#include "u.h"#include "lib.h"#include "mem.h"#include "dat.h"#include "fns.h"#include "io.h"#include <flate.h> typedef struct Biobuf	Biobuf; struct Biobuf{	uchar *bp;	uchar *p;	uchar *ep;}; static int	header(Biobuf*);static int	trailer(Biobuf*, Biobuf*);static int	getc(void*);static ulong	offset(Biobuf*);static int	crcwrite(void *out, void *buf, int n);static ulong	get4(Biobuf *b);static ulong	Boffset(Biobuf *bp); /* GZIP flags */enum {	Ftext=		(1<<0),	Fhcrc=		(1<<1),	Fextra=		(1<<2),	Fname=		(1<<3),	Fcomment=	(1<<4), 	GZCRCPOLY	= 0xedb88320UL,}; static ulong	*crctab;static ulong	crc; intgunzip(uchar *out, int outn, uchar *in, int inn){	Biobuf bin, bout;	int err; 	crc = 0;	crctab = mkcrctab(GZCRCPOLY);	err = inflateinit();	if(err != FlateOk)		print("inflateinit failed: %s\n", flateerr(err)); 	bin.bp = bin.p = in;	bin.ep = in+inn;	bout.bp = bout.p = out;	bout.ep = out+outn; 	err = header(&bin);	if(err != FlateOk)		return err; 	err = inflate(&bout, crcwrite, &bin, getc);	if(err != FlateOk)		print("inflate failed: %s\n", flateerr(err)); 	err = trailer(&bout, &bin);	if(err != FlateOk)		return err; 	return Boffset(&bout);} static intheader(Biobuf *bin){	int i, flag; 	if(getc(bin) != 0x1f || getc(bin) != 0x8b){		print("bad magic\n");		return FlateCorrupted;	}	if(getc(bin) != 8){		print("unknown compression type\n");		return FlateCorrupted;	}		flag = getc(bin);		/* mod time */	get4(bin);		/* extra flags */	getc(bin);		/* OS type */	getc(bin); 	if(flag & Fextra)		for(i=getc(bin); i>0; i--)			getc(bin);		/* name */	if(flag&Fname)		while(getc(bin) != 0)			; 	/* comment */	if(flag&Fcomment)		while(getc(bin) != 0)			; 	/* crc16 */	if(flag&Fhcrc) {		getc(bin);		getc(bin);	}			return FlateOk;} static inttrailer(Biobuf *bout, Biobuf *bin){	/* crc32 */	ulong x; 	x = get4(bin);	if(crc != x){		print("crc mismatch %lux %lux\n", crc, x);		return FlateCorrupted;	} 	/* length */	if(get4(bin) != Boffset(bout)){		print("bad output len\n");		return FlateCorrupted;	}	return FlateOk;} static ulongget4(Biobuf *b){	ulong v;	int i, c; 	v = 0;	for(i = 0; i < 4; i++){		c = getc(b);		v |= c << (i * 8);	}	return v;} static intgetc(void *in){	Biobuf *bp = in; 	if((bp->p - bp->bp) % 10000 == 0)		print(".");	if(bp->p >= bp->ep)		return -1;	return *bp->p++;} static ulongBoffset(Biobuf *bp){	return bp->p - bp->bp;} static intcrcwrite(void *out, void *buf, int n){	Biobuf *bp; 	crc = blockcrc(crctab, crc, buf, n);	bp = out;	if(n > bp->ep-bp->p)		n = bp->ep-bp->p;	memmove(bp->p, buf, n);	bp->p += n;	return n;} #undef malloc#undef free static ulong ibrkp = ~0; void *malloc(ulong n){	ulong rv; 	if(ibrkp == ~0)		ibrkp = ((ulong)end)+1024*1024;	n = (n+3)>>2;	n <<= 2;	rv = ibrkp;	ibrkp += n;	return (void*)rv;} voidfree(void *){}