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Code Activity

What I've done:

Browse Source 
1. Rewritten libpq to allow asynchronous clients.

2. Implemented client side of cancel protocol in library,
   and patched psql.c to send a cancel request upon SIGINT.  The
   backend doesn't notice it yet :-(

3. Implemented 'Z' protocol message addition and renaming of
   copy in/out start messages.  These are implemented conditionally,
   ie, the client protocol version is checked; so the code should
   still work with 1.0 clients.

4. Revised protocol and libpq sgml documents (don't have an SGML
   compiler, though, so there may be some markup glitches here).


What remains to be done:

1. Implement addition of atttypmod field to RowDescriptor messages.
   The client-side code is there but ifdef'd out.  I have no idea
   what to change on the backend side.  The field should be sent
   only if protocol >= 2.0, of course.

2. Implement backend response to cancel requests received as OOB
   messages.  (This prolly need not be conditional on protocol
   version; just do it if you get SIGURG.)

3. Update libpq.3.  (I'm hoping this can be generated mechanically
   from libpq.sgml... if not, will do it by hand.)  Is there any
   other doco to fix?

4. Update non-libpq interfaces as necessary.  I patched libpgtcl
   so that it would compile, but haven't tested it.  Dunno what
   needs to be done with the other interfaces.

Have at it!

Tom Lane
This commit is contained in:
Bruce Momjian
1998-05-06 23:51:16 +00:00
parent 2e12331d42
commit edbd51395c
15 changed files with 2664 additions and 2146 deletions
Download Patch File Download Diff File Expand all files Collapse all files

107
src/backend/tcop/dest.c
View File

@ -7,7 +7,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/backend/tcop/dest.c,v 1.17 1998/02/26 04:36:24 momjian Exp $
* $Header: /cvsroot/pgsql/src/backend/tcop/dest.c,v 1.18 1998/05/06 23:49:59 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -15,7 +15,8 @@
* 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
* NullCommand - tell dest that an empty query string was recognized
* ReadyForQuery - tell dest that we are ready for a new query
*
* NOTES
* These routines do the appropriate work before and after
@ -115,16 +116,10 @@ EndCommand(char *commandTag, CommandDest dest)
sprintf(buf, "%s%s", commandTag, CommandInfo);
CommandInfo[0] = 0;
pq_putstr(buf);
pq_flush();
break;
case Local:
case Debug:
break;
case CopyEnd:
pq_putnchar("Z", 1);
pq_flush();
break;
case None:
default:
break;
@ -139,28 +134,37 @@ EndCommand(char *commandTag, CommandDest dest)
*
* COPY rel FROM stdin
*
* NOTE: the message code letters are changed at protocol version 2.0
* to eliminate possible confusion with data tuple messages.
*/
void
SendCopyBegin(void)
{
pq_putnchar("B", 1);
/* pq_putint(0, 4); */
pq_flush();
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
pq_putnchar("H", 1); /* new way */
else
pq_putnchar("B", 1); /* old way */
}
void
ReceiveCopyBegin(void)
{
pq_putnchar("D", 1);
/* pq_putint(0, 4); */
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
pq_putnchar("G", 1); /* new way */
else
pq_putnchar("D", 1); /* old way */
/* We *must* flush here to ensure FE knows it can send. */
pq_flush();
}
/* ----------------
* NullCommand - tell dest that the last of a query sequence was processed
* NullCommand - tell dest that an empty query string was recognized
*
* Necessary to implement the hacky FE/BE interface to handle
* multiple-return queries.
* In FE/BE protocol version 1.0, this hack is necessary to support
* libpq's crufty way of determining whether a multiple-command
* query string is done. In protocol 2.0 it's probably not really
* necessary to distinguish empty queries anymore, but we still do it
* for backwards compatibility with 1.0.
* ----------------
*/
void
@ -168,46 +172,46 @@ NullCommand(CommandDest dest)
{
switch (dest)
{
case RemoteInternal:
case Remote:
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, sizeof(int4));
pq_putstr(nPtr->relname);
pq_putint(nPtr->be_pid, sizeof(nPtr->be_pid));
PQremoveNotify(nPtr);
}
pq_flush();
PQcleanNotify();/* garbage collect */
MemoryContextSwitchTo(orig);
#endif
/* ----------------
* tell the fe that the last of the queries has finished
* tell the fe that we saw an empty query string
* ----------------
*/
/* pq_putnchar("I", 1); */
pq_putstr("I");
/* pq_putint(0, 4); */
}
break;
case Local:
case Debug:
case None:
default:
break;
}
}
/* ----------------
* ReadyForQuery - tell dest that we are ready for a new query
*
* The ReadyForQuery message is sent in protocol versions 2.0 and up
* so that the FE can tell when we are done processing a query string.
*
* Note that by flushing the stdio buffer here, we can avoid doing it
* most other places and thus reduce the number of separate packets sent.
* ----------------
*/
void
ReadyForQuery(CommandDest dest)
{
switch (dest)
{
case RemoteInternal:
case Remote:
{
if (PG_PROTOCOL_MAJOR(FrontendProtocol) >= 2)
pq_putnchar("Z", 1);
/* Flush output at end of cycle in any case. */
pq_flush();
}
break;
@ -264,7 +268,6 @@ BeginCommand(char *pname,
* send fe info on tuples we're about to send
* ----------------
*/
pq_flush();
pq_putnchar("P", 1);/* new portal.. */
pq_putstr(pname); /* portal name */