Hi,
I did some work on the gzip.c example plugin:
-made it working again (current code failes on asserts from
TSMimeHdrFieldValueStringGet),
-made it compress using the same deflateinit2 call as mod_gzip, for better
browser compatibility (ie issues).
Regards,
Otto van der Schaaf
/** @file
Transforms content using gzip
@section license License
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements. See the NOTICE file
distributed with this work for additional information
regarding copyright ownership. The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#include <limits.h>
#include <stdio.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/file.h>
#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>
#include <assert.h>
#include <ts/ts.h>
#define DICT_PATH_MAX 512
#define DICT_ENTRY_MAX 2048
typedef struct
{
TSHttpTxn txn;
TSVIO output_vio;
TSIOBuffer output_buffer;
TSIOBufferReader output_reader;
int output_length;
z_stream zstrm;
uLong crc;
int state;
} GzipData;
char preload_file[1024];
uLong dictId;
int preload = 0;
char dictionary[800000];
void
load_dictionary(char *dict, uLong * adler)
{
FILE *fp;
int i = 0;
fp = fopen(preload_file, "r");
if (!fp) {
TSError("gzip-transform: ERROR: Unable to open dict file %s\n",
preload_file);
exit(0);
}
/* dict = (char *) calloc(8000,sizeof(char)); */
i = 0;
while (!feof(fp)) {
if (fscanf(fp, "%s\n", dict + i) == 1) {
i = strlen(dict);
strcat(dict + i, " ");
i++;
}
}
dict[i - 1] = '\0';
/* TODO get the adler compute right */
*adler = adler32(*adler, (const Byte *) dict, sizeof(dict));
}
static voidpf
gzip_alloc(voidpf opaque, uInt items, uInt size)
{
return (voidpf) TSmalloc(items * size);
}
static void
gzip_free(voidpf opaque, voidpf address)
{
TSfree(address);
}
static GzipData *
gzip_data_alloc()
{
GzipData *data;
int err;
data = (GzipData *) TSmalloc(sizeof(GzipData));
data->output_vio = NULL;
data->output_buffer = NULL;
data->output_reader = NULL;
data->output_length = 0;
data->state = 0;
data->crc = crc32(0L, Z_NULL, 0);
data->zstrm.next_in = Z_NULL;
data->zstrm.avail_in = 0;
data->zstrm.total_in = 0;
data->zstrm.next_out = Z_NULL;
data->zstrm.avail_out = 0;
data->zstrm.total_out = 0;
data->zstrm.zalloc = gzip_alloc;
data->zstrm.zfree = gzip_free;
data->zstrm.opaque = (voidpf) 0;
data->zstrm.data_type = Z_ASCII;
/*
rc =
deflateInit2(
&zlib_ctx->strm,
compression_level,
Z_DEFLATED,
MOD_GZIP_ZLIB_WINDOWSIZE,
MOD_GZIP_ZLIB_CFACTOR,
Z_DEFAULT_STRATEGY
);
*/
//os: from mod_gzip
#define MOD_GZIP_ZLIB_WINDOWSIZE -15
#define MOD_GZIP_ZLIB_CFACTOR 9
#define MOD_GZIP_ZLIB_BSIZE 8096
/* ZLIB's deflate() compression algorithm uses the same */
/* 0-9 based scale that GZIP does where '1' is 'Best speed' */
/* and '9' is 'Best compression'. Testing has proved level '6' */
/* to be about the best level to use in an HTTP Server. */
#define MOD_GZIP_DEFLATE_DEFAULT_COMPRESSION_LEVEL 6
err = deflateInit2(
&data->zstrm,
MOD_GZIP_DEFLATE_DEFAULT_COMPRESSION_LEVEL,
Z_DEFLATED,
MOD_GZIP_ZLIB_WINDOWSIZE,
MOD_GZIP_ZLIB_CFACTOR,
Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
TSError("gzip-transform: ERROR: deflateInit (%d)!", err);
exit(1);
}
if (preload) {
assert(&data->zstrm);
err = deflateSetDictionary(&data->zstrm, (const Bytef *) dictionary,
strlen(dictionary));
if (err != Z_OK) {
TSError("gzip-transform: ERROR: deflateSetDictionary (%d)!", err);
}
}
return data;
}
static void
gzip_data_destroy(GzipData * data)
{
int err;
if (data) {
err = deflateEnd(&data->zstrm);
if (err != Z_OK) {
TSError("gzip-transform: ERROR: deflateEnd (%d)!", err);
}
if (data->output_buffer)
TSIOBufferDestroy(data->output_buffer);
TSfree(data);
}
}
static void
gzip_transform_init(TSCont contp, GzipData * data)
{
TSVConn output_conn;
TSMBuffer bufp;
TSMLoc hdr_loc;
TSMLoc ce_loc; /* for the content encoding mime field */
data->state = 1;
/*
* Mark the output data as having gzip content encoding
*/
TSHttpTxnTransformRespGet(data->txn, &bufp, &hdr_loc);
TSMimeHdrFieldCreate(bufp, hdr_loc, &ce_loc); /* Probably should check for
errors */
TSMimeHdrFieldNameSet(bufp, hdr_loc, ce_loc, "Content-Encoding", -1);
TSMimeHdrFieldValueStringInsert(bufp, hdr_loc, ce_loc, -1, "deflate", -1);
TSMimeHdrFieldAppend(bufp, hdr_loc, ce_loc);
TSHandleMLocRelease(bufp, hdr_loc, ce_loc);
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
/* Get the output connection where we'll write data to. */
output_conn = TSTransformOutputVConnGet(contp);
data->output_buffer = TSIOBufferCreate();
data->output_reader = TSIOBufferReaderAlloc(data->output_buffer);
data->output_vio = TSVConnWrite(output_conn, contp, data->output_reader,
INT64_MAX);
}
static void
gzip_transform_one(GzipData * data, TSIOBufferReader input_reader, int
amount)
{
TSIOBufferBlock blkp;
const char *ibuf;
char *obuf;
int64_t ilength, olength;
int err;
while (amount > 0) {
blkp = TSIOBufferReaderStart(input_reader);
ibuf = TSIOBufferBlockReadStart(blkp, input_reader, &ilength);
if (ilength > amount) {
ilength = amount;
}
data->zstrm.next_in = (unsigned char *) ibuf;
data->zstrm.avail_in = ilength;
while (data->zstrm.avail_in > 0) {
blkp = TSIOBufferStart(data->output_buffer);
obuf = TSIOBufferBlockWriteStart(blkp, &olength);
data->zstrm.next_out = (unsigned char *) obuf;
data->zstrm.avail_out = olength;
/* Encode */
err = deflate(&data->zstrm, Z_NO_FLUSH);
if (olength > data->zstrm.avail_out) {
TSIOBufferProduce(data->output_buffer, olength -
data->zstrm.avail_out);
data->output_length += (olength - data->zstrm.avail_out);
}
if (data->zstrm.avail_out > 0) {
if (data->zstrm.avail_in != 0) {
TSError("gzip-transform: ERROR: avail_in is (%d): should be 0",
data->zstrm.avail_in);
}
}
}
/* compute CRC for error checking at client */
data->crc = crc32(data->crc, (unsigned char *) ibuf, ilength);
TSIOBufferReaderConsume(input_reader, ilength);
amount -= ilength;
}
}
static void
gzip_transform_finish(GzipData * data)
{
if (data->state == 1) {
TSIOBufferBlock blkp;
char *obuf;
int64_t olength;
int err;
data->state = 2;
for (;;) {
blkp = TSIOBufferStart(data->output_buffer);
obuf = TSIOBufferBlockWriteStart(blkp, &olength);
data->zstrm.next_out = (unsigned char *) obuf;
data->zstrm.avail_out = olength;
/* Encode remaining data */
err = deflate(&data->zstrm, Z_FINISH);
if (olength > data->zstrm.avail_out) {
TSIOBufferProduce(data->output_buffer, olength -
data->zstrm.avail_out);
data->output_length += (olength - data->zstrm.avail_out);
}
if (err == Z_OK) { /* some more data to encode */
continue;
}
/* done! */
if (err != Z_STREAM_END) {
TSDebug("gzip-transform", "deflate should report Z_STREAM_END\n");
}
break;
}
if (data->output_length != (data->zstrm.total_out)) {
TSError("gzip-transform: ERROR: output lengths don't match (%d, %ld)",
data->output_length,
data->zstrm.total_out);
}
/* compute/append crc to end of stream */
/*
blkp = TSIOBufferStart (data->output_buffer);
char crcbuf[8];
char* buf=crcbuf;
uLong tmp = data->crc;
buf[0] = tmp & 0xff; tmp >>= 8;
buf[1] = tmp & 0xff; tmp >>= 8;
buf[2] = tmp & 0xff; tmp >>= 8;
buf[3] = tmp & 0xff;
tmp = data->zstrm.total_in;
buf[4] = tmp & 0xff; tmp >>= 8;
buf[5] = tmp & 0xff; tmp >>= 8;
buf[6] = tmp & 0xff; tmp >>= 8;
buf[7] = tmp & 0xff;
char*p = buf;
int length;
length = 8;
while (length > 0) {
obuf = TSIOBufferBlockWriteStart (blkp, &olength);
if (olength > length) {
olength = length;
}
memcpy (obuf, p, olength);
p += olength;
length -= olength;
TSIOBufferProduce (data->output_buffer, olength);
}
data->output_length += 8;*/
}
}
static void
gzip_transform_do(TSCont contp)
{
TSVIO write_vio;
GzipData *data;
int towrite;
int avail;
int length;
/* Get our data structure for this operation. The private data
structure contains the output vio and output buffer. If the
private data structure pointer is NULL, then we'll create it
and initialize its internals. */
data = TSContDataGet(contp);
if (data->state == 0) {
gzip_transform_init(contp, data);
}
/* Get the write vio for the write operation that was performed on
ourself. This vio contains the buffer that we are to read from
as well as the continuation we are to call when the buffer is
empty. */
write_vio = TSVConnWriteVIOGet(contp);
length = data->output_length;
/* We also check to see if the write vio's buffer is non-NULL. A
NULL buffer indicates that the write operation has been
shutdown and that the continuation does not want us to send any
more WRITE_READY or WRITE_COMPLETE events. For this simplistic
transformation that means we're done. In a more complex
transformation we might have to finish writing the transformed
data to our output connection. */
if (!TSVIOBufferGet(write_vio)) {
gzip_transform_finish(data);
TSVIONBytesSet(data->output_vio, data->output_length);
TSDebug("gzip-transform", "Compressed size %d (bytes)",
data->output_length);
if (data->output_length > length) {
TSVIOReenable(data->output_vio);
}
return;
}
/* Determine how much data we have left to read. For this gzip
transform plugin this is also the amount of data we have left
to write to the output connection. */
towrite = TSVIONTodoGet(write_vio);
if (towrite > 0) {
/* The amount of data left to read needs to be truncated by
the amount of data actually in the read buffer. */
avail = TSIOBufferReaderAvail(TSVIOReaderGet(write_vio));
if (towrite > avail) {
towrite = avail;
}
if (towrite > 0) {
gzip_transform_one(data, TSVIOReaderGet(write_vio), towrite);
/* Modify the write vio to reflect how much data we've
completed. */
TSVIONDoneSet(write_vio, TSVIONDoneGet(write_vio) + towrite);
}
}
/* Now we check the write vio to see if there is data left to
read. */
if (TSVIONTodoGet(write_vio) > 0) {
if (towrite > 0) {
/* If we output some data then we reenable the output
connection by reenabling the output vio. This will wakeup
the output connection and allow it to consume data from the
output buffer. */
if (data->output_length > length) {
TSVIOReenable(data->output_vio);
}
/* Call back the write vio continuation to let it know that we
are ready for more data. */
TSContCall(TSVIOContGet(write_vio), TS_EVENT_VCONN_WRITE_READY,
write_vio);
}
} else {
/* If there is no data left to read, then we modify the output
vio to reflect how much data the output connection should
expect. This allows the output connection to know when it
is done reading. We then reenable the output connection so
that it can consume the data we just gave it. */
gzip_transform_finish(data);
TSVIONBytesSet(data->output_vio, data->output_length);
TSDebug("gzip-transform", "Compressed size %d (bytes)",
data->output_length);
if (data->output_length > length) {
TSVIOReenable(data->output_vio);
}
/* Call back the write vio continuation to let it know that we
have completed the write operation. */
TSContCall(TSVIOContGet(write_vio), TS_EVENT_VCONN_WRITE_COMPLETE,
write_vio);
}
}
static int
gzip_transform(TSCont contp, TSEvent event, void *edata)
{
/* Check to see if the transformation has been closed by a call to
TSVConnClose. */
if (TSVConnClosedGet(contp)) {
gzip_data_destroy(TSContDataGet(contp));
TSContDestroy(contp);
return 0;
} else {
switch (event) {
case TS_EVENT_ERROR:
{
TSVIO write_vio;
/* Get the write vio for the write operation that was
performed on ourself. This vio contains the continuation of
our parent transformation. */
write_vio = TSVConnWriteVIOGet(contp);
/* Call back the write vio continuation to let it know that we
have completed the write operation. */
TSContCall(TSVIOContGet(write_vio), TS_EVENT_ERROR, write_vio);
}
break;
case TS_EVENT_VCONN_WRITE_COMPLETE:
/* When our output connection says that it has finished
reading all the data we've written to it then we should
shutdown the write portion of its connection to
indicate that we don't want to hear about it anymore. */
TSVConnShutdown(TSTransformOutputVConnGet(contp), 0, 1);
break;
case TS_EVENT_VCONN_WRITE_READY:
default:
/* If we get a WRITE_READY event or any other type of
event (sent, perhaps, because we were reenabled) then
we'll attempt to transform more data. */
gzip_transform_do(contp);
break;
}
}
return 0;
}
static int gzip_transformable(TSHttpTxn txnp, int server)
{
/* Server response header */
TSMBuffer bufp;
TSMLoc hdr_loc;
TSMLoc field_loc;
/* Client request header */
TSMBuffer cbuf;
TSMLoc chdr;
TSMLoc cfield;
const char *value;
int nvalues;
int i, deflate_flag;
TSDebug("gzip-transform", "@ chk transformable 1");
TSHttpTxnClientReqGet(txnp, &cbuf, &chdr);
/* check if client accepts "deflate" */
TSDebug("gzip-transform", "@ chk transformable 2");
cfield = TSMimeHdrFieldFind(cbuf, chdr, TS_MIME_FIELD_ACCEPT_ENCODING,
-1);
TSDebug("gzip-transform", "@ chk transformable 3");
if (TS_NULL_MLOC != cfield) {
nvalues = TSMimeHdrFieldValuesCount(cbuf, chdr, cfield);
TSDebug("gzip-transform", "@ chk transformable 4:
nvalues:%d,chdr:%d,cfield:%d",nvalues,chdr,cfield);
int len;
value = TSMimeHdrFieldValueStringGet(cbuf, chdr, cfield, 0, &len);
TSDebug("gzip-transform", "@ chk transformable 5:%d",len);
TSDebug("gzip-transform", "@ test->%s",value);
deflate_flag = 0;
i = 0;
while (nvalues > 0) {
if (value && (strncasecmp(value, "deflate", sizeof("deflate") - 1) ==
0)) {
deflate_flag = 1;
break;
}
i++;
TSDebug("gzip-transform", "@ chk transformable 6.1");
value = TSMimeHdrFieldValueStringGet(cbuf, chdr, cfield, i, &len);
TSDebug("gzip-transform", "@ chk transformable 6.2");
nvalues--;
}
TSDebug("gzip-transform", "@ chk transformable 7");
if (!deflate_flag) {
return -7;
}
TSDebug("gzip-transform", "@ chk transformable 8");
TSHandleMLocRelease(cbuf, chdr, cfield);
TSHandleMLocRelease(cbuf, TS_NULL_MLOC, chdr);
} else {
TSDebug("gzip-transform", "@ chk transformable 345");
TSHandleMLocRelease(cbuf, chdr, cfield);
TSHandleMLocRelease(cbuf, TS_NULL_MLOC, chdr);
return -6;
}
TSDebug("gzip-transform", "@ chk transformable 10");
if (server) {
TSHttpTxnServerRespGet(txnp, &bufp, &hdr_loc);
} else {
TSHttpTxnCachedRespGet(txnp, &bufp, &hdr_loc);
}
TSDebug("gzip-transform", "@ chk transformable 11");
/* If there already exists a content encoding then we don't want
to do anything. */
field_loc = TSMimeHdrFieldFind(bufp, hdr_loc,
TS_MIME_FIELD_CONTENT_ENCODING, -1);
if (field_loc) {
TSHandleMLocRelease(bufp, hdr_loc, field_loc);
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
return -3;
}
TSDebug("gzip-transform", "@ chk transformable 12");
TSHandleMLocRelease(bufp, hdr_loc, field_loc);
TSDebug("gzip-transform", "@ chk transformable 13");
/* We only want to do gzip compression on documents that have a
content type of "text/" or "application/x-javascript". */
field_loc = TSMimeHdrFieldFind(bufp, hdr_loc, TS_MIME_FIELD_CONTENT_TYPE,
-1);
if (!field_loc) {
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
return -4;
}
TSDebug("gzip-transform", "@ chk transformable 14");
int len;
value = TSMimeHdrFieldValueStringGet(bufp, hdr_loc, field_loc, 0, &len);
if (value && (strncasecmp(value, "text/", sizeof("text/") - 1) == 0)) {
TSHandleMLocRelease(bufp, hdr_loc, field_loc);
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
TSDebug("gzip-transform", "@ transformable, it is text/*");
return 0;
} else if (value && (strncasecmp(value, "application/x-javascript",
(sizeof("application/x-javascript") - 1)) == 0)) {
TSHandleMLocRelease(bufp, hdr_loc, field_loc);
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
TSDebug("gzip-transform", "@ transformable, it is
application/x-javascript");
return 0;
} else {
TSDebug("gzip-transform", "@ not a transformable content type");
TSHandleMLocRelease(bufp, hdr_loc, field_loc);
TSHandleMLocRelease(bufp, TS_NULL_MLOC, hdr_loc);
return -5;
}
}
static void gzip_transform_add(TSHttpTxn txnp, int server)
{
TSVConn connp;
GzipData *data;
TSDebug("gzip-transform", "@ zip_transform_add()");
connp = TSTransformCreate(gzip_transform, txnp);
data = gzip_data_alloc();
data->txn = txnp;
TSContDataSet(connp, data);
TSHttpTxnHookAdd(txnp, TS_HTTP_RESPONSE_TRANSFORM_HOOK, connp);
}
static int
transform_plugin(TSCont contp, TSEvent event, void *edata)
{
TSHttpTxn txnp = (TSHttpTxn) edata;
int reason;
TSDebug("gzip-transform", "@ transform_plugin()");
switch (event) {
case TS_EVENT_HTTP_READ_RESPONSE_HDR:
reason = gzip_transformable(txnp, 1);
if (reason >= 0) {
TSDebug("gzip-transform", "server content transformable");
gzip_transform_add(txnp, 1);
} else {
TSDebug("gzip-transform", "server content NOT transformable [%d]",
reason);
}
TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
break;
case TS_EVENT_HTTP_READ_CACHE_HDR:
reason = gzip_transformable(txnp, 0);
if (reason >= 0) {
TSDebug("gzip-transform", "cached content transformable");
gzip_transform_add(txnp, 1);
} else {
TSDebug("gzip-transform", "cached data: forwarding unchanged (%d)",
reason);
}
TSHttpTxnReenable(txnp, TS_EVENT_HTTP_CONTINUE);
break;
default:
exit(1);
}
return 0;
}
void
TSPluginInit(int argc, const char *argv[])
{
dictId = adler32(0L, Z_NULL, 0);
if (argc == 2) {
strcpy(preload_file, argv[1]);
preload = 1;
load_dictionary(dictionary, &dictId);
}
TSDebug("gzip-transform", "gzip plugin loads");
TSHttpHookAdd(TS_HTTP_READ_RESPONSE_HDR_HOOK,
TSContCreate(transform_plugin, NULL));
TSHttpHookAdd(TS_HTTP_READ_CACHE_HDR_HOOK, TSContCreate(transform_plugin,
NULL));
}
