public LogBuffers(string logFileName)
{
var fileInfo = new FileInfo(logFileName);
var logLength = fileInfo.Length;
var termLength = LogBufferDescriptor.ComputeTermLength(logLength);
LogBufferDescriptor.CheckTermLength(termLength);
_termLength = termLength;
// if log length exceeds MAX_INT we need multiple mapped buffers, (see FileChannel.map doc).
if (logLength < int.MaxValue)
{
var mappedBuffer = IoUtil.MapExistingFile(logFileName);
_mappedByteBuffers = new[] { mappedBuffer };
var metaDataSectionOffset = termLength * LogBufferDescriptor.PARTITION_COUNT;
for (var i = 0; i < LogBufferDescriptor.PARTITION_COUNT; i++)
{
var metaDataOffset = metaDataSectionOffset + (i * LogBufferDescriptor.TERM_META_DATA_LENGTH);
_atomicBuffers[i] = new UnsafeBuffer(mappedBuffer.Pointer, i * termLength, termLength);
_atomicBuffers[i + LogBufferDescriptor.PARTITION_COUNT] = new UnsafeBuffer(mappedBuffer.Pointer, metaDataOffset, LogBufferDescriptor.TERM_META_DATA_LENGTH);
}
_atomicBuffers[_atomicBuffers.Length - 1] = new UnsafeBuffer(mappedBuffer.Pointer, (int)(logLength - LogBufferDescriptor.LOG_META_DATA_LENGTH), LogBufferDescriptor.LOG_META_DATA_LENGTH);
}
else
{
_mappedByteBuffers = new MappedByteBuffer[LogBufferDescriptor.PARTITION_COUNT + 1];
var metaDataSectionOffset = termLength * (long)LogBufferDescriptor.PARTITION_COUNT;
var metaDataSectionLength = (int)(logLength - metaDataSectionOffset);
var memoryMappedFile = IoUtil.OpenMemoryMappedFile(logFileName);
var metaDataMappedBuffer = new MappedByteBuffer(memoryMappedFile, metaDataSectionOffset, metaDataSectionLength);
_mappedByteBuffers[_mappedByteBuffers.Length - 1] = metaDataMappedBuffer;
for (var i = 0; i < LogBufferDescriptor.PARTITION_COUNT; i++)
{
_mappedByteBuffers[i] = new MappedByteBuffer(memoryMappedFile, termLength * (long)i, termLength);
_atomicBuffers[i] = new UnsafeBuffer(_mappedByteBuffers[i].Pointer, termLength);
_atomicBuffers[i + LogBufferDescriptor.PARTITION_COUNT] = new UnsafeBuffer(metaDataMappedBuffer.Pointer, i * LogBufferDescriptor.TERM_META_DATA_LENGTH, LogBufferDescriptor.TERM_META_DATA_LENGTH);
}
_atomicBuffers[_atomicBuffers.Length - 1] = new UnsafeBuffer(metaDataMappedBuffer.Pointer, metaDataSectionLength - LogBufferDescriptor.LOG_META_DATA_LENGTH, LogBufferDescriptor.LOG_META_DATA_LENGTH);
}
// TODO try/catch
foreach (var buffer in _atomicBuffers)
{
buffer.VerifyAlignment();
}
}
public LogBuffers(string logFileName, int termLength = LogBufferDescriptor.TERM_MIN_LENGTH)
{
try {
long logLength = LogBufferDescriptor.PARTITION_COUNT *
(LogBufferDescriptor.TERM_META_DATA_LENGTH + termLength) +
LogBufferDescriptor.LOG_META_DATA_LENGTH;
termLength = LogBufferDescriptor.ComputeTermLength(logLength);
LogBufferDescriptor.CheckTermLength(termLength);
_df = new DirectFile(logFileName, logLength);
_termLength = termLength;
// if log length exceeds MAX_INT we need multiple mapped buffers, (see FileChannel.map doc).
if (logLength < int.MaxValue)
{
int metaDataSectionOffset = termLength * LogBufferDescriptor.PARTITION_COUNT;
for (int i = 0; i < LogBufferDescriptor.PARTITION_COUNT; i++)
{
int metaDataOffset = metaDataSectionOffset + (i * LogBufferDescriptor.TERM_META_DATA_LENGTH);
_buffers[i] = new DirectBuffer(termLength, _df.Buffer.Data + i * termLength);
_buffers[i + LogBufferDescriptor.PARTITION_COUNT] = new DirectBuffer(LogBufferDescriptor.TERM_META_DATA_LENGTH, _df.Buffer.Data + metaDataOffset);
_partitions[i] = new LogBufferPartition(_buffers[i], _buffers[i + LogBufferDescriptor.PARTITION_COUNT]);
}
_buffers[_buffers.Length - 1] = new DirectBuffer(LogBufferDescriptor.LOG_META_DATA_LENGTH,
_df.Buffer.Data + (int)(logLength - LogBufferDescriptor.LOG_META_DATA_LENGTH));
}
else
{
throw new NotImplementedException("TODO Check .NET mapping limit");
}
} catch (IOException ex) {
throw new AggregateException(ex);
}
foreach (var buffer in _buffers)
{
buffer.VerifyAlignment(8);
}
}