Refactor code converting a publication name List to a StringInfo

The existing get_publications_str() is renamed to GetPublicationsStr()
and is moved to pg_subscription.c, so as it is possible to reuse it at
two locations of the tablesync code where the same logic was duplicated.

fetch_remote_table_info() was doing two List->StringInfo conversions
when dealing with a server of version 15 or newer.  The conversion
happens only once now.

This refactoring leads to less code overall.

Author: Peter Smith
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/CAHut+PtJMk4bKXqtpvqVy9ckknCgK9P6=FeG8zHF=6+Em_Snpw@mail.gmail.com

diff --git a/src/backend/catalog/pg_subscription.c b/src/backend/catalog/pg_subscription.c
index 9efc9159f2c22eb791317d8d2c0c862c59e90e4a..89bf5ec9337ec9e5d3aef65a9dac3dfa3ab89ff8 100644 (file)
--- a/src/backend/catalog/pg_subscription.c
+++ b/src/backend/catalog/pg_subscription.c
@@ -34,6 +34,37 @@
 
 static List *textarray_to_stringlist(ArrayType *textarray);
 
+/*
+ * Add a comma-separated list of publication names to the 'dest' string.
+ */
+void
+GetPublicationsStr(List *publications, StringInfo dest, bool quote_literal)
+{
+   ListCell   *lc;
+   bool        first = true;
+
+   Assert(publications != NIL);
+
+   foreach(lc, publications)
+   {
+       char       *pubname = strVal(lfirst(lc));
+
+       if (first)
+           first = false;
+       else
+           appendStringInfoString(dest, ", ");
+
+       if (quote_literal)
+           appendStringInfoString(dest, quote_literal_cstr(pubname));
+       else
+       {
+           appendStringInfoChar(dest, '"');
+           appendStringInfoString(dest, pubname);
+           appendStringInfoChar(dest, '"');
+       }
+   }
+}
+
 /*
  * Fetch the subscription from the syscache.
  */

diff --git a/src/backend/commands/subscriptioncmds.c b/src/backend/commands/subscriptioncmds.c
index 02ccc636b807c973172a1f247259918ead19d6fb..33575614e727e8c07713367f32e7c1b81cd001a8 100644 (file)
--- a/src/backend/commands/subscriptioncmds.c
+++ b/src/backend/commands/subscriptioncmds.c
@@ -439,37 +439,6 @@ parse_subscription_options(ParseState *pstate, List *stmt_options,
    }
 }
 
-/*
- * Add publication names from the list to a string.
- */
-static void
-get_publications_str(List *publications, StringInfo dest, bool quote_literal)
-{
-   ListCell   *lc;
-   bool        first = true;
-
-   Assert(publications != NIL);
-
-   foreach(lc, publications)
-   {
-       char       *pubname = strVal(lfirst(lc));
-
-       if (first)
-           first = false;
-       else
-           appendStringInfoString(dest, ", ");
-
-       if (quote_literal)
-           appendStringInfoString(dest, quote_literal_cstr(pubname));
-       else
-       {
-           appendStringInfoChar(dest, '"');
-           appendStringInfoString(dest, pubname);
-           appendStringInfoChar(dest, '"');
-       }
-   }
-}
-
 /*
  * Check that the specified publications are present on the publisher.
  */
@@ -486,7 +455,7 @@ check_publications(WalReceiverConn *wrconn, List *publications)
    appendStringInfoString(cmd, "SELECT t.pubname FROM\n"
                           " pg_catalog.pg_publication t WHERE\n"
                           " t.pubname IN (");
-   get_publications_str(publications, cmd, true);
+   GetPublicationsStr(publications, cmd, true);
    appendStringInfoChar(cmd, ')');
 
    res = walrcv_exec(wrconn, cmd->data, 1, tableRow);
@@ -523,7 +492,7 @@ check_publications(WalReceiverConn *wrconn, List *publications)
        /* Prepare the list of non-existent publication(s) for error message. */
        StringInfo  pubnames = makeStringInfo();
 
-       get_publications_str(publicationsCopy, pubnames, false);
+       GetPublicationsStr(publicationsCopy, pubnames, false);
        ereport(WARNING,
                errcode(ERRCODE_UNDEFINED_OBJECT),
                errmsg_plural("publication %s does not exist on the publisher",
@@ -2151,7 +2120,7 @@ check_publications_origin(WalReceiverConn *wrconn, List *publications,
                           "     JOIN pg_subscription_rel PS ON (GPT.relid = PS.srrelid),\n"
                           "     pg_class C JOIN pg_namespace N ON (N.oid = C.relnamespace)\n"
                           "WHERE C.oid = GPT.relid AND P.pubname IN (");
-   get_publications_str(publications, &cmd, true);
+   GetPublicationsStr(publications, &cmd, true);
    appendStringInfoString(&cmd, ")\n");
 
    /*
@@ -2208,7 +2177,7 @@ check_publications_origin(WalReceiverConn *wrconn, List *publications,
        StringInfo  pubnames = makeStringInfo();
 
        /* Prepare the list of publication(s) for warning message. */
-       get_publications_str(publist, pubnames, false);
+       GetPublicationsStr(publist, pubnames, false);
        ereport(WARNING,
                errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
                errmsg("subscription \"%s\" requested copy_data with origin = NONE but might copy data that had a different origin",
@@ -2243,17 +2212,17 @@ fetch_table_list(WalReceiverConn *wrconn, List *publications)
    List       *tablelist = NIL;
    int         server_version = walrcv_server_version(wrconn);
    bool        check_columnlist = (server_version >= 150000);
+   StringInfo  pub_names = makeStringInfo();
 
    initStringInfo(&cmd);
 
+   /* Build the pub_names comma-separated string. */
+   GetPublicationsStr(publications, pub_names, true);
+
    /* Get the list of tables from the publisher. */
    if (server_version >= 160000)
    {
-       StringInfoData pub_names;
-
        tableRow[2] = INT2VECTOROID;
-       initStringInfo(&pub_names);
-       get_publications_str(publications, &pub_names, true);
 
        /*
         * From version 16, we allowed passing multiple publications to the
@@ -2275,9 +2244,7 @@ fetch_table_list(WalReceiverConn *wrconn, List *publications)
                         "                FROM pg_publication\n"
                         "                WHERE pubname IN ( %s )) AS gpt\n"
                         "             ON gpt.relid = c.oid\n",
-                        pub_names.data);
-
-       pfree(pub_names.data);
+                        pub_names->data);
    }
    else
    {
@@ -2288,12 +2255,13 @@ fetch_table_list(WalReceiverConn *wrconn, List *publications)
        if (check_columnlist)
            appendStringInfoString(&cmd, ", t.attnames\n");
 
-       appendStringInfoString(&cmd, "FROM pg_catalog.pg_publication_tables t\n"
-                              " WHERE t.pubname IN (");
-       get_publications_str(publications, &cmd, true);
-       appendStringInfoChar(&cmd, ')');
+       appendStringInfo(&cmd, "FROM pg_catalog.pg_publication_tables t\n"
+                        " WHERE t.pubname IN ( %s )",
+                        pub_names->data);
    }
 
+   destroyStringInfo(pub_names);
+
    res = walrcv_exec(wrconn, cmd.data, check_columnlist ? 3 : 2, tableRow);
    pfree(cmd.data);
 

diff --git a/src/backend/replication/logical/tablesync.c b/src/backend/replication/logical/tablesync.c
index e03e761392667c6e01b8abd2e8f6c73f03212337..d4b5d210e3ebc51de600ec17aca750259b7f65a5 100644 (file)
--- a/src/backend/replication/logical/tablesync.c
+++ b/src/backend/replication/logical/tablesync.c
@@ -802,7 +802,7 @@ fetch_remote_table_info(char *nspname, char *relname,
    Oid         qualRow[] = {TEXTOID};
    bool        isnull;
    int         natt;
-   ListCell   *lc;
+   StringInfo  pub_names = NULL;
    Bitmapset  *included_cols = NULL;
 
    lrel->nspname = nspname;
@@ -856,15 +856,10 @@ fetch_remote_table_info(char *nspname, char *relname,
        WalRcvExecResult *pubres;
        TupleTableSlot *tslot;
        Oid         attrsRow[] = {INT2VECTOROID};
-       StringInfoData pub_names;
 
-       initStringInfo(&pub_names);
-       foreach(lc, MySubscription->publications)
-       {
-           if (foreach_current_index(lc) > 0)
-               appendStringInfoString(&pub_names, ", ");
-           appendStringInfoString(&pub_names, quote_literal_cstr(strVal(lfirst(lc))));
-       }
+       /* Build the pub_names comma-separated string. */
+       pub_names = makeStringInfo();
+       GetPublicationsStr(MySubscription->publications, pub_names, true);
 
        /*
         * Fetch info about column lists for the relation (from all the
@@ -881,7 +876,7 @@ fetch_remote_table_info(char *nspname, char *relname,
                         " WHERE gpt.relid = %u AND c.oid = gpt.relid"
                         "   AND p.pubname IN ( %s )",
                         lrel->remoteid,
-                        pub_names.data);
+                        pub_names->data);
 
        pubres = walrcv_exec(LogRepWorkerWalRcvConn, cmd.data,
                             lengthof(attrsRow), attrsRow);
@@ -936,8 +931,6 @@ fetch_remote_table_info(char *nspname, char *relname,
        ExecDropSingleTupleTableSlot(tslot);
 
        walrcv_clear_result(pubres);
-
-       pfree(pub_names.data);
    }
 
    /*
@@ -1039,19 +1032,8 @@ fetch_remote_table_info(char *nspname, char *relname,
     */
    if (walrcv_server_version(LogRepWorkerWalRcvConn) >= 150000)
    {
-       StringInfoData pub_names;
-
-       /* Build the pubname list. */
-       initStringInfo(&pub_names);
-       foreach_node(String, pubstr, MySubscription->publications)
-       {
-           char       *pubname = strVal(pubstr);
-
-           if (foreach_current_index(pubstr) > 0)
-               appendStringInfoString(&pub_names, ", ");
-
-           appendStringInfoString(&pub_names, quote_literal_cstr(pubname));
-       }
+       /* Reuse the already-built pub_names. */
+       Assert(pub_names != NULL);
 
        /* Check for row filters. */
        resetStringInfo(&cmd);
@@ -1062,7 +1044,7 @@ fetch_remote_table_info(char *nspname, char *relname,
                         " WHERE gpt.relid = %u"
                         "   AND p.pubname IN ( %s )",
                         lrel->remoteid,
-                        pub_names.data);
+                        pub_names->data);
 
        res = walrcv_exec(LogRepWorkerWalRcvConn, cmd.data, 1, qualRow);
 
@@ -1101,6 +1083,7 @@ fetch_remote_table_info(char *nspname, char *relname,
        ExecDropSingleTupleTableSlot(slot);
 
        walrcv_clear_result(res);
+       destroyStringInfo(pub_names);
    }
 
    pfree(cmd.data);

diff --git a/src/include/catalog/pg_subscription.h b/src/include/catalog/pg_subscription.h
index 0aa14ec4a27ed168180648b5bc6874bfd49118db..b25f3fea566a0b6f992ed687b23d40bad99f37a2 100644 (file)
--- a/src/include/catalog/pg_subscription.h
+++ b/src/include/catalog/pg_subscription.h
@@ -20,7 +20,7 @@
 #include "access/xlogdefs.h"
 #include "catalog/genbki.h"
 #include "catalog/pg_subscription_d.h"
-
+#include "lib/stringinfo.h"
 #include "nodes/pg_list.h"
 
 /*
@@ -180,4 +180,7 @@ extern void DisableSubscription(Oid subid);
 
 extern int CountDBSubscriptions(Oid dbid);
 
+extern void GetPublicationsStr(List *publications, StringInfo dest,
+                              bool quote_literal);
+
 #endif                         /* PG_SUBSCRIPTION_H */