/*
 * This file is part of the UCB release of Plan 9. It is subject to the license
 * terms in the LICENSE file found in the top-level directory of this
 * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
 * part of the UCB release of Plan 9, including this file, may be copied,
 * modified, propagated, or distributed except according to the terms contained
 * in the LICENSE file.
 */
/* Portions of this file are Copyright (C) 2015-2018 Giacomo Tesio <giacomo@tesio.it>
 * See /doc/license/gpl-2.0.txt for details about the licensing.
 */
/* Portions of this file are Copyright (C) 9front's team.
 * See /doc/license/9front-mit for details about the licensing.
 * See http://code.9front.org/hg/plan9front/ for a list of authors.
 */
typedef struct PaqHeader PaqHeader;
typedef struct PaqBlock PaqBlock;
typedef struct PaqTrailer PaqTrailer;
typedef struct PaqDir PaqDir;

enum {
	HeaderMagic = 0x529ab12b,
	HeaderSize = 44,
	BigHeaderMagic = 0x25a9,
	BlockMagic = 0x198a1cbf,
	BlockSize = 12,
	BigBlockMagic = 0x91a8,
	TrailerMagic = 0x6b46e688,
	TrailerSize = 28,
	Version = 1,
	MaxBlockSize = 512*1024,
	MinBlockSize = 512,
	MinDirSize = 28,
};

/* block types */
enum {
	DirBlock,
	DataBlock,
	PointerBlock,
};

/* encodings */
enum {
	NoEnc,
	DeflateEnc,
};

struct PaqHeader
{
	uint32_t	magic;
	uint16_t	version;
	uint32_t	blocksize;
	uint32_t	time;
	char	label[32];
};

struct PaqBlock
{
	uint32_t	magic;
	uint32_t	size;		/* data size - always <= blocksize */
	uint8_t	type;
	uint8_t	encoding;
	uint32_t	adler32;	/* applied to unencoded data */
};

struct PaqTrailer
{
	uint32_t	magic;
	uint32_t	root;
	uint8_t	sha1[20];
};

struct PaqDir
{
	uint32_t	qid;
	uint32_t	mode;
	uint32_t	mtime;
	uint32_t	length;
	uint32_t	offset;		/* to pointer block */
	char 	*name;
	char	*uid;
	char	*gid;
};