Misc cleanup in libpagestore.c.

- Fix typos
- Change Zenith -> Neon in the ZENITH_SMGR tag that's printed in error
  messages that is user-visible, and in various function names and comments
  that are not user-visible.
- pgindent
- Remove comment about zm_to_string() leaking memory. It doesn't.
- Re-word some error messages to match PostgreSQL error message style guide

Author: hlinnaka

contrib/zenith/libpagestore.c

@@ -1,14 +1,14 @@
 /*-------------------------------------------------------------------------
  *
- * libpqpagestore.c
+ * libpagestore.c
  *	  Handles network communications with the remote pagestore.
  *
  * Portions Copyright (c) 1996-2021, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
  *
  * IDENTIFICATION
- *	 contrib/zenith/libpqpagestore.c
+ *	 contrib/zenith/libpagestore.c
  *
  *-------------------------------------------------------------------------
  */
@@ -34,23 +34,23 @@ void		_PG_init(void);
 
 #define PqPageStoreTrace DEBUG5
 
-#define ZENITH_TAG "[ZENITH_SMGR] "
-#define zenith_log(tag, fmt, ...) ereport(tag, \
-		(errmsg(ZENITH_TAG fmt, ## __VA_ARGS__), \
+#define NEON_TAG "[NEON_SMGR] "
+#define neon_log(tag, fmt, ...) ereport(tag, \
+		(errmsg(NEON_TAG fmt, ## __VA_ARGS__), \
 		 errhidestmt(true), errhidecontext(true)))
 
 bool		connected = false;
 PGconn	   *pageserver_conn = NULL;
 
 char	   *page_server_connstring_raw;
 
-static ZenithResponse *zenith_call(ZenithRequest *request);
+static ZenithResponse *pageserver_call(ZenithRequest *request);
 page_server_api api = {
-	.request = zenith_call
+	.request = pageserver_call
 };
 
 static void
-zenith_connect()
+pageserver_connect()
 {
 	char	   *query;
 	int			ret;
@@ -67,7 +67,7 @@ zenith_connect()
 		pageserver_conn = NULL;
 		ereport(ERROR,
 				(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
-				 errmsg("[ZENITH_SMGR] could not establish connection"),
+				 errmsg("[NEON_SMGR] could not establish connection to pageserver"),
 				 errdetail_internal("%s", msg)));
 	}
 
@@ -84,8 +84,7 @@ zenith_connect()
 		{
 			PQfinish(pageserver_conn);
 			pageserver_conn = NULL;
-			zenith_log(ERROR,
-					   "[ZENITH_SMGR] callmemaybe command failed");
+			neon_log(ERROR, "[NEON_SMGR] callmemaybe command failed");
 		}
 		PQclear(res);
 	}
@@ -96,8 +95,7 @@ zenith_connect()
 	{
 		PQfinish(pageserver_conn);
 		pageserver_conn = NULL;
-		zenith_log(ERROR,
-				   "[ZENITH_SMGR] failed to start dispatcher_loop on pageserver");
+		neon_log(ERROR, "[NEON_SMGR] could not send pagestream command to pageserver");
 	}
 
 	while (PQisBusy(pageserver_conn))
@@ -124,14 +122,14 @@ zenith_connect()
 				PQfinish(pageserver_conn);
 				pageserver_conn = NULL;
 
-				zenith_log(ERROR, "[ZENITH_SMGR] failed to get handshake from pageserver: %s",
-						   msg);
+				neon_log(ERROR, "[NEON_SMGR] could not complete handshake with pageserver: %s",
+						 msg);
 			}
 		}
 	}
 
-	// FIXME: when auth is enabled this ptints JWT to logs
-	zenith_log(LOG, "libpqpagestore: connected to '%s'", page_server_connstring);
+	/* FIXME: when auth is enabled this prints JWT to logs */
+	neon_log(LOG, "libpagestore: connected to '%s'", page_server_connstring);
 
 	connected = true;
 }
@@ -145,7 +143,7 @@ call_PQgetCopyData(PGconn *conn, char **buffer)
 	int			ret;
 
 retry:
-	ret = PQgetCopyData(conn, buffer, 1 /* async */);
+	ret = PQgetCopyData(conn, buffer, 1 /* async */ );
 
 	if (ret == 0)
 	{
@@ -165,8 +163,8 @@ call_PQgetCopyData(PGconn *conn, char **buffer)
 		if (wc & WL_SOCKET_READABLE)
 		{
 			if (!PQconsumeInput(conn))
-				zenith_log(ERROR, "could not get response from pageserver: %s",
-						   PQerrorMessage(conn));
+				neon_log(ERROR, "could not get response from pageserver: %s",
+						 PQerrorMessage(conn));
 		}
 
 		goto retry;
@@ -177,7 +175,7 @@ call_PQgetCopyData(PGconn *conn, char **buffer)
 
 
 static ZenithResponse *
-zenith_call(ZenithRequest *request)
+pageserver_call(ZenithRequest *request)
 {
 	StringInfoData req_buff;
 	StringInfoData resp_buff;
@@ -194,7 +192,7 @@ zenith_call(ZenithRequest *request)
 		}
 
 		if (!connected)
-			zenith_connect();
+			pageserver_connect();
 
 		req_buff = zm_pack_request(request);
 
@@ -203,21 +201,21 @@ zenith_call(ZenithRequest *request)
 		 *
 		 * In principle, this could block if the output buffer is full, and we
 		 * should use async mode and check for interrupts while waiting. In
-		 * practice, our requests are small enough to always fit in the output and
-		 * TCP buffer.
+		 * practice, our requests are small enough to always fit in the output
+		 * and TCP buffer.
 		 */
 		if (PQputCopyData(pageserver_conn, req_buff.data, req_buff.len) <= 0 || PQflush(pageserver_conn))
 		{
-			zenith_log(ERROR, "failed to send page request: %s",
-					   PQerrorMessage(pageserver_conn));
+			neon_log(ERROR, "failed to send page request: %s",
+					 PQerrorMessage(pageserver_conn));
 		}
 		pfree(req_buff.data);
 
 		if (message_level_is_interesting(PqPageStoreTrace))
 		{
 			char	   *msg = zm_to_string((ZenithMessage *) request);
 
-			zenith_log(PqPageStoreTrace, "Sent request: %s", msg);
+			neon_log(PqPageStoreTrace, "sent request: %s", msg);
 			pfree(msg);
 		}
 
@@ -226,9 +224,9 @@ zenith_call(ZenithRequest *request)
 		resp_buff.cursor = 0;
 
 		if (resp_buff.len == -1)
-			zenith_log(ERROR, "end of COPY");
+			neon_log(ERROR, "end of COPY");
 		else if (resp_buff.len == -2)
-			zenith_log(ERROR, "could not read COPY data: %s", PQerrorMessage(pageserver_conn));
+			neon_log(ERROR, "could not read COPY data: %s", PQerrorMessage(pageserver_conn));
 
 		resp = zm_unpack_response(&resp_buff);
 		PQfreemem(resp_buff.data);
@@ -237,14 +235,9 @@ zenith_call(ZenithRequest *request)
 		{
 			char	   *msg = zm_to_string((ZenithMessage *) resp);
 
-			zenith_log(PqPageStoreTrace, "Got response: %s", msg);
+			neon_log(PqPageStoreTrace, "got response: %s", msg);
 			pfree(msg);
 		}
-
-		/*
-		 * XXX: zm_to_string leak strings. Check with what memory contex all this
-		 * methods are called.
-		 */
 	}
 	PG_CATCH();
 	{
@@ -257,7 +250,7 @@ zenith_call(ZenithRequest *request)
 		 */
 		if (connected)
 		{
-			zenith_log(LOG, "dropping connection to page server due to error");
+			neon_log(LOG, "dropping connection to page server due to error");
 			PQfinish(pageserver_conn);
 			pageserver_conn = NULL;
 			connected = false;
@@ -290,11 +283,13 @@ substitute_pageserver_password(const char *page_server_connstring_raw)
 	PQconninfoOption *conn_options;
 	PQconninfoOption *conn_option;
 	MemoryContext oldcontext;
+
 	/*
-	 * Here we substitute password in connection string with an environment variable.
-	 * To simplify things we construct a connection string back with only known options.
-	 * In particular: host port user and password. We do not currently use other options and
-	 * constructing full connstring in an URI shape is quite messy.
+	 * Here we substitute password in connection string with an environment
+	 * variable. To simplify things we construct a connection string back with
+	 * only known options. In particular: host port user and password. We do
+	 * not currently use other options and constructing full connstring in an
+	 * URI shape is quite messy.
 	 */
 
 	if (page_server_connstring_raw == NULL || page_server_connstring_raw[0] == '\0')
@@ -321,15 +316,18 @@ substitute_pageserver_password(const char *page_server_connstring_raw)
 	 */
 	for (conn_option = conn_options; conn_option->keyword != NULL; conn_option++)
 	{
-		if (strcmp(conn_option->keyword, "host") == 0) {
+		if (strcmp(conn_option->keyword, "host") == 0)
+		{
 			if (conn_option->val != NULL && conn_option->val[0] != '\0')
 				host = conn_option->val;
 		}
-		else if (strcmp(conn_option->keyword, "port") == 0) {
+		else if (strcmp(conn_option->keyword, "port") == 0)
+		{
 			if (conn_option->val != NULL && conn_option->val[0] != '\0')
 				port = conn_option->val;
 		}
-		else if (strcmp(conn_option->keyword, "user") == 0) {
+		else if (strcmp(conn_option->keyword, "user") == 0)
+		{
 			if (conn_option->val != NULL && conn_option->val[0] != '\0')
 				user = conn_option->val;
 		}
@@ -343,7 +341,7 @@ substitute_pageserver_password(const char *page_server_connstring_raw)
 							(errcode(ERRCODE_CONNECTION_EXCEPTION),
 							 errmsg("expected placeholder value in pageserver password starting from $ but found: %s", &conn_option->val[1])));
 
-				zenith_log(LOG, "found auth token placeholder in pageserver conn string %s", &conn_option->val[1]);
+				neon_log(LOG, "found auth token placeholder in pageserver conn string '%s'", &conn_option->val[1]);
 				auth_token = getenv(&conn_option->val[1]);
 				if (!auth_token)
 				{
@@ -353,12 +351,16 @@ substitute_pageserver_password(const char *page_server_connstring_raw)
 				}
 				else
 				{
-					zenith_log(LOG, "using auth token from environment passed via env");
+					neon_log(LOG, "using auth token from environment passed via env");
 				}
 			}
 		}
 	}
-	// allocate connection string in a TopMemoryContext to make sure it is not freed
+
+	/*
+	 * allocate connection string in TopMemoryContext to make sure it is not
+	 * freed
+	 */
 	oldcontext = CurrentMemoryContext;
 	MemoryContextSwitchTo(TopMemoryContext);
 	page_server_connstring = psprintf("postgresql://%s:%s@%s:%s", user, auth_token ? auth_token : "", host, port);
@@ -426,15 +428,15 @@ _PG_init(void)
 							-1, -1, INT_MAX,
 							PGC_SIGHUP,
 							GUC_UNIT_MB,
-							NULL, NULL,	NULL);
+							NULL, NULL, NULL);
 
 	relsize_hash_init();
 	EmitWarningsOnPlaceholders("zenith");
 
 	if (page_server != NULL)
-		zenith_log(ERROR, "libpqpagestore already loaded");
+		neon_log(ERROR, "libpagestore already loaded");
 
-	zenith_log(PqPageStoreTrace, "libpqpagestore already loaded");
+	neon_log(PqPageStoreTrace, "libpagestore already loaded");
 	page_server = &api;
 
 	/* substitute password in pageserver_connstring */
@@ -443,18 +445,22 @@ _PG_init(void)
 	/* Is there more correct way to pass CustomGUC to postgres code? */
 	zenith_timeline_walproposer = zenith_timeline;
 	zenith_tenant_walproposer = zenith_tenant;
-	/* Walproposer instructcs safekeeper which pageserver to use for replication */
+
+	/*
+	 * Walproposer instructs safekeeper which pageserver to use for
+	 * replication
+	 */
 	zenith_pageserver_connstring_walproposer = page_server_connstring;
 
 	if (wal_redo)
 	{
-		zenith_log(PqPageStoreTrace, "set inmem_smgr hook");
+		neon_log(PqPageStoreTrace, "set inmem_smgr hook");
 		smgr_hook = smgr_inmem;
 		smgr_init_hook = smgr_init_inmem;
 	}
 	else if (page_server_connstring && page_server_connstring[0])
 	{
-		zenith_log(PqPageStoreTrace, "set zenith_smgr hook");
+		neon_log(PqPageStoreTrace, "set neon_smgr hook");
 		smgr_hook = smgr_zenith;
 		smgr_init_hook = smgr_init_zenith;
 		dbsize_hook = zenith_dbsize;