diff options
Diffstat (limited to 'generic/tclIO.c')
| -rw-r--r-- | generic/tclIO.c | 177 |
1 files changed, 50 insertions, 127 deletions
diff --git a/generic/tclIO.c b/generic/tclIO.c index 6add83f..57ef02e 100644 --- a/generic/tclIO.c +++ b/generic/tclIO.c @@ -181,7 +181,6 @@ static int CloseChannelPart(Tcl_Interp *interp, Channel *chanPtr, int errorCode, int flags); static int CloseWrite(Tcl_Interp *interp, Channel *chanPtr); static void CommonGetsCleanup(Channel *chanPtr); -static int CopyBuffer(Channel *chanPtr, char *result, int space); static int CopyData(CopyState *csPtr, int mask); static void CopyEventProc(ClientData clientData, int mask); static void CreateScriptRecord(Tcl_Interp *interp, @@ -5405,63 +5404,77 @@ Tcl_Read( int Tcl_ReadRaw( Tcl_Channel chan, /* The channel from which to read. */ - char *bufPtr, /* Where to store input read. */ + char *readBuf, /* Where to store input read. */ int bytesToRead) /* Maximum number of bytes to read. */ { Channel *chanPtr = (Channel *) chan; ChannelState *statePtr = chanPtr->state; /* State info for channel */ - int nread, copied, copiedNow = INT_MAX; - - /* - * The check below does too much because it will reject a call to this - * function with a channel which is part of an 'fcopy'. But we have to - * allow this here or else the chaining in the transformation drivers will - * fail with 'file busy' error instead of retrieving and transforming the - * data to copy. - * - * We let the check procedure now believe that there is no fcopy in - * progress. A better solution than this might be an additional flag - * argument to switch off specific checks. - */ + int copied = 0; if (CheckChannelErrors(statePtr, TCL_READABLE | CHANNEL_RAW_MODE) != 0) { return -1; } - /* - * Check for information in the push-back buffers. If there is some, use - * it. Go to the driver only if there is none (anymore) and the caller - * requests more bytes. - */ + /* First read bytes from the push-back buffers. */ - Tcl_Preserve(chanPtr); - for (copied = 0; bytesToRead > 0 && copiedNow > 0; - bufPtr+=copiedNow, bytesToRead-=copiedNow, copied+=copiedNow) { - copiedNow = CopyBuffer(chanPtr, bufPtr, bytesToRead); + while (chanPtr->inQueueHead && bytesToRead > 0) { + ChannelBuffer *bufPtr = chanPtr->inQueueHead; + int bytesInBuffer = BytesLeft(bufPtr); + int toCopy = (bytesInBuffer < bytesToRead) ? bytesInBuffer + : bytesToRead; + + /* Copy the current chunk into the read buffer. */ + + memcpy(readBuf, RemovePoint(bufPtr), (size_t) toCopy); + bufPtr->nextRemoved += toCopy; + copied += toCopy; + readBuf += toCopy; + bytesToRead -= toCopy; + + /* If the current buffer is empty recycle it. */ + + if (IsBufferEmpty(bufPtr)) { + chanPtr->inQueueHead = bufPtr->nextPtr; + if (chanPtr->inQueueHead == NULL) { + chanPtr->inQueueTail = NULL; + } + RecycleBuffer(chanPtr->state, bufPtr, 0); + } } + /* Go to the driver if more data needed. */ + if (bytesToRead > 0) { - /* - * Now go to the driver to get as much as is possible to - * fill the remaining request. Since we're directly filling - * the caller's buffer, retain the blocked flag. - */ - nread = ChanRead(chanPtr, bufPtr, bytesToRead); - if (nread < 0) { + int nread = ChanRead(chanPtr, readBuf+copied, bytesToRead); + + if (nread > 0) { + /* Successful read (short is OK) - add to bytes copied */ + copied += nread; + } else if (nread < 0) { + /* + * An error signaled. If CHANNEL_BLOCKED, then the error + * is not real, but an indication of blocked state. In + * that case, retain the flag and let caller receive the + * short read of copied bytes from the pushback. + * HOWEVER, if copied==0 bytes from pushback then repeat + * signalling the blocked state as an error to caller so + * there is no false report of an EOF. + * When !CHANNEL_BLOCKED, the error is real and passes on + * to caller. + */ if (!GotFlag(statePtr, CHANNEL_BLOCKED) || copied == 0) { copied = -1; } - } else { - copied += nread; - } - if (copied != 0) { + } else if (copied > 0) { + /* + * nread == 0. Driver is at EOF, but if copied>0 bytes + * from pushback, then we should not signal it yet. + */ ResetFlag(statePtr, CHANNEL_EOF); } } - - Tcl_Release(chanPtr); return copied; } @@ -9354,96 +9367,6 @@ DoRead( /* *---------------------------------------------------------------------- * - * CopyBuffer -- - * - * Copy at most one buffer of input to the result space. - * - * Results: - * Number of bytes stored in the result buffer. May return zero if no - * input is available. - * - * Side effects: - * Consumes buffered input. May deallocate one buffer. - * - *---------------------------------------------------------------------- - */ - -static int -CopyBuffer( - Channel *chanPtr, /* Channel from which to read input. */ - char *result, /* Where to store the copied input. */ - int space) /* How many bytes are available in result to - * store the copied input? */ -{ - ChannelBuffer *bufPtr; /* The buffer from which to copy bytes. */ - int bytesInBuffer; /* How many bytes are available to be copied - * in the current input buffer? */ - int copied; /* How many characters were already copied - * into the destination space? */ - - /* - * If there is no input at all, return zero. The invariant is that either - * there is no buffer in the queue, or if the first buffer is empty, it is - * also the last buffer (and thus there is no input in the queue). Note - * also that if the buffer is empty, we don't leave it in the queue, but - * recycle it. - */ - - if (chanPtr->inQueueHead == NULL) { - return 0; - } - bufPtr = chanPtr->inQueueHead; - bytesInBuffer = BytesLeft(bufPtr); - - copied = 0; - - if (bytesInBuffer == 0) { - RecycleBuffer(chanPtr->state, bufPtr, 0); - chanPtr->inQueueHead = NULL; - chanPtr->inQueueTail = NULL; - return 0; - } - - /* - * Copy the current chunk into the result buffer. - */ - - if (bytesInBuffer < space) { - space = bytesInBuffer; - } - - memcpy(result, RemovePoint(bufPtr), (size_t) space); - bufPtr->nextRemoved += space; - copied = space; - - /* - * We don't care about in-stream EOF characters here as the data read here - * may still flow through one or more transformations, i.e. is not in its - * final state yet. - */ - - /* - * If the current buffer is empty recycle it. - */ - - if (IsBufferEmpty(bufPtr)) { - chanPtr->inQueueHead = bufPtr->nextPtr; - if (chanPtr->inQueueHead == NULL) { - chanPtr->inQueueTail = NULL; - } - RecycleBuffer(chanPtr->state, bufPtr, 0); - } - - /* - * Return the number of characters copied into the result buffer. - */ - - return copied; -} - -/* - *---------------------------------------------------------------------- - * * CopyEventProc -- * * This routine is invoked as a channel event handler for the background |