88 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			88 lines
		
	
	
		
			2.0 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* inflate_util.c -- data and routines common to blocks and codes
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|  * Copyright (C) 1995-2002 Mark Adler
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|  * For conditions of distribution and use, see copyright notice in zlib.h 
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|  */
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| 
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| #include "zutil.h"
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| #include "infblock.h"
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| #include "inftrees.h"
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| #include "infcodes.h"
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| #include "infutil.h"
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| 
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| struct inflate_codes_state {int dummy;}; /* for buggy compilers */
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| 
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| /* And'ing with mask[n] masks the lower n bits */
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| uInt inflate_mask[17] = {
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|     0x0000,
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|     0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
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|     0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
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| };
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| 
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| 
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| /* copy as much as possible from the sliding window to the output area */
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| int inflate_flush(s, z, r)
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| inflate_blocks_statef *s;
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| z_streamp z;
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| int r;
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| {
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|   uInt n;
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|   Bytef *p;
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|   Bytef *q;
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| 
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|   /* local copies of source and destination pointers */
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|   p = z->next_out;
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|   q = s->read;
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| 
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|   /* compute number of bytes to copy as far as end of window */
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|   n = (uInt)((q <= s->write ? s->write : s->end) - q);
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|   if (n > z->avail_out) n = z->avail_out;
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|   if (n && r == Z_BUF_ERROR) r = Z_OK;
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| 
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|   /* update counters */
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|   z->avail_out -= n;
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|   z->total_out += n;
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| 
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|   /* update check information */
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|   if (s->checkfn != Z_NULL)
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|     z->adler = s->check = (*s->checkfn)(s->check, q, n);
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| 
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|   /* copy as far as end of window */
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|   zmemcpy(p, q, n);
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|   p += n;
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|   q += n;
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| 
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|   /* see if more to copy at beginning of window */
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|   if (q == s->end)
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|   {
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|     /* wrap pointers */
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|     q = s->window;
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|     if (s->write == s->end)
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|       s->write = s->window;
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| 
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|     /* compute bytes to copy */
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|     n = (uInt)(s->write - q);
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|     if (n > z->avail_out) n = z->avail_out;
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|     if (n && r == Z_BUF_ERROR) r = Z_OK;
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| 
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|     /* update counters */
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|     z->avail_out -= n;
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|     z->total_out += n;
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| 
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|     /* update check information */
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|     if (s->checkfn != Z_NULL)
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|       z->adler = s->check = (*s->checkfn)(s->check, q, n);
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| 
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|     /* copy */
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|     zmemcpy(p, q, n);
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|     p += n;
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|     q += n;
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|   }
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| 
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|   /* update pointers */
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|   z->next_out = p;
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|   s->read = q;
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| 
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|   /* done */
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|   return r;
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| }
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