VFS.h

/*
 * Copyright (c) 2008-2014, Pedigree Developers
 *
 * Please see the CONTRIB file in the root of the source tree for a full
 * list of contributors.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#ifndef VFS_H
#define VFS_H

#include "Filesystem.h"
#include "pedigree/kernel/compiler.h"
#include "pedigree/kernel/processor/types.h"
#include "pedigree/kernel/utilities/HashTable.h"
#include "pedigree/kernel/utilities/List.h"
#include "pedigree/kernel/utilities/LruCache.h"
#include "pedigree/kernel/utilities/String.h"
#include "pedigree/kernel/utilities/Tree.h"
#include "pedigree/kernel/utilities/utility.h"

class Disk;
class File;
class StringView;
class HashedStringView;

#define VFS_WITH_LRU_CACHES 0

class EXPORTED_PUBLIC VFS
{
  public:
    typedef void (*MountCallback)();

    typedef HashTable<String, Filesystem *, HashedStringView> AliasTable;

    VFS();
    ~VFS();

    static VFS &instance();

    bool mount(Disk *pDisk, String &alias);

    void addAlias(Filesystem *pFs, const String &alias);
    void addAlias(const String &oldAlias, const String &newAlias);

    String getUniqueAlias(const String &alias);

    bool aliasExists(const String &alias);

    inline AliasTable &getAliases()
    {
        return m_Aliases;
    }

    inline Tree<Filesystem *, List<String *> *> &getMounts()
    {
        return m_Mounts;
    }

    void removeAlias(const String &alias);

    void removeAllAliases(Filesystem *pFs, bool canDelete=true);

    Filesystem *lookupFilesystem(const String &alias);
    Filesystem *lookupFilesystem(const HashedStringView &alias);

    File *find(const String &path, File *pStartNode = 0);

    bool createFile(const String &path, uint32_t mask, File *pStartNode = 0);

    bool
    createDirectory(const String &path, uint32_t mask, File *pStartNode = 0);

    bool createSymlink(
        const String &path, const String &value, File *pStartNode = 0);

    bool createLink(const String &path, File *target, File *pStartNode = 0);

    bool remove(const String &path, File *pStartNode = 0);

    void addProbeCallback(Filesystem::ProbeCallback callback);

    void addMountCallback(MountCallback callback);

    static bool
    checkAccess(File *pFile, bool bRead, bool bWrite, bool bExecute);

    static constexpr const char *mountSeparator()
    {
        return "»";
    }

  private:
    ssize_t findColon(const String &path);

    static VFS m_Instance;

    static File *m_EmptyFile;

    AliasTable m_Aliases;
    Tree<Filesystem *, List<String *> *> m_Mounts;

    List<Filesystem::ProbeCallback *> m_ProbeCallbacks;
    List<MountCallback *> m_MountCallbacks;

    LruCache<String, Filesystem *> m_AliasCache;
    LruCache<String, File *> m_FindCache;
};

#endif