Teach the Raft protocol to DTMD.

Author: kvap

contrib/pg_dtm/dtmd/Makefile

@@ -15,9 +15,9 @@ all: bin/dtmd bin/heart
 	@echo Done.
 	@echo Feel free to run the tests with \'make check\'.
 
-bin/dtmd: obj/server.o obj/main.o obj/clog.o obj/clogfile.o obj/util.o obj/transaction.o obj/snapshot.o | bindir objdir
+bin/dtmd: obj/server.o obj/raft.o obj/main.o obj/clog.o obj/clogfile.o obj/util.o obj/transaction.o obj/snapshot.o | bindir objdir
 	$(CC) -o bin/dtmd $(CFLAGS) \
-		obj/server.o obj/main.o \
+		obj/server.o obj/raft.o obj/main.o \
 		obj/clog.o obj/clogfile.o obj/util.o obj/transaction.o \
 		obj/snapshot.o \
 		$(SOCKHUB_LDFLAGS)

contrib/pg_dtm/dtmd/include/proto.h

@@ -10,6 +10,7 @@
 
 #define RES_FAILED 0xDEADBEEF
 #define RES_OK 0xC0FFEE
+#define RES_REDIRECT 404
 #define RES_TRANSACTION_COMMITTED 1
 #define RES_TRANSACTION_ABORTED 2
 #define RES_TRANSACTION_INPROGRESS 3

contrib/pg_dtm/dtmd/include/server.h

@@ -40,16 +40,37 @@ server_t server_init(
 	ondisconnect_callback_t ondisconnect
 );
 
+/*
+ * Assigns the given raft socket to the server. The server will add the socket
+ * to the 'select' calls and give you the incoming messages.
+ */
+void server_set_raft_socket(server_t server, int sock);
+
 /*
  * Starts the server. Returns 'true' on success, 'false' otherwise.
  */
 bool server_start(server_t server);
 
 /*
- * The main server loop. Does not return, so use the callbacks and signal
- * handlers to add more logic.
+ * The main server loop. Returns true if there is a raft message ready, or NULL
+ * if timed out. Use the callbacks and signal handlers to add more logic.
+ */
+bool server_tick(server_t server, int timeout_ms);
+
+/*
+ * Closes all client connections on the server and refuses to accept new ones.
+ */
+void server_disable(server_t server);
+
+/*
+ * Allows the server to accept new connections.
  */
-void server_loop(server_t server);
+void server_enable(server_t server);
+
+/*
+ * Enables or disables the server depending on the argument.
+ */
+void server_set_enabled(server_t server, bool enable);
 
 /*
  * These two methods allow you to set and get your custom 'userdata' for the
@@ -98,4 +119,11 @@ bool client_message_finish(client_t client);
  */
 bool client_message_shortcut(client_t client, xid_t arg);
 
+/*
+ * A shortcut to send the 'redirect' message.
+ *
+ * Returns 'true' on success, 'false' otherwise.
+ */
+bool client_redirect(client_t client, unsigned addr, int port);
+
 #endif

contrib/pg_dtm/dtmd/include/util.h

@@ -7,6 +7,7 @@
 
 #include <stdbool.h>
 #include <sys/stat.h>
+#include <sys/time.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -29,6 +30,17 @@ static inline int rand_between(int min, int max) {
 	return rand() % (max - min + 1) + min;
 }
 
+// ------ timing ------
+
+typedef struct mstimer_t {
+	struct timeval tv;
+} mstimer_t;
+
+int mstimer_reset(mstimer_t *t);
+struct timeval ms2tv(int ms);
+
+// ------ logging ------
+
 #ifndef DEBUG
 #define debug(...)
 #else

contrib/pg_dtm/dtmd/src/heart.c

@@ -46,23 +46,6 @@ static void show_status() {
 	shout("\n");
 }
 
-typedef struct mstimer_t {
-	struct timeval tv;
-} mstimer_t;
-
-static int mstimer_reset(mstimer_t *t) {
-	struct timeval newtime;
-	gettimeofday(&newtime, NULL);
-
-	int ms =
-		(newtime.tv_sec - t->tv.tv_sec) * 1000 +
-		(newtime.tv_usec - t->tv.tv_usec) / 1000;
-
-	t->tv = newtime;
-
-	return ms;
-}
-
 static void main_loop() {
 	mstimer_t t;
 	mstimer_reset(&t);