Shallow Clone Support

include/git2/common.h

@@ -224,7 +224,8 @@ typedef enum {
 	GIT_OPT_GET_OWNER_VALIDATION,
 	GIT_OPT_SET_OWNER_VALIDATION,
 	GIT_OPT_GET_HOMEDIR,
-	GIT_OPT_SET_HOMEDIR
+	GIT_OPT_SET_HOMEDIR,
+	GIT_OPT_ENABLE_SHALLOW
 } git_libgit2_opt_t;
 
 /**
@@ -461,6 +462,9 @@ typedef enum {
  *      > { "!noop", "newext" } indicates that the caller does not want
  *      > to support repositories with the `noop` extension but does want
  *      > to support repositories with the `newext` extension.
+ *	
+ * 	 opts(GIT_OPT_ENABLE_SHALLOW, int enabled)
+ *		> Enable or disable shallow clone support completely.
  *
  *   opts(GIT_OPT_GET_OWNER_VALIDATION, int *enabled)
  *      > Gets the owner validation setting for repository

include/git2/errors.h

@@ -109,7 +109,8 @@ typedef enum {
 	GIT_ERROR_WORKTREE,
 	GIT_ERROR_SHA,
 	GIT_ERROR_HTTP,
-	GIT_ERROR_INTERNAL
+	GIT_ERROR_INTERNAL,
+	GIT_ERROR_GRAFTS
 } git_error_t;
 
 /**

include/git2/remote.h

@@ -743,6 +743,20 @@ typedef struct {
 	 */
 	git_proxy_options proxy_opts;
 
+	/**
+	 * Depth of the fetch to perform. Depth <= 0 fetches the full history.
+	 *
+	 * The default is -1.
+	 */
+	int depth;
+
+	/**
+	 * Convert a shallow repository to a full repository.
+	 *
+	 * The default is 0, which means the flag is off.
+	 */
+	int unshallow;
+
 	/**
 	 * Whether to allow off-site redirects.  If this is not
 	 * specified, the `http.followRedirects` configuration setting
@@ -758,7 +772,7 @@ typedef struct {
 
 #define GIT_FETCH_OPTIONS_VERSION 1
 #define GIT_FETCH_OPTIONS_INIT { GIT_FETCH_OPTIONS_VERSION, GIT_REMOTE_CALLBACKS_INIT, GIT_FETCH_PRUNE_UNSPECIFIED, 1, \
-				 GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED, GIT_PROXY_OPTIONS_INIT }
+				 GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED, GIT_PROXY_OPTIONS_INIT, -1, 0 }
 
 /**
  * Initialize git_fetch_options structure

include/git2/sys/transport.h

@@ -25,6 +25,15 @@
 
 GIT_BEGIN_DECL
 
+typedef struct git_shallowarray git_shallowarray;
+
+typedef struct {
+	const git_remote_head * const *refs;
+	size_t count;
+	git_shallowarray *shallow_roots;
+	int depth;
+} git_fetch_negotiation;
+
 struct git_transport {
 	unsigned int version; /**< The struct version */
 
@@ -96,8 +105,7 @@ struct git_transport {
 	int GIT_CALLBACK(negotiate_fetch)(
 		git_transport *transport,
 		git_repository *repo,
-		const git_remote_head * const *refs,
-		size_t count);
+		const git_fetch_negotiation *fetch_data);
 
 	/**
 	 * Start downloading the packfile from the remote repository.
@@ -442,6 +450,11 @@ GIT_EXTERN(int) git_smart_subtransport_ssh(
 	git_transport *owner,
 	void *param);
 
+GIT_EXTERN(size_t) git_shallowarray_count(git_shallowarray *array);
+GIT_EXTERN(const git_oid *) git_shallowarray_get(git_shallowarray *array, size_t idx);
+GIT_EXTERN(int) git_shallowarray_add(git_shallowarray *array, git_oid *oid);
+GIT_EXTERN(int) git_shallowarray_remove(git_shallowarray *array, git_oid *oid);
+
 /** @} */
 GIT_END_DECL
 #endif

src/libgit2/clone.c

@@ -420,7 +420,9 @@ static int clone_into(
 
 	memcpy(&fetch_opts, opts, sizeof(git_fetch_options));
 	fetch_opts.update_fetchhead = 0;
-	fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
+
+	if (opts->depth <= 0)
+		fetch_opts.download_tags = GIT_REMOTE_DOWNLOAD_TAGS_ALL;
 
 	if ((error = git_remote_connect_options__from_fetch_opts(&connect_opts, remote, &fetch_opts)) < 0)
 		goto cleanup;

src/libgit2/commit.c

@@ -22,6 +22,7 @@
 #include "object.h"
 #include "array.h"
 #include "oidarray.h"
+#include "grafts.h"
 
 void git_commit__free(void *_commit)
 {
@@ -427,10 +428,6 @@ static int commit_parse(
 		buffer += tree_len;
 	}
 
-	/*
-	 * TODO: commit grafts!
-	 */
-
 	while (git_object__parse_oid_header(&parent_id,
 			&buffer, buffer_end, "parent ",
 			opts->oid_type) == 0) {
@@ -532,16 +529,44 @@ int git_commit__parse_raw(
 	return commit_parse(commit, data, size, &parse_options);
 }
 
+static int assign_commit_parents_from_graft(git_commit *commit, git_commit_graft *graft) {
+	size_t idx;
+	git_oid *oid;
+
+	git_array_clear(commit->parent_ids);
+	git_array_init_to_size(commit->parent_ids, git_array_size(graft->parents));
+	git_array_foreach(graft->parents, idx, oid) {
+		git_oid *id = git_array_alloc(commit->parent_ids);
+		GIT_ERROR_CHECK_ALLOC(id);
+
+		git_oid_cpy(id, oid);
+	}
+
+	return 0;
+}
+
 int git_commit__parse_ext(
 	git_commit *commit,
 	git_odb_object *odb_obj,
 	git_commit__parse_options *parse_opts)
 {
-	return commit_parse(
-		commit,
-		git_odb_object_data(odb_obj),
-		git_odb_object_size(odb_obj),
-		parse_opts);
+	git_repository *repo = git_object_owner((git_object *)commit);
+	git_commit_graft *graft;
+	int error;
+
+	if ((error = commit_parse(commit, git_odb_object_data(odb_obj),
+				  git_odb_object_size(odb_obj), parse_opts)) < 0)
+		return error;
+
+	if (!git_shallow__enabled)
+		return 0;
+
+	/* Perform necessary grafts */
+	if (git_grafts_get(&graft, repo->grafts, git_odb_object_id(odb_obj)) != 0 &&
+		git_grafts_get(&graft, repo->shallow_grafts, git_odb_object_id(odb_obj)) != 0)
+		return 0;
+
+	return assign_commit_parents_from_graft(commit, graft);
 }
 
 #define GIT_COMMIT_GETTER(_rvalue, _name, _return, _invalid) \

src/libgit2/fetch.c

@@ -20,6 +20,7 @@
 #include "netops.h"
 #include "repository.h"
 #include "refs.h"
+#include "transports/smart.h"
 
 static int maybe_want(git_remote *remote, git_remote_head *head, git_refspec *tagspec, git_remote_autotag_option_t tagopt)
 {
@@ -59,8 +60,10 @@ static int mark_local(git_remote *remote)
 		return -1;
 
 	git_vector_foreach(&remote->refs, i, head) {
-		/* If we have the object, mark it so we don't ask for it */
-		if (git_odb_exists(odb, &head->oid))
+		/* If we have the object, mark it so we don't ask for it.
+		   However if we are unshallowing, we need to ask for it 
+		   even though the head exists locally. */
+		if (remote->nego.depth != INT_MAX && git_odb_exists(odb, &head->oid))
 			head->local = 1;
 		else
 			remote->need_pack = 1;
@@ -169,31 +172,55 @@ int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts)
 
 	remote->need_pack = 0;
 
+	if (!opts)
+		remote->nego.depth = -1;
+	else
+		remote->nego.depth = opts->unshallow ? INT_MAX : opts->depth;
+
 	if (filter_wants(remote, opts) < 0)
 		return -1;
 
 	/* Don't try to negotiate when we don't want anything */
 	if (!remote->need_pack)
 		return 0;
 
+	if (opts && opts->unshallow && opts->depth > 0) {
+		git_error_set(GIT_ERROR_INVALID, "options '--depth' and '--unshallow' cannot be used together");
+		return -1;
+	}
+
 	/*
 	 * Now we have everything set up so we can start tell the
 	 * server what we want and what we have.
 	 */
+	remote->nego.refs = (const git_remote_head * const *)remote->refs.contents;
+	remote->nego.count = remote->refs.length;
+	remote->nego.shallow_roots = git__malloc(sizeof(*remote->nego.shallow_roots));
+
+	git_array_init(remote->nego.shallow_roots->array);
+
+	git_repository__shallow_roots(&remote->nego.shallow_roots->array, remote->repo);
+
 	return t->negotiate_fetch(t,
 		remote->repo,
-		(const git_remote_head * const *)remote->refs.contents,
-		remote->refs.length);
+		&remote->nego);
 }
 
 int git_fetch_download_pack(git_remote *remote)
 {
 	git_transport *t = remote->transport;
+	int error;
 
 	if (!remote->need_pack)
 		return 0;
 
-	return t->download_pack(t, remote->repo, &remote->stats);
+	if ((error = t->download_pack(t, remote->repo, &remote->stats)) != 0)
+		return error;
+
+	if ((error = git_repository__shallow_roots_write(remote->repo, remote->nego.shallow_roots->array)) != 0)
+		return error;
+
+	return 0;
 }
 
 int git_fetch_options_init(git_fetch_options *opts, unsigned int version)