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Commit6779c55

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committed
Clean up BeginCommand and related routines. BeginCommand and EndCommand
are now both invoked once per received SQL command (raw parsetree) frompg_exec_query_string. BeginCommand is actually just an empty routineat the moment --- all its former operations have been pushed into tuplereceiver setup routines in printtup.c. This makes for a clean distinctionbetween BeginCommand/EndCommand (once per command) and the tuple receiversetup/teardown routines (once per ExecutorRun call), whereas the old codewas quite ad hoc. Along the way, clean up the calling conventions forExecutorRun a little bit.
1 parente22c9c4 commit6779c55

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15 files changed

+266
-361
lines changed

15 files changed

+266
-361
lines changed

‎src/backend/access/common/printtup.c

Lines changed: 70 additions & 12 deletions
Original file line numberDiff line numberDiff line change
@@ -1,15 +1,15 @@
11
/*-------------------------------------------------------------------------
22
*
33
* printtup.c
4-
* Routines to print out tuples to the destination (binary or non-binary
5-
* portals, frontend/interactive backend, etc.).
4+
* Routines to print out tuples to the destination (both frontend
5+
* clients and interactive backends are supported here).
6+
*
67
*
78
* Portions Copyright (c) 1996-2001, PostgreSQL Global Development Group
89
* Portions Copyright (c) 1994, Regents of the University of California
910
*
10-
*
1111
* IDENTIFICATION
12-
* $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.60 2001/10/25 05:49:20 momjian Exp $
12+
* $Header: /cvsroot/pgsql/src/backend/access/common/printtup.c,v 1.61 2002/02/27 19:34:09 tgl Exp $
1313
*
1414
*-------------------------------------------------------------------------
1515
*/
@@ -18,10 +18,12 @@
1818
#include"access/heapam.h"
1919
#include"access/printtup.h"
2020
#include"catalog/pg_type.h"
21+
#include"libpq/libpq.h"
2122
#include"libpq/pqformat.h"
2223
#include"utils/syscache.h"
2324

24-
staticvoidprinttup_setup(DestReceiver*self,TupleDesctypeinfo);
25+
staticvoidprinttup_setup(DestReceiver*self,intoperation,
26+
constchar*portalName,TupleDesctypeinfo);
2527
staticvoidprinttup(HeapTupletuple,TupleDesctypeinfo,DestReceiver*self);
2628
staticvoidprinttup_internal(HeapTupletuple,TupleDesctypeinfo,DestReceiver*self);
2729
staticvoidprinttup_cleanup(DestReceiver*self);
@@ -97,17 +99,56 @@ printtup_create_DR(bool isBinary)
9799
}
98100

99101
staticvoid
100-
printtup_setup(DestReceiver*self,TupleDesctypeinfo)
102+
printtup_setup(DestReceiver*self,intoperation,
103+
constchar*portalName,TupleDesctypeinfo)
101104
{
105+
/*
106+
* Send portal name to frontend.
107+
*
108+
* If portal name not specified, use "blank" portal.
109+
*/
110+
if (portalName==NULL)
111+
portalName="blank";
112+
113+
pq_puttextmessage('P',portalName);
114+
115+
/*
116+
* if this is a retrieve, then we send back the tuple
117+
* descriptor of the tuples.
118+
*/
119+
if (operation==CMD_SELECT)
120+
{
121+
Form_pg_attribute*attrs=typeinfo->attrs;
122+
intnatts=typeinfo->natts;
123+
inti;
124+
StringInfoDatabuf;
125+
126+
pq_beginmessage(&buf);
127+
pq_sendbyte(&buf,'T');/* tuple descriptor message type */
128+
pq_sendint(&buf,natts,2);/* # of attrs in tuples */
129+
130+
for (i=0;i<natts;++i)
131+
{
132+
pq_sendstring(&buf,NameStr(attrs[i]->attname));
133+
pq_sendint(&buf, (int)attrs[i]->atttypid,
134+
sizeof(attrs[i]->atttypid));
135+
pq_sendint(&buf,attrs[i]->attlen,
136+
sizeof(attrs[i]->attlen));
137+
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >=2)
138+
pq_sendint(&buf,attrs[i]->atttypmod,
139+
sizeof(attrs[i]->atttypmod));
140+
}
141+
pq_endmessage(&buf);
142+
}
143+
102144
/* ----------------
103145
* We could set up the derived attr info at this time, but we postpone it
104-
* until the first call of printtup, for3 reasons:
146+
* until the first call of printtup, for2 reasons:
105147
* 1. We don't waste time (compared to the old way) if there are no
106148
* tuples at all to output.
107149
* 2. Checking in printtup allows us to handle the case that the tuples
108150
* change type midway through (although this probably can't happen in
109151
* the current executor).
110-
* 3. Right now, ExecutorRun passes a NULL for typeinfo anyway :-(
111152
* ----------------
112153
*/
113154
}
@@ -267,12 +308,12 @@ printatt(unsigned attributeId,
267308
*showatts
268309
* ----------------
269310
*/
270-
void
271-
showatts(char*name,TupleDesctupleDesc)
311+
staticvoid
312+
showatts(constchar*name,TupleDesctupleDesc)
272313
{
273-
inti;
274314
intnatts=tupleDesc->natts;
275315
Form_pg_attribute*attinfo=tupleDesc->attrs;
316+
inti;
276317

277318
puts(name);
278319
for (i=0;i<natts;++i)
@@ -281,7 +322,24 @@ showatts(char *name, TupleDesc tupleDesc)
281322
}
282323

283324
/* ----------------
284-
*debugtup
325+
*debugSetup - prepare to print tuples for an interactive backend
326+
* ----------------
327+
*/
328+
void
329+
debugSetup(DestReceiver*self,intoperation,
330+
constchar*portalName,TupleDesctypeinfo)
331+
{
332+
/*
333+
* show the return type of the tuples
334+
*/
335+
if (portalName==NULL)
336+
portalName="blank";
337+
338+
showatts(portalName,typeinfo);
339+
}
340+
341+
/* ----------------
342+
*debugtup - print one tuple for an interactive backend
285343
* ----------------
286344
*/
287345
void

‎src/backend/access/common/tupdesc.c

Lines changed: 2 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.76 2001/10/25 05:49:20 momjian Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/access/common/tupdesc.c,v 1.77 2002/02/27 19:34:11 tgl Exp $
1212
*
1313
* NOTES
1414
* some of the executor utility code such as "ExecTypeFromTL" should be
@@ -432,7 +432,7 @@ TupleDescInitEntry(TupleDesc desc,
432432
*
433433
* (Why not just make the atttypid point to the OID type, instead of the
434434
* type the query returns?Because the executor uses the atttypid to
435-
* tell the front end what type will be returned (in BeginCommand),
435+
* tell the front end what type will be returned,
436436
* and in the end the type returned will be the result of the query,
437437
* not an OID.)
438438
*

‎src/backend/commands/command.c

Lines changed: 35 additions & 45 deletions
Original file line numberDiff line numberDiff line change
@@ -8,7 +8,7 @@
88
*
99
*
1010
* IDENTIFICATION
11-
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.155 2002/02/26 22:47:04 tgl Exp $
11+
* $Header: /cvsroot/pgsql/src/backend/commands/Attic/command.c,v 1.156 2002/02/27 19:34:38 tgl Exp $
1212
*
1313
* NOTES
1414
* The PerformAddAttribute() code, like most of the relation
@@ -113,6 +113,7 @@ PerformPortalFetch(char *name,
113113
QueryDesc*queryDesc;
114114
EState*estate;
115115
MemoryContextoldcontext;
116+
ScanDirectiondirection;
116117
CommandIdsavedId;
117118
booltemp_desc= false;
118119

@@ -145,6 +146,9 @@ PerformPortalFetch(char *name,
145146
*/
146147
oldcontext=MemoryContextSwitchTo(PortalGetHeapMemory(portal));
147148

149+
queryDesc=PortalGetQueryDesc(portal);
150+
estate=PortalGetState(portal);
151+
148152
/*
149153
* If the requested destination is not the same as the query's
150154
* original destination, make a temporary QueryDesc with the proper
@@ -156,9 +160,6 @@ PerformPortalFetch(char *name,
156160
* original dest. This is necessary since a FETCH command will pass
157161
* dest = Remote, not knowing whether the cursor is binary or not.
158162
*/
159-
queryDesc=PortalGetQueryDesc(portal);
160-
estate=PortalGetState(portal);
161-
162163
if (dest!=queryDesc->dest&&
163164
!(queryDesc->dest==RemoteInternal&&dest==Remote))
164165
{
@@ -170,19 +171,6 @@ PerformPortalFetch(char *name,
170171
temp_desc= true;
171172
}
172173

173-
/*
174-
* Tell the destination to prepare to receive some tuples.
175-
*/
176-
BeginCommand(name,
177-
queryDesc->operation,
178-
PortalGetTupleDesc(portal),
179-
false,/* portal fetches don't end up in
180-
* relations */
181-
false,/* this is a portal fetch, not a "retrieve
182-
* portal" */
183-
NULL,/* not used */
184-
queryDesc->dest);
185-
186174
/*
187175
* Restore the scanCommandId that was current when the cursor was
188176
* opened. This ensures that we see the same tuples throughout the
@@ -194,47 +182,49 @@ PerformPortalFetch(char *name,
194182
/*
195183
* Determine which direction to go in, and check to see if we're
196184
* already at the end of the available tuples in that direction. If
197-
* so, do nothing.(This check exists because not all plan node types
185+
* so, set the direction to NoMovement to avoid trying to fetch any
186+
* tuples. (This check exists because not all plan node types
198187
* are robust about being called again if they've already returned
199-
* NULL once.)If it's OK to do the fetch, call the executor. Then,
200-
* update the atStart/atEnd state depending on the number of tuples
201-
* that were retrieved.
188+
* NULL once.) Then call the executor (we must not skip this, because
189+
* the destination needs to see a setup and shutdown even if no tuples
190+
* are available). Finally, update the atStart/atEnd state depending
191+
* on the number of tuples that were retrieved.
202192
*/
203193
if (forward)
204194
{
205-
if (!portal->atEnd)
206-
{
207-
ExecutorRun(queryDesc,estate,EXEC_FOR, (long)count);
195+
if (portal->atEnd)
196+
direction=NoMovementScanDirection;
197+
else
198+
direction=ForwardScanDirection;
208199

209-
if (estate->es_processed>0)
210-
portal->atStart= false;/* OK to back up now */
211-
if (count <=0|| (int)estate->es_processed<count)
212-
portal->atEnd= true;/* we retrieved 'em all */
200+
ExecutorRun(queryDesc,estate,direction, (long)count);
213201

214-
if (completionTag)
215-
snprintf(completionTag,COMPLETION_TAG_BUFSIZE,"%s %u",
216-
(dest==None) ?"MOVE" :"FETCH",
217-
estate->es_processed);
218-
}
202+
if (estate->es_processed>0)
203+
portal->atStart= false;/* OK to back up now */
204+
if (count <=0|| (int)estate->es_processed<count)
205+
portal->atEnd= true;/* we retrieved 'em all */
219206
}
220207
else
221208
{
222-
if (!portal->atStart)
223-
{
224-
ExecutorRun(queryDesc,estate,EXEC_BACK, (long)count);
209+
if (portal->atStart)
210+
direction=NoMovementScanDirection;
211+
else
212+
direction=BackwardScanDirection;
225213

226-
if (estate->es_processed>0)
227-
portal->atEnd= false;/* OK to go forward now */
228-
if (count <=0|| (int)estate->es_processed<count)
229-
portal->atStart= true;/* we retrieved 'em all */
214+
ExecutorRun(queryDesc,estate,direction, (long)count);
230215

231-
if (completionTag)
232-
snprintf(completionTag,COMPLETION_TAG_BUFSIZE,"%s %u",
233-
(dest==None) ?"MOVE" :"FETCH",
234-
estate->es_processed);
235-
}
216+
if (estate->es_processed>0)
217+
portal->atEnd= false;/* OK to go forward now */
218+
if (count <=0|| (int)estate->es_processed<count)
219+
portal->atStart= true;/* we retrieved 'em all */
236220
}
237221

222+
/* Return command status if wanted */
223+
if (completionTag)
224+
snprintf(completionTag,COMPLETION_TAG_BUFSIZE,"%s %u",
225+
(dest==None) ?"MOVE" :"FETCH",
226+
estate->es_processed);
227+
238228
/*
239229
* Restore outer command ID.
240230
*/

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