tcliogt.c

来自「tcl是工具命令语言」· C语言 代码 · 共 1,454 行 · 第 1/3 页

	    break;
    }

    Tcl_ResetResult(dataPtr->interp);

    if (preserve) {
	Tcl_RestoreResult(dataPtr->interp, &ciSave);
    }

    return res;

    cleanup:
    if (preserve) {
	Tcl_RestoreResult(dataPtr->interp, &ciSave);
    }

    if (command != (Tcl_Obj*) NULL) {
        Tcl_DecrRefCount(command);
    }

    return res;
}

/*
 *------------------------------------------------------*
 *
 *	TransformBlockModeProc --
 *
 *	Trap handler. Called by the generic IO system
 *	during option processing to change the blocking
 *	mode of the channel.
 *
 *	Sideeffects:
 *		Forwards the request to the underlying
 *		channel.
 *
 *	Result:
 *		0 if successful, errno when failed.
 *
 *------------------------------------------------------*
 */

static int
TransformBlockModeProc (instanceData, mode)
    ClientData  instanceData; /* State of transformation */
    int         mode;         /* New blocking mode */
{
    TransformChannelData* dataPtr = (TransformChannelData*) instanceData;

    if (mode == TCL_MODE_NONBLOCKING) {
        dataPtr->flags |= CHANNEL_ASYNC;
    } else {
        dataPtr->flags &= ~(CHANNEL_ASYNC);
    }
    return 0;
}

/*
 *------------------------------------------------------*
 *
 *	TransformCloseProc --
 *
 *	Trap handler. Called by the generic IO system
 *	during destruction of the transformation channel.
 *
 *	Sideeffects:
 *		Releases the memory allocated in
 *		'Tcl_TransformObjCmd'.
 *
 *	Result:
 *		None.
 *
 *------------------------------------------------------*
 */

static int
TransformCloseProc (instanceData, interp)
    ClientData  instanceData;
    Tcl_Interp* interp;
{
    TransformChannelData* dataPtr = (TransformChannelData*) instanceData;

    /*
     * Important: In this procedure 'dataPtr->self' already points to
     * the underlying channel.
     */

    /*
     * There is no need to cancel an existing channel handler, this is already
     * done. Either by 'Tcl_UnstackChannel' or by the general cleanup in
     * 'Tcl_Close'.
     *
     * But we have to cancel an active timer to prevent it from firing on the
     * removed channel.
     */

    if (dataPtr->timer != (Tcl_TimerToken) NULL) {
        Tcl_DeleteTimerHandler (dataPtr->timer);
	dataPtr->timer = (Tcl_TimerToken) NULL;
    }

    /*
     * Now flush data waiting in internal buffers to output and input. The
     * input must be done despite the fact that there is no real receiver
     * for it anymore. But the scripts might have sideeffects other parts
     * of the system rely on (f.e. signaling the close to interested parties).
     */

    if (dataPtr->mode & TCL_WRITABLE) {
        ExecuteCallback (dataPtr, interp, A_FLUSH_WRITE,
		NULL, 0, TRANSMIT_DOWN, 1);
    }

    if ((dataPtr->mode & TCL_READABLE) && !dataPtr->readIsFlushed) {
	dataPtr->readIsFlushed = 1;
        ExecuteCallback (dataPtr, interp, A_FLUSH_READ,
		NULL, 0, TRANSMIT_IBUF, 1);
    }

    if (dataPtr->mode & TCL_WRITABLE) {
        ExecuteCallback (dataPtr, interp, A_DELETE_WRITE,
		NULL, 0, TRANSMIT_DONT, 1);
    }

    if (dataPtr->mode & TCL_READABLE) {
        ExecuteCallback (dataPtr, interp, A_DELETE_READ,
		NULL, 0, TRANSMIT_DONT, 1);
    }

    /*
     * General cleanup
     */

    ResultClear(&dataPtr->result);
    Tcl_DecrRefCount(dataPtr->command);
    ckfree((VOID*) dataPtr);

    return TCL_OK;
}

/*
 *------------------------------------------------------*
 *
 *	TransformInputProc --
 *
 *	Called by the generic IO system to convert read data.
 *
 *	Sideeffects:
 *		As defined by the conversion.
 *
 *	Result:
 *		A transformed buffer.
 *
 *------------------------------------------------------*
 */

static int
TransformInputProc (instanceData, buf, toRead, errorCodePtr)
    ClientData instanceData;
    char*      buf;
    int	       toRead;
    int*       errorCodePtr;
{
    TransformChannelData* dataPtr = (TransformChannelData*) instanceData;
    int gotBytes, read, res, copied;
    Tcl_Channel downChan;

    /* should assert (dataPtr->mode & TCL_READABLE) */

    if (toRead == 0) {
	/* Catch a no-op.
	 */
	return 0;
    }

    gotBytes = 0;
    downChan = Tcl_GetStackedChannel(dataPtr->self);

    while (toRead > 0) {
        /*
	 * Loop until the request is satisfied (or no data is available from
	 * below, possibly EOF).
	 */

        copied    = ResultCopy (&dataPtr->result, UCHARP (buf), toRead);

	toRead   -= copied;
	buf      += copied;
	gotBytes += copied;

	if (toRead == 0) {
	    /* The request was completely satisfied from our buffers.
	     * We can break out of the loop and return to the caller.
	     */
	    return gotBytes;
	}

	/*
	 * Length (dataPtr->result) == 0, toRead > 0 here . Use the incoming
	 * 'buf'! as target to store the intermediary information read
	 * from the underlying channel.
	 *
	 * Ask the tcl level how much data it allows us to read from
	 * the underlying channel. This feature allows the transform to
	 * signal EOF upstream although there is none downstream. Useful
	 * to control an unbounded 'fcopy', either through counting bytes,
	 * or by pattern matching.
	 */

	ExecuteCallback (dataPtr, NO_INTERP, A_QUERY_MAXREAD,
		NULL, 0, TRANSMIT_NUM /* -> maxRead */, 1);

	if (dataPtr->maxRead >= 0) {
	    if (dataPtr->maxRead < toRead) {
	        toRead = dataPtr->maxRead;
	    }
	} /* else: 'maxRead < 0' == Accept the current value of toRead */

	if (toRead <= 0) {
	    return gotBytes;
	}

	read = Tcl_ReadRaw(downChan, buf, toRead);

	if (read < 0) {
	    /* Report errors to caller. EAGAIN is a special situation.
	     * If we had some data before we report that instead of the
	     * request to re-try.
	     */

	    if ((Tcl_GetErrno() == EAGAIN) && (gotBytes > 0)) {
	        return gotBytes;
	    }

	    *errorCodePtr = Tcl_GetErrno();
	    return -1;      
	}

	if (read == 0) {
	    /*
	     * Check wether we hit on EOF in the underlying channel or
	     * not. If not differentiate between blocking and
	     * non-blocking modes. In non-blocking mode we ran
	     * temporarily out of data. Signal this to the caller via
	     * EWOULDBLOCK and error return (-1). In the other cases
	     * we simply return what we got and let the caller wait
	     * for more. On the other hand, if we got an EOF we have
	     * to convert and flush all waiting partial data.
	     */

	    if (! Tcl_Eof (downChan)) {
	        if ((gotBytes == 0) && (dataPtr->flags & CHANNEL_ASYNC)) {
		    *errorCodePtr = EWOULDBLOCK;
		    return -1;
		} else {
		    return gotBytes;
		}
	    } else {
	        if (dataPtr->readIsFlushed) {
		    /* Already flushed, nothing to do anymore
		     */
		    return gotBytes;
		}

		dataPtr->readIsFlushed = 1;

		ExecuteCallback (dataPtr, NO_INTERP, A_FLUSH_READ,
			NULL, 0, TRANSMIT_IBUF, P_PRESERVE);

		if (ResultLength (&dataPtr->result) == 0) {
		    /* we had nothing to flush */
		    return gotBytes;
		}

		continue; /* at: while (toRead > 0) */
	    }
	} /* read == 0 */

	/* Transform the read chunk and add the result to our
	 * read buffer (dataPtr->result)
	 */

	res = ExecuteCallback (dataPtr, NO_INTERP, A_READ,
		UCHARP (buf), read, TRANSMIT_IBUF, P_PRESERVE);

	if (res != TCL_OK) {
	    *errorCodePtr = EINVAL;
	    return -1;
	}
    } /* while toRead > 0 */

    return gotBytes;
}

/*
 *------------------------------------------------------*
 *
 *	TransformOutputProc --
 *
 *	Called by the generic IO system to convert data
 *	waiting to be written.
 *
 *	Sideeffects:
 *		As defined by the transformation.
 *
 *	Result:
 *		A transformed buffer.
 *
 *------------------------------------------------------*
 */

static int
TransformOutputProc (instanceData, buf, toWrite, errorCodePtr)
    ClientData instanceData;
    CONST char*      buf;
    int        toWrite;
    int*       errorCodePtr;
{
    TransformChannelData* dataPtr = (TransformChannelData*) instanceData;
    int res;

    /* should assert (dataPtr->mode & TCL_WRITABLE) */

    if (toWrite == 0) {
	/* Catch a no-op.
	 */
	return 0;
    }

    res = ExecuteCallback (dataPtr, NO_INTERP, A_WRITE,
	    UCHARP (buf), toWrite,
	    TRANSMIT_DOWN, P_NO_PRESERVE);

    if (res != TCL_OK) {
        *errorCodePtr = EINVAL;
	return -1;
    }

    return toWrite;
}

/*
 *------------------------------------------------------*
 *
 *	TransformSeekProc --
 *
 *	This procedure is called by the generic IO level
 *	to move the access point in a channel.
 *
 *	Sideeffects:
 *		Moves the location at which the channel
 *		will be accessed in future operations.
 *		Flushes all transformation buffers, then
 *		forwards it to the underlying channel.
 *
 *	Result:
 *		-1 if failed, the new position if
 *		successful. An output argument contains
 *		the POSIX error code if an error
 *		occurred, or zero.
 *
 *------------------------------------------------------*
 */

static int
TransformSeekProc (instanceData, offset, mode, errorCodePtr)
    ClientData  instanceData;	/* The channel to manipulate */
    long	offset;		/* Size of movement. */
    int         mode;		/* How to move */
    int*        errorCodePtr;	/* Location of error flag. */
{
    TransformChannelData* dataPtr	= (TransformChannelData*) instanceData;
    Tcl_Channel           parent        = Tcl_GetStackedChannel(dataPtr->self);
    Tcl_ChannelType*      parentType	= Tcl_GetChannelType(parent);
    Tcl_DriverSeekProc*   parentSeekProc = Tcl_ChannelSeekProc(parentType);

    if ((offset == 0) && (mode == SEEK_CUR)) {
        /* This is no seek but a request to tell the caller the current
	 * location. Simply pass the request down.
	 */

	return (*parentSeekProc) (Tcl_GetChannelInstanceData(parent),
		offset, mode, errorCodePtr);
    }

    /*
     * It is a real request to change the position. Flush all data waiting
     * for output and discard everything in the input buffers. Then pass
     * the request down, unchanged.
     */

    if (dataPtr->mode & TCL_WRITABLE) {
        ExecuteCallback (dataPtr, NO_INTERP, A_FLUSH_WRITE,
		NULL, 0, TRANSMIT_DOWN, P_NO_PRESERVE);
    }

    if (dataPtr->mode & TCL_READABLE) {
        ExecuteCallback (dataPtr, NO_INTERP, A_CLEAR_READ,
		NULL, 0, TRANSMIT_DONT, P_NO_PRESERVE);
	ResultClear(&dataPtr->result);
	dataPtr->readIsFlushed = 0;
    }

    return (*parentSeekProc) (Tcl_GetChannelInstanceData(parent),
	    offset, mode, errorCodePtr);
}

/*
 *----------------------------------------------------------------------
 *
 * TransformWideSeekProc --
 *
 *	This procedure is called by the generic IO level to move the
 *	access point in a channel, with a (potentially) 64-bit offset.
 *
 * Side effects:
 *	Moves the location at which the channel will be accessed in
 *	future operations.  Flushes all transformation buffers, then
 *	forwards it to the underlying channel.
 *
 * Result:
 *	-1 if failed, the new position if successful. An output
 *	argument contains the POSIX error code if an error occurred,
 *	or zero.
 *
 *----------------------------------------------------------------------
 */

static Tcl_WideInt
TransformWideSeekProc (instanceData, offset, mode, errorCodePtr)
    ClientData  instanceData;	/* The channel to manipulate */
    Tcl_WideInt offset;		/* Size of movement. */
    int         mode;		/* How to move */
    int*        errorCodePtr;	/* Location of error flag. */
{
    TransformChannelData* dataPtr =
	(TransformChannelData*) instanceData;
    Tcl_Channel parent =
	Tcl_GetStackedChannel(dataPtr->self);
    Tcl_ChannelType* parentType	=
	Tcl_GetChannelType(parent);
    Tcl_DriverSeekProc* parentSeekProc =
	Tcl_ChannelSeekProc(parentType);
    Tcl_DriverWideSeekProc* parentWideSeekProc =
	Tcl_ChannelWideSeekProc(parentType);
    ClientData parentData =
	Tcl_GetChannelInstanceData(parent);

    if ((offset == Tcl_LongAsWide(0)) && (mode == SEEK_CUR)) {
        /*
	 * This is no seek but a request to tell the caller the current
	 * location. Simply pass the request down.
	 */

	if (parentWideSeekProc != NULL) {
	    return (*parentWideSeekProc) (parentData, offset, mode,
		    errorCodePtr);
	}

	return Tcl_LongAsWide((*parentSeekProc) (parentData, 0, mode,
		errorCodePtr));
    }

    /*
     * It is a real request to change the position. Flush all data waiting
     * for output and discard everything in the input buffers. Then pass
     * the request down, unchanged.
     */

    if (dataPtr->mode & TCL_WRITABLE) {
        ExecuteCallback (dataPtr, NO_INTERP, A_FLUSH_WRITE,
		NULL, 0, TRANSMIT_DOWN, P_NO_PRESERVE);
    }

    if (dataPtr->mode & TCL_READABLE) {
        ExecuteCallback (dataPtr, NO_INTERP, A_CLEAR_READ,
		NULL, 0, TRANSMIT_DONT, P_NO_PRESERVE);
	ResultClear(&dataPtr->result);
	dataPtr->readIsFlushed = 0;
    }

    /*
     * If we have a wide seek capability, we should stick with that.
     */
    if (parentWideSeekProc != NULL) {