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(void)
  23         {
  24         return(&rle_method);
  25         }
  26
  27 static int rle_compress_block(COMP_CTX *ctx, unsigned char *out,
  28              unsigned int olen, unsigned char *in, unsigned int ilen)
  29         {
  30         /* int i; */
  31
  32         if (olen < (ilen+1))
  33                 {
  34                 /* ZZZZZZZZZZZZZZZZZZZZZZ */
  35                 return(-1);
  36                 }
  37
  38         *(out++)=0;
  39         memcpy(out,in,ilen);
  40         return(ilen+1);
  41         }
  42
  43 static int rle_expand_block(COMP_CTX *ctx, unsigned char *out,
  44              unsigned int olen, unsigned char *in, unsigned int ilen)
  45         {
  46         int i;
  47
  48         if (olen < (ilen-1))
  49                 {
  50                 /* ZZZZZZZZZZZZZZZZZZZZZZ */
  51                 return(-1);
  52                 }
  53
  54         i= *(in++);
  55         if (i == 0)
  56                 {
  57                 memcpy(out,in,ilen-1);
  58                 }
  59         return(ilen-1);
  60         }
  61