[PATCH 4/5] Make builtin-commit-tree use a strbuf instead of hand-rolled realloc buffer.

["Kristian Høgsberg" <krh@redhat.com>]

From: Kristian Høgsberg <krh@redhat.com>

With the new strbuf_printf() function we can now just a strbuf for
building up the commit object.

Signed-off-by: Kristian Høgsberg <krh@redhat.com>
---
 builtin-commit-tree.c |   57 +++++++++++-------------------------------------
 1 files changed, 13 insertions(+), 44 deletions(-)

diff --git a/builtin-commit-tree.c b/builtin-commit-tree.c
index ccbcbe3..72884eb 100644
--- a/builtin-commit-tree.c
+++ b/builtin-commit-tree.c
@@ -8,42 +8,13 @@
 #include "tree.h"
 #include "builtin.h"
 #include "utf8.h"
+#include "strbuf.h"
 
 #define BLOCKING (1ul << 14)
 
 /*
  * FIXME! Share the code with "write-tree.c"
  */
-static void init_buffer(char **bufp, unsigned int *sizep)
-{
-	*bufp = xmalloc(BLOCKING);
-	*sizep = 0;
-}
-
-static void add_buffer(char **bufp, unsigned int *sizep, const char *fmt, ...)
-{
-	char one_line[2048];
-	va_list args;
-	int len;
-	unsigned long alloc, size, newsize;
-	char *buf;
-
-	va_start(args, fmt);
-	len = vsnprintf(one_line, sizeof(one_line), fmt, args);
-	va_end(args);
-	size = *sizep;
-	newsize = size + len + 1;
-	alloc = (size + 32767) & ~32767;
-	buf = *bufp;
-	if (newsize > alloc) {
-		alloc = (newsize + 32767) & ~32767;
-		buf = xrealloc(buf, alloc);
-		*bufp = buf;
-	}
-	*sizep = newsize - 1;
-	memcpy(buf + size, one_line, len);
-}
-
 static void check_valid(unsigned char *sha1, enum object_type expect)
 {
 	enum object_type type = sha1_object_info(sha1, NULL);
@@ -88,8 +59,7 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 	unsigned char tree_sha1[20];
 	unsigned char commit_sha1[20];
 	char comment[1000];
-	char *buffer;
-	unsigned int size;
+	struct strbuf sb;
 	int encoding_is_utf8;
 
 	git_config(git_default_config);
@@ -118,8 +88,8 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 	/* Not having i18n.commitencoding is the same as having utf-8 */
 	encoding_is_utf8 = is_encoding_utf8(git_commit_encoding);
 
-	init_buffer(&buffer, &size);
-	add_buffer(&buffer, &size, "tree %s\n", sha1_to_hex(tree_sha1));
+	strbuf_init(&sb);
+	strbuf_printf(&sb, "tree %s\n", sha1_to_hex(tree_sha1));
 
 	/*
 	 * NOTE! This ordering means that the same exact tree merged with a
@@ -127,26 +97,25 @@ int cmd_commit_tree(int argc, const char **argv, const char *prefix)
 	 * if everything else stays the same.
 	 */
 	for (i = 0; i < parents; i++)
-		add_buffer(&buffer, &size, "parent %s\n", sha1_to_hex(parent_sha1[i]));
+		strbuf_printf(&sb, "parent %s\n", sha1_to_hex(parent_sha1[i]));
 
 	/* Person/date information */
-	add_buffer(&buffer, &size, "author %s\n", git_author_info(1));
-	add_buffer(&buffer, &size, "committer %s\n", git_committer_info(1));
+	strbuf_printf(&sb, "author %s\n", git_author_info(1));
+	strbuf_printf(&sb, "committer %s\n", git_committer_info(1));
 	if (!encoding_is_utf8)
-		add_buffer(&buffer, &size,
-				"encoding %s\n", git_commit_encoding);
-	add_buffer(&buffer, &size, "\n");
+		strbuf_printf(&sb, "encoding %s\n", git_commit_encoding);
+	strbuf_printf(&sb, "\n");
 
 	/* And add the comment */
 	while (fgets(comment, sizeof(comment), stdin) != NULL)
-		add_buffer(&buffer, &size, "%s", comment);
+		strbuf_printf(&sb, "%s", comment);
 
 	/* And check the encoding */
-	buffer[size] = '\0';
-	if (encoding_is_utf8 && !is_utf8(buffer))
+	strbuf_add_char(&sb, '\0');
+	if (encoding_is_utf8 && !is_utf8(sb.buf))
 		fprintf(stderr, commit_utf8_warn);
 
-	if (!write_sha1_file(buffer, size, commit_type, commit_sha1)) {
+	if (!write_sha1_file(sb.buf, sb.len - 1, commit_type, commit_sha1)) {
 		printf("%s\n", sha1_to_hex(commit_sha1));
 		return 0;
 	}
-- 
1.5.2.GIT