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Second round of FE/BE protocol changes. Frontend->backend messages now

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have length counts, and COPY IN data is packetized into messages.
This commit is contained in:
Tom Lane
2003-04-19 00:02:30 +00:00
parent 54b38d293e
commit bd8d441775
24 changed files with 1337 additions and 982 deletions
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129
src/interfaces/libpq/fe-exec.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.128 2003/03/25 02:44:36 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-exec.c,v 1.129 2003/04/19 00:02:30 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -734,7 +734,6 @@ addTuple(PGresult *res, PGresAttValue * tup)
* Returns: 1 if successfully submitted
* 0 if error (conn->errorMessage is set)
*/
int
PQsendQuery(PGconn *conn, const char *query)
{
@ -770,51 +769,24 @@ PQsendQuery(PGconn *conn, const char *query)
conn->result = NULL;
conn->curTuple = NULL;
/* send the query to the backend; */
/* construct the outgoing Query message */
if (pqPutMsgStart('Q', conn) < 0 ||
pqPuts(query, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
{
handleSendFailure(conn);
return 0;
}
/*
* in order to guarantee that we don't send a partial query where we
* would become out of sync with the backend and/or block during a
* non-blocking connection we must first flush the send buffer before
* sending more data
*
* an alternative is to implement 'queue reservations' where we are able
* to roll up a transaction (the 'Q' along with our query) and make
* sure we have enough space for it all in the send buffer.
* Give the data a push. In nonblock mode, don't complain if we're
* unable to send it all; PQconsumeInput() will do any additional flushing
* needed.
*/
if (pqIsnonblocking(conn))
if (pqFlush(conn) < 0)
{
/*
* the buffer must have emptied completely before we allow a new
* query to be buffered
*/
if (pqFlush(conn))
return 0;
/* 'Q' == queries */
/* XXX: if we fail here we really ought to not block */
if (pqPutc('Q', conn) != 0 || pqPuts(query, conn) != 0)
{
handleSendFailure(conn);
return 0;
}
/*
* give the data a push, ignore the return value as ConsumeInput()
* will do any additional flushing if needed
*/
pqFlush(conn);
}
else
{
/*
* the frontend-backend protocol uses 'Q' to designate queries
*/
if (pqPutc('Q', conn) != 0 || pqPuts(query, conn) != 0 ||
pqFlush(conn) != 0)
{
handleSendFailure(conn);
return 0;
}
handleSendFailure(conn);
return 0;
}
/* OK, it's launched! */
@ -830,7 +802,6 @@ PQsendQuery(PGconn *conn, const char *query)
*
* NOTE: this routine should only be called in PGASYNC_IDLE state.
*/
static void
handleSendFailure(PGconn *conn)
{
@ -854,13 +825,23 @@ handleSendFailure(PGconn *conn)
* 0 return: some kind of trouble
* 1 return: no problem
*/
int
PQconsumeInput(PGconn *conn)
{
if (!conn)
return 0;
/*
* for non-blocking connections try to flush the send-queue,
* otherwise we may never get a response for something that may
* not have already been sent because it's in our write buffer!
*/
if (pqIsnonblocking(conn))
{
if (pqFlush(conn) < 0)
return 0;
}
/*
* Load more data, if available. We do this no matter what state we
* are in, since we are probably getting called because the
@ -868,16 +849,8 @@ PQconsumeInput(PGconn *conn)
* we will NOT block waiting for more input.
*/
if (pqReadData(conn) < 0)
{
/*
* for non-blocking connections try to flush the send-queue
* otherwise we may never get a responce for something that may
* not have already been sent because it's in our write buffer!
*/
if (pqIsnonblocking(conn))
(void) pqFlush(conn);
return 0;
}
/* Parsing of the data waits till later. */
return 1;
}
@ -1733,14 +1706,13 @@ PQgetlineAsync(PGconn *conn, char *buffer, int bufsize)
* PQputline -- sends a string to the backend.
* Returns 0 if OK, EOF if not.
*
* Chiefly here so that applications can use "COPY <rel> from stdin".
* This exists to support "COPY <rel> from stdin". The backend will ignore
* the string if not doing COPY.
*/
int
PQputline(PGconn *conn, const char *s)
{
if (!conn || conn->sock < 0)
return EOF;
return pqPutnchar(s, strlen(s), conn);
return PQputnbytes(conn, s, strlen(s));
}
/*
@ -1752,7 +1724,14 @@ PQputnbytes(PGconn *conn, const char *buffer, int nbytes)
{
if (!conn || conn->sock < 0)
return EOF;
return pqPutnchar(buffer, nbytes, conn);
if (nbytes > 0)
{
if (pqPutMsgStart('d', conn) < 0 ||
pqPutnchar(buffer, nbytes, conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return EOF;
}
return 0;
}
/*
@ -1780,6 +1759,14 @@ PQendcopy(PGconn *conn)
return 1;
}
/* Send the CopyDone message if needed */
if (conn->asyncStatus == PGASYNC_COPY_IN)
{
if (pqPutMsgStart('c', conn) < 0 ||
pqPutMsgEnd(conn) < 0)
return 1;
}
/*
* make sure no data is waiting to be sent, abort if we are
* non-blocking and the flush fails
@ -1884,9 +1871,10 @@ PQfn(PGconn *conn,
return NULL;
}
if (pqPuts("F ", conn) != 0 || /* function */
pqPutInt(fnid, 4, conn) != 0 || /* function id */
pqPutInt(nargs, 4, conn) != 0) /* # of args */
if (pqPutMsgStart('F', conn) < 0 || /* function call msg */
pqPuts("", conn) < 0 || /* useless string */
pqPutInt(fnid, 4, conn) < 0 || /* function id */
pqPutInt(nargs, 4, conn) < 0) /* # of args */
{
handleSendFailure(conn);
return NULL;
@ -1917,7 +1905,9 @@ PQfn(PGconn *conn,
}
}
}
if (pqFlush(conn))
if (pqPutMsgEnd(conn) < 0 ||
pqFlush(conn))
{
handleSendFailure(conn);
return NULL;
@ -2409,7 +2399,6 @@ PQgetisnull(const PGresult *res, int tup_num, int field_num)
int
PQsetnonblocking(PGconn *conn, int arg)
{
arg = (arg == TRUE) ? 1 : 0;
/* early out if the socket is already in the state requested */
if (arg == conn->nonblocking)
@ -2437,7 +2426,6 @@ PQsetnonblocking(PGconn *conn, int arg)
int
PQisnonblocking(const PGconn *conn)
{
return (pqIsnonblocking(conn));
}
@ -2445,18 +2433,9 @@ PQisnonblocking(const PGconn *conn)
int
PQflush(PGconn *conn)
{
return (pqFlush(conn));
}
/* try to force data out, really only useful for non-blocking users.
* This implementation actually works for non-blocking connections */
int
PQsendSome(PGconn *conn)
{
return pqSendSome(conn);
}
/*
* PQfreeNotify - free's the memory associated with a PGnotify
*
@ -2473,5 +2452,3 @@ PQfreeNotify(PGnotify *notify)
{
PQfreemem(notify);
}