@ -25,7 +25,7 @@
*
*
* IDENTIFICATION
* $ Header : / cvsroot / pgsql / src / interfaces / libpq / fe - misc . c , v 1.65 2001 / 12 / 03 00 : 28 : 24 tgl Exp $
* $ Header : / cvsroot / pgsql / src / interfaces / libpq / fe - misc . c , v 1.66 2002 / 03 / 05 05 : 20 : 12 momjian Exp $
*
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
*/
@ -110,54 +110,82 @@ pqPutc(char c, PGconn *conn)
static int
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
* Strategy to handle blocking and non - blocking connections : Fill the
* output buffer and flush it repeatedly until either all data has
* been sent or is at least queued in the buffer .
*
* For non - blocking connections , grow the buffer if not all data fits
* into it and the buffer can ' t be sent because the socket would
* block .
*/
if ( pqIsnonblocking ( conn ) & & nbytes > avail & & pqFlush ( conn ) )
while ( nbytes )
{
size_t avail ,
remaining ;
/* fill the output buffer */
avail = Max ( conn - > outBufSize - conn - > outCount , 0 ) ;
remaining = Min ( avail , nbytes ) ;
memcpy ( conn - > outBuffer + conn - > outCount , s , remaining ) ;
conn - > outCount + = remaining ;
s + = remaining ;
nbytes - = remaining ;
/*
* 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 the data didn ' t fit completely into the buffer , try to flush
* the buffer
*/
if ( nbytes > Max ( conn - > outBufSize - conn - > outCount , 0 ) )
if ( nbytes )
{
printfPQExpBuffer ( & conn - > errorMessage ,
libpq_gettext ( " could not flush enough data (space available: %d, space needed %d) \n " ) ,
( int ) Max ( conn - > outBufSize - conn - > outCount , 0 ) ,
( int ) nbytes ) ;
return EOF ;
}
/* fixup avail for while loop */
avail = Max ( conn - > outBufSize - conn - > outCount , 0 ) ;
}
int send_result = pqSendSome ( conn ) ;
/*
* 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 ) ;
conn - > outCount + = avail ;
s + = avail ;
nbytes - = avail ;
if ( pqFlush ( conn ) )
return EOF ;
avail = conn - > outBufSize ;
}
/* if there were errors, report them */
if ( send_result < 0 )
return EOF ;
/*
* if not all data could be sent , increase the output buffer ,
* put the rest of s into it and return successfully . This
* case will only happen in a non - blocking connection
*/
if ( send_result > 0 )
{
/*
* try to grow the buffer . FIXME : The new size could be
* chosen more intelligently .
*/
size_t buflen = conn - > outCount + nbytes ;
if ( buflen > conn - > outBufSize )
{
char * newbuf = realloc ( conn - > outBuffer , buflen ) ;
if ( ! newbuf )
{
/* realloc failed. Probably out of memory */
printfPQExpBuffer ( & conn - > errorMessage ,
" cannot allocate memory for output buffer \n " ) ;
return EOF ;
}
conn - > outBuffer = newbuf ;
conn - > outBufSize = buflen ;
}
/* put the data into it */
memcpy ( conn - > outBuffer + conn - > outCount , s , nbytes ) ;
conn - > outCount + = nbytes ;
/* report success. */
return 0 ;
}
}
memcpy ( conn - > outBuffer + conn - > outCount , s , nbytes ) ;
conn - > outCount + = nbytes ;
/*
* pqSendSome was able to send all data . Continue with the next
* chunk of s .
*/
} /* while */
return 0 ;
}
@ -603,11 +631,22 @@ definitelyFailed:
return - 1 ;
}
/*
* pqFlush : send any data waiting in the output buffer
/* pqSendSome: send any data waiting in the output buffer and return 0
* if all data was sent , - 1 if an error occurred or 1 if not all data
* could be written because the socket would have blocked .
*
* For a blocking connection all data will be sent unless an error
* occurrs . - 1 will only be returned if the connection is non - blocking .
*
* Internally , the case of data remaining in the buffer after pqSendSome
* could be determined by looking at outCount , but this function also
* serves as the implementation of the new API function PQsendsome .
*
* FIXME : perhaps it would be more useful to return the number of bytes
* remaining ?
*/
int
pqFlush ( PGconn * conn )
pqSendSome ( PGconn * conn )
{
char * ptr = conn - > outBuffer ;
int len = conn - > outCount ;
@ -685,14 +724,14 @@ pqFlush(PGconn *conn)
* the socket open until pqReadData finds no more data
* can be read .
*/
return EOF ;
return - 1 ;
default :
printfPQExpBuffer ( & conn - > errorMessage ,
libpq_gettext ( " could not send data to server: %s \n " ) ,
SOCK_STRERROR ( SOCK_ERRNO ) ) ;
/* We don't assume it's a fatal error... */
return EOF ;
return - 1 ;
}
}
else
@ -707,7 +746,7 @@ pqFlush(PGconn *conn)
/*
* if the socket is in non - blocking mode we may need to abort
* here
* here and return 1 to indicate that data is still pending .
*/
# ifdef USE_SSL
/* can't do anything for our SSL users yet */
@ -719,14 +758,14 @@ pqFlush(PGconn *conn)
/* shift the contents of the buffer */
memmove ( conn - > outBuffer , ptr , len ) ;
conn - > outCount = len ;
return EOF ;
return 1 ;
}
# ifdef USE_SSL
}
# endif
if ( pqWait ( FALSE , TRUE , conn ) )
return EOF ;
return - 1 ;
}
}
@ -738,6 +777,23 @@ pqFlush(PGconn *conn)
return 0 ;
}
/*
* pqFlush : send any data waiting in the output buffer
*
* Implemented in terms of pqSendSome to recreate the old behavior which
* returned 0 if all data was sent or EOF . EOF was sent regardless of
* whether an error occurred or not all data was sent on a non - blocking
* socket .
*/
int
pqFlush ( PGconn * conn )
{
if ( pqSendSome ( conn ) )
return EOF ;
return 0 ;
}
/*
* pqWait : wait until we can read or write the connection socket
*
@ -756,7 +812,7 @@ pqWait(int forRead, int forWrite, PGconn *conn)
{
printfPQExpBuffer ( & conn - > errorMessage ,
libpq_gettext ( " connection not open \n " ) ) ;
return EOF ;
return - 1 ;
}
if ( forRead | | forWrite )
@ -857,19 +913,20 @@ libpq_gettext(const char *msgid)
* strerror replacement for windows :
*
* This works on WIN2000 and newer , but we don ' t know where to find WinSock
* error strings on older Windows flavors . If you know , clue us in .
* error strings on older Windows flavors . If you know , clue us in .
*/
const char *
winsock_strerror ( int eno )
{
static char err_buf [ 512 ] ;
# define WSSE_MAXLEN (sizeof(err_buf)-1-13) /* 13 for " (0x00000000)" */
static char err_buf [ 512 ] ;
# define WSSE_MAXLEN (sizeof(err_buf)-1-13) /* 13 for " (0x00000000)" */
int length ;
/* First try the "system table", this works on Win2k and up */
if ( FormatMessage (
FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM ,
FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM ,
0 ,
eno ,
MAKELANGID ( LANG_NEUTRAL , SUBLANG_DEFAULT ) ,
Bruce Momjian
24 years ago