X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/5267aefd85739afd26bd19bfba998005119db446..6a3f8b4f1f1c802df93ce7bc05588536cb7a4dad:/interface/wx/file.h diff --git a/interface/wx/file.h b/interface/wx/file.h index 4f693d2dea..10efe6534d 100644 --- a/interface/wx/file.h +++ b/interface/wx/file.h @@ -8,8 +8,8 @@ /** - We redefine these constants here because S_IREAD &c are _not_ standard - however, we do assume that the values correspond to the Unix umask bits. + We redefine these constants here because S_IREAD &c are _not_ standard. + However, we do assume that the values correspond to the Unix umask bits. */ enum wxPosixPermissions { @@ -44,7 +44,7 @@ enum wxPosixPermissions //@} /// Default mode for the new files: allow reading/writing them to everybody but - /// the effective file mode will be set after anding this value with umask and + /// the effective file mode will be set after ANDing this value with umask and /// so won't include wxS_IW{GRP,OTH} for the default 022 umask value wxS_DEFAULT = (wxPOSIX_USER_READ | wxPOSIX_USER_WRITE | \ wxPOSIX_GROUP_READ | wxPOSIX_GROUP_WRITE | \ @@ -52,7 +52,7 @@ enum wxPosixPermissions /// Default mode for the new directories (see wxFileName::Mkdir): allow /// reading/writing/executing them to everybody, but just like wxS_DEFAULT - /// the effective directory mode will be set after anding this value with umask + /// the effective directory mode will be set after ANDing this value with umask wxS_DIR_DEFAULT = (wxPOSIX_USER_READ | wxPOSIX_USER_WRITE | wxPOSIX_USER_EXECUTE | \ wxPOSIX_GROUP_READ | wxPOSIX_GROUP_WRITE | wxPOSIX_GROUP_EXECUTE | \ wxPOSIX_OTHERS_READ | wxPOSIX_OTHERS_WRITE | wxPOSIX_OTHERS_EXECUTE) @@ -84,12 +84,12 @@ enum wxPosixPermissions file by default, you should explicitly call wxTempFile::Commit() to do it. Calling wxTempFile::Discard() explicitly discards any modifications: it closes and deletes the temporary file and leaves the original file unchanged. - If you don't call neither of Commit() and Discard(), the destructor will + If you call neither Commit() nor Discard(), the destructor will call Discard() automatically. To summarize: if you want to replace another file, create an instance of - wxTempFile passing the name of the file to be replaced to the constructor - (you may also use default constructor and pass the file name to wxTempFile::Open). + wxTempFile passing the name of the file to be replaced to the constructor. + (You may also use default constructor and pass the file name to wxTempFile::Open.) Then you can write to wxTempFile using wxFile-like functions and later call wxTempFile::Commit() to replace the old file (and close this one) or call wxTempFile::Discard() to cancel the modifications. @@ -102,12 +102,14 @@ class wxTempFile public: /** Associates wxTempFile with the file to be replaced and opens it. - You should use IsOpened() to verify if the constructor succeeded. + + @warning + You should use IsOpened() to verify that the constructor succeeded. */ wxTempFile(const wxString& strName); /** - Destructor calls Discard() if temporary file is still opened. + Destructor calls Discard() if temporary file is still open. */ ~wxTempFile(); @@ -116,17 +118,29 @@ public: file to the old name. Returns @true if both actions succeeded. If @false is returned it may unfortunately mean two quite different things: - either that either the old file couldn't be deleted or that the new file + either that the old file couldn't be deleted or that the new file couldn't be renamed to the old name. */ bool Commit(); /** - Discard changes: the old file contents is not changed, temporary file is - deleted. + Discard changes: the old file contents are not changed, the temporary + file is deleted. */ void Discard(); + /** + Flush the data written to the file to disk. + + This simply calls wxFile::Flush() for the underlying file and may be + necessary with file systems such as XFS and Ext4 under Linux. Calling + this function may however have serious performance implications and + also is not necessary with many other file systems so it is not done by + default -- but you can call it before calling Commit() to absolutely + ensure that the data was indeed written to the disk correctly. + */ + bool Flush(); + /** Returns @true if the file was successfully opened. */ @@ -135,9 +149,8 @@ public: /** Returns the length of the file. - This method may return wxInvalidOffset if the length couldn't be - determined or also 0 even for non-empty files if the file is not - seekable. + This method may return ::wxInvalidOffset if the length couldn't be + determined or 0 even for non-empty files if the file is not seekable. In general, the only way to determine if the file for which this function returns 0 is really empty or not is to try reading from it. @@ -161,7 +174,7 @@ public: wxSeekMode mode = wxFromStart); /** - Returns the current position or wxInvalidOffset if file is not opened or + Returns the current position or ::wxInvalidOffset if file is not opened or if another error occurred. */ wxFileOffset Tell() const; @@ -180,20 +193,11 @@ public: /** @class wxFile - A wxFile performs raw file I/O. - - This is a very small class designed to minimize the overhead of using it - in fact, - there is hardly any overhead at all, but using it brings you automatic error - checking and hides differences between platforms and compilers. - - wxFile also automatically closes the file in its destructor making it unnecessary - to worry about forgetting to do it. - A wxFile performs raw file I/O. This is a very small class designed to minimize the overhead of using it - in fact, there is hardly any overhead at all, but using it brings you automatic error checking and hides differences between platforms and compilers. wxFile also automatically closes the file in - its destructor making it unnecessary to worry about forgetting to do it. + its destructor so you won't forget to do so. wxFile is a wrapper around @c file descriptor. - see also wxFFile for a wrapper around @c FILE structure. @@ -226,7 +230,7 @@ public: read_write, /** Open file for appending: the file is opened for writing, but the old contents - of the file is not erased and the file pointer is initially placed at the end + of the file are not erased and the file pointer is initially placed at the end of the file; can not be used with Access(). This is the same as OpenMode::write if the file doesn't exist. @@ -258,6 +262,9 @@ public: The filename. @param mode The mode in which to open the file. + + @warning + You should use IsOpened() to verify that the constructor succeeded. */ wxFile(const wxString& filename, wxFile::OpenMode mode = wxFile::read); @@ -273,7 +280,7 @@ public: /** Destructor will close the file. - @note it is not virtual so you should not use wxFile polymorphically. + @note This destructor is not virtual so you should not use wxFile polymorphically. */ ~wxFile(); @@ -285,7 +292,7 @@ public: /** Attaches an existing file descriptor to the wxFile object. - Example of predefined file descriptors are 0, 1 and 2 which correspond to + Examples of predefined file descriptors are 0, 1 and 2 which correspond to stdin, stdout and stderr (and have symbolic names of @c wxFile::fd_stdin, @c wxFile::fd_stdout and @c wxFile::fd_stderr). @@ -321,7 +328,7 @@ public: /** Returns @true if the end of the file has been reached. - Note that the behaviour of the file pointer based class wxFFile is + Note that the behaviour of the file pointer-based class wxFFile is different as wxFFile::Eof() will return @true here only if an attempt has been made to read @b past the last byte of the file, while wxFile::Eof() will return @true even before such attempt is made if the @@ -329,7 +336,7 @@ public: Note also that this function doesn't work on unseekable file descriptors (examples include pipes, terminals and sockets under Unix) and an attempt to - use it will result in an error message in such case. + use it will result in an error message. So, to read the entire file into memory, you should write a loop which uses Read() repeatedly and tests its return condition instead of using Eof() @@ -339,7 +346,7 @@ public: /** Returns @true if the given name specifies an existing regular file - (not a directory or a link) + (not a directory or a link). */ static bool Exists(const wxString& filename); @@ -375,9 +382,8 @@ public: @param mode The mode in which to open the file. @param access - An OR-combination of wxPosixPermissions enumeration values. + An OR-combination of ::wxPosixPermissions enumeration values. */ - bool Open(const wxString& filename, bool Open(const wxString& filename, wxFile::OpenMode mode = wxFile::read, int access = wxS_DEFAULT); @@ -389,7 +395,7 @@ public: @param count Bytes to read - @return The number of bytes read, or the symbol wxInvalidOffset. + @return The number of bytes read, or the symbol ::wxInvalidOffset. */ ssize_t Read(void* buffer, size_t count); @@ -401,7 +407,7 @@ public: @param mode One of wxFromStart, wxFromEnd, wxFromCurrent. - @return The actual offset position achieved, or wxInvalidOffset on + @return The actual offset position achieved, or ::wxInvalidOffset on failure. */ wxFileOffset Seek(wxFileOffset ofs, @@ -415,13 +421,13 @@ public: @param ofs Number of bytes before the end of the file. - @return The actual offset position achieved, or wxInvalidOffset on + @return The actual offset position achieved, or ::wxInvalidOffset on failure. */ wxFileOffset SeekEnd(wxFileOffset ofs = 0); /** - Returns the current position or wxInvalidOffset if file is not opened or + Returns the current position or ::wxInvalidOffset if file is not opened or if another error occurred. */ wxFileOffset Tell() const;