Avoid unnecessary copying of parameter values in BIND. This allows

efficient insertion of large bytea values through the BIND interface.

diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index f444302e9651d8b72955aa65e32e8f9daa6c0a90..a37ed5a9b692c20ea0d83cdc121879d39237d770 100644 (file)
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *   $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.342 2003/05/09 18:08:48 tgl Exp $
+ *   $Header: /cvsroot/pgsql/src/backend/tcop/postgres.c,v 1.343 2003/05/12 16:48:17 tgl Exp $
  *
  * NOTES
  *   this is the "main" module of the postgres backend and
@@ -1265,13 +1265,9 @@ exec_bind_message(StringInfo input_message)
    if (numParams > 0)
    {
        bool    isaborted = IsAbortedTransactionBlockState();
-       StringInfoData pbuf;
        List   *l;
        MemoryContext oldContext;
 
-       /* Note that the string buffer lives in MessageContext */
-       initStringInfo(&pbuf);
-
        oldContext = MemoryContextSwitchTo(PortalGetHeapMemory(portal));
 
        params = (ParamListInfo)
@@ -1289,14 +1285,7 @@ exec_bind_message(StringInfo input_message)
 
            if (!isNull)
            {
-               /* Reset pbuf to empty, and insert raw data into it */
-               pbuf.len = 0;
-               pbuf.data[0] = '\0';
-               pbuf.cursor = 0;
-
-               appendBinaryStringInfo(&pbuf,
-                                      pq_getmsgbytes(input_message, plength),
-                                      plength);
+               const char *pvalue = pq_getmsgbytes(input_message, plength);
 
                if (isaborted)
                {
@@ -1306,6 +1295,8 @@ exec_bind_message(StringInfo input_message)
                else
                {
                    int16   pformat;
+                   StringInfoData pbuf;
+                   char    csave;
 
                    if (numPFormats > 1)
                        pformat = pformats[i];
@@ -1314,6 +1305,23 @@ exec_bind_message(StringInfo input_message)
                    else
                        pformat = 0;        /* default = text */
 
+                   /*
+                    * Rather than copying data around, we just set up a phony
+                    * StringInfo pointing to the correct portion of the
+                    * message buffer.  We assume we can scribble on the
+                    * message buffer so as to maintain the convention that
+                    * StringInfos have a trailing null.  This is grotty but
+                    * is a big win when dealing with very large parameter
+                    * strings.
+                    */
+                   pbuf.data = (char *) pvalue;
+                   pbuf.maxlen = plength + 1;
+                   pbuf.len = plength;
+                   pbuf.cursor = 0;
+
+                   csave = pbuf.data[plength];
+                   pbuf.data[plength] = '\0';
+
                    if (pformat == 0)
                    {
                        Oid         typInput;
@@ -1322,11 +1330,8 @@ exec_bind_message(StringInfo input_message)
 
                        getTypeInputInfo(ptype, &typInput, &typElem);
                        /*
-                        * Since stringinfo.c keeps a trailing null in
-                        * place even for binary data, the contents of
-                        * pbuf are a valid C string.  We have to do
-                        * encoding conversion before calling the typinput
-                        * routine, though.
+                        * We have to do encoding conversion before calling
+                        * the typinput routine.
                         */
                        pstring = (char *)
                            pg_client_to_server((unsigned char *) pbuf.data,
@@ -1362,6 +1367,9 @@ exec_bind_message(StringInfo input_message)
                    {
                        elog(ERROR, "Invalid format code %d", pformat);
                    }
+
+                   /* Restore message buffer contents */
+                   pbuf.data[plength] = csave;
                }
            }
 
@@ -2524,7 +2532,7 @@ PostgresMain(int argc, char *argv[], const char *username)
    if (!IsUnderPostmaster)
    {
        puts("\nPOSTGRES backend interactive interface ");
-       puts("$Revision: 1.342 $ $Date: 2003/05/09 18:08:48 $\n");
+       puts("$Revision: 1.343 $ $Date: 2003/05/12 16:48:17 $\n");
    }
 
    /*