Tcl Source Code

static int		WriteBytes(Channel *chanPtr, const char *src,
			    int srcLen);
static int		WriteChars(Channel *chanPtr, const char *src,
			    int srcLen);
static Tcl_Obj *	FixLevelCode(Tcl_Obj *msg);
static void		SpliceChannel(Tcl_Channel chan);
static void		CutChannel(Tcl_Channel chan);
static int WillRead(Channel *chanPtr);

/*
 * Simplifying helper macros. All may use their argument(s) multiple times.
 * The ANSI C "prototypes" for the macros are listed below, together with a
 * short description of what the macro does.
 *
 * --------------------------------------------------------------------------

    ((objPtr)->internalRep.twoPtrValue.ptr2 = (void *) (storePtr))

#define BUSY_STATE(st,fl) \
     ((((st)->csPtrR) && ((fl) & TCL_READABLE)) || \
      (((st)->csPtrW) && ((fl) & TCL_WRITABLE)))

#define MAX_CHANNEL_BUFFER_SIZE (1024*1024)

/*
 * ChanRead, dropped here by a time traveler, see 8.6
 */
static inline int
ChanRead(
    Channel *chanPtr,
    char *dst,
    int dstSize,
    int *errnoPtr)
{
    if (WillRead(chanPtr) < 0) {
        return -1;
    }

    return chanPtr->typePtr->inputProc(chanPtr->instanceData, dst, dstSize,
	    errnoPtr);
}

static inline Tcl_WideInt
ChanSeek(
    Channel *chanPtr,
    Tcl_WideInt offset,
    int mode,
    int *errnoPtr)
{
    /*
     * Note that we prefer the wideSeekProc if that field is available in the
     * type and non-NULL.
     */

    if (HaveVersion(chanPtr->typePtr, TCL_CHANNEL_VERSION_3) &&
	    chanPtr->typePtr->wideSeekProc != NULL) {
	return chanPtr->typePtr->wideSeekProc(chanPtr->instanceData,
		offset, mode, errnoPtr);
    }

    if (offset<Tcl_LongAsWide(LONG_MIN) || offset>Tcl_LongAsWide(LONG_MAX)) {
	*errnoPtr = EOVERFLOW;
	return Tcl_LongAsWide(-1);
    }

    return Tcl_LongAsWide(chanPtr->typePtr->seekProc(chanPtr->instanceData,
	    Tcl_WideAsLong(offset), mode, errnoPtr));
}


/*
 *---------------------------------------------------------------------------
 *
 * TclInitIOSubsystem --
 *
 *	Initialize all resources used by this subsystem on a per-process

	src = (char *) Tcl_GetByteArrayFromObj(objPtr, &srcLen);
	return WriteBytes(chanPtr, src, srcLen);
    } else {
	src = TclGetStringFromObj(objPtr, &srcLen);
	return WriteChars(chanPtr, src, srcLen);
    }
}

static void WillWrite(Channel *chanPtr)
{
    int inputBuffered;

    if ((chanPtr->typePtr->seekProc != NULL)
        && ((inputBuffered = Tcl_InputBuffered((Tcl_Channel) chanPtr)) > 0)) {
        int ignore;
        DiscardInputQueued(chanPtr->state, 0);
        ChanSeek(chanPtr, - inputBuffered, SEEK_CUR, &ignore);
    }
}

static int WillRead(Channel *chanPtr)
{
    if ((chanPtr->typePtr->seekProc != NULL)
        && (Tcl_OutputBuffered((Tcl_Channel) chanPtr) > 0)) {
        if ((chanPtr->state->curOutPtr != NULL)
            && IsBufferReady(chanPtr->state->curOutPtr)) {
            SetFlag(chanPtr->state, BUFFER_READY);
        }
        if (FlushChannel(NULL, chanPtr, 0) != 0) {
            return -1;
        }
    }
    return 0;
}

/*
 *----------------------------------------------------------------------
 *
 * WriteBytes --
 *
 *	Write a sequence of bytes into an output buffer, may queue the buffer

    int srcLen)			/* Number of bytes to write. */
{
    ChannelState *statePtr = chanPtr->state;
				/* State info for channel */
    ChannelBuffer *bufPtr;
    char *dst;
    int dstMax, sawLF, savedLF, total, dstLen, toWrite, translate;

    if (srcLen) {
        WillWrite(chanPtr);
    }

    total = 0;
    sawLF = 0;
    savedLF = 0;
    translate = (statePtr->flags & CHANNEL_LINEBUFFERED)
	|| (statePtr->outputTranslation != TCL_TRANSLATE_LF);

    ChannelBuffer *bufPtr;
    char *dst, *stage;
    int saved, savedLF, sawLF, total, dstLen, stageMax, dstWrote;
    int stageLen, toWrite, stageRead, endEncoding, result;
    int consumedSomething, translate;
    Tcl_Encoding encoding;
    char safe[BUFFER_PADDING];

    if (srcLen) {
        WillWrite(chanPtr);
    }

    total = 0;
    sawLF = 0;
    savedLF = 0;
    saved = 0;
    encoding = statePtr->encoding;

		 * the remaining request. Do all the error handling by
		 * ourselves. The code was stolen from 'GetInput' and slightly
		 * adapted (different return value here).
		 *
		 * The case of 'bytesToRead == 0' at this point cannot happen.
		 */

		nread = ChanRead(chanPtr, bufPtr + copied,
			bytesToRead - copied, &result);

#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
	    }
#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */

	    if (nread > 0) {
		/*

	 */

	nread = -1;
	result = EWOULDBLOCK;
    } else {
#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */


	nread = ChanRead(chanPtr, InsertPoint(bufPtr), toRead, &result);

#ifdef TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING
    }
#endif /* TCL_IO_TRACK_OS_FOR_DRIVER_WITH_BAD_BLOCKING */

    if (nread > 0) {
	bufPtr->nextAdded += nread;

     * is buffered, cannot compute the current position.
     */

    inputBuffered = Tcl_InputBuffered(chan);
    outputBuffered = Tcl_OutputBuffered(chan);

    if ((inputBuffered != 0) && (outputBuffered != 0)) {
	//Tcl_SetErrno(EFAULT);
	//return Tcl_LongAsWide(-1);
    }

    /*
     * Get the current position in the device and compute the position where
     * the next character will be read or written. Note that we prefer the
     * wideSeekProc if that is available and non-NULL...
     */

    if (HaveVersion(chanPtr->typePtr, TCL_CHANNEL_VERSION_3) &&
	    chanPtr->typePtr->wideSeekProc != NULL) {
	curPos = (chanPtr->typePtr->wideSeekProc) (chanPtr->instanceData,
		Tcl_LongAsWide(0), SEEK_CUR, &result);
    } else {
	curPos = Tcl_LongAsWide((chanPtr->typePtr->seekProc) (
		chanPtr->instanceData, 0, SEEK_CUR, &result));
    }
    if (curPos == Tcl_LongAsWide(-1)) {
	Tcl_SetErrno(result);
	return Tcl_LongAsWide(-1);
    }

    if (inputBuffered != 0) {
	return curPos - inputBuffered;
    }
    return curPos + outputBuffered;
}

/*

    }

    /*
     * Seek first to force a total flush of all pending buffers and ditch any
     * pre-read input data.
     */

    WillWrite(chanPtr);

    if (WillRead(chanPtr) < 0) {
        return TCL_ERROR;
    }

    /*
     * We're all flushed to disk now and we also don't have any unfortunate
     * input baggage around either; can truncate with impunity.
     */