public static Task TranscodeAsync <T>(
string input,
string output,
ITimeSeriesDecoder <T> decoder,
ITimeSeriesEncoder <T> encoder,
Func <T, T> transform = null)
{
return(TranscodeAsync <T, T>(input, output, decoder, encoder, transform ?? (x => x)));
}
// Reads all chunks from the ChunkIO file named `input`, decodes their content with `decoder`,
// transforms records with `transform`, encodes them with `encoder` and appends to the ChunkIO
// file named `output`.
//
// The output ChunkIO file is written with default WriterOptions. Some input chunks may get
// merged but no chunks get split.
public static async Task TranscodeAsync <T, U>(
string input,
string output,
ITimeSeriesDecoder <T> decoder,
ITimeSeriesEncoder <U> encoder,
Func <T, U> transform)
{
using (var reader = new TimeSeriesReader <T>(input, decoder)) {
var writer = new TimeSeriesWriter <U>(output, encoder);
try {
long len = await reader.FlushRemoteWriterAsync(flushToDisk : false);
await reader.ReadAfter(DateTime.MinValue, 0, len).ForEachAsync(async(IDecodedChunk <T> c) => {
await writer.WriteBatchAsync(c.Select(transform));
});
} finally {
await writer.DisposeAsync();
}
}
}
public TimeSeriesWriter(string fname, ITimeSeriesEncoder <T> encoder)
: this(fname, encoder, new WriterOptions())
{
}
// The file must be exclusively writable. If it exists, it gets appended to.
// You can use TimeSeriesReader to read the file. You can even do it while
// having an active writer.
//
// Takes ownership of the encoder. TimeSeriesWriter.Dispose() will dispose it.
public TimeSeriesWriter(string fname, ITimeSeriesEncoder <T> encoder, WriterOptions opt)
{
Encoder = encoder ?? throw new ArgumentNullException(nameof(encoder));
_writer = new BufferedWriter(fname, opt);
}
