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/*
* Copyright (C) 2007-2023 Xagasoft, All rights reserved.
*
* This file is part of the libbu++ library and is released under the
* terms of the license contained in the file LICENSE.
*/
#ifndef MYRIAD_FS_H
#define MYRIAD_FS_H
#include <sys/types.h>
#include "bu/myriad.h"
#include "bu/readwritemutex.h"
namespace Bu
{
class Stream;
subExceptionDecl( MyriadFsException );
/**
* A POSIX compliant, node based filesystem built on top of Myriad.
*
* A header is placed into stream 1.
* Header format:
* int32_t iMagicHeader (A7188B39)
* int8_t iVersion (1)
* int32_t iNumNodes
* NodeLookup[iNumNodes] nNode
*
* Node lookup:
* int32_t iInode
* int32_t iPosition
*
* The node headers or inode structures have a base size of 44 bytes.
* The name is stored in the directory format.
* Basic node header format:
* int32_t iNode
* int32_t iUser
* int32_t iGroup
* uint16_t uPerms
* int16_t iLinks
* uint32_t uStreamIndex
* int64_t iATime
* int64_t iMTime
* int64_t iCTime
*
* Some types get special formats for their assosiated data stream, or
* other special considerations, here's a list:
*
* - typeFifo: No stream, uStreamIndex unused (probably)
* - typeChrDev: No stream, uStreamIndex is device hi/lo
* - typeDir: The stream contains a directory contents listing, described
* below
* - typeBlkDev: No stream, uStreamIndex is device hi/lo
* - typeRegFile: The stream is the file data
* - typeSymLink: The stream is the destination of the symlink
* - typeSocket: No steram, uStreamIndex unused (probably)
*
* Directory streams have this simple listing format. They contain a list
* of all child elements, with no particular order at the moment. The . and
* .. entries are not listed, they are implicit:
* int32_t iNumNodes
* NodeTable[iNumNodes] nChildren
*
* NodeTable:
* int32_t iInode
* uint8_t uNameSize
* char[uNameSize] sName
*/
class MyriadFs
{
public:
MyriadFs( Bu::Stream &rStore, int iBlockSize=512 );
virtual ~MyriadFs();
enum
{
permOthX = 0000001,
permOthW = 0000002,
permOthR = 0000004,
permGrpX = 0000010,
permGrpW = 0000020,
permGrpR = 0000040,
permUsrX = 0000100,
permUsrW = 0000200,
permUsrR = 0000400,
permSticky = 0001000,
permSetGid = 0002000,
permSetUid = 0004000,
permMask = 0007777,
typeFifo = 0010000,
typeChrDev = 0020000,
typeDir = 0040000,
typeBlkDev = 0060000,
typeRegFile = 0100000,
typeSymLink = 0120000,
typeSocket = 0140000,
typeMask = 0170000
};
enum
{
Read = 0x01, ///< Open file for reading
Write = 0x02, ///< Open file for writing
Create = 0x04, ///< Create file if it doesn't exist
Truncate = 0x08, ///< Truncate file if it does exist
Append = 0x10, ///< Always append on every write
NonBlock = 0x20, ///< Open file in non-blocking mode
Exclusive = 0x44, ///< Create file, if it exists then fail
// Helpful mixes
ReadWrite = 0x03, ///< Open for reading and writing
WriteNew = 0x0E ///< Create a file (or truncate) for writing.
/// Same as Write|Create|Truncate
};
class Stat
{
public:
int32_t iNode;
int32_t iUser;
int32_t iGroup;
uint16_t uPerms;
int16_t iLinks;
int64_t iATime;
int64_t iMTime;
int64_t iCTime;
int32_t iSize;
uint32_t uDev;
Bu::String sName;
};
typedef Bu::List<Stat> Dir;
void stat( const Bu::String &sPath, Stat &rBuf );
MyriadStream open( const Bu::String &sPath, int iMode,
uint16_t uPerms=0664 );
void create( const Bu::String &sPath, uint16_t iPerms );
void create( const Bu::String &sPath, uint16_t iPerms,
uint16_t iDevHi, uint16_t iDevLo );
void create( const Bu::String &sPath, uint16_t iPerms,
uint32_t uSpecial );
void mkDir( const Bu::String &sPath, uint16_t iPerms );
void mkSymLink( const Bu::String &sTarget, const Bu::String &sPath );
void mkHardLink( const Bu::String &sTarget, const Bu::String &sPath );
Bu::String readSymLink( const Bu::String &sPath );
Dir readDir( const Bu::String &sPath );
void setTimes( const Bu::String &sPath, int64_t iATime,
int64_t iMTime );
void unlink( const Bu::String &sPath );
void setFileSize( const Bu::String &sPath, int32_t iSize );
void rename( const Bu::String &sFrom, const Bu::String &sTo );
static dev_t devToSys( uint32_t uDev );
static uint32_t sysToDev( dev_t uDev );
private:
class RawStat
{
public:
int32_t iNode;
int32_t iUser;
int32_t iGroup;
uint16_t uPerms;
int16_t iLinks;
uint32_t uStreamIndex;
int64_t iATime;
int64_t iMTime;
int64_t iCTime;
};
typedef Bu::Hash<int32_t, int32_t> NodeIndex;
private:
int32_t lookupInode( const Bu::String &sPath, int32_t &iParent );
int32_t lookupInode( Bu::String::const_iterator iStart,
int32_t iNode, int32_t &iParent );
void readInode( int32_t iNode, RawStat &rs, MyriadStream &rIs );
void readInode( int32_t iNode, RawStat &rs );
void writeInode( const RawStat &rs );
void writeInode( const RawStat &rs, MyriadStream &rOs );
Dir readDir( int32_t iNode );
MyriadStream openByInode( int32_t iNode );
void addToDir( int32_t iDir, int32_t iNode, const Bu::String &sName );
int32_t create( int32_t iParent, const Bu::String &sName,
uint16_t uPerms, uint32_t uSpecial );
int32_t allocInode( uint16_t uPerms, uint32_t uSpecial );
void stat( int32_t iNode, Stat &rBuf, MyriadStream &rIs );
void writeHeader();
void setTimes( int32_t iNode, int64_t iATime, int64_t iMTime );
void destroyNode( int32_t iNode );
Bu::String filePart( const Bu::String &sPath );
private:
Bu::Stream &rStore;
Bu::Myriad mStore;
Bu::ReadWriteMutex mNodeIndex;
NodeIndex hNodeIndex;
int32_t iUser;
int32_t iGroup;
};
};
#endif
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