Mirrors/libwebsockets
1
0
Fork 0
mirror of https://github.com/warmcat/libwebsockets.git synced 2025-03-16 00:00:07 +01:00
Code Issues Releases Wiki Activity
libwebsockets/lib/extension-deflate-frame.c
Andy Green 623a98dab0 unionize mutually exclusive wsi members 
Large chunks of struct libwebsocket members actually have a mutually
exclusive lifecycle, eg, once the http headers are finished they sit
there unused until the instance is destroyed.

This makes a big improvement in memory efficiency by making four
categories of member: always needed, needed for header processing,
needed for http processing, and needed for ws processing.  The last
three are mutually exclusive and bound into a union inside the wsi.

Care needs taking now at "union transitions", although we zeroed down
the struct at init, the other union siblings have been writing the
same memory by the time later member siblings start to use it.  So
it must be cleared down appropriately when we cross from one
mutually-exclusive use to another.

Signed-off-by: Andy Green <andy.green@linaro.org>
2013-01-21 11:06:34 +08:00

296 lines
7.9 KiB
C
Raw Blame History

#include "private-libwebsockets.h"
#include "extension-deflate-frame.h"
#include <stdio.h>
#include <string.h>
#include <assert.h>
#define LWS_ZLIB_WINDOW_BITS 15
#define LWS_ZLIB_MEMLEVEL 8
#define MIN_SIZE_TO_DEFLATE 4
int lws_extension_callback_deflate_frame(
struct libwebsocket_context *context,
struct libwebsocket_extension *ext,
struct libwebsocket *wsi,
enum libwebsocket_extension_callback_reasons reason,
void *user, void *in, size_t len)
{
struct lws_ext_deflate_frame_conn *conn =
(struct lws_ext_deflate_frame_conn *)user;
struct lws_tokens *eff_buf = (struct lws_tokens *)in;
size_t current_payload, remaining_payload, total_payload;
int n;
size_t len_so_far;
switch (reason) {
/*
* for deflate-frame, both client and server sides act the same
*/
case LWS_EXT_CALLBACK_CLIENT_CONSTRUCT:
case LWS_EXT_CALLBACK_CONSTRUCT:
conn->zs_in.zalloc = conn->zs_out.zalloc = Z_NULL;
conn->zs_in.zfree = conn->zs_out.zfree = Z_NULL;
conn->zs_in.opaque = conn->zs_out.opaque = Z_NULL;
n = inflateInit2(&conn->zs_in, -LWS_ZLIB_WINDOW_BITS);
if (n != Z_OK) {
lwsl_ext("deflateInit returned %d\n", n);
return 1;
}
n = deflateInit2(&conn->zs_out,
(context->listen_port ?
DEFLATE_FRAME_COMPRESSION_LEVEL_SERVER :
DEFLATE_FRAME_COMPRESSION_LEVEL_CLIENT),
Z_DEFLATED,
-LWS_ZLIB_WINDOW_BITS, LWS_ZLIB_MEMLEVEL,
Z_DEFAULT_STRATEGY);
if (n != Z_OK) {
lwsl_ext("deflateInit2 returned %d\n", n);
return 1;
}
conn->buf_pre_used = 0;
conn->buf_pre_length = 0;
conn->buf_in_length = MAX_USER_RX_BUFFER;
conn->buf_out_length = MAX_USER_RX_BUFFER;
conn->compressed_out = 0;
conn->buf_pre = NULL;
conn->buf_in = (unsigned char *)
malloc(LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_in_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_in)
goto bail;
conn->buf_out = (unsigned char *)
malloc(LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_out_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_out)
goto bail;
lwsl_ext("zlibs constructed\n");
break;
bail:
lwsl_err("Out of mem\n");
(void)inflateEnd(&conn->zs_in);
(void)deflateEnd(&conn->zs_out);
return -1;
case LWS_EXT_CALLBACK_DESTROY:
if (conn->buf_pre)
free(conn->buf_pre);
free(conn->buf_in);
free(conn->buf_out);
conn->buf_pre_used = 0;
conn->buf_pre_length = 0;
conn->buf_in_length = 0;
conn->buf_out_length = 0;
conn->compressed_out = 0;
(void)inflateEnd(&conn->zs_in);
(void)deflateEnd(&conn->zs_out);
lwsl_ext("zlibs destructed\n");
break;
case LWS_EXT_CALLBACK_PAYLOAD_RX:
if (!(wsi->u.ws.rsv & 0x40))
return 0;
/*
* inflate the incoming payload
*/
current_payload = eff_buf->token_len;
remaining_payload = wsi->u.ws.rx_packet_length;
if (remaining_payload) {
total_payload = conn->buf_pre_used +
current_payload +
remaining_payload;
if (conn->buf_pre_length < total_payload) {
conn->buf_pre_length = total_payload;
if (conn->buf_pre)
free(conn->buf_pre);
conn->buf_pre =
(unsigned char *)malloc(total_payload + 4);
if (!conn->buf_pre) {
lwsl_err("Out of memory\n");
return -1;
}
}
memcpy(conn->buf_pre + conn->buf_pre_used,
eff_buf->token, current_payload);
conn->buf_pre_used += current_payload;
eff_buf->token = NULL;
eff_buf->token_len = 0;
return 0;
}
if (conn->buf_pre_used) {
total_payload = conn->buf_pre_used +
current_payload;
memcpy(conn->buf_pre + conn->buf_pre_used,
eff_buf->token, current_payload);
conn->buf_pre_used = 0;
conn->zs_in.next_in = conn->buf_pre;
} else {
total_payload = current_payload;
conn->zs_in.next_in = (unsigned char *)eff_buf->token;
}
conn->zs_in.next_in[total_payload + 0] = 0;
conn->zs_in.next_in[total_payload + 1] = 0;
conn->zs_in.next_in[total_payload + 2] = 0xff;
conn->zs_in.next_in[total_payload + 3] = 0xff;
conn->zs_in.avail_in = total_payload + 4;
conn->zs_in.next_out = conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING;
conn->zs_in.avail_out = conn->buf_in_length;
while (1) {
n = inflate(&conn->zs_in, Z_SYNC_FLUSH);
switch (n) {
case Z_NEED_DICT:
case Z_STREAM_ERROR:
case Z_DATA_ERROR:
case Z_MEM_ERROR:
/*
* screwed.. close the connection... we will get a
* destroy callback to take care of closing nicely
*/
lwsl_err("zlib error inflate %d: %s\n",
n, conn->zs_in.msg);
return -1;
}
if (conn->zs_in.avail_out)
break;
len_so_far = conn->zs_in.next_out -
(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING);
conn->buf_in_length *= 2;
if (conn->buf_in_length > LWS_MAX_ZLIB_CONN_BUFFER) {
lwsl_ext("zlib in buffer tried to exceed "
"max allowed of %u\n",
LWS_MAX_ZLIB_CONN_BUFFER);
return -1;
}
conn->buf_in = (unsigned char *)realloc(conn->buf_in,
LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_in_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_in) {
lwsl_err("Out of memory\n");
return -1;
}
lwsl_debug(
"deflate-frame ext RX did realloc to %ld\n",
conn->buf_in_length);
conn->zs_in.next_out = conn->buf_in +
LWS_SEND_BUFFER_PRE_PADDING + len_so_far;
conn->zs_in.avail_out =
conn->buf_in_length - len_so_far;
}
/* rewrite the buffer pointers and length */
eff_buf->token = (char *)(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING);
eff_buf->token_len = (int)(conn->zs_in.next_out -
(conn->buf_in + LWS_SEND_BUFFER_PRE_PADDING));
return 0;
case LWS_EXT_CALLBACK_PAYLOAD_TX:
/*
* deflate the outgoing payload
*/
current_payload = eff_buf->token_len;
if (current_payload < MIN_SIZE_TO_DEFLATE)
return 0;
conn->zs_out.next_in = (unsigned char *)eff_buf->token;
conn->zs_out.avail_in = current_payload;
conn->zs_out.next_out = conn->buf_out + LWS_SEND_BUFFER_PRE_PADDING;
conn->zs_out.avail_out = conn->buf_out_length;
while (1) {
n = deflate(&conn->zs_out, Z_SYNC_FLUSH);
if (n == Z_STREAM_ERROR) {
/*
* screwed.. close the connection... we will get a
* destroy callback to take care of closing nicely
*/
lwsl_ext("zlib error deflate\n");
return -1;
}
if (conn->zs_out.avail_out)
break;
len_so_far = (conn->zs_out.next_out -
(conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING));
conn->buf_out_length *= 2;
if (conn->buf_out_length > LWS_MAX_ZLIB_CONN_BUFFER) {
lwsl_ext("zlib out buffer tried to exceed "
"max allowed of %u\n",
LWS_MAX_ZLIB_CONN_BUFFER);
return -1;
}
conn->buf_out = (unsigned char *)realloc(
conn->buf_out,
LWS_SEND_BUFFER_PRE_PADDING +
conn->buf_out_length +
LWS_SEND_BUFFER_POST_PADDING);
if (!conn->buf_out) {
lwsl_err("Out of memory\n");
return -1;
}
lwsl_debug(
"deflate-frame ext TX did realloc to %ld\n",
conn->buf_in_length);
conn->zs_out.next_out = (conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING + len_so_far);
conn->zs_out.avail_out =
(conn->buf_out_length - len_so_far);
}
conn->compressed_out = 1;
/* rewrite the buffer pointers and length */
eff_buf->token = (char *)(conn->buf_out +
LWS_SEND_BUFFER_PRE_PADDING);
eff_buf->token_len = (int)(conn->zs_out.next_out -
(conn->buf_out + LWS_SEND_BUFFER_PRE_PADDING)) - 4;
return 0;
case LWS_EXT_CALLBACK_PACKET_TX_PRESEND:
if (conn->compressed_out) {
conn->compressed_out = 0;
*((unsigned char *)eff_buf->token) |= 0x40;
}
break;
case LWS_EXT_CALLBACK_CHECK_OK_TO_PROPOSE_EXTENSION:
/* Avoid x-webkit-deflate-frame extension on client */
if (!strcmp((char *)in, "x-webkit-deflate-frame"))
return 1;
break;
default:
break;
}
return 0;
}
Reference in a new issue View git blame Copy permalink