2 files changed, 52 insertions, 0 deletions

diff --git a/src/server.c b/src/server.c
index 047f8d22e..766726798 100644
--- a/src/server.c
+++ b/src/server.c
@@ -29,6 +29,8 @@ void git_server_free(git_server *server)
 	if (server == NULL)
 		return;
 
+	git_array_clear(server->wants);
+	git_array_clear(server->common);
 	git__free(server->path);
 	git__free(server);
 }
@@ -98,6 +100,50 @@ cleanup:
 	return error;
 }
 
+int git_server__negotiation(git_server *server, git_pkt *_pkt)
+{
+	git_oid *id, *have_id;
+	git_pkt_have_want *pkt;
+	git_odb *odb = NULL;
+	int error;
+
+	if (_pkt->type != GIT_PKT_HAVE && _pkt->type != GIT_PKT_WANT) {
+		giterr_set(GITERR_NET, "invalid pkt for negotiation");
+		return -1;
+	}
+
+	pkt = (git_pkt_have_want *) _pkt;
+
+	if (pkt->type == GIT_PKT_WANT) {
+		id = git_array_alloc(server->wants);
+		GITERR_CHECK_ALLOC(id);
+
+		git_oid_cpy(id, &pkt->id);
+		return 0;
+	}
+
+	/* we know it's a 'have', so we check to see if it's common */
+	have_id = &pkt->id;
+	if ((error = git_repository_odb(&odb, server->repo)) < 0)
+		return error;
+
+	if ((error = git_odb_exists(odb, have_id)) < 0)
+		goto cleanup;
+
+	if (error == 1) {
+		error = 0;
+		id = git_array_alloc(server->common);
+		GITERR_CHECK_ALLOC(id);
+
+		git_oid_cpy(id, &pkt->id);
+	}
+
+cleanup:
+	git_odb_free(odb);
+
+	return error;
+}
+
 int git_server_run(git_server *server)
 {
 	/* 65535 is the max size of a pkt frame */
diff --git a/src/server.h b/src/server.h
index eff5dd4ec..943eaa2cd 100644
--- a/src/server.h
+++ b/src/server.h
@@ -9,6 +9,9 @@
 
 #include "common.h"
 #include "transports/smart.h"
+#include "array.h"
+
+typedef git_array_t(git_oid) git_oid_array;
 
 struct git_server {
 	enum git_request_type type;
@@ -16,12 +19,15 @@ struct git_server {
 	gitno_socket s;
 	int rpc;
 	char *path;
+	git_oid_array common;
+	git_oid_array wants;
 };
 
 extern int git_server_new(git_server **out, git_repository *repo, int fd);
 extern void git_server_free(git_server *server);
 extern int git_server__handle_request(git_server *server, git_pkt *pkt);
 extern int git_server__ls(git_buf *out, git_server *server);
+extern int git_server__negotiation(git_server *server, git_pkt *_pkt);
 
 #endif