filebuf: add option not to buffer the contents at all

The new indexer needs to be able to bypass any kind of buffering, as
it's trying to map data that it has just written to disk.

1 files changed, 10 insertions, 2 deletions

diff --git a/src/filebuf.c b/src/filebuf.c
index a9de165d5..6538aea66 100644
--- a/src/filebuf.c
+++ b/src/filebuf.c
@@ -194,14 +194,19 @@ int git_filebuf_open(git_filebuf *file, const char *path, int flags)
 
 	memset(file, 0x0, sizeof(git_filebuf));
 
+	if (flags & GIT_FILEBUF_DO_NOT_BUFFER)
+		file->do_not_buffer = true;
+
 	file->buf_size = WRITE_BUFFER_SIZE;
 	file->buf_pos = 0;
 	file->fd = -1;
 	file->last_error = BUFERR_OK;
 
 	/* Allocate the main cache buffer */
-	file->buffer = git__malloc(file->buf_size);
-	GITERR_CHECK_ALLOC(file->buffer);
+	if (!file->do_not_buffer) {
+		file->buffer = git__malloc(file->buf_size);
+		GITERR_CHECK_ALLOC(file->buffer);
+	}
 
 	/* If we are hashing on-write, allocate a new hash context */
 	if (flags & GIT_FILEBUF_HASH_CONTENTS) {
@@ -345,6 +350,9 @@ int git_filebuf_write(git_filebuf *file, const void *buff, size_t len)
 
 	ENSURE_BUF_OK(file);
 
+	if (file->do_not_buffer)
+		return file->write(file, (void *)buff, len);
+
 	for (;;) {
 		size_t space_left = file->buf_size - file->buf_pos;