Selectively compress only large packets greater than one MTU and identify lz4 compatible clients immediately

src/ckpool.c

@@ -732,7 +732,7 @@ int write_cs(connsock_t *cs, const char *buf, int len)
 	int ret = -1;
 
 	/* Connsock doesn't expect lz4 compressed messages */
-	if (!cs->lz4) {
+	if (!cs->lz4 || len <= 1492) {
 		ret = write_socket(cs->fd, buf, len);
 		goto out;
 	}
@@ -744,12 +744,6 @@ int write_cs(connsock_t *cs, const char *buf, int len)
 		ret = write_socket(cs->fd, buf, len);
 		goto out;
 	}
-	if (compsize + 12 >= len) {
-		/* Selectively send compressed packets only when they're
-		 * smaller. */
-		ret = write_socket(cs->fd, buf, len);
-		goto out;
-	}
 	LOGDEBUG("Writing connsock message compressed %d from %d", compsize, decompsize);
 	/* Copy lz4 magic header */
 	sprintf(dest, "lz4\n");

src/connector.c

@@ -499,8 +499,6 @@ compressed:
 		LOGDEBUG("Received client message compressed %d from %d",
 			 client->compsize, client->decompsize);
 		msg[ret] = '\0';
-		/* Flag this client as able to receive lz4 compressed data now */
-		client->lz4 = true;
 		client->bufofs -= client->compsize;
 		if (client->bufofs)
 			memmove(client->buf, client->buf + buflen, client->bufofs);
@@ -1000,8 +998,9 @@ static void send_client(cdata_t *cdata, const int64_t id, char *buf)
 			test_redirector_shares(ckp, client, buf);
 	}
 
-	/* Does this client accept compressed data? */
+	/* Does this client accept compressed data? Only compress if it's
-	if (client->lz4) {
+	 * larger than one MTU. */
+	if (client->lz4 && len > 1492) {
 		char *dest = ckalloc(len + 12);
 		uint32_t msglen;
 		int compsize;
@@ -1012,11 +1011,6 @@ static void send_client(cdata_t *cdata, const int64_t id, char *buf)
 			free(dest);
 			goto out;
 		}
-		if (compsize + 12 >= len) {
-			/* Only end it compressed if it's smaller */
-			free(dest);
-			goto out;
-		}
 		LOGDEBUG("Sending client message compressed %d from %d", compsize, len);
 		/* Copy lz4 magic header */
 		sprintf(dest, "lz4\n");
@@ -1237,10 +1231,15 @@ retry:
 		sscanf(buf, "loglevel=%d", &ckp->loglevel);
 	} else if (cmdmatch(buf, "shutdown")) {
 		goto out;
-	} else if (cmdmatch(buf, "passthrough")) {
+	} else if (cmdmatch(buf, "pass")) {
 		client_instance_t *client;
+		bool lz4 = false;
 
-		ret = sscanf(buf, "passthrough=%"PRId64, &client_id);
+		if (strstr(buf, "lz4")) {
+			lz4 = true;
+			ret = sscanf(buf, "passlz4=%"PRId64, &client_id);
+		} else
+			ret = sscanf(buf, "passthrough=%"PRId64, &client_id);
 		if (ret < 0) {
 			LOGDEBUG("Connector failed to parse passthrough command: %s", buf);
 			goto retry;
@@ -1250,6 +1249,7 @@ retry:
 			LOGINFO("Connector failed to find client id %"PRId64" to pass through", client_id);
 			goto retry;
 		}
+		client->lz4 = lz4;
 		passthrough_client(cdata, client);
 		dec_instance_ref(cdata, client);
 	} else if (cmdmatch(buf, "getxfd")) {

src/stratifier.c

@@ -5186,10 +5186,11 @@ static void add_mining_node(sdata_t *sdata, stratum_instance_t *client)
 
 /* Enter with client holding ref count */
 static void parse_method(ckpool_t *ckp, sdata_t *sdata, stratum_instance_t *client,
-			 const int64_t client_id, json_t *id_val, json_t *method_val,
+			 const int64_t client_id, json_t *val, json_t *id_val, json_t *method_val,
 			 json_t *params_val)
 {
 	const char *method;
+	bool var;
 
 	/* Random broken clients send something not an integer as the id so we
 	 * copy the json item for id_val as is for the response. By far the
@@ -5237,8 +5238,12 @@ static void parse_method(ckpool_t *ckp, sdata_t *sdata, stratum_instance_t *clie
 
 		/* Add this client as a passthrough in the connector and
 		 * add it to the list of mining nodes in the stratifier */
+		json_get_bool(&var, val, "lz4");
 		add_mining_node(sdata, client);
-		snprintf(buf, 255, "passthrough=%"PRId64, client_id);
+		if (var)
+			snprintf(buf, 255, "passlz4=%"PRId64, client_id);
+		else
+			snprintf(buf, 255, "passthrough=%"PRId64, client_id);
 		send_proc(ckp->connector, buf);
 		return;
 	}
@@ -5250,8 +5255,12 @@ static void parse_method(ckpool_t *ckp, sdata_t *sdata, stratum_instance_t *clie
 		 * is a passthrough and to manage its messages accordingly. No
 		 * data from this client id should ever come back to this
 		 * stratifier after this so drop the client in the stratifier. */
+		json_get_bool(&var, val, "lz4");
 		LOGNOTICE("Adding passthrough client %"PRId64" %s", client_id, client->address);
-		snprintf(buf, 255, "passthrough=%"PRId64, client_id);
+		if (var)
+			snprintf(buf, 255, "passlz4=%"PRId64, client_id);
+		else
+			snprintf(buf, 255, "passthrough=%"PRId64, client_id);
 		send_proc(ckp->connector, buf);
 		drop_client(ckp, sdata, client_id);
 		return;
@@ -5469,7 +5478,7 @@ static void parse_instance_msg(ckpool_t *ckp, sdata_t *sdata, smsg_t *msg, strat
 		send_json_err(sdata, client_id, id_val, "-1:params not found");
 		goto out;
 	}
-	parse_method(ckp, sdata, client, client_id, id_val, method, params);
+	parse_method(ckp, sdata, client, client_id, val, id_val, method, params);
 out:
 	free_smsg(msg);
 }