/* 31/01/01 Libtiny compression/decompression library v1.0 source file
		Decompression routine using zlib inflate
		Inflate code:	inflate 1.1.3 Copyright 1995-1998 Mark Adler */

/* includes */
#include	<libps.h>
#include	"stdio.h"

#include	"zlib.h"
#include	"zconf.h"

#include	"tiny.h"


/* Decompress zlib compressed data,
		*source_p - pointer to data to decompress,
		destination_p - pointer to buffer to store decompressed data
	 Return values
	 	>0							 decompressed data size in bytes,
	 	-1(T_ID_ERROR)	 bad header id value, should be ID_ZLIB,
	 	-2(T_MEM_ERROR)	 out of memory, workspace couldn't be allocated,
	 	-3(T_BUF_ERROR)  destination buffer too small, should never be returned unless header
	 									 has become corrupted,
	 	-4(T_DATA_ERROR) header or compressed data has been corrupted */
int	z_uncompress(u_char	*source_p, u_char *destination_p)
{
	S_HDR	header;
	S_HDR	*header_p = (S_HDR *) source_p;
	u_int	sourcelen,destlen;
	int	status = T_ID_ERROR;
	
	header = *header_p;							/* get header info */
	
	if(header.id == ID_ZLIB)
	{
		sourcelen = header.comp_size;
		destlen = header.orig_size;	/*destination buffer size is the same as the original data length */
		
		source_p += sizeof(S_HDR);		/* bump pointer past header */
		
		status = uncompress((Bytef *)destination_p,(uLongf *)&destlen,(Bytef *)source_p,(uLong)sourcelen);

		switch(status)
		{
			case	Z_OK:
				if(destlen == header.orig_size)
					status = (int) destlen;				/* success, return decompressed data length */
				else
					status = T_DATA_ERROR;				/* header data corrupt */
				break;
			case	Z_MEM_ERROR:
				status = T_MEM_ERROR;					/* malloc failure */
				break;
			case	Z_BUF_ERROR:							/* destination buffer too small */
				status = T_BUF_ERROR;
				break;
			case	Z_DATA_ERROR:
				status = T_DATA_ERROR;				/* compressed data corrupt */
		}
	}
	return status;
}