1 files changed, 214 insertions, 0 deletions
diff --git a/src/libgit2/fetch.c b/src/libgit2/fetch.c
new file mode 100644
index 000000000..e9f30d9bc
--- /dev/null
+++ b/src/libgit2/fetch.c
@@ -0,0 +1,214 @@
+/*
+ * 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 "fetch.h"
+
+#include "git2/oid.h"
+#include "git2/refs.h"
+#include "git2/revwalk.h"
+#include "git2/transport.h"
+#include "git2/sys/remote.h"
+
+#include "remote.h"
+#include "refspec.h"
+#include "pack.h"
+#include "netops.h"
+#include "repository.h"
+#include "refs.h"
+
+static int maybe_want(git_remote *remote, git_remote_head *head, git_refspec *tagspec, git_remote_autotag_option_t tagopt)
+{
+	int match = 0, valid;
+
+	if (git_reference_name_is_valid(&valid, head->name) < 0)
+		return -1;
+
+	if (!valid)
+		return 0;
+
+	if (tagopt == GIT_REMOTE_DOWNLOAD_TAGS_ALL) {
+		/*
+		 * If tagopt is --tags, always request tags
+		 * in addition to the remote's refspecs
+		 */
+		if (git_refspec_src_matches(tagspec, head->name))
+			match = 1;
+	}
+
+	if (!match && git_remote__matching_refspec(remote, head->name))
+		match = 1;
+
+	if (!match)
+		return 0;
+
+	return git_vector_insert(&remote->refs, head);
+}
+
+static int mark_local(git_remote *remote)
+{
+	git_remote_head *head;
+	git_odb *odb;
+	size_t i;
+
+	if (git_repository_odb__weakptr(&odb, remote->repo) < 0)
+		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))
+			head->local = 1;
+		else
+			remote->need_pack = 1;
+	}
+
+	return 0;
+}
+
+static int maybe_want_oid(git_remote *remote, git_refspec *spec)
+{
+	git_remote_head *oid_head;
+
+	oid_head = git__calloc(1, sizeof(git_remote_head));
+	GIT_ERROR_CHECK_ALLOC(oid_head);
+
+	git_oid_fromstr(&oid_head->oid, spec->src);
+
+	if (spec->dst) {
+		oid_head->name = git__strdup(spec->dst);
+		GIT_ERROR_CHECK_ALLOC(oid_head->name);
+	}
+
+	if (git_vector_insert(&remote->local_heads, oid_head) < 0 ||
+	    git_vector_insert(&remote->refs, oid_head) < 0)
+		return -1;
+
+	return 0;
+}
+
+static int filter_wants(git_remote *remote, const git_fetch_options *opts)
+{
+	git_remote_head **heads;
+	git_refspec tagspec, head, *spec;
+	int error = 0;
+	git_odb *odb;
+	size_t i, heads_len;
+	unsigned int remote_caps;
+	unsigned int oid_mask = GIT_REMOTE_CAPABILITY_TIP_OID |
+	                        GIT_REMOTE_CAPABILITY_REACHABLE_OID;
+	git_remote_autotag_option_t tagopt = remote->download_tags;
+
+	if (opts && opts->download_tags != GIT_REMOTE_DOWNLOAD_TAGS_UNSPECIFIED)
+		tagopt = opts->download_tags;
+
+	git_vector_clear(&remote->refs);
+	if ((error = git_refspec__parse(&tagspec, GIT_REFSPEC_TAGS, true)) < 0)
+		return error;
+
+	/*
+	 * The fetch refspec can be NULL, and what this means is that the
+	 * user didn't specify one. This is fine, as it means that we're
+	 * not interested in any particular branch but just the remote's
+	 * HEAD, which will be stored in FETCH_HEAD after the fetch.
+	 */
+	if (remote->active_refspecs.length == 0) {
+		if ((error = git_refspec__parse(&head, "HEAD", true)) < 0)
+			goto cleanup;
+
+		error = git_refspec__dwim_one(&remote->active_refspecs, &head, &remote->refs);
+		git_refspec__dispose(&head);
+
+		if (error < 0)
+			goto cleanup;
+	}
+
+	if ((error = git_repository_odb__weakptr(&odb, remote->repo)) < 0)
+		goto cleanup;
+
+	if ((error = git_remote_ls((const git_remote_head ***)&heads, &heads_len, remote)) < 0 ||
+	    (error = git_remote_capabilities(&remote_caps, remote)) < 0)
+		goto cleanup;
+
+	/* Handle remote heads */
+	for (i = 0; i < heads_len; i++) {
+		if ((error = maybe_want(remote, heads[i], &tagspec, tagopt)) < 0)
+			goto cleanup;
+	}
+
+	/* Handle explicitly specified OID specs */
+	git_vector_foreach(&remote->active_refspecs, i, spec) {
+		if (!git_oid__is_hexstr(spec->src))
+			continue;
+
+		if (!(remote_caps & oid_mask)) {
+			git_error_set(GIT_ERROR_INVALID, "cannot fetch a specific object from the remote repository");
+			error = -1;
+			goto cleanup;
+		}
+
+		if ((error = maybe_want_oid(remote, spec)) < 0)
+			goto cleanup;
+	}
+
+	error = mark_local(remote);
+
+cleanup:
+	git_refspec__dispose(&tagspec);
+
+	return error;
+}
+
+/*
+ * In this first version, we push all our refs in and start sending
+ * them out. When we get an ACK we hide that commit and continue
+ * traversing until we're done
+ */
+int git_fetch_negotiate(git_remote *remote, const git_fetch_options *opts)
+{
+	git_transport *t = remote->transport;
+
+	remote->need_pack = 0;
+
+	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;
+
+	/*
+	 * Now we have everything set up so we can start tell the
+	 * server what we want and what we have.
+	 */
+	return t->negotiate_fetch(t,
+		remote->repo,
+		(const git_remote_head * const *)remote->refs.contents,
+		remote->refs.length);
+}
+
+int git_fetch_download_pack(git_remote *remote)
+{
+	git_transport *t = remote->transport;
+
+	if (!remote->need_pack)
+		return 0;
+
+	return t->download_pack(t, remote->repo, &remote->stats);
+}
+
+int git_fetch_options_init(git_fetch_options *opts, unsigned int version)
+{
+	GIT_INIT_STRUCTURE_FROM_TEMPLATE(
+		opts, version, git_fetch_options, GIT_FETCH_OPTIONS_INIT);
+	return 0;
+}
+
+#ifndef GIT_DEPRECATE_HARD
+int git_fetch_init_options(git_fetch_options *opts, unsigned int version)
+{
+	return git_fetch_options_init(opts, version);
+}
+#endif