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/* libimap library.
* Copyright (C) 2003-2010 Pawel Salek.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
* 02111-1307, USA.
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <zlib.h>
#include "siobuf.h"
#include "imap-handle.h"
#include "imap_private.h"
/** Arbitrary. Current choice is as good as any other. */
static const unsigned IMAP_COMPRESS_BUFFER_SIZE = 8192;
static int
imap_compress_cb(char **dstbuf, int *dstlen,
const char *srcbuf, int srclen, void *arg)
{
struct ImapCompressContext *icb = &((ImapMboxHandle*)arg)->compress;
int err;
*dstbuf = icb->out_buffer;
if (*dstlen == 0) { /* first call */
icb->out_stream.next_in = (Bytef*)srcbuf;
icb->out_stream.avail_in = srclen;
icb->out_uncompressed += srclen;
}
icb->out_stream.next_out = (Byte*)*dstbuf;
icb->out_stream.avail_out = IMAP_COMPRESS_BUFFER_SIZE;
err = deflate(&icb->out_stream, srclen ? Z_NO_FLUSH : Z_SYNC_FLUSH);
if ( !(err == Z_OK || err == Z_STREAM_END || err == Z_BUF_ERROR) ) {
fprintf(stderr, "deflate error1 %d\n", err);
*dstlen = -1;
} else {
*dstlen = IMAP_COMPRESS_BUFFER_SIZE - icb->out_stream.avail_out;
/* printf("imap_compress_cb %d bytes to %d\n", srclen, *dstlen); */
icb->out_compressed += *dstlen;
}
return *dstlen;
}
static int
imap_decompress_cb(char **dstbuf, int *dstlen,
const char *srcbuf, int srclen, void *arg)
{
struct ImapCompressContext *icb = &((ImapMboxHandle*)arg)->compress;
int err;
*dstbuf = icb->in_buffer;
if (srclen) {
icb->in_stream.next_in = (Bytef*)srcbuf;
icb->in_stream.avail_in = srclen;
icb->in_compressed += srclen;
}
icb->in_stream.next_out = (Byte*)*dstbuf;
icb->in_stream.avail_out = IMAP_COMPRESS_BUFFER_SIZE;
err = inflate(&icb->in_stream, Z_SYNC_FLUSH);
if (!(err == Z_OK || err == Z_BUF_ERROR || err == Z_STREAM_END)) {
fprintf(stderr, "inflate error %d\n", err);
*dstlen = -1;
} else {
*dstlen = IMAP_COMPRESS_BUFFER_SIZE - icb->in_stream.avail_out;
/* printf("imap_decompress_cb %d bytes to %d\n", srclen, *dstlen); */
icb->in_uncompressed += *dstlen;
}
return *dstlen;
}
/** Enables COMPRESS extension if available. Assumes that the handle
is already locked. */
ImapResponse
imap_compress(ImapMboxHandle *handle)
{
struct ImapCompressContext *icb;
int err;
if (!handle->enable_compress ||
!imap_mbox_handle_can_do(handle, IMCAP_COMPRESS_DEFLATE))
return IMR_NO;
if (imap_cmd_exec(handle, "COMPRESS DEFLATE") != IMR_OK)
return IMR_NO;
icb = &handle->compress;
icb->in_buffer = malloc(IMAP_COMPRESS_BUFFER_SIZE);
icb->out_buffer = malloc(IMAP_COMPRESS_BUFFER_SIZE);
if (!icb->in_buffer || !icb->out_buffer)
return IMR_NO;
/* Compression enabled. Everything that we send and receive now must
go through compression/decompression routines enabled in sio. */
icb->out_stream.zalloc = Z_NULL;
icb->out_stream.zfree = Z_NULL;
icb->out_stream.opaque = (voidpf)0;
/* amazingly enough, deflateInit() won't do */
err = deflateInit2(&icb->out_stream, Z_DEFAULT_COMPRESSION, Z_DEFLATED,
-15, 8, Z_DEFAULT_STRATEGY);
if (err != Z_OK) {
fprintf(stderr, "deflateInit error: %d\n", err);
return IMR_NO;
}
icb->in_stream.next_in = Z_NULL;
icb->in_stream.avail_in = 0;
icb->in_stream.zalloc = Z_NULL;
icb->in_stream.zfree = Z_NULL;
icb->in_stream.opaque = (voidpf)0;
/* amazingly enough, inflateInit() won't do */
err = inflateInit2(&icb->in_stream, -15);
if (err != Z_OK) {
fprintf(stderr, "inflateInit error: %d\n", err);
return IMR_NO;
}
if (handle->sio) {
sio_set_securitycb(handle->sio, imap_compress_cb, imap_decompress_cb,
handle);
return IMR_OK;
} else {
fprintf(stderr, "SIO not set!\n");
return IMR_NO;
}
}
void
imap_compress_init(struct ImapCompressContext *buf)
{
memset(buf, 0, sizeof(buf));
}
/** releases any data that might have been allocated by compression routines. */
void
imap_compress_release(struct ImapCompressContext *buf)
{
if (buf->in_buffer) {
inflateEnd(&buf->in_stream);
free(buf->in_buffer);
}
if (buf->out_buffer) {
deflateEnd(&buf->out_stream);
free(buf->out_buffer);
}
if (buf->in_uncompressed) {
printf("IMAP server compression %lu -> %lu sent %5.1f %% over wire\n",
buf->in_compressed, buf->in_uncompressed,
100.0*(buf->in_compressed/(float)buf->in_uncompressed));
}
if (buf->in_uncompressed) {
printf("IMAP client compression %lu -> %lu sent %5.1f %% over wire\n",
buf->out_uncompressed, buf->out_compressed,
100.0*(buf->out_compressed/(float)buf->out_uncompressed));
}
}
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