[PATCH 1/3] tree.c: update read_tree_recursive callback to pass strbuf as base

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

This allows the callback to use 'base' as a temporary buffer to
quickly assemble full path "without" extra allocation. The callback
has to restore it afterwards of course.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
---
 archive.c          | 34 +++++++++++++++++++++-------------
 builtin/checkout.c |  8 ++++----
 builtin/log.c      |  2 +-
 builtin/ls-tree.c  |  9 +++++----
 merge-recursive.c  | 15 ++++++---------
 tree.c             | 16 +++++++++++-----
 tree.h             |  3 ++-
 7 files changed, 50 insertions(+), 37 deletions(-)

diff --git a/archive.c b/archive.c
index 94a9981..9e30246 100644
--- a/archive.c
+++ b/archive.c
@@ -157,18 +157,26 @@ static int write_archive_entry(const unsigned char *sha1, const char *base,
 	return write_entry(args, sha1, path.buf, path.len, mode);
 }
 
+static int write_archive_entry_buf(const unsigned char *sha1, struct strbuf *base,
+		const char *filename, unsigned mode, int stage,
+		void *context)
+{
+	return write_archive_entry(sha1, base->buf, base->len,
+				     filename, mode, stage, context);
+}
+
 static void queue_directory(const unsigned char *sha1,
-		const char *base, int baselen, const char *filename,
+		struct strbuf *base, const char *filename,
 		unsigned mode, int stage, struct archiver_context *c)
 {
 	struct directory *d;
-	d = xmallocz(sizeof(*d) + baselen + 1 + strlen(filename));
+	d = xmallocz(sizeof(*d) + base->len + 1 + strlen(filename));
 	d->up	   = c->bottom;
-	d->baselen = baselen;
+	d->baselen = base->len;
 	d->mode	   = mode;
 	d->stage   = stage;
 	c->bottom  = d;
-	d->len = sprintf(d->path, "%.*s%s/", baselen, base, filename);
+	d->len = sprintf(d->path, "%.*s%s/", (int)base->len, base->buf, filename);
 	hashcpy(d->sha1, sha1);
 }
 
@@ -191,28 +199,28 @@ static int write_directory(struct archiver_context *c)
 }
 
 static int queue_or_write_archive_entry(const unsigned char *sha1,
-		const char *base, int baselen, const char *filename,
+		struct strbuf *base, const char *filename,
 		unsigned mode, int stage, void *context)
 {
 	struct archiver_context *c = context;
 
 	while (c->bottom &&
-	       !(baselen >= c->bottom->len &&
-		 !strncmp(base, c->bottom->path, c->bottom->len))) {
+	       !(base->len >= c->bottom->len &&
+		 !strncmp(base->buf, c->bottom->path, c->bottom->len))) {
 		struct directory *next = c->bottom->up;
 		free(c->bottom);
 		c->bottom = next;
 	}
 
 	if (S_ISDIR(mode)) {
-		queue_directory(sha1, base, baselen, filename,
+		queue_directory(sha1, base, filename,
 				mode, stage, c);
 		return READ_TREE_RECURSIVE;
 	}
 
 	if (write_directory(c))
 		return -1;
-	return write_archive_entry(sha1, base, baselen, filename, mode,
+	return write_archive_entry(sha1, base->buf, base->len, filename, mode,
 				   stage, context);
 }
 
@@ -260,7 +268,7 @@ int write_archive_entries(struct archiver_args *args,
 	err = read_tree_recursive(args->tree, "", 0, 0, &args->pathspec,
 				  args->pathspec.has_wildcard ?
 				  queue_or_write_archive_entry :
-				  write_archive_entry,
+				  write_archive_entry_buf,
 				  &context);
 	if (err == READ_TREE_RECURSIVE)
 		err = 0;
@@ -286,14 +294,14 @@ static const struct archiver *lookup_archiver(const char *name)
 	return NULL;
 }
 
-static int reject_entry(const unsigned char *sha1, const char *base,
-			int baselen, const char *filename, unsigned mode,
+static int reject_entry(const unsigned char *sha1, struct strbuf *base,
+			const char *filename, unsigned mode,
 			int stage, void *context)
 {
 	int ret = -1;
 	if (S_ISDIR(mode)) {
 		struct strbuf sb = STRBUF_INIT;
-		strbuf_addstr(&sb, base);
+		strbuf_addbuf(&sb, base);
 		strbuf_addstr(&sb, filename);
 		if (!match_pathspec(context, sb.buf, sb.len, 0, NULL, 1))
 			ret = READ_TREE_RECURSIVE;
diff --git a/builtin/checkout.c b/builtin/checkout.c
index 5410dac..8adf48d 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -62,7 +62,7 @@ static int post_checkout_hook(struct commit *old, struct commit *new,
 
 }
 
-static int update_some(const unsigned char *sha1, const char *base, int baselen,
+static int update_some(const unsigned char *sha1, struct strbuf *base,
 		const char *pathname, unsigned mode, int stage, void *context)
 {
 	int len;
@@ -71,11 +71,11 @@ static int update_some(const unsigned char *sha1, const char *base, int baselen,
 	if (S_ISDIR(mode))
 		return READ_TREE_RECURSIVE;
 
-	len = baselen + strlen(pathname);
+	len = base->len + strlen(pathname);
 	ce = xcalloc(1, cache_entry_size(len));
 	hashcpy(ce->sha1, sha1);
-	memcpy(ce->name, base, baselen);
-	memcpy(ce->name + baselen, pathname, len - baselen);
+	memcpy(ce->name, base->buf, base->len);
+	memcpy(ce->name + base->len, pathname, len - base->len);
 	ce->ce_flags = create_ce_flags(0) | CE_UPDATE;
 	ce->ce_namelen = len;
 	ce->ce_mode = create_ce_mode(mode);
diff --git a/builtin/log.c b/builtin/log.c
index 734aab3..f2a9f01 100644
--- a/builtin/log.c
+++ b/builtin/log.c
@@ -489,7 +489,7 @@ static int show_tag_object(const unsigned char *sha1, struct rev_info *rev)
 }
 
 static int show_tree_object(const unsigned char *sha1,
-		const char *base, int baselen,
+		struct strbuf *base,
 		const char *pathname, unsigned mode, int stage, void *context)
 {
 	printf("%s%s\n", pathname, S_ISDIR(mode) ? "/" : "");
diff --git a/builtin/ls-tree.c b/builtin/ls-tree.c
index 51184df..1ab0381 100644
--- a/builtin/ls-tree.c
+++ b/builtin/ls-tree.c
@@ -61,7 +61,7 @@ static int show_recursive(const char *base, int baselen, const char *pathname)
 	}
 }
 
-static int show_tree(const unsigned char *sha1, const char *base, int baselen,
+static int show_tree(const unsigned char *sha1, struct strbuf *base,
 		const char *pathname, unsigned mode, int stage, void *context)
 {
 	int retval = 0;
@@ -79,7 +79,7 @@ static int show_tree(const unsigned char *sha1, const char *base, int baselen,
 		 */
 		type = commit_type;
 	} else if (S_ISDIR(mode)) {
-		if (show_recursive(base, baselen, pathname)) {
+		if (show_recursive(base->buf, base->len, pathname)) {
 			retval = READ_TREE_RECURSIVE;
 			if (!(ls_options & LS_SHOW_TREES))
 				return retval;
@@ -90,7 +90,8 @@ static int show_tree(const unsigned char *sha1, const char *base, int baselen,
 		return 0;
 
 	if (chomp_prefix &&
-	    (baselen < chomp_prefix || memcmp(ls_tree_prefix, base, chomp_prefix)))
+	    (base->len < chomp_prefix ||
+	     memcmp(ls_tree_prefix, base->buf, chomp_prefix)))
 		return 0;
 
 	if (!(ls_options & LS_NAME_ONLY)) {
@@ -112,7 +113,7 @@ static int show_tree(const unsigned char *sha1, const char *base, int baselen,
 			printf("%06o %s %s\t", mode, type,
 			       find_unique_abbrev(sha1, abbrev));
 	}
-	write_name_quotedpfx(base + chomp_prefix, baselen - chomp_prefix,
+	write_name_quotedpfx(base->buf + chomp_prefix, base->len - chomp_prefix,
 			  pathname, stdout, line_termination);
 	return retval;
 }
diff --git a/merge-recursive.c b/merge-recursive.c
index fdb7d0f..25c067e 100644
--- a/merge-recursive.c
+++ b/merge-recursive.c
@@ -275,23 +275,20 @@ struct tree *write_tree_from_memory(struct merge_options *o)
 }
 
 static int save_files_dirs(const unsigned char *sha1,
-		const char *base, int baselen, const char *path,
+		struct strbuf *base, const char *path,
 		unsigned int mode, int stage, void *context)
 {
-	int len = strlen(path);
-	char *newpath = xmalloc(baselen + len + 1);
+	int baselen = base->len;
 	struct merge_options *o = context;
 
-	memcpy(newpath, base, baselen);
-	memcpy(newpath + baselen, path, len);
-	newpath[baselen + len] = '\0';
+	strbuf_addstr(base, path);
 
 	if (S_ISDIR(mode))
-		string_list_insert(&o->current_directory_set, newpath);
+		string_list_insert(&o->current_directory_set, base->buf);
 	else
-		string_list_insert(&o->current_file_set, newpath);
-	free(newpath);
+		string_list_insert(&o->current_file_set, base->buf);
 
+	strbuf_setlen(base, baselen);
 	return (S_ISDIR(mode) ? READ_TREE_RECURSIVE : 0);
 }
 
diff --git a/tree.c b/tree.c
index bb02c1c..58ebfce 100644
--- a/tree.c
+++ b/tree.c
@@ -30,9 +30,12 @@ static int read_one_entry_opt(const unsigned char *sha1, const char *base, int b
 	return add_cache_entry(ce, opt);
 }
 
-static int read_one_entry(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage, void *context)
+static int read_one_entry(const unsigned char *sha1, struct strbuf *base,
+			  const char *pathname, unsigned mode, int stage,
+			  void *context)
 {
-	return read_one_entry_opt(sha1, base, baselen, pathname, mode, stage,
+	return read_one_entry_opt(sha1, base->buf, base->len, pathname,
+				  mode, stage,
 				  ADD_CACHE_OK_TO_ADD|ADD_CACHE_SKIP_DFCHECK);
 }
 
@@ -40,9 +43,12 @@ static int read_one_entry(const unsigned char *sha1, const char *base, int basel
  * This is used when the caller knows there is no existing entries at
  * the stage that will conflict with the entry being added.
  */
-static int read_one_entry_quick(const unsigned char *sha1, const char *base, int baselen, const char *pathname, unsigned mode, int stage, void *context)
+static int read_one_entry_quick(const unsigned char *sha1, struct strbuf *base,
+				const char *pathname, unsigned mode, int stage,
+				void *context)
 {
-	return read_one_entry_opt(sha1, base, baselen, pathname, mode, stage,
+	return read_one_entry_opt(sha1, base->buf, base->len, pathname,
+				  mode, stage,
 				  ADD_CACHE_JUST_APPEND);
 }
 
@@ -70,7 +76,7 @@ static int read_tree_1(struct tree *tree, struct strbuf *base,
 				continue;
 		}
 
-		switch (fn(entry.sha1, base->buf, base->len,
+		switch (fn(entry.sha1, base,
 			   entry.path, entry.mode, stage, context)) {
 		case 0:
 			continue;
diff --git a/tree.h b/tree.h
index d84ac63..d24125f 100644
--- a/tree.h
+++ b/tree.h
@@ -4,6 +4,7 @@
 #include "object.h"
 
 extern const char *tree_type;
+struct strbuf;
 
 struct tree {
 	struct object object;
@@ -22,7 +23,7 @@ void free_tree_buffer(struct tree *tree);
 struct tree *parse_tree_indirect(const unsigned char *sha1);
 
 #define READ_TREE_RECURSIVE 1
-typedef int (*read_tree_fn_t)(const unsigned char *, const char *, int, const char *, unsigned int, int, void *);
+typedef int (*read_tree_fn_t)(const unsigned char *, struct strbuf *, const char *, unsigned int, int, void *);
 
 extern int read_tree_recursive(struct tree *tree,
 			       const char *base, int baselen,
-- 
2.2.0.60.gb7b3c64