crypto/comp/c_rle.c

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <string.h>
   4 #include "objects.h"
   5 #include "comp.h"
   6
   7 static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
   8         unsigned int olen, unsigned char *in, unsigned int ilen);
   9 static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
  10         unsigned int olen, unsigned char *in, unsigned int ilen);
  11
  12 static COMP_METHOD rle_method={
  13         NID_rle_compression,
  14         LN_rle_compression,
  15         NULL,
  16         NULL,
  17         rle_compress_block,
  18         rle_expand_block,
  19         NULL,
  20         };
  21
  22 COMP_METHOD *COMP_rle()
  23         {
  24         return(&rle_method);
  25         }
  26
  27 static int rle_compress_block(ctx,out,olen,in,ilen)
  28 COMP_CTX *ctx;
  29 unsigned char *out;
  30 unsigned int olen;
  31 unsigned char *in;
  32 unsigned int ilen;
  33         {
  34         /* int i; */
  35
  36         if (olen < (ilen+1))
  37                 {
  38                 /* ZZZZZZZZZZZZZZZZZZZZZZ */
  39                 return(-1);
  40                 }
  41
  42         *(out++)=0;
  43         memcpy(out,in,ilen);
  44         return(ilen+1);
  45         }
  46
  47 static int rle_expand_block(ctx,out,olen,in,ilen)
  48 COMP_CTX *ctx;
  49 unsigned char *out;
  50 unsigned int olen;
  51 unsigned char *in;
  52 unsigned int ilen;
  53         {
  54         int i;
  55
  56         if (olen < (ilen-1))
  57                 {
  58                 /* ZZZZZZZZZZZZZZZZZZZZZZ */
  59                 return(-1);
  60                 }
  61
  62         i= *(in++);
  63         if (i == 0)
  64                 {
  65                 memcpy(out,in,ilen-1);
  66                 }
  67         return(ilen-1);
  68         }
  69