First hack at TIP#234

1 files changed, 2567 insertions, 0 deletions

diff --git a/generic/tclZlib.c b/generic/tclZlib.c
new file mode 100644
index 0000000..bdccaeb
--- /dev/null
+++ b/generic/tclZlib.c
@@ -0,0 +1,2567 @@
+/*
+ * tclZlib.c --
+ *
+ *	This file provides the interface to the Zlib library.
+ *
+ * Copyright (C) 2004, 2005 Pascal Scheffers <pascal@scheffers.net>
+ * Copyright (C) 2005 Unitas Software B.V.
+ * Copyright (c) 2008 Donal K. Fellows
+ *
+ * Parts written by Jean-Claude Wippler, as part of Tclkit, placed in the
+ * public domain March 2003.
+ *
+ * See the file "license.terms" for information on usage and redistribution of
+ * this file, and for a DISCLAIMER OF ALL WARRANTIES.
+ *
+ * RCS: @(#) $Id: tclZlib.c,v 1.1 2008/12/11 01:21:52 dkf Exp $
+ */
+
+#if 0
+#include "tclInt.h"
+#include <zlib.h>
+
+typedef struct {
+    z_stream stream;
+    gz_header header;
+    Tcl_Interp *interp;
+    Tcl_Command cmd;
+
+} StreamInfo;
+typedef struct ThreadSpecificData {
+    int counter;
+} ThreadSpecificData;
+static Tcl_ThreadDataKey tsdKey;
+
+static void		ConvertError(Tcl_Interp *interp, int code);
+static int		GenerateHeader(Tcl_Interp *interp, Tcl_Obj *dictObj,
+			    gz_header *headerPtr);
+static void		ExtractHeader(gz_header *headerPtr, Tcl_Obj *dictObj);
+static int		ZlibStream(ClientData clientData, Tcl_Interp *interp,
+			    int objc, Tcl_Obj *const objv[]);
+static void		DeleteStream(ClientData clientData);
+// TODO: Write streaming C API
+// TODO: Write Tcl API
+
+static void
+ConvertError(
+    Tcl_Interp *interp,
+    int code)
+{
+    if (interp == NULL) {
+	return;
+    }
+
+    if (code == Z_ERRNO) {
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_PosixError(interp),-1));
+    } else {
+	const char *codeStr;
+	char codeStr2[TCL_INTEGER_SPACE];
+
+	switch (code) {
+	case Z_STREAM_ERROR:	codeStr = "STREAM";	break;
+	case Z_DATA_ERROR:	codeStr = "DATA";	break;
+	case Z_MEM_ERROR:	codeStr = "MEM";	break;
+	case Z_BUF_ERROR:	codeStr = "BUF";	break;
+	case Z_VERSION_ERROR:	codeStr = "VERSION";	break;
+	default:
+	    codeStr = "unknown";
+	    sprintf(codeStr2, "%d", code);
+	    break;
+	}
+	Tcl_SetObjResult(interp, Tcl_NewStringObj(zError(code), -1));
+	Tcl_SetErrorCode(interp, "TCL", "ZLIB", codeStr, codeStr2, NULL);
+    }
+}
+
+static inline int
+GetValue(
+    Tcl_Interp *interp,
+    Tcl_Obj *dictObj,
+    const char *nameStr,
+    Tcl_Obj **valuePtrPtr)
+{
+    Tcl_Obj *name = Tcl_NewStringObj(nameStr, -1);
+    int result =  Tcl_DictObjGet(interp, dictObj, name, valuePtrPtr);
+
+    TclDecrRefCount(name);
+    return result;
+}
+
+static int
+GenerateHeader(
+    Tcl_Interp *interp,
+    Tcl_Obj *dictObj,
+    gz_header *headerPtr)
+{
+    Tcl_Obj *value;
+    static const char *types[] = {
+	"binary", "text"
+    };
+
+    if (GetValue(interp, dictObj, "comment", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL) {
+	headerPtr->comment = (Bytef *) Tcl_GetString(value);
+    }
+
+    if (GetValue(interp, dictObj, "crc", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL &&
+	    Tcl_GetBooleanFromObj(interp, value, &headerPtr->hcrc)) {
+	return TCL_ERROR;
+    }
+
+    if (GetValue(interp, dictObj, "filename", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL) {
+	headerPtr->name = (Bytef *) Tcl_GetString(value);
+    }
+
+    if (GetValue(interp, dictObj, "os", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL &&
+	    Tcl_GetIntFromObj(interp, value, &headerPtr->os) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    /*
+     * Ignore the 'size' field.
+     */
+
+    if (GetValue(interp, dictObj, "time", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL && Tcl_GetLongFromObj(interp, value,
+	    (long *) &headerPtr->time) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    if (GetValue(interp, dictObj, "type", &value) != TCL_OK) {
+	return TCL_ERROR;
+    } else if (value != NULL && Tcl_GetIndexFromObj(interp, value, types,
+	    "type", TCL_EXACT, &headerPtr->text) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    return TCL_OK;
+}
+
+static inline void
+SetValue(
+    Tcl_Obj *dictObj,
+    const char *key,
+    Tcl_Obj *value)
+{
+    Tcl_Obj *keyObj = Tcl_NewStringObj(key, -1);
+
+    Tcl_IncrRefCount(keyObj);
+    Tcl_DictObjPut(NULL, dictObj, keyObj, value);
+    TclDecrRefCount(keyObj);
+}
+
+static void
+ExtractHeader(
+    gz_header *headerPtr,
+    Tcl_Obj *dictObj)
+{
+    if (headerPtr->comment != Z_NULL) {
+	SetValue(dictObj, "comment",
+		Tcl_NewStringObj((char *) headerPtr->comment, -1));
+    }
+    SetValue(dictObj, "crc", Tcl_NewBooleanObj(headerPtr->hcrc));
+    if (headerPtr->name != Z_NULL) {
+	SetValue(dictObj, "filename",
+		Tcl_NewStringObj((char *) headerPtr->name, -1));
+    }
+    if (headerPtr->os != 255) {
+	SetValue(dictObj, "os", Tcl_NewIntObj(headerPtr->os));
+    }
+    if (headerPtr->time != 0 /* magic - no time */) {
+	SetValue(dictObj, "time", Tcl_NewLongObj((long) headerPtr->time));
+    }
+    if (headerPtr->text != Z_UNKNOWN) {
+	SetValue(dictObj, "type",
+		Tcl_NewStringObj(headerPtr->text ? "text" : "binary", -1));
+    }
+}
+
+Tcl_Obj *
+Tcl_ZlibDeflate(
+    Tcl_Interp *interp,
+    int format,
+    Tcl_Obj *dataObj,
+    int level,
+    Tcl_Obj *dictObj)
+{
+    int rawLength;
+    unsigned char *rawBytes = Tcl_GetByteArrayFromObj(dataObj, &rawLength);
+    z_stream stream;
+    gz_header header, *headerPtr = NULL;
+    Tcl_Obj *outObj = Tcl_NewObj();
+    int code, bits;
+
+    switch (format) {
+    case TCL_ZLIB_FORMAT_RAW:
+	bits = -15;
+	break;
+    case TCL_ZLIB_FORMAT_ZLIB:
+	bits = 15;
+	break;
+    case TCL_ZLIB_FORMAT_GZIP:
+	bits = 15 | /* gzip magic */ 16;
+	if (dictObj != NULL) {
+	    headerPtr = &header;
+	    memset(headerPtr, 0, sizeof(gz_header));
+	    if (GenerateHeader(interp, dictObj, headerPtr) != TCL_OK) {
+		Tcl_DecrRefCount(outObj);
+		return NULL;
+	    }
+	}
+	break;
+    default:
+	Tcl_Panic("bad compression format: %d", format);
+	return NULL;
+    }
+
+    stream.avail_in = (uInt) rawLength;
+    stream.next_in = rawBytes;
+    stream.avail_out = (uInt) rawLength + rawLength/1000 + 12;
+    stream.next_out = Tcl_SetByteArrayLength(outObj, stream.avail_out);
+    stream.zalloc = NULL;
+    stream.zfree = NULL;
+    stream.opaque = NULL;
+
+    code = deflateInit2(&stream, level, Z_DEFLATED, bits, MAX_MEM_LEVEL,
+	    Z_DEFAULT_STRATEGY);
+    if (code != Z_OK) {
+	goto error;
+    }
+    if (headerPtr != NULL) {
+	deflateSetHeader(&stream, headerPtr);
+	if (code != Z_OK) {
+	    goto error;
+	}
+    }
+    code = deflate(&stream, Z_FINISH);
+    if (code != Z_STREAM_END) {
+	deflateEnd(&stream);
+	if (code == Z_OK) {
+	    code = Z_BUF_ERROR;
+	}
+    } else {
+	code = deflateEnd(&stream);
+    }
+
+    if (code == Z_OK) {
+	Tcl_SetByteArrayLength(outObj, stream.total_out);
+	return outObj;
+    }
+
+  error:
+    Tcl_DecrRefCount(outObj);
+    ConvertError(interp, code);
+    return NULL;
+}
+
+Tcl_Obj *
+Tcl_ZlibInflate(
+    Tcl_Interp *interp,
+    int format,
+    Tcl_Obj *dataObj,
+    Tcl_Obj *dictObj)
+{
+    int compressedLength;
+    unsigned char *compressedBytes =
+	    Tcl_GetByteArrayFromObj(dataObj, &compressedLength);
+    z_stream stream;
+    gz_header header, *headerPtr = NULL;
+    Tcl_Obj *outObj = Tcl_NewObj();
+    unsigned int outSize = 16 * 1024;
+    int code = Z_BUF_ERROR, bits;
+    char *nameBuf = NULL, *commentBuf = NULL;
+
+    stream.avail_in = (uInt) compressedLength + 1;
+    stream.next_in = compressedBytes;
+    stream.opaque = NULL;
+
+    switch (format) {
+    case TCL_ZLIB_FORMAT_RAW:
+	bits = -15;
+	break;
+    case TCL_ZLIB_FORMAT_ZLIB:
+	bits = 15;
+	break;
+    case TCL_ZLIB_FORMAT_GZIP:
+	bits = 15 | /* gzip magic */ 16;
+	if (dictObj != NULL) {
+	    goto allocHeader;
+	}
+	break;
+    case TCL_ZLIB_FORMAT_AUTO:
+	bits = 15 | /* auto magic */ 32;
+	if (dictObj != NULL) {
+	allocHeader:
+	    headerPtr = &header;
+	    memset(headerPtr, 0, sizeof(gz_header));
+	    nameBuf = ckalloc(PATH_MAX);
+	    header.name = (void *) nameBuf;
+	    header.name_max = PATH_MAX;
+	    commentBuf = ckalloc(256);
+	    header.comment = (void *) commentBuf;
+	    header.comm_max = 256;
+	}
+	break;
+    default:
+	Tcl_Panic("unrecognized format: %d", format);
+	return NULL;
+    }
+
+    /*
+     * Loop trying to decompress until we've got enough space. Inefficient,
+     * but works.
+     */
+
+    for (; (outSize > 1024) && (code == Z_BUF_ERROR) ; outSize *= 2) {
+	stream.zalloc = NULL;
+	stream.zfree = NULL;
+	stream.avail_out = (uInt) outSize;
+	stream.next_out = Tcl_SetByteArrayLength(outObj, outSize);
+
+	code = inflateInit2(&stream, bits);
+	if (code != Z_OK) {
+	    goto error;
+	}
+
+	if (headerPtr != NULL) {
+	    inflateGetHeader(&stream, headerPtr);
+	    if (code != Z_OK) {
+		goto error;
+	    }
+	}
+
+	code = inflate(&stream, Z_FINISH);
+
+	if (code != Z_STREAM_END) {
+	    inflateEnd(&stream);
+	    if (code == Z_OK) {
+		code = Z_BUF_ERROR;
+	    }
+	} else {
+	    code = inflateEnd(&stream);
+	}
+    }
+
+    if (code == Z_OK) {
+	if (headerPtr != NULL) {
+	    ExtractHeader(headerPtr, dictObj);
+	    SetValue(dictObj, "size", Tcl_NewLongObj((long)stream.total_out));
+	    ckfree(nameBuf);
+	    ckfree(commentBuf);
+	}
+	Tcl_SetByteArrayLength(outObj, stream.total_out);
+	return outObj;
+    }
+
+  error:
+    Tcl_DecrRefCount(outObj);
+    if (headerPtr != NULL) {
+	ckfree(nameBuf);
+	ckfree(commentBuf);
+    }
+    ConvertError(interp, code);
+    return NULL;
+}
+
+unsigned int
+Tcl_ZlibCRC32(
+    const char *bytes,
+    int length)
+{
+    unsigned int initValue = crc32(0, NULL, 0);
+
+    return crc32(initValue, (unsigned char *) bytes, (unsigned) length);
+}
+
+unsigned int
+Tcl_ZlibAdler32(
+    const char *bytes,
+    int length)
+{
+    unsigned int initValue = adler32(0, NULL, 0);
+
+    return adler32(initValue, (unsigned char *) bytes, (unsigned) length);
+}
+
+int
+Tcl_ZlibStreamInit(
+    Tcl_Interp *interp,
+    int mode,
+    int format,
+    int level,
+    Tcl_Obj *dictObj,
+    Tcl_ZlibStream *zshandlePtr)
+{
+    StreamInfo *siPtr = (StreamInfo *) ckalloc(sizeof(StreamInfo));
+    ThreadSpecificData *tsdPtr = TCL_TSD_INIT(&tsdKey);
+    char buf[TCL_INTEGER_SPACE+8];
+
+    memset(&siPtr->stream, 0, sizeof(z_stream));
+    memset(&siPtr->header, 0, sizeof(gz_header));
+
+    siPtr->interp = interp;
+    sprintf(buf, "zstream%d", tsdPtr->counter++);
+    siPtr->cmd = Tcl_CreateObjCommand(interp, buf, ZlibStream, siPtr,
+	    DeleteStream);
+
+    Tcl_Panic("unimplemented");
+
+    *zshandlePtr = (Tcl_ZlibStream) siPtr;
+    return TCL_OK;
+}
+
+Tcl_Obj *
+Tcl_ZlibStreamGetCommandName(
+    Tcl_ZlibStream zshandle)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    Tcl_Obj *cmdnameObj = Tcl_NewObj();
+
+    Tcl_GetCommandFullName(siPtr->interp, siPtr->cmd, cmdnameObj);
+    return cmdnameObj;
+}
+
+int
+Tcl_ZlibStreamEof(
+    Tcl_ZlibStream zshandle)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    Tcl_Panic("unimplemented");
+    return -1;
+}
+
+int
+Tcl_ZlibStreamClose(
+    Tcl_ZlibStream zshandle)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    int code = -1;
+
+    Tcl_Panic("unimplemented");
+
+    if (siPtr->cmd) {
+	/*
+	 * Must be last in this function!
+	 */
+
+	register Tcl_Command cmd = siPtr->cmd;
+
+	siPtr->cmd = NULL;
+	Tcl_DeleteCommandFromToken(siPtr->interp, cmd);
+    }
+    return code;
+}
+
+int
+Tcl_ZlibStreamAdler32(
+    Tcl_ZlibStream zshandle)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    Tcl_Panic("unimplemented");
+    return -1;
+}
+
+int
+Tcl_ZlibStreamPut(
+    Tcl_ZlibStream zshandle,
+    const char *bytes,
+    int length,
+    int flush)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    Tcl_Panic("unimplemented");
+    return -1;
+}
+
+int
+Tcl_ZlibStreamGet(
+    Tcl_ZlibStream zshandle,
+    const char *bytes,
+    int length)
+{
+    StreamInfo *siPtr = (StreamInfo *) zshandle;
+    Tcl_Panic("unimplemented");
+    return -1;
+}
+
+static void
+DeleteStream(
+    ClientData clientData)
+{
+    register StreamInfo *siPtr = clientData;
+
+    if (siPtr->cmd) {
+	siPtr->cmd = NULL;
+	Tcl_ZlibStreamClose(clientData);
+    }
+    ckfree(clientData);
+}
+
+static int
+ZlibStream(
+    ClientData clientData,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    StreamInfo *siPtr = clientData;
+    static const char *subcmds[] = {
+	"adler32", "close", "eof", "finalize", "flush", "fullflush", "get",
+	"put", NULL
+    };
+
+    if (objc < 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "subcommand ...");
+	return TCL_ERROR;
+    }
+    Tcl_SetResult(interp, "unimplemented", TCL_STATIC);
+    return TCL_ERROR;
+}
+
+#else /* !REIMPLEMENT */
+
+#include "tcl.h"
+#include <zlib.h>
+#include <string.h>
+
+/*
+ * Structure used for the Tcl_ZlibStream* commands and [zlib stream ...]
+ */
+
+typedef struct {
+    Tcl_Interp *interp;
+    z_stream stream;
+    int streamend;
+    Tcl_Obj *indata, *outdata;	/* Input / output buffers (lists) */
+    Tcl_Obj *current_input;	/* Pointer to what is currently being
+				 * inflated. */
+    int inpos, outpos;
+    int mode;			/* ZLIB_DEFLATE || ZLIB_INFLATE */
+    int format;			/* ZLIB_FORMAT_* */
+    int level;			/* Default 5, 0-9 */
+    int flush;			/* Stores the flush param for deferred the
+				 * decompression. */
+    int wbits;
+    Tcl_Obj *cmdname;		/* Name of the associated Tcl command */
+} zlibStreamHandle;
+
+
+/*
+ * Prototypes for private procedures defined later in this file:
+ */
+
+static int		ZlibCmd(ClientData dummy, Tcl_Interp *ip, int objc,
+			    Tcl_Obj *const objv[]);
+static int		ZlibStreamCmd(ClientData cd, Tcl_Interp *interp,
+			    int objc, Tcl_Obj *const objv[]);
+static void		ZlibStreamCmdDelete(ClientData cd);
+static void		ZlibStreamCleanup(zlibStreamHandle *zsh);
+
+/*
+ * Prototypes for private procedures used by channel stacking:
+ */
+
+#ifdef ENABLE_CHANSTACKING
+static int		ChanClose(ClientData instanceData,
+			    Tcl_Interp *interp);
+static int		ChanInput(ClientData instanceData, char *buf,
+			    int toRead, int *errorCodePtr);
+static int		ChanOutput(ClientData instanceData, const char *buf,
+			    int toWrite, int*errorCodePtr);
+static int		ChanSeek(ClientData instanceData, long offset,
+			    int mode, int *errorCodePtr);
+static int		ChanSetOption(ClientData instanceData,
+			    Tcl_Interp *interp, const char *optionName,
+			    const char *value);
+static int		ChanGetOption(ClientData instanceData,
+			    Tcl_Interp *interp, const char *optionName,
+			    Tcl_DString *dsPtr);
+static void		ChanWatch(ClientData instanceData, int mask);
+static int		ChanGetHandle(ClientData instanceData, int direction,
+			    ClientData *handlePtr);
+static int		ChanClose2(ClientData instanceData,
+			    Tcl_Interp *interp, int flags);
+static int		ChanBlockMode(ClientData instanceData, int mode);
+static int		ChanFlush(ClientData instanceData);
+static int		ChanHandler(ClientData instanceData,
+			    int interestMask);
+static Tcl_WideInt	ChanWideSeek(ClientData instanceData,
+			    Tcl_WideInt offset, int mode, int *errorCodePtr);
+
+static Tcl_ChannelType zlibChannelType = {
+    "zlib",
+    TCL_CHANNEL_VERSION_3,
+    ChanClose,
+    ChanInput,
+    ChanOutput,
+    NULL, /* ChanSeek, */
+    NULL, /* ChanSetOption, */
+    NULL, /* ChanGetOption, */
+    ChanWatch,
+    ChanGetHandle,
+    NULL, /* ChanClose2, */
+    ChanBlockMode,
+    ChanFlush,
+    ChanHandler,
+    NULL /* ChanWideSeek */
+};
+
+typedef struct {
+    /* Generic channel info */
+    Tcl_Channel channel;
+    Tcl_TimerToken timer;
+    int flags;
+    int mask;
+
+    /* Zlib specific channel state */
+    int inFormat;
+    int outFormat;
+    z_stream instream;
+    z_stream outstream;
+    char *inbuffer;
+    int inAllocated, inUsed, inPos;
+    char *outbuffer;
+    int outAllocated, outUsed, outPos;
+} Zlib_ChannelData;
+
+/* Flag values */
+#define ASYNC 1
+#endif /* ENABLE_CHANSTACKING */
+
+#ifdef TCLKIT_BUILD
+/*
+ * Structure for the old zlib sdeflate/sdecompress commands
+ * Deprecated!
+ */
+
+typedef struct {
+    z_stream stream;
+    Tcl_Obj *indata;
+} zlibstream;
+
+static int
+zstreamincmd(
+    ClientData cd,
+    Tcl_Interp *ip,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    zlibstream *zp = cd;
+    int count = 0;
+    int e, index;
+    Tcl_Obj *obj;
+
+    static const char* cmds[] = { "fill", "drain", NULL, };
+
+    if (Tcl_GetIndexFromObj(ip, objv[1], cmds, "option", 0,
+	    &index) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    switch (index) {
+    case 0: /* fill ?data? */
+	if (objc >= 3) {
+	    Tcl_IncrRefCount(objv[2]);
+	    Tcl_DecrRefCount(zp->indata);
+	    zp->indata = objv[2];
+	    zp->stream.next_in =
+		    Tcl_GetByteArrayFromObj(zp->indata, &zp->stream.avail_in);
+	}
+	Tcl_SetObjResult(ip, Tcl_NewIntObj(zp->stream.avail_in));
+	break;
+    case 1: /* drain count */
+	if (objc != 3) {
+	    Tcl_WrongNumArgs(ip, 2, objv, "count");
+	    return TCL_ERROR;
+	}
+	if (Tcl_GetIntFromObj(ip, objv[2], &count) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	obj = Tcl_GetObjResult(ip);
+	Tcl_SetByteArrayLength(obj, count);
+	zp->stream.next_out =
+		Tcl_GetByteArrayFromObj(obj, &zp->stream.avail_out);
+	e = inflate(&zp->stream, Z_NO_FLUSH);
+	if (e != Z_OK && e != Z_STREAM_END) {
+	    Tcl_SetResult(ip, (char *) zError(e), TCL_STATIC);
+	    return TCL_ERROR;
+	}
+	Tcl_SetByteArrayLength(obj, count - zp->stream.avail_out);
+	break;
+    }
+    return TCL_OK;
+}
+
+static void
+zstreamdelproc(
+    ClientData cd)
+{
+    zlibstream *zp = cd;
+
+    inflateEnd(&zp->stream);
+    Tcl_DecrRefCount(zp->indata);
+    ckfree((void*) zp);
+}
+
+static int
+ZlibCmdO(
+    ClientData dummy,
+    Tcl_Interp *ip,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    int e = TCL_OK, index, dlen, wbits = -MAX_WBITS;
+    unsigned flag;
+    Byte *data;
+    z_stream stream;
+    Tcl_Obj *obj = Tcl_GetObjResult(ip);
+
+    static const char* cmds[] = {
+	"adler32", "crc32", "compress", "deflate", "decompress", "inflate",
+	"sdecompress", "sinflate", NULL,
+    };
+
+    if (objc < 3 || objc > 4) {
+	Tcl_WrongNumArgs(ip, 1, objv, "option data ?...?");
+	return TCL_ERROR;
+    }
+
+    if (Tcl_GetIndexFromObj(ip, objv[1], cmds, "option", 0,
+	    &index) != TCL_OK || (objc > 3 &&
+	    Tcl_GetIntFromObj(ip, objv[3], &flag)) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    data = Tcl_GetByteArrayFromObj(objv[2], &dlen);
+
+    switch (index) {
+    case 0: /* adler32 str ?start? -> checksum */
+	if (objc < 4) {
+	    flag = adler32(0, 0, 0);
+	}
+	Tcl_SetIntObj(obj, adler32(flag, data, dlen));
+	return TCL_OK;
+    case 1: /* crc32 str ?start? -> checksum */
+	if (objc < 4) {
+	    flag = crc32(0, 0, 0);
+	}
+	Tcl_SetIntObj(obj, crc32(flag, data, dlen));
+	return TCL_OK;
+    case 2: /* compress data ?level? -> data */
+	wbits = MAX_WBITS;
+    case 3: /* deflate data ?level? -> data */
+	if (objc < 4) {
+	    flag = Z_DEFAULT_COMPRESSION;
+	}
+
+	stream.avail_in = (uInt) dlen;
+	stream.next_in = data;
+
+	stream.avail_out = (uInt) dlen + dlen / 1000 + 12;
+	Tcl_SetByteArrayLength(obj, stream.avail_out);
+	stream.next_out = Tcl_GetByteArrayFromObj(obj, NULL);
+
+	stream.zalloc = 0;
+	stream.zfree = 0;
+	stream.opaque = 0;
+
+	e = deflateInit2(&stream, flag, Z_DEFLATED, wbits,
+		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+	if (e != Z_OK) {
+	    break;
+	}
+
+	e = deflate(&stream, Z_FINISH);
+	if (e != Z_STREAM_END) {
+	    deflateEnd(&stream);
+	    if (e == Z_OK) {
+		e = Z_BUF_ERROR;
+	    }
+	} else {
+	    e = deflateEnd(&stream);
+	}
+	break;
+    case 4: /* decompress data ?bufsize? -> data */
+	wbits = MAX_WBITS;
+    case 5: /* inflate data ?bufsize? -> data */
+	if (objc < 4) {
+	    flag = 16 * 1024;
+	}
+
+	for (;;) {
+	    stream.zalloc = 0;
+	    stream.zfree = 0;
+
+	    /*
+	     * +1 because ZLIB can "over-request" input (but ignore it)
+	     */
+
+	    stream.avail_in = (uInt) dlen +  1;
+	    stream.next_in = data;
+
+	    stream.avail_out = (uInt) flag;
+	    Tcl_SetByteArrayLength(obj, stream.avail_out);
+	    stream.next_out = Tcl_GetByteArrayFromObj(obj, NULL);
+
+	    /*
+	     * Negative value suppresses ZLIB header
+	     */
+
+	    e = inflateInit2(&stream, wbits);
+	    if (e == Z_OK) {
+		e = inflate(&stream, Z_FINISH);
+		if (e != Z_STREAM_END) {
+		    inflateEnd(&stream);
+		    if (e == Z_OK) {
+			e = Z_BUF_ERROR;
+		    }
+		} else {
+		    e = inflateEnd(&stream);
+		}
+	    }
+
+	    if (e == Z_OK || e != Z_BUF_ERROR) {
+		break;
+	    }
+
+	    Tcl_SetByteArrayLength(obj, 0);
+	    flag *= 2;
+	}
+	break;
+    case 6: /* sdecompress cmdname -> */
+	wbits = MAX_WBITS;
+    case 7: { /* sinflate cmdname -> */
+	zlibstream *zp = (zlibstream *) ckalloc(sizeof(zlibstream));
+
+	zp->indata = Tcl_NewObj();
+	Tcl_IncrRefCount(zp->indata);
+	zp->stream.zalloc = 0;
+	zp->stream.zfree = 0;
+	zp->stream.opaque = 0;
+	zp->stream.next_in = 0;
+	zp->stream.avail_in = 0;
+	inflateInit2(&zp->stream, wbits);
+	Tcl_CreateObjCommand(ip, Tcl_GetStringFromObj(objv[2], 0),
+		zstreamincmd, (ClientData) zp, zstreamdelproc);
+	return TCL_OK;
+    }
+    }
+
+    if (e != Z_OK) {
+	Tcl_SetResult(ip, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    Tcl_SetByteArrayLength(obj, stream.total_out);
+    return TCL_OK;
+}
+#endif /* TCLKIT_BUILD */
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ZlibStreamInit --
+ *
+ *	This command initializes a (de)compression context/handle for
+ *	(de)compressing data in chunks.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	zshandle is initialised and memory allocated for internal state.
+ *	Additionally, if interp is not null, a Tcl command is created and its
+ *	name placed in the interp result obj.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ZlibStreamInit(
+    Tcl_Interp *interp,
+    int mode,			/* ZLIB_INFLATE || ZLIB_DEFLATE */
+    int format,			/* ZLIB_FORMAT_* */
+    int level,			/* 0-9 or ZLIB_DEFAULT_COMPRESSION */
+    Tcl_ZlibStream *zshandle)
+{
+    int wbits = 0;
+    int e;
+    zlibStreamHandle *zsh = NULL;
+    Tcl_DString cmdname;
+    Tcl_CmdInfo cmdinfo;
+
+    if (mode == TCL_ZLIB_STREAM_DEFLATE) {
+	/*
+	 * Compressed format is specified by the wbits parameter. See zlib.h
+	 * for details.
+	 */
+
+	if (format == TCL_ZLIB_FORMAT_RAW) {
+	    wbits = -MAX_WBITS;
+	} else if (format == TCL_ZLIB_FORMAT_GZIP) {
+	    wbits = MAX_WBITS+16;
+	} else if (format == TCL_ZLIB_FORMAT_ZLIB) {
+	    wbits = MAX_WBITS;
+	} else {
+	    Tcl_Panic("incorrect zlib data format, must be "
+		    "TCL_ZLIB_FORMAT_ZLIB, TCL_ZLIB_FORMAT_GZIP or "
+		    "TCL_ZLIB_FORMAT_RAW");
+	}
+	if (level < -1 || level > 9) {
+	    if (interp) {
+		Tcl_SetResult(interp, "Compression level should be between "
+			"0 (no compression) and 9 (best compression) or -1 "
+			"for default compression level.", TCL_STATIC);
+	    }
+	    return TCL_ERROR;
+	}
+    } else {
+	/*
+	 * mode == ZLIB_INFLATE
+	 * wbits are the same as DEFLATE, but FORMAT_AUTO is valid too.
+	 */
+
+	if (format == TCL_ZLIB_FORMAT_RAW) {
+	    wbits = -MAX_WBITS;
+	} else if (format == TCL_ZLIB_FORMAT_GZIP) {
+	    wbits = MAX_WBITS+16;
+	} else if (format == TCL_ZLIB_FORMAT_ZLIB) {
+	    wbits = MAX_WBITS;
+	} else if (format == TCL_ZLIB_FORMAT_AUTO) {
+	    wbits = MAX_WBITS+32;
+	} else {
+	    Tcl_Panic("incorrect zlib data format, must be "
+		    "TCL_ZLIB_FORMAT_ZLIB, TCL_ZLIB_FORMAT_GZIP, "
+		    "TCL_ZLIB_FORMAT_RAW or TCL_ZLIB_FORMAT_AUTO");
+	}
+    }
+
+    zsh = (zlibStreamHandle *) ckalloc(sizeof(zlibStreamHandle));
+    zsh->interp = interp;
+    zsh->mode = mode;
+    zsh->format = format;
+    zsh->level = level;
+    zsh->wbits = wbits;
+    zsh->current_input = NULL;
+    zsh->streamend = 0;
+    zsh->stream.avail_in = 0;
+    zsh->stream.next_in = 0;
+    zsh->stream.zalloc = 0;
+    zsh->stream.zfree = 0;
+    zsh->stream.opaque = 0;		/* Must be initialized before calling
+					 * (de|in)flateInit2 */
+
+    /*
+     * No output buffer available yet
+     */
+
+    zsh->stream.avail_out = 0;
+    zsh->stream.next_out = NULL;
+
+    if (mode == TCL_ZLIB_STREAM_DEFLATE) {
+	e = deflateInit2(&zsh->stream, level, Z_DEFLATED, wbits,
+		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+    } else {
+	e = inflateInit2(&zsh->stream, wbits);
+    }
+
+    if (e != Z_OK) {
+	if (interp) {
+	    Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	}
+	goto error;
+    }
+
+    /*
+     * I could do all this in C, but this is easier.
+     */
+
+    if (interp != NULL) {
+	if (Tcl_Eval(interp, "incr ::zlib::cmdcounter") != TCL_OK) {
+	    goto error;
+	}
+	Tcl_DStringInit(&cmdname);
+	Tcl_DStringAppend(&cmdname, "::zlib::streamcmd-", -1);
+	Tcl_DStringAppend(&cmdname, Tcl_GetString(Tcl_GetObjResult(interp)),
+		-1);
+	if (Tcl_GetCommandInfo(interp, Tcl_DStringValue(&cmdname),
+		&cmdinfo) == 1 ) {
+	    Tcl_SetResult(interp,
+		    "BUG: Stream command name already exists", TCL_STATIC);
+	    goto error;
+	}
+	Tcl_ResetResult(interp);
+
+	/*
+	 * Create the command.
+	 */
+
+	Tcl_CreateObjCommand(interp, Tcl_DStringValue(&cmdname),
+		ZlibStreamCmd, zsh, ZlibStreamCmdDelete);
+
+	/*
+	 * Create the cmdname obj for future reference.
+	 */
+
+	zsh->cmdname = Tcl_NewStringObj(Tcl_DStringValue(&cmdname),
+		Tcl_DStringLength(&cmdname));
+	Tcl_IncrRefCount(zsh->cmdname);
+	Tcl_DStringFree(&cmdname);
+    } else {
+	zsh->cmdname = NULL;
+    }
+
+    /*
+     * Prepare the buffers for use.
+     */
+
+    zsh->indata = Tcl_NewListObj(0, NULL);
+    Tcl_IncrRefCount(zsh->indata);
+    zsh->outdata = Tcl_NewListObj(0, NULL);
+    Tcl_IncrRefCount(zsh->outdata);
+
+    zsh->inpos = 0;
+    zsh->outpos = 0;
+
+    /*
+     * Now set the int pointed to by *zshandle to the pointer to the zsh
+     * struct.
+     */
+
+    if (zshandle) {
+	*zshandle = (Tcl_ZlibStream) zsh;
+    }
+
+    return TCL_OK;
+ error:
+    ckfree((char *) zsh);
+    return TCL_ERROR;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ZlibStreamCmdDelete --
+ *
+ *	This is the delete command which Tcl invokes when a zlibstream command
+ *	is deleted from the interpreter (on stream close, usually).
+ *
+ * Results:
+ *	None
+ *
+ * Side effects:
+ *	Invalidates the zlib stream handle as obtained from Tcl_ZlibStreamInit
+ *
+ *----------------------------------------------------------------------
+ */
+
+static void
+ZlibStreamCmdDelete(
+    ClientData cd)
+{
+    zlibStreamHandle *zsh = cd;
+
+    ZlibStreamCleanup(zsh);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ZlibStreamClose --
+ *
+ *	This procedure must be called after (de)compression is done to ensure
+ *	memory is freed and the command is deleted from the interpreter (if
+ *	any).
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Invalidates the zlib stream handle as obtained from Tcl_ZlibStreamInit
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ZlibStreamClose(
+    Tcl_ZlibStream zshandle)	/* As obtained from Tcl_ZlibStreamInit. */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle *) zshandle;
+
+    /*
+     * If the interp is set, deleting the command will trigger
+     * ZlibStreamCleanup in ZlibStreamCmdDelete. If no interp is set, call
+     * ZlibStreamCleanup directly.
+     */
+
+    if (zsh->interp && zsh->cmdname) {
+	Tcl_DeleteCommand(zsh->interp,
+		Tcl_GetStringFromObj(zsh->cmdname, NULL));
+    } else {
+	ZlibStreamCleanup(zsh);
+    }
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * ZlibStreamCleanup --
+ *
+ *	This procedure is called by either Tcl_ZlibStreamClose or
+ *	ZlibStreamCmdDelete to cleanup the stream context.
+ *
+ * Results:
+ *	None
+ *
+ * Side effects:
+ *	Invalidates the zlib stream handle.
+ *
+ *----------------------------------------------------------------------
+ */
+
+void
+ZlibStreamCleanup(
+    zlibStreamHandle *zsh)
+{
+    if (!zsh->streamend) {
+	if (zsh->mode == TCL_ZLIB_STREAM_DEFLATE) {
+	    deflateEnd(&zsh->stream);
+	} else {
+	    inflateEnd(&zsh->stream);
+	}
+    }
+
+    if (zsh->indata) {
+	Tcl_DecrRefCount(zsh->indata);
+    }
+    if (zsh->outdata) {
+	Tcl_DecrRefCount(zsh->outdata);
+    }
+    if (zsh->cmdname) {
+	Tcl_DecrRefCount(zsh->cmdname);
+    }
+    if (zsh->current_input) {
+	Tcl_DecrRefCount(zsh->current_input);
+    }
+
+    ckfree((void *) zsh);
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ZlibStreamReset --
+ *
+ *	This procedure will reinitialize an existing stream handle.
+ *
+ * Results:
+ *	A standard Tcl result.
+ *
+ * Side effects:
+ *	Any data left in the (de)compression buffer is lost.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ZlibStreamReset(
+    Tcl_ZlibStream zshandle)	/* As obtained from Tcl_ZlibStreamInit */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle*) zshandle;
+    int e;
+
+    if (!zsh->streamend) {
+	if (zsh->mode == TCL_ZLIB_STREAM_DEFLATE) {
+	    deflateEnd(&zsh->stream);
+	} else {
+	    inflateEnd(&zsh->stream);
+	}
+    }
+    Tcl_SetByteArrayLength(zsh->indata, 0);
+    Tcl_SetByteArrayLength(zsh->outdata, 0);
+    if (zsh->current_input) {
+	Tcl_DecrRefCount(zsh->current_input);
+	zsh->current_input=NULL;
+    }
+
+    zsh->inpos = 0;
+    zsh->outpos = 0;
+    zsh->streamend = 0;
+    zsh->stream.avail_in = 0;
+    zsh->stream.next_in = 0;
+    zsh->stream.zalloc = 0;
+    zsh->stream.zfree = 0;
+    zsh->stream.opaque = 0;		/* Must be initialized before calling
+					 * (de|in)flateInit2 */
+
+    /* No output buffer available yet */
+    zsh->stream.avail_out = 0;
+    zsh->stream.next_out = NULL;
+
+    if (zsh->mode == TCL_ZLIB_STREAM_DEFLATE) {
+	e = deflateInit2(&zsh->stream, zsh->level, Z_DEFLATED, zsh->wbits,
+		MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+    } else {
+	e = inflateInit2(&zsh->stream, zsh->wbits);
+    }
+
+    if ( e != Z_OK ) {
+	if (zsh->interp) {
+	    Tcl_SetResult(zsh->interp, (char*) zError(e), TCL_STATIC);
+	}
+	/* TODOcleanup */
+	return TCL_ERROR;
+    }
+
+    return TCL_OK;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ZlibStreamGetCommandName --
+ *
+ *	This procedure will return the command name associated with the
+ *	stream.
+ *
+ * Results:
+ *	A Tcl_Obj with the name of the Tcl command or NULL if no command is
+ *	associated with the stream.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+Tcl_Obj *
+Tcl_ZlibStreamGetCommandName(
+    Tcl_ZlibStream zshandle) /* as obtained from Tcl_ZlibStreamInit */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle*) zshandle;
+
+    return zsh->cmdname;
+}
+
+/*
+ *----------------------------------------------------------------------
+ *
+ * Tcl_ZlibStreamEof --
+ *
+ *	This procedure This function returns 0 or 1 depending on the state of
+ *	the (de)compressor. For decompression, eof is reached when the entire
+ *	compressed stream has been decompressed. For compression, eof is
+ *	reached when the stream has been flushed with ZLIB_FINALIZE.
+ *
+ * Results:
+ *	Integer.
+ *
+ * Side effects:
+ *	None.
+ *
+ *----------------------------------------------------------------------
+ */
+
+int
+Tcl_ZlibStreamEof(
+    Tcl_ZlibStream zshandle)	/* As obtained from Tcl_ZlibStreamInit */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle*) zshandle;
+
+    return zsh->streamend;
+}
+
+int
+Tcl_ZlibStreamAdler32(
+    Tcl_ZlibStream zshandle)	/* As obtained from Tcl_ZlibStreamInit */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle*) zshandle;
+
+    return zsh->stream.adler;
+}
+
+#ifdef DISABLED_CODE
+int
+Tcl_ZlibStreamAdd(
+    Tcl_ZlibStream zshandle,	/* As obtained from Tcl_ZlibStreamInit */
+    char *data,			/* Data to compress/decompress */
+    int size,			/* Byte length of data */
+    int flush,			/* 0, ZLIB_FLUSH, ZLIB_FULLFLUSH,
+				 * ZLIB_FINALIZE */
+    Tcl_Obj *outdata,		/* An object to append the compressed data
+				 * to. */
+    int buffersize)		/* Hint of the expected output size of
+				 * inflate/deflate */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle*) zshandle;
+    char *datatmp=0, *outptr=0;
+    int e, outsize;
+
+    zsh->stream.next_in = data;
+    zsh->stream.avail_in = size;
+
+    if (zsh->mode == ZLIB_DEFLATE) {
+	if (buffersize < 6) {
+	    /*
+	     * The 6 comes from the zlib.h description of deflate. If the
+	     * suggested buffer size is below 6, use deflateBound to get the
+	     * minimum number of bytes needed from zlib.
+	     */
+
+	    zsh->stream.avail_out =
+		    deflateBound(&zsh->stream, zsh->stream.avail_in);
+	} else {
+	    zsh->stream.avail_out=buffersize;
+	}
+	datatmp = ckalloc(zsh->stream.avail_out);
+	zsh->stream.next_out = datatmp;
+	e = deflate(&zsh->stream, flush);
+	while ((e==Z_OK || e==Z_BUF_ERROR) && zsh->stream.avail_out==0) {
+	    /* Output buffer too small */
+	    Tcl_Panic("StreamAdd/Deflate - Buffer growing not implemented yet");
+	}
+
+	/*
+	 * Now append the (de)compressed data to outdata.
+	 */
+
+	Tcl_GetByteArrayFromObj(outdata, &outsize);
+	outptr = Tcl_SetByteArrayLength(outdata,
+		outsize + zsh->stream.total_out);
+	memcpy(&outptr[outsize], datatmp, zsh->stream.total_out);
+    } else {
+	if (buffersize == 0) {
+	    /* Start with a buffer 3 times the size of the input data */
+	    /* TODO: integer bounds/overflow check */
+	    buffersize = 3*zsh->stream.avail_in;
+	}
+	Tcl_Panic("StreamAdd/Inflate - not implemented yet");
+    }
+    return TCL_OK;
+}
+#endif /* DISABLED_CODE */
+
+int
+Tcl_ZlibStreamPut(
+    Tcl_ZlibStream zshandle,	/* As obtained from Tcl_ZlibStreamInit */
+    Tcl_Obj *data,		/* Data to compress/decompress */
+    int flush)			/* 0, ZLIB_FLUSH, ZLIB_FULLFLUSH,
+				 * ZLIB_FINALIZE */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle *) zshandle;
+    char *datatmp = 0;
+    int e, size, outsize;
+    Tcl_Obj *obj;
+
+    if (zsh->streamend) {
+	if (zsh->interp) {
+	    Tcl_SetResult(zsh->interp, "already past compressed stream end",
+		    TCL_STATIC);
+	}
+	return TCL_ERROR;
+    }
+
+    if (zsh->mode == TCL_ZLIB_STREAM_DEFLATE) {
+	zsh->stream.next_in = Tcl_GetByteArrayFromObj(data, &size);
+	zsh->stream.avail_in = size;
+
+	/*
+	 * Deflatebound doesn't seem to take various header sizes into
+	 * account, so we add 100 extra bytes.
+	 */
+
+	outsize = deflateBound(&zsh->stream, zsh->stream.avail_in) + 100;
+	zsh->stream.avail_out = outsize;
+	datatmp = ckalloc(zsh->stream.avail_out);
+	zsh->stream.next_out = (Bytef *) datatmp;
+
+	e = deflate(&zsh->stream, flush);
+	if ((e==Z_OK || e==Z_BUF_ERROR) && (zsh->stream.avail_out == 0)) {
+	    if (outsize - zsh->stream.avail_out > 0) {
+		/*
+		 * Output buffer too small.
+		 */
+
+		obj = Tcl_NewByteArrayObj((unsigned char *) datatmp,
+			outsize - zsh->stream.avail_out);
+		/*
+		 * Now append the compressed data to the outbuffer.
+		 */
+		Tcl_ListObjAppendElement(zsh->interp, zsh->outdata, obj);
+	    }
+	    if (outsize < 0xFFFF) {
+		outsize = 0xFFFF;	/* There may be *lots* of data left to
+					 * output... */
+		ckfree(datatmp);
+		datatmp = ckalloc(outsize);
+	    }
+	    zsh->stream.avail_out = outsize;
+	    zsh->stream.next_out = (Bytef *) datatmp;
+
+	    e = deflate(&zsh->stream, flush);
+	}
+
+	/*
+	 * And append the final data block.
+	 */
+
+	if (outsize - zsh->stream.avail_out > 0) {
+	    obj = Tcl_NewByteArrayObj((unsigned char *) datatmp,
+		    outsize - zsh->stream.avail_out);
+
+	    /*
+	     * Now append the compressed data to the outbuffer.
+	     */
+
+	    Tcl_ListObjAppendElement(zsh->interp, zsh->outdata, obj);
+	}
+    } else {
+	/*
+	 * This is easy. Just append to inbuffer.
+	 */
+
+	Tcl_ListObjAppendElement(zsh->interp, zsh->indata, data);
+
+	/*
+	 * and we'll need the flush parameter for the Inflate call.
+	 */
+
+	zsh->flush = flush;
+    }
+
+    return TCL_OK;
+}
+
+int
+Tcl_ZlibStreamGet(
+    Tcl_ZlibStream zshandle,	/* As obtained from Tcl_ZlibStreamInit */
+    Tcl_Obj *data,		/* A place to put the data */
+    int count)			/* Number of bytes to grab as a maximum, you
+				 * may get less! */
+{
+    zlibStreamHandle *zsh = (zlibStreamHandle *) zshandle;
+    int e, i;
+    int llength, itemlen, datapos=0;
+    Tcl_Obj *lobj;
+    unsigned char *dataptr, *itemptr;
+
+    /*
+     * Getting beyond the of stream, just return empty string.
+     */
+
+    if (zsh->streamend) {
+	return TCL_OK;
+    }
+
+    if (zsh->mode == TCL_ZLIB_STREAM_INFLATE) {
+	if (count == -1) {
+	    /*
+	     * The only safe thing to do is restict to 65k. We might cause a
+	     * panic for out of memory if we just kept growing the buffer.
+	     */
+
+	    count = 65536;
+	}
+
+	/*
+	 * Prepare the place to store the data.
+	 */
+
+	dataptr = Tcl_SetByteArrayLength(data, count);
+
+	zsh->stream.next_out = dataptr;
+	zsh->stream.avail_out = count;
+	if (zsh->stream.avail_in == 0) {
+	    /*
+	     * zlib will probably need more data to decompress.
+	     */
+
+	    if (zsh->current_input) {
+		Tcl_DecrRefCount(zsh->current_input);
+		zsh->current_input=0;
+	    }
+	    if (Tcl_ListObjLength(zsh->interp, zsh->indata,
+		    &llength) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    if (llength > 0) {
+		/*
+		 * There is more input available, get it from the list and
+		 * give it to zlib.
+		 */
+
+		if (Tcl_ListObjIndex(zsh->interp, zsh->indata, 0,
+			&lobj) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		itemptr = Tcl_GetByteArrayFromObj(lobj, &itemlen);
+		Tcl_IncrRefCount(lobj);
+		zsh->current_input = lobj;
+		zsh->stream.next_in = itemptr;
+		zsh->stream.avail_in = itemlen;
+
+		/*
+		 * And remove it from the list
+		 */
+
+		Tcl_ListObjReplace(NULL, zsh->indata, 0, 1, 0, NULL);
+		llength--;
+	    }
+	}
+
+	e = inflate(&zsh->stream, zsh->flush);
+	if (Tcl_ListObjLength(zsh->interp, zsh->indata, &llength) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	/*printf("llength %d, e==%d, avail_out %d\n", llength, e, zsh->stream.avail_out);*/
+	while ((zsh->stream.avail_out > 0) && (e==Z_OK || e==Z_BUF_ERROR)
+		&& (llength > 0)) {
+	    /*
+	     * State: We have not satisfied the request yet and there may be
+	     * more to inflate.
+	     */
+
+	    if (zsh->stream.avail_in > 0) {
+		if (zsh->interp) {
+		    Tcl_SetResult(zsh->interp,
+			"Unexpected zlib internal state during decompression",
+			TCL_STATIC);
+		}
+		return TCL_ERROR;
+	    }
+
+	    if (zsh->current_input) {
+		Tcl_DecrRefCount(zsh->current_input);
+		zsh->current_input = 0;
+	    }
+
+	    if (Tcl_ListObjIndex(zsh->interp, zsh->indata, 0,
+		   &lobj) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	    itemptr = Tcl_GetByteArrayFromObj(lobj, &itemlen);
+	    Tcl_IncrRefCount(lobj);
+	    zsh->current_input = lobj;
+	    zsh->stream.next_in = itemptr;
+	    zsh->stream.avail_in = itemlen;
+
+	    /*
+	     * And remove it from the list.
+	     */
+
+	    Tcl_ListObjReplace(NULL, zsh->indata, 0, 1, 0, NULL);
+	    llength--;
+
+	    /*
+	     * And call inflate again
+	     */
+
+	    e = inflate(&zsh->stream, zsh->flush);
+	}
+	if (zsh->stream.avail_out > 0) {
+	    Tcl_SetByteArrayLength(data, count - zsh->stream.avail_out);
+	}
+	if (!(e==Z_OK || e==Z_STREAM_END || e==Z_BUF_ERROR)) {
+	    if (zsh->interp) {
+		Tcl_SetResult(zsh->interp, zsh->stream.msg, TCL_VOLATILE);
+	    }
+	    return TCL_ERROR;
+	}
+	if (e == Z_STREAM_END) {
+	    zsh->streamend = 1;
+	    if (zsh->current_input) {
+		Tcl_DecrRefCount(zsh->current_input);
+		zsh->current_input = 0;
+	    }
+	    inflateEnd(&zsh->stream);
+	}
+    } else {
+	if (Tcl_ListObjLength(zsh->interp, zsh->outdata,
+		&llength) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+
+	if (count == -1) {
+	    count = 0;
+	    for (i=0; i<llength; i++) {
+		if (Tcl_ListObjIndex(zsh->interp, zsh->outdata, i,
+			&lobj) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+		itemptr = Tcl_GetByteArrayFromObj(lobj, &itemlen);
+		if (i == 0) {
+		    count += itemlen - zsh->outpos;
+		} else {
+		    count += itemlen;
+		}
+	    }
+	}
+
+	/*
+	 * Prepare the place to store the data.
+	 */
+
+	dataptr = Tcl_SetByteArrayLength(data, count);
+
+	while ((count > datapos) && (Tcl_ListObjLength(zsh->interp,
+		zsh->outdata, &llength) == TCL_OK) && (llength > 0)) {
+	    Tcl_ListObjIndex(zsh->interp, zsh->outdata, 0, &lobj);
+	    itemptr = Tcl_GetByteArrayFromObj(lobj, &itemlen);
+	    if (itemlen-zsh->outpos >= count-datapos) {
+		memcpy(dataptr+datapos, itemptr+zsh->outpos, count-datapos);
+		zsh->outpos += count - datapos;
+		datapos += count-datapos;
+		if (zsh->outpos == itemlen) {
+		    zsh->outpos = 0;
+		}
+	    } else {
+		memcpy(dataptr+datapos, itemptr+zsh->outpos,
+			itemlen-zsh->outpos);
+		datapos += itemlen- zsh->outpos;
+		zsh->outpos = 0;
+	    }
+	    if (zsh->outpos == 0) {
+		Tcl_ListObjReplace(NULL, zsh->outdata, 0, 1, 0, NULL);
+	    }
+	}
+	Tcl_SetByteArrayLength(data, datapos);
+    }
+    return TCL_OK;
+}
+
+/*
+ * Deflate the contents of Tcl_Obj *data with compression level in output
+ * format.
+ */
+
+int
+Tcl_ZlibDeflate(
+    Tcl_Interp *interp,
+    int format,
+    Tcl_Obj *data,
+    int level)
+{
+    int wbits = 0, bdlen = 0, e = 0;
+    Byte *bdata = 0;
+    z_stream stream;
+    Tcl_Obj *obj;
+
+    /*
+     * We pass the data back in the interp result obj...
+     */
+
+    if (!interp) {
+	return TCL_ERROR;
+    }
+    obj = Tcl_GetObjResult(interp);
+
+    /*
+     * Compressed format is specified by the wbits parameter. See zlib.h for
+     * details.
+     */
+
+    if (format == TCL_ZLIB_FORMAT_RAW) {
+	wbits = -MAX_WBITS;
+    } else if (format == TCL_ZLIB_FORMAT_GZIP) {
+	wbits = MAX_WBITS + 16;
+    } else if (format == TCL_ZLIB_FORMAT_ZLIB) {
+	wbits = MAX_WBITS;
+    } else {
+	Tcl_Panic("incorrect zlib data format, must be TCL_ZLIB_FORMAT_ZLIB, "
+		"TCL_ZLIB_FORMAT_GZIP or TCL_ZLIB_FORMAT_ZLIB");
+    }
+
+    if (level < -1 || level > 9) {
+	Tcl_Panic("compression level should be between 0 (uncompressed) and "
+		"9 (best compression) or -1 for default compression level");
+    }
+
+    /*
+     * Obtain the pointer to the byte array, we'll pass this pointer straight
+     * to the deflate command.
+     */
+
+    bdata = Tcl_GetByteArrayFromObj(data, &bdlen);
+    stream.avail_in = (uInt) bdlen;
+    stream.next_in = bdata;
+    stream.zalloc = 0;
+    stream.zfree = 0;
+    stream.opaque = 0;			/* Must be initialized before calling
+					 * deflateInit2 */
+
+    /*
+     * No output buffer available yet, will alloc after deflateInit2.
+     */
+
+    stream.avail_out = 0;
+    stream.next_out = NULL;
+
+    e = deflateInit2(&stream, level, Z_DEFLATED, wbits, MAX_MEM_LEVEL,
+	    Z_DEFAULT_STRATEGY);
+
+    if (e != Z_OK) {
+	Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Allocate the output buffer from the value of deflateBound(). This is
+     * probably too much space. Before returning to the caller, we will reduce
+     * it back to the actual compressed size.
+     */
+
+    stream.avail_out = deflateBound(&stream, bdlen);
+    /* TODO: What happens if this next call fails? */
+    Tcl_SetByteArrayLength(obj, stream.avail_out);
+
+    /*
+     * And point the output buffer to the obj buffer.
+     */
+
+    stream.next_out = Tcl_GetByteArrayFromObj(obj, NULL);
+
+    /*
+     * Perform the compression, Z_FINISH means do it in one go.
+     */
+
+    e = deflate(&stream, Z_FINISH);
+
+    if (e != Z_STREAM_END) {
+	deflateEnd(&stream);
+
+	/*
+	 * deflateEnd() returns Z_OK when there are bytes left to compress, at
+	 * this point we consider that an error, although we could continue by
+	 * allocating more memory and calling deflate() again.
+	 */
+
+	if (e == Z_OK) {
+	    e = Z_BUF_ERROR;
+	}
+    } else {
+	e = deflateEnd(&stream);
+    }
+
+    if (e != Z_OK) {
+	Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Reduce the BA length to the actual data length produced by deflate.
+     */
+
+    Tcl_SetByteArrayLength(obj, stream.total_out);
+
+    return TCL_OK;
+}
+
+int
+Tcl_ZlibInflate(
+    Tcl_Interp *interp,
+    int format,
+    Tcl_Obj *data,
+    int buffersize)
+{
+    int wbits = 0 , inlen = 0, e = 0, newbuffersize;
+    Byte *indata = NULL, *outdata = NULL, *newoutdata = NULL;
+    z_stream stream;
+    Tcl_Obj *obj;
+
+    /*
+     * We pass the data back in the interp result obj...
+     */
+
+    if (!interp) {
+	return TCL_ERROR;
+    }
+    obj = Tcl_GetObjResult(interp);
+
+    /*
+     * Compressed format is specified by the wbits parameter. See zlib.h for
+     * details.
+     */
+
+    if (format == TCL_ZLIB_FORMAT_RAW) {
+	wbits = -MAX_WBITS;
+    } else if (format == TCL_ZLIB_FORMAT_GZIP) {
+	wbits = MAX_WBITS+16;
+    } else if (format == TCL_ZLIB_FORMAT_ZLIB) {
+	wbits = MAX_WBITS;
+    } else if (format == TCL_ZLIB_FORMAT_AUTO) {
+	wbits = MAX_WBITS+32;
+    } else {
+	Tcl_Panic("incorrect zlib data format, must be TCL_ZLIB_FORMAT_ZLIB, "
+	      "TCL_ZLIB_FORMAT_GZIP, TCL_ZLIB_FORMAT_RAW or ZLIB_FORMAT_AUTO");
+    }
+
+    indata = Tcl_GetByteArrayFromObj(data,&inlen);
+    if (buffersize == 0) {
+	/*
+	 * Start with a buffer 3 times the size of the input data.
+	 *
+	 * TODO: integer bounds/overflow check
+	 */
+
+	buffersize = 3*inlen;
+    }
+
+    outdata = Tcl_SetByteArrayLength(obj, buffersize);
+    stream.zalloc = 0;
+    stream.zfree = 0;
+    stream.avail_in = (uInt) inlen+1;	/* +1 because ZLIB can "over-request"
+					 * input (but ignore it!) */
+    stream.next_in = indata;
+    stream.avail_out = buffersize;
+    stream.next_out = outdata;
+
+    /*
+     * Start the decompression cycle.
+     */
+
+    e = inflateInit2(&stream, wbits);
+    if (e != Z_OK) {
+	Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+    while (1) {
+	e = inflate(&stream, Z_FINISH);
+	if (e != Z_BUF_ERROR) {
+	    break;
+	}
+
+	/*
+	 * Not enough room in the output buffer. Increase it by five times the
+	 * bytes still in the input buffer. (Because 3 times didn't do the
+	 * trick before, 5 times is what we do next.) Further optimization
+	 * should be done by the user, specify the decompressed size!
+	 */
+
+	if ((stream.avail_in == 0) && (stream.avail_out > 0)) {
+	    Tcl_SetResult(interp, "decompression failed, input truncated?",
+		    TCL_STATIC);
+	    return TCL_ERROR;
+	}
+	newbuffersize = buffersize + 5 * stream.avail_in;
+	if (newbuffersize == buffersize) {
+	    newbuffersize = buffersize+1000;
+	}
+	newoutdata = Tcl_SetByteArrayLength(obj, newbuffersize);
+
+	/*
+	 * Set next out to the same offset in the new location.
+	 */
+
+	stream.next_out = newoutdata + stream.total_out;
+
+	/*
+	 * And increase avail_out with the number of new bytes allocated.
+	 */
+
+	stream.avail_out += newbuffersize - buffersize;
+	outdata = newoutdata;
+	buffersize = newbuffersize;
+    }
+
+    if (e != Z_STREAM_END) {
+	inflateEnd(&stream);
+	Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    e = inflateEnd(&stream);
+    if (e != Z_OK) {
+	Tcl_SetResult(interp, (char*) zError(e), TCL_STATIC);
+	return TCL_ERROR;
+    }
+
+    /*
+     * Reduce the BA length to the actual data length produced by deflate.
+     */
+
+    Tcl_SetByteArrayLength(obj, stream.total_out);
+    return TCL_OK;
+}
+
+unsigned int
+Tcl_ZlibCRC32(
+    unsigned int crc,
+    const char *buf,
+    unsigned int len)
+{
+    /* Nothing much to do, just wrap the crc32(). */
+    return crc32(crc, (Bytef *) buf, len);
+}
+
+unsigned int
+Tcl_ZlibAdler32(
+    unsigned int adler,
+    const char *buf,
+    unsigned int len)
+{
+    return adler32(adler, (Bytef *) buf, len);
+}
+
+static int
+ZlibCmd(
+    ClientData notUsed,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    int command, dlen, mode, format;
+#ifdef TCLKIT_BUILD
+    int wbits = -MAX_WBITS;
+#endif
+    unsigned start, level = -1, buffersize = 0;
+    Tcl_ZlibStream zh;
+    Byte *data;
+    Tcl_Obj *obj = Tcl_GetObjResult(interp);
+    static const char *commands[] = {
+	"adler32", "compress", "crc32", "decompress", "deflate", "gunzip",
+	"gzip", "inflate",
+#ifdef TCLKIT_BUILD
+	"sdecompress", "sinflate",
+#endif
+	"stack", "stream", "unstack",
+	NULL
+    };
+    enum zlibCommands {
+	z_adler32, z_compress, z_crc32, z_decompress, z_deflate, z_gunzip,
+	z_gzip, z_inflate,
+#ifdef TCLKIT_BUILD
+	z_sdecompress, z_sinflate,
+#endif
+	z_stack, z_stream, z_unstack
+    };
+    static const char *stream_formats[] = {
+	"compress", "decompress", "deflate", "gunzip", "gzip", "inflate",
+	NULL
+    };
+    enum zlibFormats {
+	f_compress, f_decompress, f_deflate, f_gunzip, f_gzip, f_inflate
+    };
+
+    if (objc < 3) {
+	Tcl_WrongNumArgs(interp, 1, objv, "command arg ?...?");
+	return TCL_ERROR;
+    }
+    if (Tcl_GetIndexFromObj(interp, objv[1], commands, "command", 0,
+	    &command) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    switch ((enum zlibCommands) command) {
+    case z_adler32: /* adler32 str ?startvalue? -> checksum */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &start) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (objc < 4) {
+	    start = Tcl_ZlibAdler32(0, 0, 0);
+	}
+	data = Tcl_GetByteArrayFromObj(objv[2], &dlen);
+	Tcl_SetIntObj(obj, (int)
+		Tcl_ZlibAdler32(start, (const char *) data, dlen));
+	return TCL_OK;
+    case z_crc32: /* crc32 str ?startvalue? -> checksum */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &start) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	if (objc < 4) {
+	    start = Tcl_ZlibCRC32(0, 0, 0);
+	}
+	data = Tcl_GetByteArrayFromObj(objv[2],&dlen);
+	Tcl_SetIntObj(obj, (int)
+		Tcl_ZlibCRC32(start, (const char *) data, dlen));
+	return TCL_OK;
+    case z_deflate: /* deflate data ?level? -> rawCompressedData */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &level) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibDeflate(interp, TCL_ZLIB_FORMAT_RAW, objv[2], level);
+    case z_compress: /* compress data ?level? -> zlibCompressedData */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &level) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibDeflate(interp, TCL_ZLIB_FORMAT_ZLIB, objv[2], level);
+    case z_gzip: /* gzip data ?level? -> gzippedCompressedData */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &level) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibDeflate(interp, TCL_ZLIB_FORMAT_GZIP, objv[2], level);
+    case z_inflate: /* inflate rawcomprdata ?bufferSize? -> decompressedData */
+	if (objc>3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &buffersize) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibInflate(interp, TCL_ZLIB_FORMAT_RAW, objv[2],
+		buffersize);
+    case z_decompress: /* decompress zlibcomprdata ?bufferSize? -> decompressedData */
+	/* We rely on TCL_ZLIB_FORMAT_AUTO to determine type. */
+    case z_gunzip: /* gunzip gzippeddata ?bufferSize? -> decompressedData */
+	if (objc > 3 && Tcl_GetIntFromObj(interp, objv[3],
+		(int *) &buffersize) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibInflate(interp, TCL_ZLIB_FORMAT_AUTO, objv[2],
+		buffersize);
+    case z_stream: /* stream deflate/inflate/...gunzip ?level?*/
+	if (Tcl_GetIndexFromObj(interp, objv[2], stream_formats,
+		"stream format", 0, &format) != TCL_OK) {
+	    Tcl_AppendResult(interp, "format error: integer", NULL);
+	    return TCL_ERROR;
+	}
+	mode = TCL_ZLIB_STREAM_INFLATE;
+	switch ((enum zlibFormats) format) {
+	case f_deflate:
+	    mode = TCL_ZLIB_STREAM_DEFLATE;
+	case f_inflate:
+	    format = TCL_ZLIB_FORMAT_RAW;
+	    break;
+	case f_compress:
+	    mode = TCL_ZLIB_STREAM_DEFLATE;
+	case f_decompress:
+	    format = TCL_ZLIB_FORMAT_ZLIB;
+	    break;
+	case f_gzip:
+	    mode = TCL_ZLIB_STREAM_DEFLATE;
+	case f_gunzip:
+	    format = TCL_ZLIB_FORMAT_GZIP;
+	    break;
+	}
+	if (objc >= 4) {
+	    if (Tcl_GetIntFromObj(interp, objv[3],
+		    (int *) &level) != TCL_OK) {
+		Tcl_AppendResult(interp, "level error: integer", NULL);
+		return TCL_ERROR;
+	    }
+	} else {
+	    level = Z_DEFAULT_COMPRESSION;
+	}
+	if (Tcl_ZlibStreamInit(interp, mode, format, level, &zh) != TCL_OK) {
+	    Tcl_AppendResult(interp, "stream init error: integer", NULL);
+	    return TCL_ERROR;
+	}
+	Tcl_SetObjResult(interp, Tcl_ZlibStreamGetCommandName(zh));
+	return TCL_OK;
+    case z_stack: /* stack */
+	break;
+    case z_unstack: /* unstack */
+	break;
+#ifdef TCLKIT_BUILD
+    case z_sdecompress: /* sdecompress cmdname -> */
+	wbits = MAX_WBITS;
+    case z_sinflate: {/* sinflate cmdname -> */
+	zlibstream *zp = (zlibstream *) ckalloc(sizeof(zlibstream));
+
+	zp->indata = Tcl_NewObj();
+	Tcl_IncrRefCount(zp->indata);
+	zp->stream.zalloc = 0;
+	zp->stream.zfree = 0;
+	zp->stream.opaque = 0;
+	zp->stream.next_in = 0;
+	zp->stream.avail_in = 0;
+	inflateInit2(&zp->stream, wbits);
+	Tcl_CreateObjCommand(interp, Tcl_GetStringFromObj(objv[2], 0),
+		zstreamincmd, zp, zstreamdelproc);
+	return TCL_OK;
+    }
+#endif /* TCLKIT_BUILD */
+    };
+
+    return TCL_ERROR;
+}
+
+static int
+ZlibStreamCmd(
+    ClientData cd,
+    Tcl_Interp *interp,
+    int objc,
+    Tcl_Obj *const objv[])
+{
+    Tcl_ZlibStream zstream = cd;
+    int command, index, count;
+    Tcl_Obj *obj = Tcl_GetObjResult(interp);
+    int buffersize;
+    int flush = -1, i;
+    static const char *cmds[] = {
+	"add", "adler32", "close", "eof", "finalize", "flush",
+	"fullflush", "get", "put", "reset",
+	NULL
+    };
+    enum zlibStreamCommands {
+	zs_add, zs_adler32, zs_close, zs_eof, zs_finalize, zs_flush,
+	zs_fullflush, zs_get, zs_put, zs_reset
+    };
+    static const char *add_options[] = {
+	"-buffer", "-finalize", "-flush", "-fullflush", NULL
+    };
+    enum addOptions {
+	ao_buffer, ao_finalize, ao_flush, ao_fullflush
+    };
+
+    if (objc < 2) {
+	Tcl_WrongNumArgs(interp, 1, objv, "option data ?...?");
+	return TCL_ERROR;
+    }
+
+    if (Tcl_GetIndexFromObj(interp, objv[1], cmds, "option", 0,
+	    &command) != TCL_OK) {
+	return TCL_ERROR;
+    }
+
+    switch ((enum zlibStreamCommands) command) {
+    case zs_add: /* add ?-flush|-fullflush|-finalize? /data/ */
+	for (i=2; i<objc-1; i++) {
+	    if (Tcl_GetIndexFromObj(interp, objv[i], add_options, "option", 0,
+		    &index) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+
+	    switch ((enum addOptions) index) {
+	    case ao_flush: /* -flush */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_SYNC_FLUSH;
+		}
+		break;
+	    case ao_fullflush: /* -fullflush */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_FULL_FLUSH;
+		}
+		break;
+	    case ao_finalize: /* -finalize */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_FINISH;
+		}
+		break;
+	    case ao_buffer: /* -buffer */
+		if (i == objc-2) {
+		    Tcl_AppendResult(interp, "\"-buffer\" option must be "
+			    "followed by integer decompression buffersize",
+			    NULL);
+		    return TCL_ERROR;
+		}
+		if (Tcl_GetIntFromObj(interp, objv[i+1],
+			&buffersize) != TCL_OK) {
+		    return TCL_ERROR;
+		}
+	    }
+
+	    if (flush == -2) {
+		Tcl_AppendResult(interp, "\"-flush\", \"-fullflush\" and "
+			"\"-finalize\" options are mutually exclusive", NULL);
+		return TCL_ERROR;
+	    }
+	}
+	if (flush == -1) {
+	    flush = 0;
+	}
+
+	if (Tcl_ZlibStreamPut(zstream, objv[objc-1],
+		flush) != TCL_OK) {
+	    return TCL_ERROR;
+	}
+	return Tcl_ZlibStreamGet(zstream, obj, -1);
+
+    case zs_put: /* put ?-flush|-fullflush|-finalize? /data/ */
+	for (i=2; i<objc-1; i++) {
+	    if (Tcl_GetIndexFromObj(interp, objv[i], add_options, "option", 0,
+		    &index) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+
+	    switch ((enum addOptions) index) {
+	    case ao_flush: /* -flush */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_SYNC_FLUSH;
+		}
+		break;
+	    case ao_fullflush: /* -fullflush */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_FULL_FLUSH;
+		}
+		break;
+	    case ao_finalize: /* -finalize */
+		if (flush > -1) {
+		    flush = -2;
+		} else {
+		    flush = Z_FINISH;
+		}
+		break;
+	    case ao_buffer:
+		Tcl_AppendResult(interp,
+			"\"-buffer\" option not supported here", NULL);
+		return TCL_ERROR;
+	    }
+	    if (flush == -2) {
+		Tcl_AppendResult(interp, "\"-flush\", \"-fullflush\" and "
+			"\"-finalize\" options are mutually exclusive", NULL);
+		return TCL_ERROR;
+	    }
+	}
+	if (flush == -1) {
+	    flush = 0;
+	}
+	return Tcl_ZlibStreamPut(zstream, objv[objc-1], flush);
+
+    case zs_get: /* get ?count? */
+	count = -1;
+	if (objc >= 3) {
+	    if (Tcl_GetIntFromObj(interp, objv[2], &count) != TCL_OK) {
+		return TCL_ERROR;
+	    }
+	}
+	return Tcl_ZlibStreamGet(zstream, obj, count);
+    case zs_flush: /* flush */
+	Tcl_SetObjLength(obj, 0);
+	return Tcl_ZlibStreamPut(zstream, obj, Z_SYNC_FLUSH);
+    case zs_fullflush: /* fullflush */
+	Tcl_SetObjLength(obj, 0);
+	return Tcl_ZlibStreamPut(zstream, obj, Z_FULL_FLUSH);
+    case zs_finalize: /* finalize */
+	/*
+	 * The flush commands slightly abuse the empty result obj as input
+	 * data.
+	 */
+
+	Tcl_SetObjLength(obj, 0);
+	return Tcl_ZlibStreamPut(zstream, obj, Z_FINISH);
+    case zs_close: /* close */
+	return Tcl_ZlibStreamClose(zstream);
+    case zs_eof: /* eof */
+	Tcl_SetIntObj(obj, Tcl_ZlibStreamEof(zstream));
+	return TCL_OK;
+    case zs_adler32: /* adler32 */
+	Tcl_SetIntObj(obj, Tcl_ZlibStreamAdler32(zstream));
+	return TCL_OK;
+    case zs_reset: /* reset */
+	return Tcl_ZlibStreamReset(zstream);
+    }
+
+    return TCL_OK;
+}
+
+#ifdef ENABLE_CHANSTACKING
+ /*
+  * Set of functions to support channel stacking
+  */
+
+static int
+ChanClose(
+    ClientData instanceData,
+    Tcl_Interp *interp)
+{
+    Zlib_ChannelData *cd = instanceData;
+    Tcl_Channel parent;
+    int e;
+
+    parent = Tcl_GetStackedChannel(cd->channel);
+
+    if (cd->inFormat != ZLIB_PASSTHROUGH) {
+	if (cd->inFormat && ZLIB_INFLATE) {
+	    e = inflateEnd(&cd->instream);
+	} else {
+	    e = deflateEnd(&cd->instream);
+	}
+    }
+
+    if (cd->outFormat != ZLIB_PASSTHROUGH) {
+	if (cd->outFormat && ZLIB_INFLATE) {
+	    e = inflateEnd(&cd->outstream);
+	} else {
+	    e = deflateEnd(&cd->outstream);
+	}
+    }
+
+    if (cd->inbuffer) {
+	ckfree(cd->inbuffer);
+	cd->inbuffer = NULL;
+    }
+
+    if (cd->outbuffer) {
+	ckfree(cd->outbuffer);
+	cd->outbuffer = NULL;
+    }
+    return TCL_OK;
+}
+
+static int
+ChanInput(
+    ClientData instanceData,
+    char *buf,
+    int toRead,
+    int *errorCodePtr)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    return TCL_OK;
+}
+
+static int
+ChanOutput(
+    ClientData instanceData,
+    const char *buf,
+    int toWrite,
+    int *errorCodePtr)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    return TCL_OK;
+}
+
+static int
+ChanSeek(
+    ClientData instanceData,
+    long offset,
+    int mode,
+    int *errorCodePtr)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    return TCL_OK;
+}
+
+static int
+ChanSetOption(			/* not used */
+    ClientData instanceData,
+    Tcl_Interp *interp,
+    const char *optionName,
+    const char *value)
+{
+    Zlib_ChannelData *cd = instanceData;
+    Tcl_Channel parent = Tcl_GetStackedChannel(cd->channel);
+    Tcl_DriverSetOptionProc *setOptionProc =
+	    Tcl_ChannelSetOptionProc(Tcl_GetChannelType(parent));
+
+    if (setOptionProc == NULL) {
+	return TCL_ERROR;
+    }
+
+    return setOptionProc(Tcl_GetChannelInstanceData(parent), interp,
+	    optionName, value);
+}
+
+static int
+ChanGetOption(			/* not used */
+    ClientData instanceData,
+    Tcl_Interp *interp,
+    const char *optionName,
+    Tcl_DString *dsPtr)
+{
+    return TCL_OK;
+}
+
+static void
+ChanWatch(
+    ClientData instanceData,
+    int mask)
+{
+    return;
+}
+
+static int
+ChanGetHandle(
+    ClientData instanceData,
+    int direction,
+    ClientData *handlePtr)
+{
+    /*
+     * No such thing as an OS handle for Zlib.
+     */
+
+    return 0;
+}
+
+static int
+ChanClose2(			/* not used */
+    ClientData instanceData,
+    Tcl_Interp *interp,
+    int flags)
+{
+    return TCL_OK;
+}
+
+static int
+ChanBlockMode(
+    ClientData instanceData,
+    int mode)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    if (mode == TCL_MODE_NONBLOCKING) {
+	cd->flags |= ASYNC;
+    } else {
+	cd->flags &= ~ASYNC;
+    }
+    return TCL_OK;
+}
+
+static int
+ChanFlush(
+    ClientData instanceData)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    return TCL_OK;
+}
+
+static int
+ChanHandler(
+    ClientData instanceData,
+    int interestMask)
+{
+    Zlib_ChannelData *cd = instanceData;
+
+    return TCL_OK;
+}
+
+Tcl_WideInt
+ChanWideSeek(			/* not used */
+    ClientData instanceData,
+    Tcl_WideInt offset,
+    int mode,
+    int *errorCodePtr)
+{
+    return TCL_OK;
+}
+
+Tcl_Channel
+Tcl_ZlibStackChannel(
+    Tcl_Interp *interp,
+    int inFormat,
+    int inLevel,
+    int outFormat,
+    int outLevel,
+    Tcl_Channel channel)
+{
+    Zlib_ChannelData *cd;
+    int outwbits = 0, inwbits = 0;
+    int e;
+
+    if (inFormat & ZLIB_FORMAT_RAW) {
+	inwbits = -MAX_WBITS;
+    } else if (inFormat & ZLIB_FORMAT_GZIP) {
+	inwbits = MAX_WBITS+16;
+    } else if (inFormat & ZLIB_FORMAT_ZLIB) {
+	inwbits = MAX_WBITS;
+    } else if ((inFormat & ZLIB_FORMAT_AUTO) && (inFormat & ZLIB_INFLATE)) {
+	inwbits = MAX_WBITS+32;
+    } else if (inFormat != ZLIB_PASSTHROUGH) {
+	Tcl_SetResult(interp, "Incorrect zlib read/input data format, must "
+		"be ZLIB_FORMAT_ZLIB, ZLIB_FORMAT_GZIP, ZLIB_FORMAT_RAW or "
+		"ZLIB_FORMAT_AUTO (only for inflate).", TCL_STATIC);
+	return NULL;
+    }
+
+    if (outFormat & ZLIB_FORMAT_RAW) {
+	outwbits = -MAX_WBITS;
+    } else if (outFormat & ZLIB_FORMAT_GZIP) {
+	outwbits = MAX_WBITS+16;
+    } else if (outFormat & ZLIB_FORMAT_ZLIB) {
+	outwbits = MAX_WBITS;
+    } else if ((outFormat & ZLIB_FORMAT_AUTO) && (outFormat & ZLIB_INFLATE)) {
+	outwbits = MAX_WBITS+32;
+    } else if (outFormat != ZLIB_PASSTHROUGH) {
+	Tcl_SetResult(interp, "Incorrect zlib write/output data format, must "
+		"be ZLIB_FORMAT_ZLIB, ZLIB_FORMAT_GZIP, ZLIB_FORMAT_RAW or "
+		"ZLIB_FORMAT_AUTO (only for inflate).", TCL_STATIC);
+	return NULL;
+    }
+
+    cd = (Zlib_ChannelData *) ckalloc(sizeof(Zlib_ChannelData));
+    cd->inFormat = inFormat;
+    cd->outFormat = outFormat;
+
+    cd->instream.zalloc = 0;
+    cd->instream.zfree = 0;
+    cd->instream.opaque = 0;
+    cd->instream.avail_in = 0;
+    cd->instream.next_in = NULL;
+    cd->instream.avail_out = 0;
+    cd->instream.next_out = NULL;
+
+    cd->outstream.zalloc = 0;
+    cd->outstream.zfree = 0;
+    cd->outstream.opaque = 0;
+    cd->outstream.avail_in = 0;
+    cd->outstream.next_in = NULL;
+    cd->outstream.avail_out = 0;
+    cd->outstream.next_out = NULL;
+
+    if (inFormat != ZLIB_PASSTHROUGH) {
+	if (inFormat & ZLIB_INFLATE) {
+	    /* Initialize for Inflate */
+	    e = inflateInit2(&cd->instream, inwbits);
+	} else {
+	    /* Initialize for Deflate */
+	    e = deflateInit2(&cd->instream, inLevel, Z_DEFLATED, inwbits,
+		    MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+	}
+    }
+
+    if (outFormat != ZLIB_PASSTHROUGH) {
+	if (outFormat && ZLIB_INFLATE) {
+	    /* Initialize for Inflate */
+	    e = inflateInit2(&cd->outstream, outwbits);
+	} else {
+	    /* Initialize for Deflate */
+	    e = deflateInit2(&cd->outstream, outLevel, Z_DEFLATED, outwbits,
+		    MAX_MEM_LEVEL, Z_DEFAULT_STRATEGY);
+	}
+    }
+
+    cd->channel = Tcl_StackChannel(interp, &zlibChannelType, cd,
+	    TCL_READABLE | TCL_WRITABLE | TCL_EXCEPTION, channel);
+    Tcl_SetObjResult(interp, Tcl_NewStringObj(Tcl_GetChannelName(channel),
+	    -1));
+    return channel;
+}
+
+#endif /* ENABLE_CHANSTACKING */
+
+/*
+ * Finaly, the TclZlibInit function. Used to install the zlib API.
+ */
+
+int
+TclZlibInit(
+    Tcl_Interp *interp)
+{
+    Tcl_Eval(interp, "namespace eval ::zlib {variable cmdcounter 0}");
+    Tcl_CreateObjCommand(interp, "zlib", ZlibCmd, 0, 0);
+    return TCL_OK;
+}
+#endif /* REIMPLEMENT */
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */