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Libpq non-blocking mode, from Alfred Perlstein

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This commit is contained in:
Bruce Momjian
2000-01-18 06:09:24 +00:00
parent b1e891dbd4
commit 10d7287ab9
6 changed files with 341 additions and 47 deletions
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68
src/interfaces/libpq/fe-misc.c
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@ -24,7 +24,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.33 1999/11/30 03:08:19 momjian Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-misc.c,v 1.34 2000/01/18 06:09:24 momjian Exp $
*
*-------------------------------------------------------------------------
*/
@ -86,6 +86,37 @@ pqPutBytes(const char *s, size_t nbytes, PGconn *conn)
{
size_t avail = Max(conn->outBufSize - conn->outCount, 0);
/*
* if we are non-blocking and the send queue is too full to buffer this
* request then try to flush some and return an error
*/
if (pqIsnonblocking(conn) && nbytes > avail && pqFlush(conn))
{
/*
* even if the flush failed we may still have written some
* data, recalculate the size of the send-queue relative
* to the amount we have to send, we may be able to queue it
* afterall even though it's not sent to the database it's
* ok, any routines that check the data coming from the
* database better call pqFlush() anyway.
*/
if (nbytes > Max(conn->outBufSize - conn->outCount, 0))
{
printfPQExpBuffer(&conn->errorMessage,
"pqPutBytes -- pqFlush couldn't flush enough"
" data: space available: %d, space needed %d\n",
Max(conn->outBufSize - conn->outCount, 0), nbytes);
return EOF;
}
}
/*
* is the amount of data to be sent is larger than the size of the
* output buffer then we must flush it to make more room.
*
* the code above will make sure the loop conditional is never
* true for non-blocking connections
*/
while (nbytes > avail)
{
memcpy(conn->outBuffer + conn->outCount, s, avail);
@ -548,6 +579,14 @@ pqFlush(PGconn *conn)
return EOF;
}
/*
* don't try to send zero data, allows us to use this function
* without too much worry about overhead
*/
if (len == 0)
return (0);
/* while there's still data to send */
while (len > 0)
{
/* Prevent being SIGPIPEd if backend has closed the connection. */
@ -556,6 +595,7 @@ pqFlush(PGconn *conn)
#endif
int sent;
#ifdef USE_SSL
if (conn->ssl)
sent = SSL_write(conn->ssl, ptr, len);
@ -585,6 +625,8 @@ pqFlush(PGconn *conn)
case EWOULDBLOCK:
break;
#endif
case EINTR:
continue;
case EPIPE:
#ifdef ECONNRESET
@ -616,13 +658,31 @@ pqFlush(PGconn *conn)
ptr += sent;
len -= sent;
}
if (len > 0)
{
/* We didn't send it all, wait till we can send more */
/* At first glance this looks as though it should block. I think
* that it will be OK though, as long as the socket is
* non-blocking. */
/*
* if the socket is in non-blocking mode we may need
* to abort here
*/
#ifdef USE_SSL
/* can't do anything for our SSL users yet */
if (conn->ssl == NULL)
{
#endif
if (pqIsnonblocking(conn))
{
/* shift the contents of the buffer */
memmove(conn->outBuffer, ptr, len);
conn->outCount = len;
return EOF;
}
#ifdef USE_SSL
}
#endif
if (pqWait(FALSE, TRUE, conn))
return EOF;
}