
 	}
 }
 
@@ -1085,6 +1115,9 @@ static int prepare_lines(struct scoreboard *sb)
 			bol = 1;
 		}
 	}
+	sb->lineno = xrealloc(sb->lineno,
+			      sizeof(int* ) * (num + incomplete + 1));
+	sb->lineno[num + incomplete] = buf - sb->final_buf;
 	sb->num_lines = num + incomplete;
 	return sb->num_lines;
 }
@@ -1118,6 +1151,7 @@ static void find_alignment(struct scoreboard *sb, int *option)
 {
 	int longest_src_lines = 0;
 	int longest_dst_lines = 0;
+	unsigned largest_score = 0;
 	struct blame_entry *e;
 
 	for (e = sb->ent; e; e = e->next) {
@@ -1143,9 +1177,12 @@ static void find_alignment(struct scoreboard *sb, int *option)
 		num = e->lno + e->num_lines;
 		if (longest_dst_lines < num)
 			longest_dst_lines = num;
+		if (largest_score < ent_score(sb, e))
+			largest_score = ent_score(sb, e);
 	}
 	max_orig_digits = lineno_width(longest_src_lines);
 	max_digits = lineno_width(longest_dst_lines);
+	max_score_digits = lineno_width(largest_score);
 }
 
 static int has_path_in_work_tree(const char *path)
@@ -1154,6 +1191,15 @@ static int has_path_in_work_tree(const char *path)
 	return !lstat(path, &st);
 }
 
+static unsigned parse_score(const char *arg)
+{
+	char *end;
+	unsigned long score = strtoul(arg, &end, 10);
+	if (*end)
+		return 0;
+	return score;
+}
+
 int cmd_pickaxe(int argc, const char **argv, const char *prefix)
 {
 	struct rev_info revs;
@@ -1183,12 +1229,15 @@ int cmd_pickaxe(int argc, const char **argv, const char *prefix)
 			output_option |= OUTPUT_LONG_OBJECT_NAME;
 		else if (!strcmp("-S", arg) && ++i < argc)
 			revs_file = argv[i];
-		else if (!strcmp("-M", arg))
+		else if (!strncmp("-M", arg, 2)) {
 			opt |= PICKAXE_BLAME_MOVE;
-		else if (!strcmp("-C", arg)) {
+			blame_move_score = parse_score(arg+2);
+		}
+		else if (!strncmp("-C", arg, 2)) {
 			if (opt & PICKAXE_BLAME_COPY)
 				opt |= PICKAXE_BLAME_COPY_HARDER;
 			opt |= PICKAXE_BLAME_COPY | PICKAXE_BLAME_MOVE;
+			blame_copy_score = parse_score(arg+2);
 		}
 		else if (!strcmp("-L", arg) && ++i < argc) {
 			char *term;
@@ -1206,6 +1255,8 @@ int cmd_pickaxe(int argc, const char **argv, const char *prefix)
 				tmp = top; top = bottom; bottom = tmp;
 			}
 		}
+		else if (!strcmp("--score-debug", arg))
+			output_option |= OUTPUT_SHOW_SCORE;
 		else if (!strcmp("-f", arg) ||
 			 !strcmp("--show-name", arg))
 			output_option |= OUTPUT_SHOW_NAME;
@@ -1224,6 +1275,11 @@ int cmd_pickaxe(int argc, const char **argv, const char *prefix)
 			argv[unk++] = arg;
 	}
 
+	if (!blame_move_score)
+		blame_move_score = BLAME_DEFAULT_MOVE_SCORE;
+	if (!blame_copy_score)
+		blame_copy_score = BLAME_DEFAULT_COPY_SCORE;
+
 	/* We have collected options unknown to us in argv[1..unk]
 	 * which are to be passed to revision machinery if we are
 	 * going to do the "bottom" procesing.

git.c

@@ -247,7 +247,7 @@ static void handle_internal_command(int argc, const char **argv, char **envp)
 		{ "mv", cmd_mv, RUN_SETUP },
 		{ "name-rev", cmd_name_rev, RUN_SETUP },
 		{ "pack-objects", cmd_pack_objects, RUN_SETUP },
-		{ "pickaxe", cmd_pickaxe, RUN_SETUP },
+		{ "pickaxe", cmd_pickaxe, RUN_SETUP | USE_PAGER },
 		{ "prune", cmd_prune, RUN_SETUP },
 		{ "prune-packed", cmd_prune_packed, RUN_SETUP },
 		{ "push", cmd_push, RUN_SETUP },