Revise backend libpq interfaces so that messages to the frontend

can be generated in a buffer and then sent to the frontend in a single
libpq call.  This solves problems with NOTICE and ERROR messages generated
in the middle of a data message or COPY OUT operation.

src/backend/commands/async.c

@@ -6,7 +6,7 @@
  * Copyright (c) 1994, Regents of the University of California
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.44 1999/02/13 23:15:00 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/async.c,v 1.45 1999/04/25 03:19:08 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -94,6 +94,7 @@
 #include "fmgr.h"
 #include "lib/dllist.h"
 #include "libpq/libpq.h"
+#include "libpq/pqformat.h"
 #include "miscadmin.h"
 #include "storage/bufmgr.h"
 #include "storage/lmgr.h"
@@ -798,9 +799,12 @@ NotifyMyFrontEnd(char *relname, int32 listenerPID)
 {
 	if (whereToSendOutput == Remote)
 	{
-		pq_putnchar("A", 1);
-		pq_putint(listenerPID, sizeof(int32));
-		pq_putstr(relname);
+		StringInfoData buf;
+		pq_beginmessage(&buf);
+		pq_sendbyte(&buf, 'A');
+		pq_sendint(&buf, listenerPID, sizeof(int32));
+		pq_sendstring(&buf, relname, strlen(relname));
+		pq_endmessage(&buf);
 		/* NOTE: we do not do pq_flush() here.  For a self-notify, it will
 		 * happen at the end of the transaction, and for incoming notifies
 		 * ProcessIncomingNotify will do it after finding all the notifies.

src/backend/commands/copy.c

@@ -6,7 +6,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.73 1999/02/13 23:15:04 momjian Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/commands/copy.c,v 1.74 1999/04/25 03:19:09 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -89,12 +89,14 @@ inline void CopyDonePeek(FILE *fp, int c, int pickup);
  *
  * CopySendString does the same for null-terminated strings
  * CopySendChar does the same for single characters
+ *
+ * NB: no data conversion is applied by these functions
  */
 inline void CopySendData(void *databuf, int datasize, FILE *fp) {
   if (!fp)
-    pq_putnchar(databuf, datasize);
+	  pq_putbytes((char*) databuf, datasize);
   else
-    fwrite(databuf, datasize, 1, fp);
+	  fwrite(databuf, datasize, 1, fp);
 }
     
 inline void CopySendString(char *str, FILE *fp) {
@@ -112,17 +114,24 @@ inline void CopySendChar(char c, FILE *fp) {
  *
  * CopyGetChar does the same for single characters
  * CopyGetEof checks if it's EOF on the input
+ *
+ * NB: no data conversion is applied by these functions
  */
 inline void CopyGetData(void *databuf, int datasize, FILE *fp) {
   if (!fp)
-    pq_getnchar(databuf, 0, datasize); 
+    pq_getbytes((char*) databuf, datasize); 
   else 
     fread(databuf, datasize, 1, fp);
 }
 
 inline int CopyGetChar(FILE *fp) {
   if (!fp) 
-    return pq_getchar();
+  {
+	  unsigned char ch;
+	  if (pq_getbytes((char*) &ch, 1))
+		  return EOF;
+	  return ch;
+  }
   else
     return getc(fp);
 }
@@ -143,7 +152,7 @@ inline int CopyGetEof(FILE *fp) {
  */
 inline int CopyPeekChar(FILE *fp) {
   if (!fp) 
-    return pq_peekchar();
+    return pq_peekbyte();
   else
     return getc(fp);
 }
@@ -153,7 +162,7 @@ inline void CopyDonePeek(FILE *fp, int c, int pickup) {
     if (pickup) {
       /* We want to pick it up - just receive again into dummy buffer */
       char c;
-      pq_getnchar(&c, 0, 1);
+      pq_getbytes(&c, 1);
     }
     /* If we didn't want to pick it up, just leave it where it sits */
   }
@@ -216,7 +225,10 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
 	 * descriptor leak.  bjm 1998/08/29
 	 */
 	if (file_opened)
+	{
 		FreeFile(fp);
+		file_opened = false;
+	}
 
 	rel = heap_openr(relname);
 	if (rel == NULL)
@@ -271,6 +283,7 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
 				if (IsUnderPostmaster)
 				{
 					SendCopyBegin();
+					pq_startcopyout();
 					fp = NULL;
 				}
 				else
@@ -301,9 +314,12 @@ DoCopy(char *relname, bool binary, bool oids, bool from, bool pipe,
 			FreeFile(fp);
 			file_opened = false;
 		}
-		else if (!from && !binary)
+		else if (!from)
 		{
-			CopySendData("\\.\n",3,fp);
+			if (!binary)
+				CopySendData("\\.\n",3,fp);
+			if (IsUnderPostmaster)
+				pq_endcopyout(false);
 		}
 	}
 }

src/backend/commands/explain.c

@@ -4,7 +4,7 @@
  *
  * Copyright (c) 1994-5, Regents of the University of California
  *
- *	  $Id: explain.c,v 1.34 1999/04/23 21:23:48 momjian Exp $
+ *	  $Id: explain.c,v 1.35 1999/04/25 03:19:09 tgl Exp $
  *
  */
 #include <stdio.h>
@@ -350,18 +350,13 @@ explain_outNode(StringInfo str, Plan *plan, int indent, ExplainState *es)
 static char *
 Explain_PlanToString(Plan *plan, ExplainState *es)
 {
-	StringInfo	str;
-	char	   *s;
+	StringInfoData	str;
 
-	if (plan == NULL)
-		return "";
-	Assert(plan != NULL);
-	str = makeStringInfo();
-	explain_outNode(str, plan, 0, es);
-	s = str->data;
-	pfree(str);
-
-	return s;
+	/* see stringinfo.h for an explanation of this maneuver */
+	initStringInfo(&str);
+	if (plan != NULL)
+		explain_outNode(&str, plan, 0, es);
+	return str.data;
 }
 
 /*