1 files changed, 354 insertions, 0 deletions
diff --git a/src/backend/tcop/dest.c b/src/backend/tcop/dest.c
new file mode 100644
index 00000000000..0e10c1403e0
--- /dev/null
+++ b/src/backend/tcop/dest.c
@@ -0,0 +1,354 @@
+/*-------------------------------------------------------------------------
+ *
+ * dest.c--
+ *    support for various communication destinations - see lib/H/tcop/dest.h
+ *
+ * Copyright (c) 1994, Regents of the University of California
+ *
+ *
+ * IDENTIFICATION
+ *    $Header: /cvsroot/pgsql/src/backend/tcop/dest.c,v 1.1.1.1 1996/07/09 06:21:59 scrappy Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+/*
+ *   INTERFACE ROUTINES
+ * 	BeginCommand - prepare destination for tuples of the given type
+ * 	EndCommand - tell destination that no more tuples will arrive
+ * 	NullCommand - tell dest that the last of a query sequence was processed
+ *	
+ *   NOTES
+ *	These routines do the appropriate work before and after
+ *	tuples are returned by a query to keep the backend and the
+ *	"destination" portals synchronized.
+ *
+ */
+#include <stdio.h>		/* for sprintf() */
+#include "postgres.h"
+
+#include "access/htup.h"
+#include "libpq/libpq-be.h"
+#include "access/printtup.h"
+#include "utils/portal.h"
+#include "utils/elog.h"
+#include "utils/palloc.h"
+
+#include "executor/executor.h"
+
+#include "tcop/dest.h"
+
+#include "catalog/pg_type.h"
+#include "utils/mcxt.h"
+
+#include "commands/async.h"
+
+/* ----------------
+ *	output functions
+ * ----------------
+ */
+void
+donothing(List *tuple, List *attrdesc)
+{
+}
+
+void (*DestToFunction(CommandDest dest))()
+{
+    switch (dest) {
+    case RemoteInternal:
+	return printtup_internal;
+	break;
+	
+    case Remote:
+	return printtup;
+	break;
+	
+    case Local:
+	return be_printtup;
+	break;
+	
+    case Debug:
+	return debugtup;
+	break;
+	
+    case None:
+    default:
+	return donothing;
+	break;
+    }	
+    
+    /*
+     * never gets here, but DECstation lint appears to be stupid...
+     */
+    
+    return donothing;
+}
+
+#define IS_INSERT_TAG(tag) (*tag == 'I' && *(tag+1) == 'N')
+
+/* ----------------
+ * 	EndCommand - tell destination that no more tuples will arrive
+ * ----------------
+ */
+void
+EndCommand(char *commandTag, CommandDest dest)
+{
+    char buf[64];
+    
+    switch (dest) {
+    case RemoteInternal:
+    case Remote:
+	/* ----------------
+	 *	tell the fe that the query is over
+	 * ----------------
+	 */
+	pq_putnchar("C", 1);
+/*	pq_putint(0, 4); */
+	if (IS_INSERT_TAG(commandTag))
+	    {
+		sprintf(buf, "%s %d", commandTag, GetAppendOid());
+		pq_putstr(buf);
+	    }
+	else
+	    pq_putstr(commandTag);
+	pq_flush();
+	break;
+	
+    case Local:
+    case Debug:
+	break;
+    case CopyEnd:
+	pq_putnchar("Z", 1);
+	pq_flush();
+	break;
+    case None:
+    default:
+	break;
+    }
+}
+
+/*
+ * These are necessary to sync communications between fe/be processes doing
+ * COPY rel TO stdout
+ * 
+ * or 
+ *
+ * COPY rel FROM stdin
+ *
+ */
+void
+SendCopyBegin()
+{
+    pq_putnchar("B", 1);
+/*    pq_putint(0, 4); */
+    pq_flush();
+}
+
+void
+ReceiveCopyBegin()
+{
+    pq_putnchar("D", 1);
+/*    pq_putint(0, 4); */
+    pq_flush();
+}
+
+/* ----------------
+ * 	NullCommand - tell dest that the last of a query sequence was processed
+ * 
+ * 	Necessary to implement the hacky FE/BE interface to handle
+ *	multiple-return queries.
+ * ----------------
+ */
+void
+NullCommand(CommandDest dest)
+{
+    switch (dest) {
+    case RemoteInternal:
+    case Remote: {
+#if 0
+	/* Do any asynchronous notification.  If front end wants to poll,
+	   it can send null queries to call this function.
+	   */
+	PQNotifyList *nPtr;
+	MemoryContext orig;
+	
+	if (notifyContext == NULL) {
+	    notifyContext = CreateGlobalMemory("notify");
+	}
+	orig = MemoryContextSwitchTo((MemoryContext)notifyContext);
+	
+	for (nPtr = PQnotifies() ;
+	     nPtr != NULL;
+	     nPtr = (PQNotifyList *)SLGetSucc(&nPtr->Node)) {
+	    pq_putnchar("A",1);
+	    pq_putint(0, 4);
+	    pq_putstr(nPtr->relname);
+	    pq_putint(nPtr->be_pid,4);
+	    PQremoveNotify(nPtr);
+	}
+	pq_flush();
+	PQcleanNotify();	/* garbage collect */
+	(void) MemoryContextSwitchTo(orig);
+#endif
+	/* ----------------
+	 *	tell the fe that the last of the queries has finished
+	 * ----------------
+	 */
+/* 	pq_putnchar("I", 1);  */
+ 	pq_putstr("I");  
+	/* pq_putint(0, 4);*/
+	pq_flush();
+    }
+	break;
+	
+    case Local:
+    case Debug:
+    case None:
+    default:
+	break;
+    }	
+}
+
+/* ----------------
+ * 	BeginCommand - prepare destination for tuples of the given type
+ * ----------------
+ */
+void
+BeginCommand(char *pname,
+	     int operation,
+	     TupleDesc tupdesc,
+	     bool isIntoRel,
+	     bool isIntoPortal,
+	     char *tag,
+	     CommandDest dest)
+{
+    PortalEntry	*entry;
+    AttributeTupleForm *attrs = tupdesc->attrs;
+    int    natts = tupdesc->natts;
+    int    i;
+    char   *p;
+
+    switch (dest) {
+    case RemoteInternal:
+    case Remote:
+	/* ----------------
+	 *	if this is a "retrieve portal" query, just return
+	 *	because nothing needs to be sent to the fe.
+	 * ----------------
+	 */
+        ResetAppendOid();
+	if (isIntoPortal)
+	    return;
+	
+	/* ----------------
+	 *	if portal name not specified for remote query,
+	 *	use the "blank" portal.
+	 * ----------------
+	 */
+	if (pname == NULL)
+	    pname = "blank";
+	
+	/* ----------------
+	 *	send fe info on tuples we're about to send
+	 * ----------------
+	 */
+	pq_flush();
+	pq_putnchar("P", 1);	/* new portal.. */
+	pq_putstr(pname);	/* portal name */
+	
+	/* ----------------
+	 *	if this is a retrieve, then we send back the tuple
+	 *	descriptor of the tuples.  "retrieve into" is an
+	 *	exception because no tuples are returned in that case.
+	 * ----------------
+	 */
+	if (operation == CMD_SELECT && !isIntoRel) {
+	    pq_putnchar("T", 1);	/* type info to follow.. */
+	    pq_putint(natts, 2);	/* number of attributes in tuples */
+	    
+	    for (i = 0; i < natts; ++i) {
+		pq_putstr(attrs[i]->attname.data);/* if 16 char name oops.. */
+		pq_putint((int) attrs[i]->atttypid, 4);
+		pq_putint(attrs[i]->attlen, 2);
+	    }
+	}
+	pq_flush();
+	break;
+	
+    case Local:
+	/* ----------------
+	 *	prepare local portal buffer for query results
+	 *	and setup result for PQexec()
+	 * ----------------
+	 */
+	entry = be_currentportal();
+	if (pname != NULL)
+	    pbuf_setportalinfo(entry, pname);
+	
+	if (operation == CMD_SELECT && !isIntoRel) {
+	    be_typeinit(entry, tupdesc, natts);
+	    p = (char *) palloc(strlen(entry->name)+2);
+	    p[0] = 'P';
+	    strcpy(p+1,entry->name);
+	} else {
+	    p = (char *) palloc(strlen(tag)+2);
+	    p[0] = 'C';
+	    strcpy(p+1,tag);
+	}
+	entry->result = p;
+	break;
+	
+    case Debug:
+	/* ----------------
+	 *	show the return type of the tuples
+	 * ----------------
+	 */
+	if (pname == NULL)
+	    pname = "blank";
+	
+	showatts(pname, tupdesc);
+	break;
+	
+    case None:
+    default:
+	break;
+    }
+}
+
+static Oid AppendOid;
+
+void
+ResetAppendOid()
+{
+    AppendOid = InvalidOid;
+}
+
+#define MULTI_TUPLE_APPEND -1
+
+void
+UpdateAppendOid(Oid newoid)
+{
+    /*
+     * First update after AppendOid was reset (at command beginning).
+     */
+    if (AppendOid == InvalidOid)
+	AppendOid = newoid;
+    /*
+     * Already detected a multiple tuple append, return a void oid ;)
+     */
+    else if (AppendOid == MULTI_TUPLE_APPEND)
+	return;
+    /*
+     * Oid has been assigned once before, tag this as a multiple tuple
+     * append.
+     */
+    else
+	AppendOid = MULTI_TUPLE_APPEND;
+}
+
+Oid
+GetAppendOid()
+{
+    if (AppendOid == MULTI_TUPLE_APPEND)
+	return InvalidOid;
+    return AppendOid;
+}