forked from etc/pineapple-src
56 lines
1.1 KiB
C
56 lines
1.1 KiB
C
|
/* $OpenBSD: c_rle.c,v 1.8 2014/11/03 16:58:28 tedu Exp $ */
|
||
|
|
#include <stdio.h>
|
||
|
|
#include <stdlib.h>
|
||
|
|
#include <string.h>
|
||
|
|
#include <openssl/objects.h>
|
||
|
|
#include <openssl/comp.h>
|
||
|
|
|
||
|
|
static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
|
||
|
|
unsigned int olen, unsigned char *in, unsigned int ilen);
|
||
|
|
static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
|
||
|
|
unsigned int olen, unsigned char *in, unsigned int ilen);
|
||
|
|
|
||
|
|
static COMP_METHOD rle_method = {
|
||
|
|
.type = NID_rle_compression,
|
||
|
|
.name = LN_rle_compression,
|
||
|
|
.compress = rle_compress_block,
|
||
|
|
.expand = rle_expand_block
|
||
|
|
};
|
||
|
|
|
||
|
|
COMP_METHOD *
|
||
|
|
COMP_rle(void)
|
||
|
|
{
|
||
|
|
return (&rle_method);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int
|
||
|
|
rle_compress_block(COMP_CTX *ctx, unsigned char *out, unsigned int olen,
|
||
|
|
unsigned char *in, unsigned int ilen)
|
||
|
|
{
|
||
|
|
|
||
|
|
if (ilen == 0 || olen < (ilen - 1)) {
|
||
|
|
return (-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
*(out++) = 0;
|
||
|
|
memcpy(out, in, ilen);
|
||
|
|
return (ilen + 1);
|
||
|
|
}
|
||
|
|
|
||
|
|
static int
|
||
|
|
rle_expand_block(COMP_CTX *ctx, unsigned char *out, unsigned int olen,
|
||
|
|
unsigned char *in, unsigned int ilen)
|
||
|
|
{
|
||
|
|
int i;
|
||
|
|
|
||
|
|
if (olen < (ilen - 1)) {
|
||
|
|
return (-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
i= *(in++);
|
||
|
|
if (i == 0) {
|
||
|
|
memcpy(out, in, ilen - 1);
|
||
|
|
}
|
||
|
|
return (ilen - 1);
|
||
|
|
}
|