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Make ssh_compress into a pair of linked classoids.

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This was mildly fiddly because there's a single vtable structure that
implements two distinct interface types, one for compression and one
for decompression - and I have actually confused them before now
(commit d4304f1b7), so I think it's important to make them actually be
separate types!
This commit is contained in:
Simon Tatham
2018-09-14 09:16:41 +01:00
parent 03fb4423af
commit d437e5402e
6 changed files with 130 additions and 99 deletions
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65
sshzlib.c
View File

@ -66,6 +66,10 @@
#define TRUE 1
#endif
typedef struct { const struct dummy *vt; } ssh_compressor;
typedef struct { const struct dummy *vt; } ssh_decompressor;
static const struct dummy { int i; } ssh_zlib;
#else
#include "ssh.h"
#endif
@ -600,37 +604,45 @@ static void zlib_match(struct LZ77Context *ectx, int distance, int len)
}
}
void *zlib_compress_init(void)
struct ssh_zlib_compressor {
struct LZ77Context ectx;
ssh_compressor sc;
};
ssh_compressor *zlib_compress_init(void)
{
struct Outbuf *out;
struct LZ77Context *ectx = snew(struct LZ77Context);
struct ssh_zlib_compressor *comp = snew(struct ssh_zlib_compressor);
lz77_init(ectx);
ectx->literal = zlib_literal;
ectx->match = zlib_match;
lz77_init(&comp->ectx);
comp->sc.vt = &ssh_zlib;
comp->ectx.literal = zlib_literal;
comp->ectx.match = zlib_match;
out = snew(struct Outbuf);
out->outbits = out->noutbits = 0;
out->firstblock = 1;
ectx->userdata = out;
comp->ectx.userdata = out;
return ectx;
return &comp->sc;
}
void zlib_compress_cleanup(void *handle)
void zlib_compress_cleanup(ssh_compressor *sc)
{
struct LZ77Context *ectx = (struct LZ77Context *)handle;
sfree(ectx->userdata);
sfree(ectx->ictx);
sfree(ectx);
struct ssh_zlib_compressor *comp =
FROMFIELD(sc, struct ssh_zlib_compressor, sc);
sfree(comp->ectx.userdata);
sfree(comp->ectx.ictx);
sfree(comp);
}
void zlib_compress_block(void *handle, unsigned char *block, int len,
void zlib_compress_block(ssh_compressor *sc, unsigned char *block, int len,
unsigned char **outblock, int *outlen,
int minlen)
{
struct LZ77Context *ectx = (struct LZ77Context *)handle;
struct Outbuf *out = (struct Outbuf *) ectx->userdata;
struct ssh_zlib_compressor *comp =
FROMFIELD(sc, struct ssh_zlib_compressor, sc);
struct Outbuf *out = (struct Outbuf *) comp->ectx.userdata;
int in_block;
out->outbuf = NULL;
@ -662,7 +674,7 @@ void zlib_compress_block(void *handle, unsigned char *block, int len,
/*
* Do the compression.
*/
lz77_compress(ectx, block, len, TRUE);
lz77_compress(&comp->ectx, block, len, TRUE);
/*
* End the block (by transmitting code 256, which is
@ -875,9 +887,11 @@ struct zlib_decompress_ctx {
int winpos;
unsigned char *outblk;
int outlen, outsize;
ssh_decompressor dc;
};
void *zlib_decompress_init(void)
ssh_decompressor *zlib_decompress_init(void)
{
struct zlib_decompress_ctx *dctx = snew(struct zlib_decompress_ctx);
unsigned char lengths[288];
@ -895,12 +909,14 @@ void *zlib_decompress_init(void)
dctx->nbits = 0;
dctx->winpos = 0;
return dctx;
dctx->dc.vt = &ssh_zlib;
return &dctx->dc;
}
void zlib_decompress_cleanup(void *handle)
void zlib_decompress_cleanup(ssh_decompressor *dc)
{
struct zlib_decompress_ctx *dctx = (struct zlib_decompress_ctx *)handle;
struct zlib_decompress_ctx *dctx =
FROMFIELD(dc, struct zlib_decompress_ctx, dc);
if (dctx->currlentable && dctx->currlentable != dctx->staticlentable)
zlib_freetable(&dctx->currlentable);
@ -958,10 +974,11 @@ static void zlib_emit_char(struct zlib_decompress_ctx *dctx, int c)
#define EATBITS(n) ( dctx->nbits -= (n), dctx->bits >>= (n) )
int zlib_decompress_block(void *handle, unsigned char *block, int len,
int zlib_decompress_block(ssh_decompressor *dc, unsigned char *block, int len,
unsigned char **outblock, int *outlen)
{
struct zlib_decompress_ctx *dctx = (struct zlib_decompress_ctx *)handle;
struct zlib_decompress_ctx *dctx =
FROMFIELD(dc, struct zlib_decompress_ctx, dc);
const coderecord *rec;
int code, blktype, rep, dist, nlen, header;
static const unsigned char lenlenmap[] = {
@ -1217,7 +1234,7 @@ int main(int argc, char **argv)
{
unsigned char buf[16], *outbuf;
int ret, outlen;
void *handle;
ssh_decompressor *handle;
int noheader = FALSE, opts = TRUE;
char *filename = NULL;
FILE *fp;
@ -1289,7 +1306,7 @@ int main(int argc, char **argv)
#else
const struct ssh_compress ssh_zlib = {
const struct ssh_compression_alg ssh_zlib = {
"zlib",
"zlib@openssh.com", /* delayed version */
zlib_compress_init,