filebuf: update git_filebuf.write signature to take non-const buffer

z_stream.next_in is non-const. Although currently Zlib doesn't modify
buffer content on deflate(), it might be change in the future. gzwrite()
already modify it.

To avoid this let's change signature of git_filebuf.write and rework
git_filebuf_write() accordingly.

Signed-off-by: Kirill A. Shutemov <kirill@shutemov.name>

src/filebuf.c

@@ -97,7 +97,7 @@ GIT_INLINE(int) flush_buffer(git_filebuf *file)
 	return result;
 }
 
-static int write_normal(git_filebuf *file, const void *source, size_t len)
+static int write_normal(git_filebuf *file, void *source, size_t len)
 {
 	int result = 0;
 
@@ -110,7 +110,7 @@ static int write_normal(git_filebuf *file, const void *source, size_t len)
 	return result;
 }
 
-static int write_deflate(git_filebuf *file, const void *source, size_t len)
+static int write_deflate(git_filebuf *file, void *source, size_t len)
 {
 	int result = Z_OK;
 	z_stream *zs = &file->zs;
@@ -315,24 +315,13 @@ int git_filebuf_write(git_filebuf *file, const void *buff, size_t len)
 			return GIT_SUCCESS;
 		}
 
-		/* flush the cache if it doesn't fit */
-		if (file->buf_pos > 0) {
-			add_to_cache(file, buf, space_left);
+		add_to_cache(file, buf, space_left);
 
-			if ((error = flush_buffer(file)) < GIT_SUCCESS)
-				return git__rethrow(error, "Failed to write to buffer");
-
-			len -= space_left;
-			buf += space_left;
-		}
+		if ((error = flush_buffer(file)) < GIT_SUCCESS)
+			return git__rethrow(error, "Failed to write to buffer");
 
-		/* write too-large chunks immediately */
-		if (len > file->buf_size) {
-			error = file->write(file, buf, len);
-			if (error < GIT_SUCCESS)
-				return git__rethrow(error, "Failed to write to buffer");
-			return GIT_SUCCESS;
-		}
+		len -= space_left;
+		buf += space_left;
 	}
 }
 

src/filebuf.h

@@ -22,8 +22,7 @@ struct git_filebuf {
 	char *path_original;
 	char *path_lock;
 
-	int (*write)(struct git_filebuf *file,
-			const void *source, size_t len);
+	int (*write)(struct git_filebuf *file, void *source, size_t len);
 
 	git_hash_ctx *digest;