/* ARGSUSED */
static void
TransformWatchProc(
ClientData instanceData, /* Channel to watch. */
int mask) /* Events of interest. */
{
TransformChannelData *dataPtr = instanceData;
Tcl_Channel downChan;
/*
* The caller expressed interest in events occuring for this channel. We
* are forwarding the call to the underlying channel now.
*/
dataPtr->watchMask = mask;
/*
* No channel handlers any more. We will be notified automatically about
* events on the channel below via a call to our 'TransformNotifyProc'.
* But we have to pass the interest down now. We are allowed to add
* additional 'interest' to the mask if we want to. But this
* transformation has no such interest. It just passes the request down,
* unchanged.
*/
if (dataPtr->self == NULL) {
return;
}
downChan = Tcl_GetStackedChannel(dataPtr->self);
Tcl_GetChannelType(downChan)->watchProc(
Tcl_GetChannelInstanceData(downChan), mask);
/*
* Management of the internal timer.
*/
if ((dataPtr->timer != NULL) &&
(!(mask & TCL_READABLE) || ResultEmpty(&dataPtr->result))) {
/*
* A pending timer exists, but either is there no (more) interest in
* the events it generates or nothing is available for reading, so
* remove it.
*/
Tcl_DeleteTimerHandler(dataPtr->timer);
dataPtr->timer = NULL;
}
if ((dataPtr->timer == NULL) && (mask & TCL_READABLE)
&& !ResultEmpty(&dataPtr->result)) {
/*
* There is no pending timer, but there is interest in readable events
* and we actually have data waiting, so generate a timer to flush
* that.
*/
dataPtr->timer = Tcl_CreateTimerHandler(FLUSH_DELAY,
TransformChannelHandlerTimer, dataPtr);
}
}
static int
TransformGetOptionProc(
ClientData instanceData,
Tcl_Interp *interp,
const char *optionName,
Tcl_DString *dsPtr)
{
TransformChannelData *dataPtr = instanceData;
Tcl_Channel downChan = Tcl_GetStackedChannel(dataPtr->self);
Tcl_DriverGetOptionProc *getOptionProc;
getOptionProc = Tcl_ChannelGetOptionProc(Tcl_GetChannelType(downChan));
if (getOptionProc != NULL) {
return getOptionProc(Tcl_GetChannelInstanceData(downChan), interp,
optionName, dsPtr);
} else if (optionName == NULL) {
/*
* Request is query for all options, this is ok.
*/
return TCL_OK;
}
/*
* Request for a specific option has to fail, since we don't have any.
*/
return TCL_ERROR;
}
static int
TransformGetFileHandleProc(
ClientData instanceData, /* Channel to query. */
int direction, /* Direction of interest. */
ClientData *handlePtr) /* Place to store the handle into. */
{
TransformChannelData *dataPtr = instanceData;
/*
* Return the handle belonging to parent channel. IOW, pass the request
* down and the result up.
*/
return Tcl_GetChannelHandle(Tcl_GetStackedChannel(dataPtr->self),
direction, handlePtr);
}
static int
TransformSeekProc(
ClientData instanceData, /* The channel to manipulate. */
long offset, /* Size of movement. */
int mode, /* How to move. */
int *errorCodePtr) /* Location of error flag. */
{
TransformChannelData *dataPtr = instanceData;
Tcl_Channel parent = Tcl_GetStackedChannel(dataPtr->self);
const 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.
*/
PreserveData(dataPtr);
if (dataPtr->mode & TCL_WRITABLE) {
ExecuteCallback(dataPtr, NULL, A_FLUSH_WRITE, NULL, 0, TRANSMIT_DOWN,
P_NO_PRESERVE);
}
if (dataPtr->mode & TCL_READABLE) {
ExecuteCallback(dataPtr, NULL, A_CLEAR_READ, NULL, 0, TRANSMIT_DONT,
P_NO_PRESERVE);
ResultClear(&dataPtr->result);
dataPtr->readIsFlushed = 0;
dataPtr->eofPending = 0;
}
ReleaseData(dataPtr);
return parentSeekProc(Tcl_GetChannelInstanceData(parent), offset, mode,
errorCodePtr);
}
static int
TransformSetOptionProc(
ClientData instanceData,
Tcl_Interp *interp,
const char *optionName,
const char *value)
{
TransformChannelData *dataPtr = instanceData;
Tcl_Channel downChan = Tcl_GetStackedChannel(dataPtr->self);
Tcl_DriverSetOptionProc *setOptionProc;
setOptionProc = Tcl_ChannelSetOptionProc(Tcl_GetChannelType(downChan));
if (setOptionProc == NULL) {
return TCL_ERROR;
}
return setOptionProc(Tcl_GetChannelInstanceData(downChan), interp,
optionName, value);
}
static Tcl_WideInt
TransformWideSeekProc(
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 = instanceData;
Tcl_Channel parent = Tcl_GetStackedChannel(dataPtr->self);
const 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.
*/
PreserveData(dataPtr);
if (dataPtr->mode & TCL_WRITABLE) {
ExecuteCallback(dataPtr, NULL, A_FLUSH_WRITE, NULL, 0, TRANSMIT_DOWN,
P_NO_PRESERVE);
}
if (dataPtr->mode & TCL_READABLE) {
ExecuteCallback(dataPtr, NULL, A_CLEAR_READ, NULL, 0, TRANSMIT_DONT,
P_NO_PRESERVE);
ResultClear(&dataPtr->result);
dataPtr->readIsFlushed = 0;
dataPtr->eofPending = 0;
}
ReleaseData(dataPtr);
/*
* If we have a wide seek capability, we should stick with that.
*/
if (parentWideSeekProc != NULL) {
return parentWideSeekProc(parentData, offset, mode, errorCodePtr);
}
/*
* We're transferring to narrow seeks at this point; this is a bit complex
* because we have to check whether the seek is possible first (i.e.
* whether we are losing information in truncating the bits of the
* offset). Luckily, there's a defined error for what happens when trying
* to go out of the representable range.
*/
if (offset<Tcl_LongAsWide(LONG_MIN) || offset>Tcl_LongAsWide(LONG_MAX)) {
*errorCodePtr = EOVERFLOW;
return Tcl_LongAsWide(-1);
}
return Tcl_LongAsWide(parentSeekProc(parentData, Tcl_WideAsLong(offset),
mode, errorCodePtr));
}
static int
TransformInputProc(
ClientData instanceData,
char *buf,
int toRead,
int *errorCodePtr)
{
TransformChannelData *dataPtr = instanceData;
int gotBytes, read, copied;
Tcl_Channel downChan;
/*
* Should assert(dataPtr->mode & TCL_READABLE);
*/
if (toRead == 0 || dataPtr->self == NULL) {
/*
* Catch a no-op. TODO: Is this a panic()?
*/
return 0;
}
gotBytes = 0;
downChan = Tcl_GetStackedChannel(dataPtr->self);
PreserveData(dataPtr);
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.
*/
break;
}
/*
* 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, NULL, A_QUERY_MAXREAD, NULL, 0,
TRANSMIT_NUM /* -> maxRead */, P_PRESERVE);
if (dataPtr->maxRead >= 0) {
if (dataPtr->maxRead < toRead) {
toRead = dataPtr->maxRead;
}
} /* else: 'maxRead < 0' == Accept the current value of toRead. */
if (toRead <= 0) {
break;
}
if (dataPtr->eofPending) {
/*
* Already saw EOF from downChan; don't ask again.
* NOTE: Could move this up to avoid the last maxRead
* execution. Believe this would still be correct behavior,
* but the test suite tests the whole command callback
* sequence, so leave it unchanged for now.
*/
break;
}
/*
* Get bytes from the underlying channel.
*/
read = Tcl_ReadRaw(downChan, buf, toRead);
if (read < 0) {
if (Tcl_InputBlocked(downChan) && (gotBytes > 0)) {
/*
* Zero bytes available from downChan because blocked.
* But nonzero bytes already copied, so total is a
* valid blocked short read. Return to caller.
*/
break;
}
/*
* Either downChan is not blocked (there's a real error).
* or it is and there are no bytes copied yet. In either
* case we want to pass the "error" along to the caller,
* either to report an error, or to signal to the caller
* that zero bytes are available because blocked.
*/
*errorCodePtr = Tcl_GetErrno();
gotBytes = -1;
break;
} else if (read == 0) {
/*
* Zero returned from Tcl_ReadRaw() always indicates EOF
* on the down channel.
*/
dataPtr->eofPending = 1;
dataPtr->readIsFlushed = 1;
ExecuteCallback(dataPtr, NULL, A_FLUSH_READ, NULL, 0,
TRANSMIT_IBUF, P_PRESERVE);
if (ResultEmpty(&dataPtr->result)) {
/*
* We had nothing to flush.
*/
break;
}
continue; /* at: while (toRead > 0) */
} /* read == 0 */
/*
* Transform the read chunk and add the result to our read buffer
* (dataPtr->result).
*/
if (ExecuteCallback(dataPtr, NULL, A_READ, UCHARP(buf), read,
TRANSMIT_IBUF, P_PRESERVE) != TCL_OK) {
*errorCodePtr = EINVAL;
gotBytes = -1;
break;
}
} /* while toRead > 0 */
if (gotBytes == 0) {
dataPtr->eofPending = 0;
}
ReleaseData(dataPtr);
return gotBytes;
}
static int
ExecuteCallback(
TransformChannelData *dataPtr,
/* Transformation with the callback. */
Tcl_Interp *interp, /* Current interpreter, possibly NULL. */
unsigned char *op, /* Operation invoking the callback. */
unsigned char *buf, /* Buffer to give to the script. */
int bufLen, /* And its length. */
int transmit, /* Flag, determines whether the result of the
* callback is sent to the underlying channel
* or not. */
int preserve) /* Flag. If true the procedure will preserve
* the result state of all accessed
* interpreters. */
{
Tcl_Obj *resObj; /* See below, switch (transmit). */
int resLen;
unsigned char *resBuf;
Tcl_InterpState state = NULL;
int res = TCL_OK;
Tcl_Obj *command = TclListObjCopy(NULL, dataPtr->command);
Tcl_Interp *eval = dataPtr->interp;
Tcl_Preserve(eval);
/*
* Step 1, create the complete command to execute. Do this by appending
* operation and buffer to operate upon to a copy of the callback
* definition. We *cannot* create a list containing 3 objects and then use
* 'Tcl_EvalObjv', because the command may contain additional prefixed
* arguments. Feather's curried commands would come in handy here.
*/
if (preserve == P_PRESERVE) {
state = Tcl_SaveInterpState(eval, res);
}
Tcl_IncrRefCount(command);
Tcl_ListObjAppendElement(NULL, command, Tcl_NewStringObj((char *) op, -1));
/*
* Use a byte-array to prevent the misinterpretation of binary data coming
* through as UTF while at the tcl level.
*/
Tcl_ListObjAppendElement(NULL, command, Tcl_NewByteArrayObj(buf, bufLen));
/*
* Step 2, execute the command at the global level of the interpreter used
* to create the transformation. Destroy the command afterward. If an
* error occured and the current interpreter is defined and not equal to
* the interpreter for the callback, then copy the error message into
* current interpreter. Don't copy if in preservation mode.
*/
res = Tcl_EvalObjEx(eval, command, TCL_EVAL_GLOBAL);
Tcl_DecrRefCount(command);
command = NULL;
if ((res != TCL_OK) && (interp != NULL) && (eval != interp)
&& (preserve == P_NO_PRESERVE)) {
Tcl_SetObjResult(interp, Tcl_GetObjResult(eval));
Tcl_Release(eval);
return res;
}
/*
* Step 3, transmit a possible conversion result to the underlying
* channel, or ourselves.
*/
switch (transmit) {
case TRANSMIT_DONT:
/* nothing to do */
break;
case TRANSMIT_DOWN:
if (dataPtr->self == NULL) {
break;
}
resObj = Tcl_GetObjResult(eval);
resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen);
Tcl_WriteRaw(Tcl_GetStackedChannel(dataPtr->self), (char *) resBuf,
resLen);
break;
case TRANSMIT_SELF:
if (dataPtr->self == NULL) {
break;
}
resObj = Tcl_GetObjResult(eval);
resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen);
Tcl_WriteRaw(dataPtr->self, (char *) resBuf, resLen);
break;
case TRANSMIT_IBUF:
resObj = Tcl_GetObjResult(eval);
resBuf = Tcl_GetByteArrayFromObj(resObj, &resLen);
ResultAdd(&dataPtr->result, resBuf, resLen);
break;
case TRANSMIT_NUM:
/*
* Interpret result as integer number.
*/
resObj = Tcl_GetObjResult(eval);
TclGetIntFromObj(eval, resObj, &dataPtr->maxRead);
break;
}
Tcl_ResetResult(eval);
if (preserve == P_PRESERVE) {
(void) Tcl_RestoreInterpState(eval, state);
}
Tcl_Release(eval);
return res;
}
static int
TransformInputProc(
ClientData instanceData,
char *buf,
int toRead,
int *errorCodePtr)
{
TransformChannelData *dataPtr = instanceData;
int gotBytes, read, 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, NULL, A_QUERY_MAXREAD, NULL, 0,
TRANSMIT_NUM /* -> maxRead */, P_PRESERVE);
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;
}
/*
* Get bytes from the underlying channel.
*/
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;
} else 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;
}
return gotBytes;
}
if (dataPtr->readIsFlushed) {
/*
* Already flushed, nothing to do anymore.
*/
return gotBytes;
}
dataPtr->readIsFlushed = 1;
ExecuteCallback(dataPtr, NULL, A_FLUSH_READ, NULL, 0,
TRANSMIT_IBUF, P_PRESERVE);
if (ResultEmpty(&dataPtr->result)) {
/*
* 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).
*/
if (ExecuteCallback(dataPtr, NULL, A_READ, UCHARP(buf), read,
TRANSMIT_IBUF, P_PRESERVE) != TCL_OK) {
*errorCodePtr = EINVAL;
return -1;
}
} /* while toRead > 0 */
return gotBytes;
}