protected void OpenFile(bool full)
{
if (reader != null)
{
reader.Seek(0);
}
else
{
try {
// We don't actually write to the file, but requesting ReadWrite access ensures
// that nobody else has the file open for writing (unless someone else set FileShare.Write,
// but that's unlikely, and this program doesn't do that).
//
// Opening with FileAccess.Read would mean that other programs could have the file open and
// modify it, thus invaliding the file offsets stored in the partially-loaded entries.
//
// We need to open with FileShare.Read because the main window and other programs need to
// read the dictionary header to populate the list. (This should probably change.)
// Of course, if we're just reading the dictionary header, we only request read access.
var access = full ? FileAccess.ReadWrite : FileAccess.Read;
// If we're only loading a header, we have to set FileShare.ReadWrite or the call
// fails if the file is already open for ReadWrite.
// If we can open the file for Read access, it should be safe to read from without it
// being modified (when writing to the dictionary, we specify FileShare.None).
var share = full ? FileShare.Read : FileShare.ReadWrite;
reader = new Utf8LineReader(Path, access, share);
} catch (IOException e) {
throw new DictionaryLoadException(e.Message, e);
} catch (ArgumentException e) {
throw new DictionaryLoadException(e.Message, e);
} catch (UnauthorizedAccessException e) {
throw new DictionaryLoadException(e.Message, e);
}
}
}
/// <summary>
/// Writes all entries to a file. There's no way to tell if the dictionary entries have been modified,
/// as of yet, so currently we must write the file whether it's necessary or not.
/// </summary>
/// <param name="path">The file name (relative or absolute) to write to.</param>
protected void Write(string path)
{
// Update the revision ID. Instead of incrementing a number, pick a random GUID and use that.
// If incrementing were used, then if a dictionary were copied to a different computer, modified,
// and copied back to the original computer, where the dictionary had also been modified, the
// cache revision ID on the original computer would still match that of the dictionary file, despite
// being invalid.
revisionID = Guid.NewGuid().ToString();
// If we're not writing cautiously, we can't read the entries on-demand while the temporary output file
// is written.
if (path == Path)
CloseFile();
PreloadPartialEntries();
Metrics.Measure(string.Format("Writing dictionary {0} to file", this.Name), delegate {
// Now dispose of the reader so that we can unlock the file.
// The file needs to be truncated anyway, so it's not possible to share the file stream
// with the Line Reader.
if (reader != null) {
reader.Dispose();
reader = null;
}
using (var stream = File.Open(path, FileMode.Create, FileAccess.Write, FileShare.None)) {
using (var writer = new LineWriter(stream)) {
writer.WriteLine(magicNumber);
if (Name != null)
writer.WriteLine("name " + Uri.EscapeDataString(Name));
if (Author != null)
writer.WriteLine("author " + Uri.EscapeDataString(Author));
if (Url != null)
writer.WriteLine("url " + Uri.EscapeDataString(Url));
writer.WriteLine("revision-id " + Uri.EscapeDataString(revisionID));
// TODO: WritePairedProperty
writer.WriteLine(string.Format("headwords-hint {0} {1}", forwards.HeadWords, backwards.HeadWords));
if (FirstLanguage != null || SecondLanguage != null)
writer.WriteLine(string.Format("languages {0} {1}", Uri.EscapeDataString(FirstLanguage), Uri.EscapeDataString(SecondLanguage)));
if (FirstLanguageCode != null || SecondLanguageCode != null)
writer.WriteLine(string.Format("language-codes {0} {1}", Uri.EscapeDataString(FirstLanguageCode), Uri.EscapeDataString(SecondLanguageCode)));
writer.WriteLine("sorted");
foreach (Entry entry in ForwardsSection)
WriteEntry(writer, "f ", entry);
foreach (Entry entry in ReverseSection)
WriteEntry(writer, "b ", entry);
}
}
});
}
protected void OpenFile(bool full)
{
if (reader != null)
reader.Seek(0);
else {
try {
// We don't actually write to the file, but requesting ReadWrite access ensures
// that nobody else has the file open for writing (unless someone else set FileShare.Write,
// but that's unlikely, and this program doesn't do that).
//
// Opening with FileAccess.Read would mean that other programs could have the file open and
// modify it, thus invaliding the file offsets stored in the partially-loaded entries.
//
// We need to open with FileShare.Read because the main window and other programs need to
// read the dictionary header to populate the list. (This should probably change.)
// Of course, if we're just reading the dictionary header, we only request read access.
var access = full ? FileAccess.ReadWrite : FileAccess.Read;
// If we're only loading a header, we have to set FileShare.ReadWrite or the call
// fails if the file is already open for ReadWrite.
// If we can open the file for Read access, it should be safe to read from without it
// being modified (when writing to the dictionary, we specify FileShare.None).
var share = full ? FileShare.Read : FileShare.ReadWrite;
reader = new Utf8LineReader(Path, access, share);
} catch (IOException e) {
throw new DictionaryLoadException(e.Message, e);
} catch (ArgumentException e) {
throw new DictionaryLoadException(e.Message, e);
} catch (UnauthorizedAccessException e) {
throw new DictionaryLoadException(e.Message, e);
}
}
}
protected void CloseFile()
{
if (reader != null) {
reader.Dispose();
reader = null;
}
}