1 files changed, 202 insertions, 0 deletions
diff --git a/src/reader.c b/src/reader.c
new file mode 100644
index 000000000..754b90a3b
--- /dev/null
+++ b/src/reader.c
@@ -0,0 +1,202 @@
+/*
+ * Copyright (C) the libgit2 contributors. All rights reserved.
+ *
+ * This file is part of libgit2, distributed under the GNU GPL v2 with
+ * a Linking Exception. For full terms see the included COPYING file.
+ */
+
+#include "reader.h"
+
+#include "fileops.h"
+#include "blob.h"
+
+#include "git2/tree.h"
+#include "git2/blob.h"
+#include "git2/index.h"
+#include "git2/repository.h"
+
+/* tree reader */
+
+typedef struct {
+	git_reader reader;
+	git_tree *tree;
+} tree_reader;
+
+static int tree_reader_read(
+	git_buf *out,
+	git_reader *_reader,
+	const char *filename)
+{
+	tree_reader *reader = (tree_reader *)_reader;
+	git_tree_entry *tree_entry = NULL;
+	git_blob *blob = NULL;
+	int error;
+
+	if ((error = git_tree_entry_bypath(&tree_entry, reader->tree, filename)) < 0 ||
+	    (error = git_blob_lookup(&blob, git_tree_owner(reader->tree), git_tree_entry_id(tree_entry))) < 0 ||
+	    (error = git_buf_set(out, git_blob_rawcontent(blob), git_blob_rawsize(blob))) < 0)
+		goto done;
+
+done:
+	git_blob_free(blob);
+	git_tree_entry_free(tree_entry);
+	return error;
+}
+
+static void tree_reader_free(git_reader *_reader)
+{
+	GIT_UNUSED(_reader);
+}
+
+int git_reader_for_tree(git_reader **out, git_tree *tree)
+{
+	tree_reader *reader;
+
+	assert(out && tree);
+
+	reader = git__calloc(1, sizeof(tree_reader));
+	GITERR_CHECK_ALLOC(reader);
+
+	reader->reader.read = tree_reader_read;
+	reader->reader.free = tree_reader_free;
+	reader->tree = tree;
+
+	*out = (git_reader *)reader;
+	return 0;
+}
+
+/* workdir reader */
+
+typedef struct {
+	git_reader reader;
+	git_repository *repo;
+} workdir_reader;
+
+static int workdir_reader_read(
+	git_buf *out,
+	git_reader *_reader,
+	const char *filename)
+{
+	workdir_reader *reader = (workdir_reader *)_reader;
+	git_buf path = GIT_BUF_INIT;
+	int error;
+
+	if ((error = git_buf_joinpath(&path,
+		git_repository_workdir(reader->repo), filename)) < 0)
+		goto done;
+
+	/* TODO: should we read the filtered data? */
+	error = git_futils_readbuffer(out, path.ptr);
+
+done:
+	git_buf_dispose(&path);
+	return error;
+}
+
+static void workdir_reader_free(git_reader *_reader)
+{
+	GIT_UNUSED(_reader);
+}
+
+int git_reader_for_workdir(git_reader **out, git_repository *repo)
+{
+	workdir_reader *reader;
+
+	assert(out && repo);
+
+	reader = git__calloc(1, sizeof(workdir_reader));
+	GITERR_CHECK_ALLOC(reader);
+
+	reader->reader.read = workdir_reader_read;
+	reader->reader.free = workdir_reader_free;
+	reader->repo = repo;
+
+	*out = (git_reader *)reader;
+	return 0;
+}
+
+/* index reader */
+
+typedef struct {
+	git_reader reader;
+	git_repository *repo;
+	git_index *index;
+} index_reader;
+
+static int index_reader_read(
+	git_buf *out,
+	git_reader *_reader,
+	const char *filename)
+{
+	index_reader *reader = (index_reader *)_reader;
+	const git_index_entry *entry;
+	git_blob *blob;
+	int error;
+
+	if ((entry = git_index_get_bypath(reader->index, filename, 0)) == NULL)
+		return GIT_ENOTFOUND;
+
+	if ((error = git_blob_lookup(&blob, reader->repo, &entry->id)) < 0)
+		goto done;
+
+	error = git_blob__getbuf(out, blob);
+
+done:
+	git_blob_free(blob);
+	return error;
+}
+
+static void index_reader_free(git_reader *_reader)
+{
+	GIT_UNUSED(_reader);
+}
+
+int git_reader_for_index(
+	git_reader **out,
+	git_repository *repo,
+	git_index *index)
+{
+	index_reader *reader;
+	int error;
+
+	assert(out && repo);
+
+	reader = git__calloc(1, sizeof(index_reader));
+	GITERR_CHECK_ALLOC(reader);
+
+	reader->reader.read = index_reader_read;
+	reader->reader.free = index_reader_free;
+	reader->repo = repo;
+
+	if (index) {
+		reader->index = index;
+	} else {
+		error = git_repository_index__weakptr(&reader->index, repo);
+
+		if (error < 0) {
+			git__free(reader);
+			return error;
+		}
+	}
+
+	*out = (git_reader *)reader;
+	return 0;
+}
+
+/* generic */
+
+int git_reader_read(git_buf *out, git_reader *reader, const char *filename)
+{
+	assert(out && reader && filename);
+
+	return reader->read(out, reader, filename);
+}
+
+void git_reader_free(git_reader *reader)
+{
+	if (!reader)
+		return;
+
+	reader->free(reader);
+	git__free(reader);
+}