public async Task<FileIndexSeekResult> SeekAsync(int index)
{
var result = new FileIndexSeekResult();
if (!FilesExist || index < 0 || index >= Length)
{
return FileIndexSeekResult.None;
}
var e = Entries[index];
if (e.Lookup < 0 || e.Length <= 0)
{
return FileIndexSeekResult.None;
}
var length = result.Length = e.Length & 0x7FFFFFFF;
result.Extra = e.Extra;
using (await _asyncLock.LockAsync())
{
if (Stream != null && (!Stream.CanRead || !Stream.CanSeek))
{
Stream.Dispose();
Stream = null;
}
if (Stream == null)
{
Stream = new FileStream(DataPath, FileMode.Open, FileAccess.Read, FileShare.Read);
}
Stream.Seek(e.Lookup, SeekOrigin.Begin);
result.Stream = new MemoryStream();
for (var offset = 0; offset < length; offset += _copyBuffer.Length)
{
var count = Math.Min(_copyBuffer.Length, length);
var numBytesRead = await Stream.ReadAsync(_copyBuffer, offset, count).ConfigureAwait(false);
await result.Stream.WriteAsync(_copyBuffer, offset, numBytesRead).ConfigureAwait(false);
}
result.Stream.Position = 0;
return result;
}
}
public async Task <FileIndexSeekResult> SeekAsync(int index)
{
var result = new FileIndexSeekResult();
if (!FilesExist || index < 0 || index >= Length)
{
return(FileIndexSeekResult.None);
}
var e = Entries[index];
if (e.Lookup < 0 || e.Length <= 0)
{
return(FileIndexSeekResult.None);
}
var length = result.Length = e.Length & 0x7FFFFFFF;
result.Extra = e.Extra;
using (await _asyncLock.LockAsync())
{
if (Stream != null && (!Stream.CanRead || !Stream.CanSeek))
{
Stream.Dispose();
Stream = null;
}
if (Stream == null)
{
Stream = new FileStream(DataPath, FileMode.Open, FileAccess.Read, FileShare.Read);
}
Stream.Seek(e.Lookup, SeekOrigin.Begin);
result.Stream = new MemoryStream();
for (var offset = 0; offset < length; offset += _copyBuffer.Length)
{
var count = Math.Min(_copyBuffer.Length, length);
var numBytesRead = await Stream.ReadAsync(_copyBuffer, offset, count).ConfigureAwait(false);
await result.Stream.WriteAsync(_copyBuffer, offset, numBytesRead).ConfigureAwait(false);
}
result.Stream.Position = 0;
return(result);
}
}
