diff options
Diffstat (limited to 'generic/tclIOGT.c')
| -rw-r--r-- | generic/tclIOGT.c | 117 |
1 files changed, 107 insertions, 10 deletions
diff --git a/generic/tclIOGT.c b/generic/tclIOGT.c index 022ba35..0bc3083 100644 --- a/generic/tclIOGT.c +++ b/generic/tclIOGT.c @@ -10,7 +10,7 @@ * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * - * CVS: $Id: tclIOGT.c,v 1.6 2002/02/15 19:58:28 andreas_kupries Exp $ + * CVS: $Id: tclIOGT.c,v 1.7 2002/05/24 21:19:06 dkf Exp $ */ #include "tclInt.h" @@ -33,8 +33,8 @@ static int TransformInputProc _ANSI_ARGS_ (( static int TransformOutputProc _ANSI_ARGS_ (( ClientData instanceData, CONST char *buf, int toWrite, int* errorCodePtr)); -static Tcl_WideInt TransformSeekProc _ANSI_ARGS_ (( - ClientData instanceData, Tcl_WideInt offset, +static int TransformSeekProc _ANSI_ARGS_ (( + ClientData instanceData, long offset, int mode, int* errorCodePtr)); static int TransformSetOptionProc _ANSI_ARGS_(( ClientData instanceData, Tcl_Interp *interp, @@ -49,6 +49,9 @@ static int TransformGetFileHandleProc _ANSI_ARGS_ (( ClientData* handlePtr)); static int TransformNotifyProc _ANSI_ARGS_ (( ClientData instanceData, int mask)); +static Tcl_WideInt TransformWideSeekProc _ANSI_ARGS_ (( + ClientData instanceData, Tcl_WideInt offset, + int mode, int* errorCodePtr)); /* * Forward declarations of internal procedures. @@ -141,6 +144,7 @@ static Tcl_ChannelType transformChannelType = { TransformBlockModeProc, /* Set blocking/nonblocking mode.*/ NULL, /* Flush proc. */ TransformNotifyProc, /* Handling of events bubbling up */ + TransformWideSeekProc, /* Wide seek proc */ }; /* @@ -843,14 +847,13 @@ TransformOutputProc (instanceData, buf, toWrite, errorCodePtr) *------------------------------------------------------* */ -static Tcl_WideInt +static int TransformSeekProc (instanceData, offset, mode, errorCodePtr) ClientData instanceData; /* The channel to manipulate */ - Tcl_WideInt offset; /* Size of movement. */ + long offset; /* Size of movement. */ int mode; /* How to move */ int* errorCodePtr; /* Location of error flag. */ { - Tcl_WideInt result; TransformChannelData* dataPtr = (TransformChannelData*) instanceData; Tcl_Channel parent = Tcl_GetStackedChannel(dataPtr->self); Tcl_ChannelType* parentType = Tcl_GetChannelType(parent); @@ -861,9 +864,8 @@ TransformSeekProc (instanceData, offset, mode, errorCodePtr) * location. Simply pass the request down. */ - result = (*parentSeekProc) (Tcl_GetChannelInstanceData(parent), + return (*parentSeekProc) (Tcl_GetChannelInstanceData(parent), offset, mode, errorCodePtr); - return result; } /* @@ -884,9 +886,104 @@ TransformSeekProc (instanceData, offset, mode, errorCodePtr) dataPtr->readIsFlushed = 0; } - result = (*parentSeekProc) (Tcl_GetChannelInstanceData(parent), + return (*parentSeekProc) (Tcl_GetChannelInstanceData(parent), offset, mode, errorCodePtr); - return result; +} + +/* + *---------------------------------------------------------------------- + * + * 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) { + 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)); } /* |