diff options
Diffstat (limited to 'generic/tclZlib.c')
| -rw-r--r-- | generic/tclZlib.c | 498 |
1 files changed, 393 insertions, 105 deletions
diff --git a/generic/tclZlib.c b/generic/tclZlib.c index 356772e..3063b59 100644 --- a/generic/tclZlib.c +++ b/generic/tclZlib.c @@ -17,6 +17,7 @@ #include "tclInt.h" #ifdef HAVE_ZLIB #include <zlib.h> +#include "tclIO.h" /* * Magic flags used with wbits fields to indicate that we're handling the gzip @@ -103,6 +104,7 @@ typedef struct { GzipHeader outHeader; /* Header to write to an output stream, when * compressing a gzip stream. */ Tcl_TimerToken timer; /* Timer used for keeping events fresh. */ + Tcl_DString decompressed; /* Buffer for decompression results. */ Tcl_Obj *compDictObj; /* Byte-array object containing compression * dictionary (not dictObj!) to use if * necessary. */ @@ -128,11 +130,10 @@ typedef struct { #define DEFAULT_BUFFER_SIZE 4096 /* - * Time to wait (in milliseconds) before flushing the channel when reading - * data through the transform. + * Time to wait before delivering a timer event. */ -#define TRANSFORM_FLUSH_DELAY 5 +#define TRANSFORM_TIMEOUT 0 /* * Prototypes for private procedures defined later in this file: @@ -143,7 +144,7 @@ static Tcl_DriverBlockModeProc ZlibTransformBlockMode; static Tcl_DriverCloseProc ZlibTransformClose; static Tcl_DriverGetHandleProc ZlibTransformGetHandle; static Tcl_DriverGetOptionProc ZlibTransformGetOption; -static Tcl_DriverHandlerProc ZlibTransformHandler; +static Tcl_DriverHandlerProc ZlibTransformEventHandler; static Tcl_DriverInputProc ZlibTransformInput; static Tcl_DriverOutputProc ZlibTransformOutput; static Tcl_DriverSetOptionProc ZlibTransformSetOption; @@ -157,6 +158,10 @@ static int GenerateHeader(Tcl_Interp *interp, Tcl_Obj *dictObj, GzipHeader *headerPtr, int *extraSizePtr); static int ZlibPushSubcmd(Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]); +static inline int ResultCopy(ZlibChannelData *cd, char *buf, + int toRead); +static int ResultGenerate(ZlibChannelData *cd, int n, int flush, + int *errorCodePtr); static Tcl_Channel ZlibStackChannelTransform(Tcl_Interp *interp, int mode, int format, int level, Tcl_Channel channel, Tcl_Obj *gzipHeaderDictPtr, @@ -164,9 +169,8 @@ static Tcl_Channel ZlibStackChannelTransform(Tcl_Interp *interp, static void ZlibStreamCleanup(ZlibStreamHandle *zshPtr); static int ZlibStreamSubcmd(Tcl_Interp *interp, int objc, Tcl_Obj *const objv[]); -static void ZlibTransformTimerKill(ZlibChannelData *cd); +static inline void ZlibTransformEventTimerKill(ZlibChannelData *cd); static void ZlibTransformTimerRun(ClientData clientData); -static void ZlibTransformTimerSetup(ZlibChannelData *cd); /* * Type of zlib-based compressing and decompressing channels. @@ -186,7 +190,7 @@ static const Tcl_ChannelType zlibChannelType = { NULL, /* close2Proc */ ZlibTransformBlockMode, NULL, /* flushProc */ - ZlibTransformHandler, + ZlibTransformEventHandler, NULL, /* wideSeekProc */ NULL, NULL @@ -2595,6 +2599,12 @@ ZlibStreamCmd( *---------------------------------------------------------------------- * Set of functions to support channel stacking. *---------------------------------------------------------------------- + * + * ZlibTransformClose -- + * + * How to shut down a stacked compressing/decompressing transform. + * + *---------------------------------------------------------------------- */ static int @@ -2609,7 +2619,7 @@ ZlibTransformClose( * Delete the support timer. */ - ZlibTransformTimerKill(cd); + ZlibTransformEventTimerKill(cd); /* * Flush any data waiting to be compressed. @@ -2654,6 +2664,8 @@ ZlibTransformClose( * Release all memory. */ + Tcl_DStringFree(&cd->decompressed); + if (cd->inBuffer) { ckfree(cd->inBuffer); cd->inBuffer = NULL; @@ -2665,6 +2677,16 @@ ZlibTransformClose( ckfree(cd); return result; } + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformInput -- + * + * Reader filter that does decompression. + * + *---------------------------------------------------------------------- + */ static int ZlibTransformInput( @@ -2676,84 +2698,144 @@ ZlibTransformInput( ZlibChannelData *cd = instanceData; Tcl_DriverInputProc *inProc = Tcl_ChannelInputProc(Tcl_GetChannelType(cd->parent)); - int e, readBytes, flush = Z_NO_FLUSH; + int readBytes, gotBytes, copied; if (cd->mode == TCL_ZLIB_STREAM_DEFLATE) { return inProc(Tcl_GetChannelInstanceData(cd->parent), buf, toRead, errorCodePtr); } - cd->inStream.next_out = (Bytef *) buf; - cd->inStream.avail_out = toRead; - if (cd->inStream.next_in == NULL) { - goto doReadFirst; - } - while (1) { - e = inflate(&cd->inStream, flush); - if (e == Z_NEED_DICT && cd->compDictObj) { - e = SetInflateDictionary(&cd->inStream, cd->compDictObj); - if (e == Z_OK) { - continue; - } - } - if ((e == Z_STREAM_END) || (e==Z_OK && cd->inStream.avail_out==0)) { - return toRead - cd->inStream.avail_out; - } - + gotBytes = 0; + while (toRead > 0) { /* - * Z_BUF_ERROR can be ignored as per http://www.zlib.net/zlib_how.html - * - * Just indicates that the zlib couldn't consume input/produce output, - * and is fixed by supplying more input. + * Loop until the request is satisfied (or no data available from + * below, possibly EOF). */ - if ((e != Z_OK) && (e != Z_BUF_ERROR)) { - Tcl_Obj *errObj = Tcl_NewListObj(0, NULL); + copied = ResultCopy(cd, buf, toRead); + toRead -= copied; + buf += copied; + gotBytes += copied; - Tcl_ListObjAppendElement(NULL, errObj, - Tcl_NewStringObj(cd->inStream.msg, -1)); - Tcl_SetChannelError(cd->parent, errObj); - *errorCodePtr = EINVAL; - return -1; + if (toRead == 0) { + return gotBytes; } /* - * Check if the inflate stopped early. + * The buffer is exhausted, but the caller wants even more. We now + * have to go to the underlying channel, get more bytes and then + * transform them for delivery. We may not get what we want (full EOF + * or temporarily out of data). + * + * Length (cd->decompressed) == 0, toRead > 0 here. + * + * The zlib transform allows us to read at most one character from the + * underlying channel to properly identify Z_STREAM_END without + * reading over the border. */ - if (cd->inStream.avail_in > 0) { - continue; - } + readBytes = Tcl_ReadRaw(cd->parent, cd->inBuffer, 1); /* - * Emptied the buffer of data from the underlying channel. Get some - * more. + * Three cases here: + * 1. Got some data from the underlying channel (readBytes > 0) so + * it should be fed through the decompression engine. + * 2. Got an error (readBytes < 0) which we should report up except + * for the case where we can convert it to a short read. + * 3. Got an end-of-data from EOF or blocking (readBytes == 0). If + * it is EOF, try flushing the data out of the decompressor. */ - doReadFirst: - /* - * Hack for Bug 2762041. Disable pre-reading of lots of input, read - * only one character. This way the Z_END_OF_STREAM can be read - * without triggering an EOF in the base channel. The higher input - * loops in DoReadChars() would react to that by stopping, despite the - * transform still having data which could be read. - * - * This is only a hack because other transforms may not be able to - * work around the general problem in this way. - */ - - readBytes = Tcl_ReadRaw(cd->parent, cd->inBuffer, 1); if (readBytes < 0) { + /* + * Report errors to caller. The state of the seek system is + * unchanged! + */ + + if ((Tcl_GetErrno() == EAGAIN) && (gotBytes > 0)) { + /* + * EAGAIN is a special situation. If we had some data before + * we report that instead of the request to re-try. + */ + + return gotBytes; + } + *errorCodePtr = Tcl_GetErrno(); return -1; } else if (readBytes == 0) { - flush = Z_SYNC_FLUSH; - } + /* + * Check wether we hit on EOF in 'parent' 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. + */ - cd->inStream.next_in = (Bytef *) cd->inBuffer; - cd->inStream.avail_in = readBytes; + if (!Tcl_Eof(cd->parent)) { + /* + * The state of the seek system is unchanged! + */ + + if ((gotBytes == 0) && (cd->flags & ASYNC)) { + *errorCodePtr = EWOULDBLOCK; + return -1; + } + return gotBytes; + } + + /* + * (Semi-)Eof in parent. + * + * Now this is a bit different. The partial data waiting is + * converted and returned. + */ + + if (ResultGenerate(cd, 0, Z_SYNC_FLUSH, errorCodePtr) != TCL_OK) { + return -1; + } + + if (Tcl_DStringLength(&cd->decompressed) == 0) { + /* + * The drain delivered nothing. Time to deliver what we've + * got. + */ + + return gotBytes; + } + + /* + * Reset eof, force caller to drain result buffer. + */ + + ((Channel *) cd->parent)->state->flags &= ~CHANNEL_EOF; + } else /* readBytes > 0 */ { + /* + * Transform the read chunk, which was not empty. Anything we get + * back is a transformation result to be put into our buffers, and + * the next iteration will put it into the result. + */ + + if (ResultGenerate(cd, readBytes, Z_NO_FLUSH, + errorCodePtr) != TCL_OK) { + return -1; + } + } } + return gotBytes; } + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformOutput -- + * + * Writer filter that does compression. + * + *---------------------------------------------------------------------- + */ static int ZlibTransformOutput( @@ -2798,6 +2880,16 @@ ZlibTransformOutput( return toWrite - cd->outStream.avail_in; } + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformSetOption -- + * + * Writing side of [fconfigure] on our channel. + * + *---------------------------------------------------------------------- + */ static int ZlibTransformSetOption( /* not used */ @@ -2871,7 +2963,7 @@ ZlibTransformSetOption( /* not used */ } if (Tcl_WriteRaw(cd->parent, cd->outBuffer, - cd->outStream.next_out - (Bytef*)cd->outBuffer) < 0) { + cd->outStream.next_out - (Bytef *) cd->outBuffer) < 0) { Tcl_AppendResult(interp, "problem flushing channel: ", Tcl_PosixError(interp), NULL); return TCL_ERROR; @@ -2888,9 +2980,24 @@ ZlibTransformSetOption( /* not used */ } } + /* + * Pass all unknown options down, to deeper transforms and/or the base + * channel. + */ + return setOptionProc(Tcl_GetChannelInstanceData(cd->parent), interp, optionName, value); } + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformGetOption -- + * + * Reading side of [fconfigure] on our channel. + * + *---------------------------------------------------------------------- + */ static int ZlibTransformGetOption( @@ -2989,6 +3096,17 @@ ZlibTransformGetOption( } return Tcl_BadChannelOption(interp, optionName, chanOptions); } + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformWatch, ZlibTransformEventHandler -- + * + * If we have data pending, trigger a readable event after a short time + * (in order to allow a real event to catch up). + * + *---------------------------------------------------------------------- + */ static void ZlibTransformWatch( @@ -3004,63 +3122,28 @@ ZlibTransformWatch( watchProc = Tcl_ChannelWatchProc(Tcl_GetChannelType(cd->parent)); watchProc(Tcl_GetChannelInstanceData(cd->parent), mask); - if (!(mask & TCL_READABLE) - || (cd->inStream.avail_in == (uInt) cd->inAllocated)) { - ZlibTransformTimerKill(cd); - } else { - ZlibTransformTimerSetup(cd); - } -} - -static int -ZlibTransformGetHandle( - ClientData instanceData, - int direction, - ClientData *handlePtr) -{ - ZlibChannelData *cd = instanceData; - return Tcl_GetChannelHandle(cd->parent, direction, handlePtr); -} - -static int -ZlibTransformBlockMode( - ClientData instanceData, - int mode) -{ - ZlibChannelData *cd = instanceData; - - if (mode == TCL_MODE_NONBLOCKING) { - cd->flags |= ASYNC; - } else { - cd->flags &= ~ASYNC; + if (!(mask & TCL_READABLE) || Tcl_DStringLength(&cd->decompressed) == 0) { + ZlibTransformEventTimerKill(cd); + } else if (cd->timer == NULL) { + cd->timer = Tcl_CreateTimerHandler(TRANSFORM_TIMEOUT, + ZlibTransformTimerRun, cd); } - return TCL_OK; } static int -ZlibTransformHandler( +ZlibTransformEventHandler( ClientData instanceData, int interestMask) { ZlibChannelData *cd = instanceData; - ZlibTransformTimerKill(cd); + ZlibTransformEventTimerKill(cd); return interestMask; } -static void -ZlibTransformTimerSetup( - ZlibChannelData *cd) -{ - if (cd->timer == NULL) { - cd->timer = Tcl_CreateTimerHandler(TRANSFORM_FLUSH_DELAY, - ZlibTransformTimerRun, cd); - } -} - -static void -ZlibTransformTimerKill( +static inline void +ZlibTransformEventTimerKill( ZlibChannelData *cd) { if (cd->timer != NULL) { @@ -3082,6 +3165,53 @@ ZlibTransformTimerRun( /* *---------------------------------------------------------------------- * + * ZlibTransformGetHandle -- + * + * Anything that needs the OS handle is told to get it from what we are + * stacked on top of. + * + *---------------------------------------------------------------------- + */ + +static int +ZlibTransformGetHandle( + ClientData instanceData, + int direction, + ClientData *handlePtr) +{ + ZlibChannelData *cd = instanceData; + + return Tcl_GetChannelHandle(cd->parent, direction, handlePtr); +} + +/* + *---------------------------------------------------------------------- + * + * ZlibTransformBlockMode -- + * + * We need to keep track of the blocking mode; it changes our behavior. + * + *---------------------------------------------------------------------- + */ + +static int +ZlibTransformBlockMode( + ClientData instanceData, + int mode) +{ + ZlibChannelData *cd = instanceData; + + if (mode == TCL_MODE_NONBLOCKING) { + cd->flags |= ASYNC; + } else { + cd->flags &= ~ASYNC; + } + return TCL_OK; +} + +/* + *---------------------------------------------------------------------- + * * ZlibStackChannelTransform -- * * Stacks either compression or decompression onto a channel. @@ -3207,6 +3337,8 @@ ZlibStackChannelTransform( } } + Tcl_DStringInit(&cd->decompressed); + chan = Tcl_StackChannel(interp, &zlibChannelType, cd, Tcl_GetChannelMode(channel), channel); if (chan == NULL) { @@ -3235,6 +3367,162 @@ ZlibStackChannelTransform( /* *---------------------------------------------------------------------- + * + * ResultCopy -- + * + * Copies the requested number of bytes from the buffer into the + * specified array and removes them from the buffer afterward. Copies + * less if there is not enough data in the buffer. + * + * Side effects: + * See above. + * + * Result: + * The number of actually copied bytes, possibly less than 'toRead'. + * + *---------------------------------------------------------------------- + */ + +static inline int +ResultCopy( + ZlibChannelData *cd, /* The location of the buffer to read from. */ + char *buf, /* The buffer to copy into */ + int toRead) /* Number of requested bytes */ +{ + int have = Tcl_DStringLength(&cd->decompressed); + + if (have == 0) { + /* + * Nothing to copy in the case of an empty buffer. + */ + + return 0; + } else if (have > toRead) { + /* + * The internal buffer contains more than requested. Copy the + * requested subset to the caller, shift the remaining bytes down, and + * truncate. + */ + + char *src = Tcl_DStringValue(&cd->decompressed); + + memcpy(buf, src, toRead); + memmove(src, src + toRead, have - toRead); + + Tcl_DStringSetLength(&cd->decompressed, have - toRead); + return toRead; + } else /* have <= toRead */ { + /* + * There is just or not enough in the buffer to fully satisfy the + * caller, so take everything as best effort. + */ + + memcpy(buf, Tcl_DStringValue(&cd->decompressed), have); + Tcl_DStringSetLength(&cd->decompressed, 0); + return have; + } +} + +/* + *---------------------------------------------------------------------- + * + * ResultGenerate -- + * + * Extract uncompressed bytes from the compression engine and store them + * in our working buffer. + * + * Result: + * TCL_OK/TCL_ERROR (with *errorCodePtr updated with reason). + * + * Side effects: + * See above. + * + *---------------------------------------------------------------------- + */ + +static int +ResultGenerate( + ZlibChannelData *cd, + int n, + int flush, + int *errorCodePtr) +{ +#define MAXBUF 1024 + unsigned char buf[MAXBUF]; + int e, written; + + cd->inStream.next_in = (Bytef *) cd->inBuffer; + cd->inStream.avail_in = n; + + while (1) { + cd->inStream.next_out = (Bytef *) buf; + cd->inStream.avail_out = MAXBUF; + + e = inflate(&cd->inStream, flush); + if (e == Z_NEED_DICT && cd->compDictObj) { + e = SetInflateDictionary(&cd->inStream, cd->compDictObj); + if (e == Z_OK) { + /* + * A repetition of Z_NEED_DICT is just an error. + */ + + cd->inStream.next_out = (Bytef *) buf; + cd->inStream.avail_out = MAXBUF; + e = inflate(&cd->inStream, flush); + } + } + + /* + * avail_out is now the left over space in the output. Therefore + * "MAXBUF - avail_out" is the amount of bytes generated. + */ + + written = MAXBUF - cd->inStream.avail_out; + if (written) { + Tcl_DStringAppend(&cd->decompressed, (char *) buf, written); + } + + /* + * The cases where we're definitely done. + */ + + if (((flush == Z_SYNC_FLUSH) && (e == Z_BUF_ERROR)) + || (e == Z_STREAM_END) + || (e == Z_OK && cd->inStream.avail_out == 0)) { + return TCL_OK; + } + + /* + * Z_BUF_ERROR can be ignored as per http://www.zlib.net/zlib_how.html + * + * Just indicates that the zlib couldn't consume input/produce output, + * and is fixed by supplying more input. + * + * Otherwise, we've got errors and need to report to higher-up. + */ + + if ((e != Z_OK) && (e != Z_BUF_ERROR)) { + Tcl_Obj *errObj = Tcl_NewListObj(0, NULL); + + Tcl_ListObjAppendElement(NULL, errObj, + Tcl_NewStringObj(cd->inStream.msg, -1)); + Tcl_SetChannelError(cd->parent, errObj); + *errorCodePtr = EINVAL; + return TCL_ERROR; + } + + /* + * Check if the inflate stopped early. + */ + + if (cd->inStream.avail_in <= 0 && flush != Z_SYNC_FLUSH) { + return TCL_OK; + } + } +} + +/* + *---------------------------------------------------------------------- * Finally, the TclZlibInit function. Used to install the zlib API. *---------------------------------------------------------------------- */ |