/*
 *    (c)Copyright 1992-1997 Obvious Implementations Corp.  Redistribution and
 *    use is allowed under the terms of the DICE-LICENSE FILE,
 *    DICE-LICENSE.TXT.
 */

/*
 * ZIPCOMP.C - ZIP COMPRESSION
 */

#include "defs.h"

#define BITS  14	/* compression size */

Prototype int Compress(BPTR fh, char *buf, long bytes);
Prototype void DeCompress(BPTR fh, char *buf, long bytes);

static long ErrorCode;
static long Fh;
static ubyte *MemBuf;
static long  MemBytes;

static ubyte Buf[4096];
static long BufIdx;
static long BufLen;


/*    WritePacket(fh, buf, bytes); */
/*    ReadPacket(fh, buf, bytes);  */

int 
Compress(BPTR fh, char *buf, long bytes)
{
    int r;

    MemBytes = bytes;
    MemBuf = buf;
    BufIdx = 0;
    BufLen = 0;
    ErrorCode = 0;
    Fh = fh;
    r = ZipCompress();
    WritePacket(fh, Buf, BufIdx);
    return(r);
}

unsigned
zfwrite(void *buf, long blkSize, long numBlks, void *fo)
{
    long n = blkSize * numBlks;

    while (n) {
	long r;

	if ((r = sizeof(Buf) - BufIdx) == 0) {
	    WritePacket(Fh, Buf, sizeof(Buf));
	    BufIdx = 0;
	    r = sizeof(Buf);
	}
	if (n < r)
	    r = n;
	movmem(buf, Buf + BufIdx, r);
	buf = (void *)((char *)buf + r);
	n -= r;
	BufIdx += r;
    }
    return(numBlks);
}

long
zfread(char *buf, long bytes)
{
    long n = (bytes > MemBytes) ? MemBytes : bytes;

    movmem(MemBuf, buf, n);
    MemBytes -= n;
    MemBuf += n;
    return(n);
}

void 
DeCompress(BPTR fh, char *buf, long bytes)
{
    MemBytes = bytes;
    MemBuf = buf;
    Fh = fh;
    BufIdx = 0;
    BufLen = 0;
    ErrorCode = 0;
    ZipDeCompress(MemBuf, MemBytes);
}

int
ReadByte(short *v)
{
    if (BufIdx == BufLen) {
	BufIdx = 0;
	BufLen = ReadPacket(Fh, Buf, sizeof(Buf));
	if (BufLen == 0)
	    return(0);
    }
    *v = Buf[BufIdx++];
    return(8);
}

long
readbuf(ubyte *buf, long n)
{
    long ttl = 0;

    while (n) {
	long r = BufLen - BufIdx;

	if (r == 0) {
	    BufIdx = 0;
	    BufLen = ReadPacket(Fh, Buf, sizeof(Buf));
	    if (BufLen == 0)
		break;
	    r = BufLen;
	}
	if (n < r)
	    r = n;
	movmem(Buf + BufIdx, buf, r);
	buf += r;
	n -= r;
	BufIdx += r;
	ttl += r;
    }
    return(ttl);
}