Merge git_buf and git_buffer

This makes the git_buf struct that was used internally into an
externally available structure and eliminates the git_buffer.

As part of that, some of the special cases that arose with the
externally used git_buffer were blended into the git_buf, such as
being careful about git_buf objects that may have a NULL ptr and
allowing for bufs with a valid ptr and size but zero asize as a
way of referring to externally owned data.

1 files changed, 19 insertions, 74 deletions

diff --git a/src/buffer.c b/src/buffer.c
index 07725b9cc..f8d47d928 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -32,7 +32,8 @@ void git_buf_init(git_buf *buf, size_t initial_size)
 		git_buf_grow(buf, initial_size);
 }
 
-int git_buf_try_grow(git_buf *buf, size_t target_size, bool mark_oom)
+int git_buf_try_grow(
+	git_buf *buf, size_t target_size, bool mark_oom, bool preserve_external)
 {
 	char *new_ptr;
 	size_t new_size;
@@ -40,6 +41,9 @@ int git_buf_try_grow(git_buf *buf, size_t target_size, bool mark_oom)
 	if (buf->ptr == git_buf__oom)
 		return -1;
 
+	if (!target_size)
+		target_size = buf->size;
+
 	if (target_size <= buf->asize)
 		return 0;
 
@@ -67,6 +71,9 @@ int git_buf_try_grow(git_buf *buf, size_t target_size, bool mark_oom)
 		return -1;
 	}
 
+	if (preserve_external && !buf->asize && buf->ptr != NULL && buf->size > 0)
+		memcpy(new_ptr, buf->ptr, min(buf->size, new_size));
+
 	buf->asize = new_size;
 	buf->ptr   = new_ptr;
 
@@ -78,11 +85,16 @@ int git_buf_try_grow(git_buf *buf, size_t target_size, bool mark_oom)
 	return 0;
 }
 
+int git_buf_grow(git_buf *buffer, size_t target_size)
+{
+	return git_buf_try_grow(buffer, target_size, true, true);
+}
+
 void git_buf_free(git_buf *buf)
 {
 	if (!buf) return;
 
-	if (buf->ptr != git_buf__initbuf && buf->ptr != git_buf__oom)
+	if (buf->asize > 0 && buf->ptr != NULL && buf->ptr != git_buf__oom)
 		git__free(buf->ptr);
 
 	git_buf_init(buf, 0);
@@ -91,11 +103,15 @@ void git_buf_free(git_buf *buf)
 void git_buf_clear(git_buf *buf)
 {
 	buf->size = 0;
+
+	if (!buf->ptr)
+		buf->ptr = git_buf__initbuf;
+
 	if (buf->asize > 0)
 		buf->ptr[0] = '\0';
 }
 
-int git_buf_set(git_buf *buf, const char *data, size_t len)
+int git_buf_set(git_buf *buf, const void *data, size_t len)
 {
 	if (len == 0 || data == NULL) {
 		git_buf_clear(buf);
@@ -485,74 +501,3 @@ int git_buf_splice(
 	buf->ptr[buf->size] = '\0';
 	return 0;
 }
-
-/*
- * Public buffers API
- */
-
-void git_buffer_free(git_buffer *buffer)
-{
-	if (!buffer)
-		return;
-
-	if (buffer->ptr != NULL && buffer->available > 0)
-		git__free(buffer->ptr);
-
-	git__memzero(buffer, sizeof(*buffer));
-}
-
-static int git_buffer__resize(
-	git_buffer *buffer, size_t want_size, int preserve_data)
-{
-	int non_allocated_buffer = 0;
-	char *new_ptr;
-
-	assert(buffer);
-
-	/* check if buffer->ptr points to memory owned elsewhere */
-	non_allocated_buffer = (buffer->ptr != NULL && buffer->available == 0);
-
-	if (non_allocated_buffer && !want_size)
-		want_size = buffer->size;
-
-	if (buffer->available >= want_size)
-		return 0;
-
-	if (non_allocated_buffer) {
-		new_ptr = NULL;
-		if (want_size < buffer->size)
-			want_size = buffer->size;
-	} else {
-		new_ptr = buffer->ptr;
-	}
-
-	want_size = (want_size + 7) & ~7; /* round up to multiple of 8 */
-
-	new_ptr = git__realloc(new_ptr, want_size);
-	GITERR_CHECK_ALLOC(new_ptr);
-
-	if (non_allocated_buffer && preserve_data)
-		memcpy(new_ptr, buffer->ptr, buffer->size);
-
-	buffer->ptr       = new_ptr;
-	buffer->available = want_size;
-
-	return 0;
-}
-
-int git_buffer_resize(git_buffer *buffer, size_t want_size)
-{
-	return git_buffer__resize(buffer, want_size, true);
-}
-
-int git_buffer_copy(
-	git_buffer *buffer, const void *data, size_t datalen)
-{
-	if (git_buffer__resize(buffer, datalen + 1, false) < 0)
-		return -1;
-	memcpy(buffer->ptr, data, datalen);
-	buffer->ptr[datalen] = '\0';
-	buffer->size = datalen;
-	return 0;
-}
-