#include "postgres_fe.h"
#include <signal.h>
#include <time.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include "libpq-fe.h"
#include "libpq-int.h"
#include "mb/pg_wchar.h"
#include "pg_config_paths.h"

Include dependency graph for fe-misc.c:

Functions
static int	pqPutMsgBytes (const void buf, size_t len, PGconn conn)

static int	pqSendSome (PGconn *conn, int len)

static int	pqSocketCheck (PGconn *conn, int forRead, int forWrite, time_t end_time)

static int	pqSocketPoll (int sock, int forRead, int forWrite, time_t end_time)

int	PQlibVersion (void)

static void	fputnbytes (FILE f, const char str, size_t n)

int	pqGetc (char result, PGconn conn)

int	pqPutc (char c, PGconn *conn)

static int	pqGets_internal (PQExpBuffer buf, PGconn *conn, bool resetbuffer)

int	pqGets (PQExpBuffer buf, PGconn *conn)

int	pqGets_append (PQExpBuffer buf, PGconn *conn)

int	pqPuts (const char s, PGconn conn)

int	pqGetnchar (char s, size_t len, PGconn conn)

int	pqSkipnchar (size_t len, PGconn *conn)

int	pqPutnchar (const char s, size_t len, PGconn conn)

int	pqGetInt (int result, size_t bytes, PGconn conn)

int	pqPutInt (int value, size_t bytes, PGconn *conn)

int	pqCheckOutBufferSpace (size_t bytes_needed, PGconn *conn)

int	pqCheckInBufferSpace (size_t bytes_needed, PGconn *conn)

int	pqPutMsgStart (char msg_type, bool force_len, PGconn *conn)

int	pqPutMsgEnd (PGconn *conn)

int	pqReadData (PGconn *conn)

int	pqFlush (PGconn *conn)

int	pqWait (int forRead, int forWrite, PGconn *conn)

int	pqWaitTimed (int forRead, int forWrite, PGconn *conn, time_t finish_time)

int	pqReadReady (PGconn *conn)

int	pqWriteReady (PGconn *conn)

int	PQmblen (const char *s, int encoding)

int	PQdsplen (const char *s, int encoding)

int	PQenv2encoding (void)

Function Documentation

static void fputnbytes	(	FILE *	f,
		const char *	str,
		size_t	n
	)

static

Definition at line 81 of file fe-misc.c.

Referenced by pqGetnchar(), pqPutnchar(), and pqSkipnchar().

 {
     while (n-- > 0)
         fputc(*str++, f);
 }

int pqCheckInBufferSpace	(	size_t	bytes_needed,
		PGconn *	conn
	)

Definition at line 410 of file fe-misc.c.

References pg_conn::errorMessage, pg_conn::inBuffer, pg_conn::inBufSize, pg_conn::inCursor, pg_conn::inEnd, pg_conn::inStart, memmove, printfPQExpBuffer(), and realloc.

Referenced by getCopyDataMessage(), PQconnectPoll(), pqFunctionCall3(), pqParseInput3(), and pqReadData().

 {
     int         newsize = conn->inBufSize;
     char       *newbuf;
 
     /* Quick exit if we have enough space */
     if (bytes_needed <= (size_t) newsize)
         return 0;
 
     /*
      * Before concluding that we need to enlarge the buffer, left-justify
      * whatever is in it and recheck.  The caller's value of bytes_needed
      * includes any data to the left of inStart, but we can delete that in
      * preference to enlarging the buffer.  It's slightly ugly to have this
      * function do this, but it's better than making callers worry about it.
      */
     bytes_needed -= conn->inStart;
 
     if (conn->inStart < conn->inEnd)
     {
         if (conn->inStart > 0)
         {
             memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
                     conn->inEnd - conn->inStart);
             conn->inEnd -= conn->inStart;
             conn->inCursor -= conn->inStart;
             conn->inStart = 0;
         }
     }
     else
     {
         /* buffer is logically empty, reset it */
         conn->inStart = conn->inCursor = conn->inEnd = 0;
     }
 
     /* Recheck whether we have enough space */
     if (bytes_needed <= (size_t) newsize)
         return 0;
 
     /*
      * If we need to enlarge the buffer, we first try to double it in size; if
      * that doesn't work, enlarge in multiples of 8K.  This avoids thrashing
      * the malloc pool by repeated small enlargements.
      *
      * Note: tests for newsize > 0 are to catch integer overflow.
      */
     do
     {
         newsize *= 2;
     } while (newsize > 0 && bytes_needed > (size_t) newsize);
 
     if (newsize > 0 && bytes_needed <= (size_t) newsize)
     {
         newbuf = realloc(conn->inBuffer, newsize);
         if (newbuf)
         {
             /* realloc succeeded */
             conn->inBuffer = newbuf;
             conn->inBufSize = newsize;
             return 0;
         }
     }
 
     newsize = conn->inBufSize;
     do
     {
         newsize += 8192;
     } while (newsize > 0 && bytes_needed > (size_t) newsize);
 
     if (newsize > 0 && bytes_needed <= (size_t) newsize)
     {
         newbuf = realloc(conn->inBuffer, newsize);
         if (newbuf)
         {
             /* realloc succeeded */
             conn->inBuffer = newbuf;
             conn->inBufSize = newsize;
             return 0;
         }
     }
 
     /* realloc failed. Probably out of memory */
     printfPQExpBuffer(&conn->errorMessage,
                       "cannot allocate memory for input buffer\n");
     return EOF;
 }

int pqCheckOutBufferSpace	(	size_t	bytes_needed,
		PGconn *	conn
	)

Definition at line 346 of file fe-misc.c.

References pg_conn::errorMessage, pg_conn::outBuffer, pg_conn::outBufSize, printfPQExpBuffer(), and realloc.

Referenced by PQputCopyData(), pqPutMsgBytes(), and pqPutMsgStart().

 {
     int         newsize = conn->outBufSize;
     char       *newbuf;
 
     /* Quick exit if we have enough space */
     if (bytes_needed <= (size_t) newsize)
         return 0;
 
     /*
      * If we need to enlarge the buffer, we first try to double it in size; if
      * that doesn't work, enlarge in multiples of 8K.  This avoids thrashing
      * the malloc pool by repeated small enlargements.
      *
      * Note: tests for newsize > 0 are to catch integer overflow.
      */
     do
     {
         newsize *= 2;
     } while (newsize > 0 && bytes_needed > (size_t) newsize);
 
     if (newsize > 0 && bytes_needed <= (size_t) newsize)
     {
         newbuf = realloc(conn->outBuffer, newsize);
         if (newbuf)
         {
             /* realloc succeeded */
             conn->outBuffer = newbuf;
             conn->outBufSize = newsize;
             return 0;
         }
     }
 
     newsize = conn->outBufSize;
     do
     {
         newsize += 8192;
     } while (newsize > 0 && bytes_needed > (size_t) newsize);
 
     if (newsize > 0 && bytes_needed <= (size_t) newsize)
     {
         newbuf = realloc(conn->outBuffer, newsize);
         if (newbuf)
         {
             /* realloc succeeded */
             conn->outBuffer = newbuf;
             conn->outBufSize = newsize;
             return 0;
         }
     }
 
     /* realloc failed. Probably out of memory */
     printfPQExpBuffer(&conn->errorMessage,
                       "cannot allocate memory for output buffer\n");
     return EOF;
 }

int PQdsplen	(	const char *	s,
		int	encoding
	)

Definition at line 1192 of file fe-misc.c.

References pg_encoding_dsplen().

Referenced by pg_wcsformat(), pg_wcssize(), pg_wcswidth(), and strlen_max_width().

 {
     return pg_encoding_dsplen(encoding, s);
 }

int PQenv2encoding ( void )

Definition at line 1201 of file fe-misc.c.

References encoding, pg_char_to_encoding(), and PG_SQL_ASCII.

Referenced by main().

 {
     char       *str;
     int         encoding = PG_SQL_ASCII;
 
     str = getenv("PGCLIENTENCODING");
     if (str && *str != '\0')
     {
         encoding = pg_char_to_encoding(str);
         if (encoding < 0)
             encoding = PG_SQL_ASCII;
     }
     return encoding;
 }

int pqFlush ( PGconn * conn )

Definition at line 963 of file fe-misc.c.

References pg_conn::outCount, pg_conn::Pfdebug, and pqSendSome().

Referenced by pg_SASL_init(), PQconnectPoll(), PQconsumeInput(), pqEndcopy2(), pqEndcopy3(), PQflush(), pqFunctionCall2(), pqFunctionCall3(), PQgetResult(), pqPacketSend(), PQputCopyData(), PQputCopyEnd(), PQsendDescribe(), PQsendPrepare(), PQsendQuery(), PQsendQueryGuts(), PQsetnonblocking(), and sendTerminateConn().

 {
     if (conn->Pfdebug)
         fflush(conn->Pfdebug);
 
     if (conn->outCount > 0)
         return pqSendSome(conn, conn->outCount);
 
     return 0;
 }

int pqGetc	(	char *	result,
		PGconn *	conn
	)

Definition at line 96 of file fe-misc.c.

References pg_conn::inBuffer, pg_conn::inCursor, pg_conn::inEnd, and pg_conn::Pfdebug.

Referenced by getCopyDataMessage(), getCopyStart(), getReadyForQuery(), PQconnectPoll(), pqFunctionCall2(), pqFunctionCall3(), pqGetErrorNotice3(), pqParseInput2(), and pqParseInput3().

 {
     if (conn->inCursor >= conn->inEnd)
         return EOF;
 
     *result = conn->inBuffer[conn->inCursor++];
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "From backend> %c\n", *result);
 
     return 0;
 }

int pqGetInt	(	int *	result,
		size_t	bytes,
		PGconn *	conn
	)

Definition at line 269 of file fe-misc.c.

References pg_conn::inBuffer, pg_conn::inCursor, pg_conn::inEnd, pg_conn::noticeHooks, pg_conn::Pfdebug, and pqInternalNotice().

Referenced by getAnotherTuple(), getCopyDataMessage(), getCopyStart(), getNotify(), getParamDescriptions(), getRowDescriptions(), PQconnectPoll(), pqFunctionCall2(), pqFunctionCall3(), pqParseInput2(), and pqParseInput3().

 {
     uint16      tmp2;
     uint32      tmp4;
 
     switch (bytes)
     {
         case 2:
             if (conn->inCursor + 2 > conn->inEnd)
                 return EOF;
             memcpy(&tmp2, conn->inBuffer + conn->inCursor, 2);
             conn->inCursor += 2;
             *result = (int) ntohs(tmp2);
             break;
         case 4:
             if (conn->inCursor + 4 > conn->inEnd)
                 return EOF;
             memcpy(&tmp4, conn->inBuffer + conn->inCursor, 4);
             conn->inCursor += 4;
             *result = (int) ntohl(tmp4);
             break;
         default:
             pqInternalNotice(&conn->noticeHooks,
                              "integer of size %lu not supported by pqGetInt",
                              (unsigned long) bytes);
             return EOF;
     }
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "From backend (#%lu)> %d\n", (unsigned long) bytes, *result);
 
     return 0;
 }

int pqGetnchar	(	char *	s,
		size_t	len,
		PGconn *	conn
	)

Definition at line 197 of file fe-misc.c.

References fputnbytes(), pg_conn::inBuffer, pg_conn::inCursor, pg_conn::inEnd, and pg_conn::Pfdebug.

Referenced by getAnotherTuple(), pg_password_sendauth(), pg_SASL_continue(), pqFunctionCall2(), and pqFunctionCall3().

 {
     if (len > (size_t) (conn->inEnd - conn->inCursor))
         return EOF;
 
     memcpy(s, conn->inBuffer + conn->inCursor, len);
     /* no terminating null */
 
     conn->inCursor += len;
 
     if (conn->Pfdebug)
     {
         fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len);
         fputnbytes(conn->Pfdebug, s, len);
         fprintf(conn->Pfdebug, "\n");
     }
 
     return 0;
 }

int pqGets	(	PQExpBuffer	buf,
		PGconn *	conn
	)

Definition at line 165 of file fe-misc.c.

References pqGets_internal().

Referenced by getNotify(), getParameterStatus(), getRowDescriptions(), pg_SASL_init(), pqGetErrorNotice2(), pqGetErrorNotice3(), pqParseInput2(), and pqParseInput3().

 {
     return pqGets_internal(buf, conn, true);
 }

int pqGets_append	(	PQExpBuffer	buf,
		PGconn *	conn
	)

Definition at line 171 of file fe-misc.c.

References pqGets_internal().

Referenced by PQconnectPoll().

 {
     return pqGets_internal(buf, conn, false);
 }

static int pqGets_internal	(	PQExpBuffer	buf,
		PGconn *	conn,
		bool	resetbuffer
	)

static

Definition at line 134 of file fe-misc.c.

References appendBinaryPQExpBuffer(), PQExpBufferData::data, pg_conn::inBuffer, pg_conn::inCursor, pg_conn::inEnd, pg_conn::Pfdebug, and resetPQExpBuffer().

Referenced by pqGets(), and pqGets_append().

 {
     /* Copy conn data to locals for faster search loop */
     char       *inBuffer = conn->inBuffer;
     int         inCursor = conn->inCursor;
     int         inEnd = conn->inEnd;
     int         slen;
 
     while (inCursor < inEnd && inBuffer[inCursor])
         inCursor++;
 
     if (inCursor >= inEnd)
         return EOF;
 
     slen = inCursor - conn->inCursor;
 
     if (resetbuffer)
         resetPQExpBuffer(buf);
 
     appendBinaryPQExpBuffer(buf, inBuffer + conn->inCursor, slen);
 
     conn->inCursor = ++inCursor;
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "From backend> \"%s\"\n",
                 buf->data);
 
     return 0;
 }

int PQlibVersion ( void )

Definition at line 69 of file fe-misc.c.

 {
     return PG_VERSION_NUM;
 }

int PQmblen	(	const char *	s,
		int	encoding
	)

Definition at line 1182 of file fe-misc.c.

References pg_encoding_mblen().

Referenced by appendStringLiteral(), command_no_begin(), do_field(), is_select_command(), pg_wcsformat(), pg_wcssize(), pg_wcswidth(), processSQLNamePattern(), quote_if_needed(), skip_white_space(), strip_quotes(), strlen_max_width(), and strtokx().

 {
     return pg_encoding_mblen(encoding, s);
 }

int pqPutc	(	char	c,
		PGconn *	conn
	)

Definition at line 114 of file fe-misc.c.

References pg_conn::Pfdebug, and pqPutMsgBytes().

Referenced by PQsendDescribe(), and PQsendQueryGuts().

 {
     if (pqPutMsgBytes(&c, 1, conn))
         return EOF;
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "To backend> %c\n", c);
 
     return 0;
 }

int pqPutInt	(	int	value,
		size_t	bytes,
		PGconn *	conn
	)

Definition at line 309 of file fe-misc.c.

References pg_conn::noticeHooks, pg_conn::Pfdebug, pqInternalNotice(), and pqPutMsgBytes().

Referenced by pg_SASL_init(), pqFunctionCall2(), pqFunctionCall3(), PQsendPrepare(), and PQsendQueryGuts().

 {
     uint16      tmp2;
     uint32      tmp4;
 
     switch (bytes)
     {
         case 2:
             tmp2 = htons((uint16) value);
             if (pqPutMsgBytes((const char *) &tmp2, 2, conn))
                 return EOF;
             break;
         case 4:
             tmp4 = htonl((uint32) value);
             if (pqPutMsgBytes((const char *) &tmp4, 4, conn))
                 return EOF;
             break;
         default:
             pqInternalNotice(&conn->noticeHooks,
                              "integer of size %lu not supported by pqPutInt",
                              (unsigned long) bytes);
             return EOF;
     }
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "To backend (%lu#)> %d\n", (unsigned long) bytes, value);
 
     return 0;
 }

static int pqPutMsgBytes	(	const void *	buf,
		size_t	len,
		PGconn *	conn
	)

static

Definition at line 566 of file fe-misc.c.

References pg_conn::outBuffer, pg_conn::outMsgEnd, and pqCheckOutBufferSpace().

Referenced by pqPutc(), pqPutInt(), pqPutnchar(), and pqPuts().

 {
     /* make sure there is room for it */
     if (pqCheckOutBufferSpace(conn->outMsgEnd + len, conn))
         return EOF;
     /* okay, save the data */
     memcpy(conn->outBuffer + conn->outMsgEnd, buf, len);
     conn->outMsgEnd += len;
     /* no Pfdebug call here, caller should do it */
     return 0;
 }

int pqPutMsgEnd ( PGconn * conn )

Definition at line 589 of file fe-misc.c.

References pg_conn::outBuffer, pg_conn::outCount, pg_conn::outMsgEnd, pg_conn::outMsgStart, pg_conn::Pfdebug, and pqSendSome().

Referenced by pg_SASL_init(), pqEndcopy3(), pqFunctionCall2(), pqFunctionCall3(), pqPacketSend(), PQputCopyData(), PQputCopyEnd(), PQsendDescribe(), PQsendPrepare(), PQsendQuery(), PQsendQueryGuts(), and sendTerminateConn().

 {
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "To backend> Msg complete, length %u\n",
                 conn->outMsgEnd - conn->outCount);
 
     /* Fill in length word if needed */
     if (conn->outMsgStart >= 0)
     {
         uint32      msgLen = conn->outMsgEnd - conn->outMsgStart;
 
         msgLen = htonl(msgLen);
         memcpy(conn->outBuffer + conn->outMsgStart, &msgLen, 4);
     }
 
     /* Make message eligible to send */
     conn->outCount = conn->outMsgEnd;
 
     if (conn->outCount >= 8192)
     {
         int         toSend = conn->outCount - (conn->outCount % 8192);
 
         if (pqSendSome(conn, toSend) < 0)
             return EOF;
         /* in nonblock mode, don't complain if unable to send it all */
     }
 
     return 0;
 }

int pqPutMsgStart	(	char	msg_type,
		bool	force_len,
		PGconn *	conn
	)

Definition at line 521 of file fe-misc.c.

References pg_conn::outBuffer, pg_conn::outCount, pg_conn::outMsgEnd, pg_conn::outMsgStart, pg_conn::Pfdebug, PG_PROTOCOL_MAJOR, pqCheckOutBufferSpace(), and pg_conn::pversion.

Referenced by pg_SASL_init(), pqEndcopy3(), pqFunctionCall2(), pqFunctionCall3(), pqPacketSend(), PQputCopyData(), PQputCopyEnd(), PQsendDescribe(), PQsendPrepare(), PQsendQuery(), PQsendQueryGuts(), and sendTerminateConn().

 {
     int         lenPos;
     int         endPos;
 
     /* allow room for message type byte */
     if (msg_type)
         endPos = conn->outCount + 1;
     else
         endPos = conn->outCount;
 
     /* do we want a length word? */
     if (force_len || PG_PROTOCOL_MAJOR(conn->pversion) >= 3)
     {
         lenPos = endPos;
         /* allow room for message length */
         endPos += 4;
     }
     else
         lenPos = -1;
 
     /* make sure there is room for message header */
     if (pqCheckOutBufferSpace(endPos, conn))
         return EOF;
     /* okay, save the message type byte if any */
     if (msg_type)
         conn->outBuffer[conn->outCount] = msg_type;
     /* set up the message pointers */
     conn->outMsgStart = lenPos;
     conn->outMsgEnd = endPos;
     /* length word, if needed, will be filled in by pqPutMsgEnd */
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "To backend> Msg %c\n",
                 msg_type ? msg_type : ' ');
 
     return 0;
 }

int pqPutnchar	(	const char *	s,
		size_t	len,
		PGconn *	conn
	)

Definition at line 248 of file fe-misc.c.

References fputnbytes(), pg_conn::Pfdebug, and pqPutMsgBytes().

Referenced by pg_SASL_init(), pqFunctionCall2(), pqFunctionCall3(), pqPacketSend(), PQputCopyData(), PQputCopyEnd(), and PQsendQueryGuts().

 {
     if (pqPutMsgBytes(s, len, conn))
         return EOF;
 
     if (conn->Pfdebug)
     {
         fprintf(conn->Pfdebug, "To backend> ");
         fputnbytes(conn->Pfdebug, s, len);
         fprintf(conn->Pfdebug, "\n");
     }
 
     return 0;
 }

int pqPuts	(	const char *	s,
		PGconn *	conn
	)

Definition at line 181 of file fe-misc.c.

References pg_conn::Pfdebug, and pqPutMsgBytes().

Referenced by pg_SASL_init(), pqFunctionCall2(), PQputCopyEnd(), PQsendDescribe(), PQsendPrepare(), PQsendQuery(), and PQsendQueryGuts().

 {
     if (pqPutMsgBytes(s, strlen(s) + 1, conn))
         return EOF;
 
     if (conn->Pfdebug)
         fprintf(conn->Pfdebug, "To backend> \"%s\"\n", s);
 
     return 0;
 }

int pqReadData ( PGconn * conn )

Definition at line 631 of file fe-misc.c.

References CONNECTION_BAD, EAGAIN, ECONNRESET, EINTR, pg_conn::errorMessage, EWOULDBLOCK, pg_conn::inBuffer, pg_conn::inBufSize, pg_conn::inCursor, pg_conn::inEnd, pg_conn::inStart, libpq_gettext, memmove, PGINVALID_SOCKET, pqCheckInBufferSpace(), pqDropConnection(), pqReadReady(), pqsecure_read(), printfPQExpBuffer(), pg_conn::sock, SOCK_ERRNO, and pg_conn::status.

Referenced by PQconnectPoll(), PQconsumeInput(), pqFunctionCall2(), pqFunctionCall3(), pqGetCopyData2(), pqGetCopyData3(), pqGetline2(), pqGetline3(), PQgetResult(), pqHandleSendFailure(), pqSendSome(), and pqSetenvPoll().

 {
     int         someread = 0;
     int         nread;
 
     if (conn->sock == PGINVALID_SOCKET)
     {
         printfPQExpBuffer(&conn->errorMessage,
                           libpq_gettext("connection not open\n"));
         return -1;
     }
 
     /* Left-justify any data in the buffer to make room */
     if (conn->inStart < conn->inEnd)
     {
         if (conn->inStart > 0)
         {
             memmove(conn->inBuffer, conn->inBuffer + conn->inStart,
                     conn->inEnd - conn->inStart);
             conn->inEnd -= conn->inStart;
             conn->inCursor -= conn->inStart;
             conn->inStart = 0;
         }
     }
     else
     {
         /* buffer is logically empty, reset it */
         conn->inStart = conn->inCursor = conn->inEnd = 0;
     }
 
     /*
      * If the buffer is fairly full, enlarge it. We need to be able to enlarge
      * the buffer in case a single message exceeds the initial buffer size. We
      * enlarge before filling the buffer entirely so as to avoid asking the
      * kernel for a partial packet. The magic constant here should be large
      * enough for a TCP packet or Unix pipe bufferload.  8K is the usual pipe
      * buffer size, so...
      */
     if (conn->inBufSize - conn->inEnd < 8192)
     {
         if (pqCheckInBufferSpace(conn->inEnd + (size_t) 8192, conn))
         {
             /*
              * We don't insist that the enlarge worked, but we need some room
              */
             if (conn->inBufSize - conn->inEnd < 100)
                 return -1;      /* errorMessage already set */
         }
     }
 
     /* OK, try to read some data */
 retry3:
     nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
                           conn->inBufSize - conn->inEnd);
     if (nread < 0)
     {
         if (SOCK_ERRNO == EINTR)
             goto retry3;
         /* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
         if (SOCK_ERRNO == EAGAIN)
             return someread;
 #endif
 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
         if (SOCK_ERRNO == EWOULDBLOCK)
             return someread;
 #endif
         /* We might get ECONNRESET here if using TCP and backend died */
 #ifdef ECONNRESET
         if (SOCK_ERRNO == ECONNRESET)
             goto definitelyFailed;
 #endif
         /* pqsecure_read set the error message for us */
         return -1;
     }
     if (nread > 0)
     {
         conn->inEnd += nread;
 
         /*
          * Hack to deal with the fact that some kernels will only give us back
          * 1 packet per recv() call, even if we asked for more and there is
          * more available.  If it looks like we are reading a long message,
          * loop back to recv() again immediately, until we run out of data or
          * buffer space.  Without this, the block-and-restart behavior of
          * libpq's higher levels leads to O(N^2) performance on long messages.
          *
          * Since we left-justified the data above, conn->inEnd gives the
          * amount of data already read in the current message.  We consider
          * the message "long" once we have acquired 32k ...
          */
         if (conn->inEnd > 32768 &&
             (conn->inBufSize - conn->inEnd) >= 8192)
         {
             someread = 1;
             goto retry3;
         }
         return 1;
     }
 
     if (someread)
         return 1;               /* got a zero read after successful tries */
 
     /*
      * A return value of 0 could mean just that no data is now available, or
      * it could mean EOF --- that is, the server has closed the connection.
      * Since we have the socket in nonblock mode, the only way to tell the
      * difference is to see if select() is saying that the file is ready.
      * Grumble.  Fortunately, we don't expect this path to be taken much,
      * since in normal practice we should not be trying to read data unless
      * the file selected for reading already.
      *
      * In SSL mode it's even worse: SSL_read() could say WANT_READ and then
      * data could arrive before we make the pqReadReady() test, but the second
      * SSL_read() could still say WANT_READ because the data received was not
      * a complete SSL record.  So we must play dumb and assume there is more
      * data, relying on the SSL layer to detect true EOF.
      */
 
 #ifdef USE_SSL
     if (conn->ssl_in_use)
         return 0;
 #endif
 
     switch (pqReadReady(conn))
     {
         case 0:
             /* definitely no data available */
             return 0;
         case 1:
             /* ready for read */
             break;
         default:
             /* we override pqReadReady's message with something more useful */
             goto definitelyEOF;
     }
 
     /*
      * Still not sure that it's EOF, because some data could have just
      * arrived.
      */
 retry4:
     nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
                           conn->inBufSize - conn->inEnd);
     if (nread < 0)
     {
         if (SOCK_ERRNO == EINTR)
             goto retry4;
         /* Some systems return EAGAIN/EWOULDBLOCK for no data */
 #ifdef EAGAIN
         if (SOCK_ERRNO == EAGAIN)
             return 0;
 #endif
 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
         if (SOCK_ERRNO == EWOULDBLOCK)
             return 0;
 #endif
         /* We might get ECONNRESET here if using TCP and backend died */
 #ifdef ECONNRESET
         if (SOCK_ERRNO == ECONNRESET)
             goto definitelyFailed;
 #endif
         /* pqsecure_read set the error message for us */
         return -1;
     }
     if (nread > 0)
     {
         conn->inEnd += nread;
         return 1;
     }
 
     /*
      * OK, we are getting a zero read even though select() says ready. This
      * means the connection has been closed.  Cope.
      */
 definitelyEOF:
     printfPQExpBuffer(&conn->errorMessage,
                       libpq_gettext(
                                     "server closed the connection unexpectedly\n"
                                     "\tThis probably means the server terminated abnormally\n"
                                     "\tbefore or while processing the request.\n"));
 
     /* Come here if lower-level code already set a suitable errorMessage */
 definitelyFailed:
     /* Do *not* drop any already-read data; caller still wants it */
     pqDropConnection(conn, false);
     conn->status = CONNECTION_BAD;  /* No more connection to backend */
     return -1;
 }

int pqReadReady ( PGconn * conn )

Definition at line 1023 of file fe-misc.c.

References pqSocketCheck().

Referenced by pqReadData().

 {
     return pqSocketCheck(conn, 1, 0, (time_t) 0);
 }

static int pqSendSome	(	PGconn *	conn,
		int	len
	)

static

Definition at line 831 of file fe-misc.c.

References EAGAIN, EINTR, pg_conn::errorMessage, EWOULDBLOCK, libpq_gettext, memmove, Min, pg_conn::outBuffer, pg_conn::outCount, PGINVALID_SOCKET, pqIsnonblocking, pqReadData(), pqsecure_write(), pqWait(), printfPQExpBuffer(), remaining, result, pg_conn::sock, SOCK_ERRNO, and TRUE.

Referenced by pqFlush(), and pqPutMsgEnd().

 {
     char       *ptr = conn->outBuffer;
     int         remaining = conn->outCount;
     int         result = 0;
 
     if (conn->sock == PGINVALID_SOCKET)
     {
         printfPQExpBuffer(&conn->errorMessage,
                           libpq_gettext("connection not open\n"));
         /* Discard queued data; no chance it'll ever be sent */
         conn->outCount = 0;
         return -1;
     }
 
     /* while there's still data to send */
     while (len > 0)
     {
         int         sent;
 
 #ifndef WIN32
         sent = pqsecure_write(conn, ptr, len);
 #else
 
         /*
          * Windows can fail on large sends, per KB article Q201213. The
          * failure-point appears to be different in different versions of
          * Windows, but 64k should always be safe.
          */
         sent = pqsecure_write(conn, ptr, Min(len, 65536));
 #endif
 
         if (sent < 0)
         {
             /* Anything except EAGAIN/EWOULDBLOCK/EINTR is trouble */
             switch (SOCK_ERRNO)
             {
 #ifdef EAGAIN
                 case EAGAIN:
                     break;
 #endif
 #if defined(EWOULDBLOCK) && (!defined(EAGAIN) || (EWOULDBLOCK != EAGAIN))
                 case EWOULDBLOCK:
                     break;
 #endif
                 case EINTR:
                     continue;
 
                 default:
                     /* pqsecure_write set the error message for us */
 
                     /*
                      * We used to close the socket here, but that's a bad idea
                      * since there might be unread data waiting (typically, a
                      * NOTICE message from the backend telling us it's
                      * committing hara-kiri...).  Leave the socket open until
                      * pqReadData finds no more data can be read.  But abandon
                      * attempt to send data.
                      */
                     conn->outCount = 0;
                     return -1;
             }
         }
         else
         {
             ptr += sent;
             len -= sent;
             remaining -= sent;
         }
 
         if (len > 0)
         {
             /*
              * We didn't send it all, wait till we can send more.
              *
              * There are scenarios in which we can't send data because the
              * communications channel is full, but we cannot expect the server
              * to clear the channel eventually because it's blocked trying to
              * send data to us.  (This can happen when we are sending a large
              * amount of COPY data, and the server has generated lots of
              * NOTICE responses.)  To avoid a deadlock situation, we must be
              * prepared to accept and buffer incoming data before we try
              * again.  Furthermore, it is possible that such incoming data
              * might not arrive until after we've gone to sleep.  Therefore,
              * we wait for either read ready or write ready.
              *
              * In non-blocking mode, we don't wait here directly, but return 1
              * to indicate that data is still pending.  The caller should wait
              * for both read and write ready conditions, and call
              * PQconsumeInput() on read ready, but just in case it doesn't, we
              * call pqReadData() ourselves before returning.  That's not
              * enough if the data has not arrived yet, but it's the best we
              * can do, and works pretty well in practice.  (The documentation
              * used to say that you only need to wait for write-ready, so
              * there are still plenty of applications like that out there.)
              */
             if (pqReadData(conn) < 0)
             {
                 result = -1;    /* error message already set up */
                 break;
             }
 
             if (pqIsnonblocking(conn))
             {
                 result = 1;
                 break;
             }
 
             if (pqWait(TRUE, TRUE, conn))
             {
                 result = -1;
                 break;
             }
         }
     }
 
     /* shift the remaining contents of the buffer */
     if (remaining > 0)
         memmove(conn->outBuffer, ptr, remaining);
     conn->outCount = remaining;
 
     return result;
 }

int pqSkipnchar	(	size_t	len,
		PGconn *	conn
	)

Definition at line 226 of file fe-misc.c.

References fputnbytes(), pg_conn::inBuffer, pg_conn::inCursor, pg_conn::inEnd, and pg_conn::Pfdebug.

Referenced by getAnotherTuple().

 {
     if (len > (size_t) (conn->inEnd - conn->inCursor))
         return EOF;
 
     if (conn->Pfdebug)
     {
         fprintf(conn->Pfdebug, "From backend (%lu)> ", (unsigned long) len);
         fputnbytes(conn->Pfdebug, conn->inBuffer + conn->inCursor, len);
         fprintf(conn->Pfdebug, "\n");
     }
 
     conn->inCursor += len;
 
     return 0;
 }

static int pqSocketCheck	(	PGconn *	conn,
		int	forRead,
		int	forWrite,
		time_t	end_time
	)

static

Definition at line 1047 of file fe-misc.c.

References EINTR, pg_conn::errorMessage, libpq_gettext, PGINVALID_SOCKET, pgtls_read_pending(), pqSocketPoll(), printfPQExpBuffer(), result, pg_conn::sock, SOCK_ERRNO, and SOCK_STRERROR.

Referenced by pqReadReady(), pqWaitTimed(), and pqWriteReady().

 {
     int         result;
 
     if (!conn)
         return -1;
     if (conn->sock == PGINVALID_SOCKET)
     {
         printfPQExpBuffer(&conn->errorMessage,
                           libpq_gettext("invalid socket\n"));
         return -1;
     }
 
 #ifdef USE_SSL
     /* Check for SSL library buffering read bytes */
     if (forRead && conn->ssl_in_use && pgtls_read_pending(conn) > 0)
     {
         /* short-circuit the select */
         return 1;
     }
 #endif
 
     /* We will retry as long as we get EINTR */
     do
         result = pqSocketPoll(conn->sock, forRead, forWrite, end_time);
     while (result < 0 && SOCK_ERRNO == EINTR);
 
     if (result < 0)
     {
         char        sebuf[256];
 
         printfPQExpBuffer(&conn->errorMessage,
                           libpq_gettext("select() failed: %s\n"),
                           SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf)));
     }
 
     return result;
 }

static int pqSocketPoll	(	int	sock,
		int	forRead,
		int	forWrite,
		time_t	end_time
	)

static

Definition at line 1097 of file fe-misc.c.

References now(), NULL, and select.

Referenced by pqSocketCheck().

 {
     /* We use poll(2) if available, otherwise select(2) */
 #ifdef HAVE_POLL
     struct pollfd input_fd;
     int         timeout_ms;
 
     if (!forRead && !forWrite)
         return 0;
 
     input_fd.fd = sock;
     input_fd.events = POLLERR;
     input_fd.revents = 0;
 
     if (forRead)
         input_fd.events |= POLLIN;
     if (forWrite)
         input_fd.events |= POLLOUT;
 
     /* Compute appropriate timeout interval */
     if (end_time == ((time_t) -1))
         timeout_ms = -1;
     else
     {
         time_t      now = time(NULL);
 
         if (end_time > now)
             timeout_ms = (end_time - now) * 1000;
         else
             timeout_ms = 0;
     }
 
     return poll(&input_fd, 1, timeout_ms);
 #else                           /* !HAVE_POLL */
 
     fd_set      input_mask;
     fd_set      output_mask;
     fd_set      except_mask;
     struct timeval timeout;
     struct timeval *ptr_timeout;
 
     if (!forRead && !forWrite)
         return 0;
 
     FD_ZERO(&input_mask);
     FD_ZERO(&output_mask);
     FD_ZERO(&except_mask);
     if (forRead)
         FD_SET(sock, &input_mask);
 
     if (forWrite)
         FD_SET(sock, &output_mask);
     FD_SET(sock, &except_mask);
 
     /* Compute appropriate timeout interval */
     if (end_time == ((time_t) -1))
         ptr_timeout = NULL;
     else
     {
         time_t      now = time(NULL);
 
         if (end_time > now)
             timeout.tv_sec = end_time - now;
         else
             timeout.tv_sec = 0;
         timeout.tv_usec = 0;
         ptr_timeout = &timeout;
     }
 
     return select(sock + 1, &input_mask, &output_mask,
                   &except_mask, ptr_timeout);
 #endif                          /* HAVE_POLL */
 }

int pqWait	(	int	forRead,
		int	forWrite,
		PGconn *	conn
	)

Definition at line 986 of file fe-misc.c.

References pqWaitTimed().

Referenced by pqFunctionCall2(), pqFunctionCall3(), pqGetCopyData2(), pqGetCopyData3(), pqGetline2(), pqGetline3(), PQgetResult(), and pqSendSome().

 {
     return pqWaitTimed(forRead, forWrite, conn, (time_t) -1);
 }

int pqWaitTimed	(	int	forRead,
		int	forWrite,
		PGconn *	conn,
		time_t	finish_time
	)

Definition at line 999 of file fe-misc.c.

References pg_conn::errorMessage, libpq_gettext, pqSocketCheck(), printfPQExpBuffer(), and result.

Referenced by connectDBComplete(), and pqWait().

 {
     int         result;
 
     result = pqSocketCheck(conn, forRead, forWrite, finish_time);
 
     if (result < 0)
         return -1;              /* errorMessage is already set */
 
     if (result == 0)
     {
         printfPQExpBuffer(&conn->errorMessage,
                           libpq_gettext("timeout expired\n"));
         return 1;
     }
 
     return 0;
 }

int pqWriteReady ( PGconn * conn )

Definition at line 1033 of file fe-misc.c.

References pqSocketCheck().

 {
     return pqSocketCheck(conn, 0, 1, (time_t) 0);
 }

Functions

Function Documentation