public Chunks(TimeSeriesReader <T> reader, DateTime after, long from, long to)
{
_reader = reader;
_after = after;
_from = from;
_to = to;
}
// 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();
}
}
}