FileSystem.h 4.0 KB

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  1. #pragma once
  2. #include "DiskDevice.h"
  3. #include "InodeIdentifier.h"
  4. #include "InodeMetadata.h"
  5. #include "Limits.h"
  6. #include "UnixTypes.h"
  7. #include <AK/ByteBuffer.h>
  8. #include <AK/HashMap.h>
  9. #include <AK/OwnPtr.h>
  10. #include <AK/Retainable.h>
  11. #include <AK/RetainPtr.h>
  12. #include <AK/AKString.h>
  13. #include <AK/Function.h>
  14. #include <AK/kstdio.h>
  15. static const dword mepoch = 476763780;
  16. class CoreInode;
  17. class FileDescriptor;
  18. class FS : public Retainable<FS> {
  19. public:
  20. static void initializeGlobals();
  21. virtual ~FS();
  22. dword id() const { return m_fsid; }
  23. static FS* from_fsid(dword);
  24. virtual bool initialize() = 0;
  25. virtual const char* class_name() const = 0;
  26. virtual InodeIdentifier root_inode() const = 0;
  27. virtual bool write_inode(InodeIdentifier, const ByteBuffer&) = 0;
  28. virtual InodeMetadata inode_metadata(InodeIdentifier) const = 0;
  29. virtual ssize_t read_inode_bytes(InodeIdentifier, Unix::off_t offset, size_t count, byte* buffer, FileDescriptor*) const = 0;
  30. struct DirectoryEntry {
  31. DirectoryEntry(const char* name, InodeIdentifier, byte fileType);
  32. DirectoryEntry(const char* name, size_t name_length, InodeIdentifier, byte fileType);
  33. char name[256];
  34. size_t name_length { 0 };
  35. InodeIdentifier inode;
  36. byte fileType { 0 };
  37. };
  38. virtual int set_atime_and_mtime(InodeIdentifier, dword atime, dword mtime) = 0;
  39. virtual InodeIdentifier create_inode(InodeIdentifier parentInode, const String& name, Unix::mode_t, unsigned size, int& error) = 0;
  40. virtual InodeIdentifier create_directory(InodeIdentifier parentInode, const String& name, Unix::mode_t, int& error) = 0;
  41. virtual InodeIdentifier find_parent_of_inode(InodeIdentifier) const = 0;
  42. virtual RetainPtr<CoreInode> get_inode(InodeIdentifier) const = 0;
  43. ByteBuffer read_entire_inode(InodeIdentifier, FileDescriptor* = nullptr) const;
  44. protected:
  45. FS();
  46. private:
  47. dword m_fsid { 0 };
  48. };
  49. class CoreInode : public Retainable<CoreInode> {
  50. friend class VFS;
  51. public:
  52. virtual ~CoreInode();
  53. FS& fs() { return m_fs; }
  54. const FS& fs() const { return m_fs; }
  55. unsigned fsid() const;
  56. unsigned index() const { return m_index; }
  57. size_t size() const { return metadata().size; }
  58. bool is_symlink() const { return metadata().isSymbolicLink(); }
  59. bool is_directory() const { return metadata().isDirectory(); }
  60. InodeIdentifier identifier() const { return { fsid(), index() }; }
  61. const InodeMetadata& metadata() const { if (!m_metadata.isValid()) { populate_metadata(); } return m_metadata; }
  62. ByteBuffer read_entire(FileDescriptor* = nullptr);
  63. virtual ssize_t read_bytes(Unix::off_t, size_t, byte* buffer, FileDescriptor*) = 0;
  64. virtual bool traverse_as_directory(Function<bool(const FS::DirectoryEntry&)>) = 0;
  65. virtual InodeIdentifier lookup(const String& name) = 0;
  66. virtual String reverse_lookup(InodeIdentifier) = 0;
  67. int set_atime_and_mtime(Unix::time_t atime, Unix::time_t mtime);
  68. protected:
  69. CoreInode(FS& fs, unsigned index)
  70. : m_fs(fs)
  71. , m_index(index)
  72. {
  73. }
  74. virtual void populate_metadata() const = 0;
  75. mutable InodeMetadata m_metadata;
  76. private:
  77. FS& m_fs;
  78. unsigned m_index { 0 };
  79. };
  80. inline FS* InodeIdentifier::fs()
  81. {
  82. return FS::from_fsid(m_fsid);
  83. }
  84. inline const FS* InodeIdentifier::fs() const
  85. {
  86. return FS::from_fsid(m_fsid);
  87. }
  88. inline InodeMetadata InodeIdentifier::metadata() const
  89. {
  90. if (!is_valid())
  91. return InodeMetadata();
  92. return fs()->inode_metadata(*this);
  93. }
  94. inline bool InodeIdentifier::is_root_inode() const
  95. {
  96. return (*this) == fs()->root_inode();
  97. }
  98. inline unsigned CoreInode::fsid() const
  99. {
  100. return m_fs.id();
  101. }
  102. namespace AK {
  103. template<>
  104. struct Traits<InodeIdentifier> {
  105. // FIXME: This is a shitty hash.
  106. static unsigned hash(const InodeIdentifier& inode) { return Traits<unsigned>::hash(inode.fsid()) + Traits<unsigned>::hash(inode.index()); }
  107. static void dump(const InodeIdentifier& inode) { kprintf("%02u:%08u", inode.fsid(), inode.index()); }
  108. };
  109. }