X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=tree-diff.c;h=852498eb49fe0cba5e1cd21661288e8321a4b20e;hb=566842f62bdf1f16c2e94fb431445d2e6c0f3f0b;hp=916f489c5b79e04035f96dd9f667f70efedb83fa;hpb=c9c3470aec3a1d753ac1e5f21358f6374c1add95;p=git.git

diff --git a/tree-diff.c b/tree-diff.c
index 916f489c5..852498eb4 100644
--- a/tree-diff.c
+++ b/tree-diff.c
@@ -5,9 +5,8 @@
 #include "diff.h"
 #include "tree.h"
 
-static char *malloc_base(const char *base, const char *path, int pathlen)
+static char *malloc_base(const char *base, int baselen, const char *path, int pathlen)
 {
-	int baselen = strlen(base);
 	char *newbase = xmalloc(baselen + pathlen + 2);
 	memcpy(newbase, base, baselen);
 	memcpy(newbase + baselen, path, pathlen);
@@ -16,9 +15,9 @@ static char *malloc_base(const char *base, const char *path, int pathlen)
 }
 
 static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
-		       const char *base);
+		       const char *base, int baselen);
 
-static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
+static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const char *base, int baselen, struct diff_options *opt)
 {
 	unsigned mode1, mode2;
 	const char *path1, *path2;
@@ -28,19 +27,18 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
 	sha1 = tree_entry_extract(t1, &path1, &mode1);
 	sha2 = tree_entry_extract(t2, &path2, &mode2);
 
-	pathlen1 = strlen(path1);
-	pathlen2 = strlen(path2);
+	pathlen1 = tree_entry_len(path1, sha1);
+	pathlen2 = tree_entry_len(path2, sha2);
 	cmp = base_name_compare(path1, pathlen1, mode1, path2, pathlen2, mode2);
 	if (cmp < 0) {
-		show_entry(opt, "-", t1, base);
+		show_entry(opt, "-", t1, base, baselen);
 		return -1;
 	}
 	if (cmp > 0) {
-		show_entry(opt, "+", t2, base);
+		show_entry(opt, "+", t2, base, baselen);
 		return 1;
 	}
-	if (!opt->find_copies_harder &&
-	    !memcmp(sha1, sha2, 20) && mode1 == mode2)
+	if (!opt->find_copies_harder && !hashcmp(sha1, sha2) && mode1 == mode2)
 		return 0;
 
 	/*
@@ -48,14 +46,14 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
 	 * file, we need to consider it a remove and an add.
 	 */
 	if (S_ISDIR(mode1) != S_ISDIR(mode2)) {
-		show_entry(opt, "-", t1, base);
-		show_entry(opt, "+", t2, base);
+		show_entry(opt, "-", t1, base, baselen);
+		show_entry(opt, "+", t2, base, baselen);
 		return 0;
 	}
 
 	if (opt->recursive && S_ISDIR(mode1)) {
 		int retval;
-		char *newbase = malloc_base(base, path1, pathlen1);
+		char *newbase = malloc_base(base, baselen, path1, pathlen1);
 		if (opt->tree_in_recursive)
 			opt->change(opt, mode1, mode2,
 				    sha1, sha2, base, path1);
@@ -68,32 +66,46 @@ static int compare_tree_entry(struct tree_desc *t1, struct tree_desc *t2, const
 	return 0;
 }
 
-static int interesting(struct tree_desc *desc, const char *base, struct diff_options *opt)
+/*
+ * Is a tree entry interesting given the pathspec we have?
+ *
+ * Return:
+ *  - 2 for "yes, and all subsequent entries will be"
+ *  - 1 for yes
+ *  - zero for no
+ *  - negative for "no, and no subsequent entries will be either"
+ */
+static int tree_entry_interesting(struct tree_desc *desc, const char *base, int baselen, struct diff_options *opt)
 {
 	const char *path;
+	const unsigned char *sha1;
 	unsigned mode;
 	int i;
-	int baselen, pathlen;
+	int pathlen;
+	int never_interesting = -1;
 
 	if (!opt->nr_paths)
 		return 1;
 
-	(void)tree_entry_extract(desc, &path, &mode);
+	sha1 = tree_entry_extract(desc, &path, &mode);
 
-	pathlen = strlen(path);
-	baselen = strlen(base);
+	pathlen = tree_entry_len(path, sha1);
 
-	for (i=0; i < opt->nr_paths; i++) {
+	for (i = 0; i < opt->nr_paths; i++) {
 		const char *match = opt->paths[i];
 		int matchlen = opt->pathlens[i];
+		int m = -1; /* signals that we haven't called strncmp() */
 
 		if (baselen >= matchlen) {
 			/* If it doesn't match, move along... */
 			if (strncmp(base, match, matchlen))
 				continue;
 
-			/* The base is a subdirectory of a path which was specified. */
-			return 1;
+			/*
+			 * The base is a subdirectory of a path which
+			 * was specified, so all of them are interesting.
+			 */
+			return 2;
 		}
 
 		/* Does the base match? */
@@ -103,6 +115,37 @@ static int interesting(struct tree_desc *desc, const char *base, struct diff_opt
 		match += baselen;
 		matchlen -= baselen;
 
+		if (never_interesting) {
+			/*
+			 * We have not seen any match that sorts later
+			 * than the current path.
+			 */
+
+			/*
+			 * Does match sort strictly earlier than path
+			 * with their common parts?
+			 */
+			m = strncmp(match, path,
+				    (matchlen < pathlen) ? matchlen : pathlen);
+			if (m < 0)
+				continue;
+
+			/*
+			 * If we come here even once, that means there is at
+			 * least one pathspec that would sort equal to or
+			 * later than the path we are currently looking at.
+			 * In other words, if we have never reached this point
+			 * after iterating all pathspecs, it means all
+			 * pathspecs are either outside of base, or inside the
+			 * base but sorts strictly earlier than the current
+			 * one.  In either case, they will never match the
+			 * subsequent entries.  In such a case, we initialized
+			 * the variable to -1 and that is what will be
+			 * returned, allowing the caller to terminate early.
+			 */
+			never_interesting = 0;
+		}
+
 		if (pathlen > matchlen)
 			continue;
 
@@ -113,44 +156,69 @@ static int interesting(struct tree_desc *desc, const char *base, struct diff_opt
 				continue;
 		}
 
-		if (strncmp(path, match, pathlen))
-			continue;
-
-		return 1;
+		if (m == -1)
+			/*
+			 * we cheated and did not do strncmp(), so we do
+			 * that here.
+			 */
+			m = strncmp(match, path, pathlen);
+
+		/*
+		 * If common part matched earlier then it is a hit,
+		 * because we rejected the case where path is not a
+		 * leading directory and is shorter than match.
+		 */
+		if (!m)
+			return 1;
 	}
-	return 0; /* No matches */
+	return never_interesting; /* No matches */
 }
 
 /* A whole sub-tree went away or appeared */
-static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base)
+static void show_tree(struct diff_options *opt, const char *prefix, struct tree_desc *desc, const char *base, int baselen)
 {
+	int all_interesting = 0;
 	while (desc->size) {
-		if (interesting(desc, base, opt))
-			show_entry(opt, prefix, desc, base);
+		int show;
+
+		if (all_interesting)
+			show = 1;
+		else {
+			show = tree_entry_interesting(desc, base, baselen,
+						      opt);
+			if (show == 2)
+				all_interesting = 1;
+		}
+		if (show < 0)
+			break;
+		if (show)
+			show_entry(opt, prefix, desc, base, baselen);
 		update_tree_entry(desc);
 	}
 }
 
 /* A file entry went away or appeared */
 static void show_entry(struct diff_options *opt, const char *prefix, struct tree_desc *desc,
-		       const char *base)
+		       const char *base, int baselen)
 {
 	unsigned mode;
 	const char *path;
 	const unsigned char *sha1 = tree_entry_extract(desc, &path, &mode);
 
 	if (opt->recursive && S_ISDIR(mode)) {
-		char type[20];
-		char *newbase = malloc_base(base, path, strlen(path));
+		enum object_type type;
+		int pathlen = tree_entry_len(path, sha1);
+		char *newbase = malloc_base(base, baselen, path, pathlen);
 		struct tree_desc inner;
 		void *tree;
+		unsigned long size;
 
-		tree = read_sha1_file(sha1, type, &inner.size);
-		if (!tree || strcmp(type, tree_type))
+		tree = read_sha1_file(sha1, &type, &size);
+		if (!tree || type != OBJ_TREE)
 			die("corrupt tree sha %s", sha1_to_hex(sha1));
 
-		inner.buf = tree;
-		show_tree(opt, prefix, &inner, newbase);
+		init_tree_desc(&inner, tree, size);
+		show_tree(opt, prefix, &inner, newbase, baselen + 1 + pathlen);
 
 		free(tree);
 		free(newbase);
@@ -159,28 +227,54 @@ static void show_entry(struct diff_options *opt, const char *prefix, struct tree
 	}
 }
 
-int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
+static void skip_uninteresting(struct tree_desc *t, const char *base, int baselen, struct diff_options *opt)
 {
-	while (t1->size | t2->size) {
-		if (opt->nr_paths && t1->size && !interesting(t1, base, opt)) {
-			update_tree_entry(t1);
-			continue;
+	int all_interesting = 0;
+	while (t->size) {
+		int show;
+
+		if (all_interesting)
+			show = 1;
+		else {
+			show = tree_entry_interesting(t, base, baselen, opt);
+			if (show == 2)
+				all_interesting = 1;
 		}
-		if (opt->nr_paths && t2->size && !interesting(t2, base, opt)) {
-			update_tree_entry(t2);
+		if (!show) {
+			update_tree_entry(t);
 			continue;
 		}
+		/* Skip it all? */
+		if (show < 0)
+			t->size = 0;
+		return;
+	}
+}
+
+int diff_tree(struct tree_desc *t1, struct tree_desc *t2, const char *base, struct diff_options *opt)
+{
+	int baselen = strlen(base);
+
+	for (;;) {
+		if (opt->quiet && opt->has_changes)
+			break;
+		if (opt->nr_paths) {
+			skip_uninteresting(t1, base, baselen, opt);
+			skip_uninteresting(t2, base, baselen, opt);
+		}
 		if (!t1->size) {
-			show_entry(opt, "+", t2, base);
+			if (!t2->size)
+				break;
+			show_entry(opt, "+", t2, base, baselen);
 			update_tree_entry(t2);
 			continue;
 		}
 		if (!t2->size) {
-			show_entry(opt, "-", t1, base);
+			show_entry(opt, "-", t1, base, baselen);
 			update_tree_entry(t1);
 			continue;
 		}
-		switch (compare_tree_entry(t1, t2, base, opt)) {
+		switch (compare_tree_entry(t1, t2, base, baselen, opt)) {
 		case -1:
 			update_tree_entry(t1);
 			continue;
@@ -200,22 +294,41 @@ int diff_tree_sha1(const unsigned char *old, const unsigned char *new, const cha
 {
 	void *tree1, *tree2;
 	struct tree_desc t1, t2;
+	unsigned long size1, size2;
 	int retval;
 
-	tree1 = read_object_with_reference(old, tree_type, &t1.size, NULL);
+	tree1 = read_object_with_reference(old, tree_type, &size1, NULL);
 	if (!tree1)
 		die("unable to read source tree (%s)", sha1_to_hex(old));
-	tree2 = read_object_with_reference(new, tree_type, &t2.size, NULL);
+	tree2 = read_object_with_reference(new, tree_type, &size2, NULL);
 	if (!tree2)
 		die("unable to read destination tree (%s)", sha1_to_hex(new));
-	t1.buf = tree1;
-	t2.buf = tree2;
+	init_tree_desc(&t1, tree1, size1);
+	init_tree_desc(&t2, tree2, size2);
 	retval = diff_tree(&t1, &t2, base, opt);
 	free(tree1);
 	free(tree2);
 	return retval;
 }
 
+int diff_root_tree_sha1(const unsigned char *new, const char *base, struct diff_options *opt)
+{
+	int retval;
+	void *tree;
+	unsigned long size;
+	struct tree_desc empty, real;
+
+	tree = read_object_with_reference(new, tree_type, &size, NULL);
+	if (!tree)
+		die("unable to read root tree (%s)", sha1_to_hex(new));
+	init_tree_desc(&real, tree, size);
+
+	init_tree_desc(&empty, "", 0);
+	retval = diff_tree(&empty, &real, base, opt);
+	free(tree);
+	return retval;
+}
+
 static int count_paths(const char **paths)
 {
 	int i = 0;