michael@0: // Copyright (c) 2012 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #ifndef BASE_PLATFORM_FILE_H_
michael@0: #define BASE_PLATFORM_FILE_H_
michael@0: 
michael@0: #include "build/build_config.h"
michael@0: #if defined(OS_WIN)
michael@0: #include <windows.h>
michael@0: #endif
michael@0: 
michael@0: #include <string>
michael@0: 
michael@0: #include "base/base_export.h"
michael@0: #include "base/basictypes.h"
michael@0: #include "base/files/file_path.h"
michael@0: #include "base/time/time.h"
michael@0: 
michael@0: namespace base {
michael@0: 
michael@0: // PLATFORM_FILE_(OPEN|CREATE).* are mutually exclusive. You should specify
michael@0: // exactly one of the five (possibly combining with other flags) when opening
michael@0: // or creating a file.
michael@0: // PLATFORM_FILE_(WRITE|APPEND) are mutually exclusive. This is so that APPEND
michael@0: // behavior will be consistent with O_APPEND on POSIX.
michael@0: enum PlatformFileFlags {
michael@0:   PLATFORM_FILE_OPEN = 1 << 0,             // Opens a file, only if it exists.
michael@0:   PLATFORM_FILE_CREATE = 1 << 1,           // Creates a new file, only if it
michael@0:                                            // does not already exist.
michael@0:   PLATFORM_FILE_OPEN_ALWAYS = 1 << 2,      // May create a new file.
michael@0:   PLATFORM_FILE_CREATE_ALWAYS = 1 << 3,    // May overwrite an old file.
michael@0:   PLATFORM_FILE_OPEN_TRUNCATED = 1 << 4,   // Opens a file and truncates it,
michael@0:                                            // only if it exists.
michael@0:   PLATFORM_FILE_READ = 1 << 5,
michael@0:   PLATFORM_FILE_WRITE = 1 << 6,
michael@0:   PLATFORM_FILE_APPEND = 1 << 7,
michael@0:   PLATFORM_FILE_EXCLUSIVE_READ = 1 << 8,   // EXCLUSIVE is opposite of Windows
michael@0:                                            // SHARE
michael@0:   PLATFORM_FILE_EXCLUSIVE_WRITE = 1 << 9,
michael@0:   PLATFORM_FILE_ASYNC = 1 << 10,
michael@0:   PLATFORM_FILE_TEMPORARY = 1 << 11,       // Used on Windows only
michael@0:   PLATFORM_FILE_HIDDEN = 1 << 12,          // Used on Windows only
michael@0:   PLATFORM_FILE_DELETE_ON_CLOSE = 1 << 13,
michael@0: 
michael@0:   PLATFORM_FILE_WRITE_ATTRIBUTES = 1 << 14,  // Used on Windows only
michael@0:   PLATFORM_FILE_ENUMERATE = 1 << 15,         // May enumerate directory
michael@0: 
michael@0:   PLATFORM_FILE_SHARE_DELETE = 1 << 16,      // Used on Windows only
michael@0: 
michael@0:   PLATFORM_FILE_TERMINAL_DEVICE = 1 << 17,   // Serial port flags
michael@0:   PLATFORM_FILE_BACKUP_SEMANTICS = 1 << 18,  // Used on Windows only
michael@0: 
michael@0:   PLATFORM_FILE_EXECUTE = 1 << 19,           // Used on Windows only
michael@0: };
michael@0: 
michael@0: // PLATFORM_FILE_ERROR_ACCESS_DENIED is returned when a call fails because of
michael@0: // a filesystem restriction. PLATFORM_FILE_ERROR_SECURITY is returned when a
michael@0: // browser policy doesn't allow the operation to be executed.
michael@0: enum PlatformFileError {
michael@0:   PLATFORM_FILE_OK = 0,
michael@0:   PLATFORM_FILE_ERROR_FAILED = -1,
michael@0:   PLATFORM_FILE_ERROR_IN_USE = -2,
michael@0:   PLATFORM_FILE_ERROR_EXISTS = -3,
michael@0:   PLATFORM_FILE_ERROR_NOT_FOUND = -4,
michael@0:   PLATFORM_FILE_ERROR_ACCESS_DENIED = -5,
michael@0:   PLATFORM_FILE_ERROR_TOO_MANY_OPENED = -6,
michael@0:   PLATFORM_FILE_ERROR_NO_MEMORY = -7,
michael@0:   PLATFORM_FILE_ERROR_NO_SPACE = -8,
michael@0:   PLATFORM_FILE_ERROR_NOT_A_DIRECTORY = -9,
michael@0:   PLATFORM_FILE_ERROR_INVALID_OPERATION = -10,
michael@0:   PLATFORM_FILE_ERROR_SECURITY = -11,
michael@0:   PLATFORM_FILE_ERROR_ABORT = -12,
michael@0:   PLATFORM_FILE_ERROR_NOT_A_FILE = -13,
michael@0:   PLATFORM_FILE_ERROR_NOT_EMPTY = -14,
michael@0:   PLATFORM_FILE_ERROR_INVALID_URL = -15,
michael@0:   PLATFORM_FILE_ERROR_IO = -16,
michael@0:   // Put new entries here and increment PLATFORM_FILE_ERROR_MAX.
michael@0:   PLATFORM_FILE_ERROR_MAX = -17
michael@0: };
michael@0: 
michael@0: // This explicit mapping matches both FILE_ on Windows and SEEK_ on Linux.
michael@0: enum PlatformFileWhence {
michael@0:   PLATFORM_FILE_FROM_BEGIN   = 0,
michael@0:   PLATFORM_FILE_FROM_CURRENT = 1,
michael@0:   PLATFORM_FILE_FROM_END     = 2
michael@0: };
michael@0: 
michael@0: // Used to hold information about a given file.
michael@0: // If you add more fields to this structure (platform-specific fields are OK),
michael@0: // make sure to update all functions that use it in file_util_{win|posix}.cc
michael@0: // too, and the ParamTraits<base::PlatformFileInfo> implementation in
michael@0: // chrome/common/common_param_traits.cc.
michael@0: struct BASE_EXPORT PlatformFileInfo {
michael@0:   PlatformFileInfo();
michael@0:   ~PlatformFileInfo();
michael@0: 
michael@0:   // The size of the file in bytes.  Undefined when is_directory is true.
michael@0:   int64 size;
michael@0: 
michael@0:   // True if the file corresponds to a directory.
michael@0:   bool is_directory;
michael@0: 
michael@0:   // True if the file corresponds to a symbolic link.
michael@0:   bool is_symbolic_link;
michael@0: 
michael@0:   // The last modified time of a file.
michael@0:   base::Time last_modified;
michael@0: 
michael@0:   // The last accessed time of a file.
michael@0:   base::Time last_accessed;
michael@0: 
michael@0:   // The creation time of a file.
michael@0:   base::Time creation_time;
michael@0: };
michael@0: 
michael@0: #if defined(OS_WIN)
michael@0: typedef HANDLE PlatformFile;
michael@0: const PlatformFile kInvalidPlatformFileValue = INVALID_HANDLE_VALUE;
michael@0: PlatformFileError LastErrorToPlatformFileError(DWORD saved_errno);
michael@0: #elif defined(OS_POSIX)
michael@0: typedef int PlatformFile;
michael@0: const PlatformFile kInvalidPlatformFileValue = -1;
michael@0: PlatformFileError ErrnoToPlatformFileError(int saved_errno);
michael@0: #endif
michael@0: 
michael@0: // Creates or opens the given file. If |created| is provided, it will be set to
michael@0: // true if a new file was created [or an old one truncated to zero length to
michael@0: // simulate a new file, which can happen with PLATFORM_FILE_CREATE_ALWAYS], and
michael@0: // false otherwise.  |error| can be NULL.
michael@0: //
michael@0: // This function fails with 'access denied' if the |name| contains path
michael@0: // traversal ('..') components.
michael@0: BASE_EXPORT PlatformFile CreatePlatformFile(const FilePath& name,
michael@0:                                             int flags,
michael@0:                                             bool* created,
michael@0:                                             PlatformFileError* error);
michael@0: 
michael@0: // Same as CreatePlatformFile but allows paths with traversal (like \..\)
michael@0: // components. Use only with extreme care.
michael@0: BASE_EXPORT PlatformFile CreatePlatformFileUnsafe(const FilePath& name,
michael@0:                                                   int flags,
michael@0:                                                   bool* created,
michael@0:                                                   PlatformFileError* error);
michael@0: 
michael@0: BASE_EXPORT FILE* FdopenPlatformFile(PlatformFile file, const char* mode);
michael@0: 
michael@0: // Closes a file handle. Returns |true| on success and |false| otherwise.
michael@0: BASE_EXPORT bool ClosePlatformFile(PlatformFile file);
michael@0: 
michael@0: // Changes current position in the file to an |offset| relative to an origin
michael@0: // defined by |whence|. Returns the resultant current position in the file
michael@0: // (relative to the start) or -1 in case of error.
michael@0: BASE_EXPORT int64 SeekPlatformFile(PlatformFile file,
michael@0:                                    PlatformFileWhence whence,
michael@0:                                    int64 offset);
michael@0: 
michael@0: // Reads the given number of bytes (or until EOF is reached) starting with the
michael@0: // given offset. Returns the number of bytes read, or -1 on error. Note that
michael@0: // this function makes a best effort to read all data on all platforms, so it is
michael@0: // not intended for stream oriented files but instead for cases when the normal
michael@0: // expectation is that actually |size| bytes are read unless there is an error.
michael@0: BASE_EXPORT int ReadPlatformFile(PlatformFile file, int64 offset,
michael@0:                                  char* data, int size);
michael@0: 
michael@0: // Same as above but without seek.
michael@0: BASE_EXPORT int ReadPlatformFileAtCurrentPos(PlatformFile file,
michael@0:                                              char* data, int size);
michael@0: 
michael@0: // Reads the given number of bytes (or until EOF is reached) starting with the
michael@0: // given offset, but does not make any effort to read all data on all platforms.
michael@0: // Returns the number of bytes read, or -1 on error.
michael@0: BASE_EXPORT int ReadPlatformFileNoBestEffort(PlatformFile file, int64 offset,
michael@0:                                              char* data, int size);
michael@0: 
michael@0: // Same as above but without seek.
michael@0: BASE_EXPORT int ReadPlatformFileCurPosNoBestEffort(PlatformFile file,
michael@0:                                                    char* data, int size);
michael@0: 
michael@0: // Writes the given buffer into the file at the given offset, overwritting any
michael@0: // data that was previously there. Returns the number of bytes written, or -1
michael@0: // on error. Note that this function makes a best effort to write all data on
michael@0: // all platforms.
michael@0: // Ignores the offset and writes to the end of the file if the file was opened
michael@0: // with PLATFORM_FILE_APPEND.
michael@0: BASE_EXPORT int WritePlatformFile(PlatformFile file, int64 offset,
michael@0:                                   const char* data, int size);
michael@0: 
michael@0: // Save as above but without seek.
michael@0: BASE_EXPORT int WritePlatformFileAtCurrentPos(PlatformFile file,
michael@0:                                               const char* data, int size);
michael@0: 
michael@0: // Save as above but does not make any effort to write all data on all
michael@0: // platforms. Returns the number of bytes written, or -1 on error.
michael@0: BASE_EXPORT int WritePlatformFileCurPosNoBestEffort(PlatformFile file,
michael@0:                                                     const char* data, int size);
michael@0: 
michael@0: // Truncates the given file to the given length. If |length| is greater than
michael@0: // the current size of the file, the file is extended with zeros. If the file
michael@0: // doesn't exist, |false| is returned.
michael@0: BASE_EXPORT bool TruncatePlatformFile(PlatformFile file, int64 length);
michael@0: 
michael@0: // Flushes the buffers of the given file.
michael@0: BASE_EXPORT bool FlushPlatformFile(PlatformFile file);
michael@0: 
michael@0: // Touches the given file.
michael@0: BASE_EXPORT bool TouchPlatformFile(PlatformFile file,
michael@0:                                    const Time& last_access_time,
michael@0:                                    const Time& last_modified_time);
michael@0: 
michael@0: // Returns some information for the given file.
michael@0: BASE_EXPORT bool GetPlatformFileInfo(PlatformFile file, PlatformFileInfo* info);
michael@0: 
michael@0: // Use this class to pass ownership of a PlatformFile to a receiver that may or
michael@0: // may not want to accept it.  This class does not own the storage for the
michael@0: // PlatformFile.
michael@0: //
michael@0: // EXAMPLE:
michael@0: //
michael@0: //  void MaybeProcessFile(PassPlatformFile pass_file) {
michael@0: //    if (...) {
michael@0: //      PlatformFile file = pass_file.ReleaseValue();
michael@0: //      // Now, we are responsible for closing |file|.
michael@0: //    }
michael@0: //  }
michael@0: //
michael@0: //  void OpenAndMaybeProcessFile(const FilePath& path) {
michael@0: //    PlatformFile file = CreatePlatformFile(path, ...);
michael@0: //    MaybeProcessFile(PassPlatformFile(&file));
michael@0: //    if (file != kInvalidPlatformFileValue)
michael@0: //      ClosePlatformFile(file);
michael@0: //  }
michael@0: //
michael@0: class BASE_EXPORT PassPlatformFile {
michael@0:  public:
michael@0:   explicit PassPlatformFile(PlatformFile* value) : value_(value) {
michael@0:   }
michael@0: 
michael@0:   // Called to retrieve the PlatformFile stored in this object.  The caller
michael@0:   // gains ownership of the PlatformFile and is now responsible for closing it.
michael@0:   // Any subsequent calls to this method will return an invalid PlatformFile.
michael@0:   PlatformFile ReleaseValue() {
michael@0:     PlatformFile temp = *value_;
michael@0:     *value_ = kInvalidPlatformFileValue;
michael@0:     return temp;
michael@0:   }
michael@0: 
michael@0:  private:
michael@0:   PlatformFile* value_;
michael@0: };
michael@0: 
michael@0: }  // namespace base
michael@0: 
michael@0: #endif  // BASE_PLATFORM_FILE_H_