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Clean up BeginCommand and related routines. BeginCommand and EndCommand

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are now both invoked once per received SQL command (raw parsetree) from
pg_exec_query_string.  BeginCommand is actually just an empty routine
at the moment --- all its former operations have been pushed into tuple
receiver setup routines in printtup.c.  This makes for a clean distinction
between BeginCommand/EndCommand (once per command) and the tuple receiver
setup/teardown routines (once per ExecutorRun call), whereas the old code
was quite ad hoc.  Along the way, clean up the calling conventions for
ExecutorRun a little bit.
This commit is contained in:
Tom Lane
2002-02-27 19:36:13 +00:00
parent e22c9c4475
commit 6779c55c22
15 changed files with 266 additions and 361 deletions
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82
src/backend/access/common/printtup.c
View File

@ -1,15 +1,15 @@
/*-------------------------------------------------------------------------
*
* printtup.c
* Routines to print out tuples to the destination (binary or non-binary
* portals, frontend/interactive backend, etc.).
* Routines to print out tuples to the destination (both frontend
* clients and interactive backends are supported here).
*
*
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.60 2001/10/25 05:49:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.61 2002/02/27 19:34:09 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -18,10 +18,12 @@
#include "access/heapam.h"
#include "access/printtup.h"
#include "catalog/pg_type.h"
#include "libpq/libpq.h"
#include "libpq/pqformat.h"
#include "utils/syscache.h"
static void printtup_setup(DestReceiver *self, TupleDesc typeinfo);
static void printtup_setup(DestReceiver *self, int operation,
const char *portalName, TupleDesc typeinfo);
static void printtup(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self);
static void printtup_internal(HeapTuple tuple, TupleDesc typeinfo, DestReceiver *self);
static void printtup_cleanup(DestReceiver *self);
@ -97,17 +99,56 @@ printtup_create_DR(bool isBinary)
}
static void
printtup_setup(DestReceiver *self, TupleDesc typeinfo)
printtup_setup(DestReceiver *self, int operation,
const char *portalName, TupleDesc typeinfo)
{
/*
* Send portal name to frontend.
*
* If portal name not specified, use "blank" portal.
*/
if (portalName == NULL)
portalName = "blank";
pq_puttextmessage('P', portalName);
/*
* if this is a retrieve, then we send back the tuple
* descriptor of the tuples.
*/
if (operation == CMD_SELECT)
{
Form_pg_attribute *attrs = typeinfo->attrs;
int natts = typeinfo->natts;
int i;
StringInfoData buf;
pq_beginmessage(&buf);
pq_sendbyte(&buf, 'T'); /* tuple descriptor message type */
pq_sendint(&buf, natts, 2); /* # of attrs in tuples */
for (i = 0; i < natts; ++i)
{
pq_sendstring(&buf, NameStr(attrs[i]->attname));
pq_sendint(&buf, (int) attrs[i]->atttypid,
sizeof(attrs[i]->atttypid));
pq_sendint(&buf, attrs[i]->attlen,
sizeof(attrs[i]->attlen));
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
pq_sendint(&buf, attrs[i]->atttypmod,
sizeof(attrs[i]->atttypmod));
}
pq_endmessage(&buf);
}
/* ----------------
* We could set up the derived attr info at this time, but we postpone it
* until the first call of printtup, for 3 reasons:
* until the first call of printtup, for 2 reasons:
* 1. We don't waste time (compared to the old way) if there are no
* tuples at all to output.
* 2. Checking in printtup allows us to handle the case that the tuples
* change type midway through (although this probably can't happen in
* the current executor).
* 3. Right now, ExecutorRun passes a NULL for typeinfo anyway :-(
* ----------------
*/
}
@ -267,12 +308,12 @@ printatt(unsigned attributeId,
* showatts
* ----------------
*/
void
showatts(char *name, TupleDesc tupleDesc)
static void
showatts(const char *name, TupleDesc tupleDesc)
{
int i;
int natts = tupleDesc->natts;
Form_pg_attribute *attinfo = tupleDesc->attrs;
int i;
puts(name);
for (i = 0; i < natts; ++i)
@ -281,7 +322,24 @@ showatts(char *name, TupleDesc tupleDesc)
}
/* ----------------
* debugtup
* debugSetup - prepare to print tuples for an interactive backend
* ----------------
*/
void
debugSetup(DestReceiver *self, int operation,
const char *portalName, TupleDesc typeinfo)
{
/*
* show the return type of the tuples
*/
if (portalName == NULL)
portalName = "blank";
showatts(portalName, typeinfo);
}
/* ----------------
* debugtup - print one tuple for an interactive backend
* ----------------
*/
void

4
src/backend/access/common/tupdesc.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.76 2001/10/25 05:49:20 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.77 2002/02/27 19:34:11 tgl Exp $
*
* NOTES
* some of the executor utility code such as "ExecTypeFromTL" should be
@ -432,7 +432,7 @@ TupleDescInitEntry(TupleDesc desc,
*
* (Why not just make the atttypid point to the OID type, instead of the
* type the query returns? Because the executor uses the atttypid to
* tell the front end what type will be returned (in BeginCommand),
* tell the front end what type will be returned,
* and in the end the type returned will be the result of the query,
* not an OID.)
*