internal bool GetLogicalAddress(Key *key, out long logicalAddress)
{
var bucket = default(HashBucket *);
var slot = default(int);
logicalAddress = Constants.kInvalidAddress;
var physicalAddress = default(long);
var info = default(RecordInfo *);
var hash = Key.GetHashCode(key);
var tag = (ushort)((ulong)hash >> Constants.kHashTagShift);
var entry = default(HashBucketEntry);
var tagExists = FindTag(hash, tag, ref bucket, ref slot, ref entry);
if (tagExists)
{
logicalAddress = entry.word & Constants.kAddressMask;
Debug.Assert(logicalAddress != 0);
if (logicalAddress >= hlog.HeadAddress)
{
physicalAddress = hlog.GetPhysicalAddress(logicalAddress);
if (!Key.Equals(key, Layout.GetKey(physicalAddress)))
{
logicalAddress = Layout.GetInfo(physicalAddress)->PreviousAddress;
TraceBackForKeyMatch(key, logicalAddress, hlog.HeadAddress, out logicalAddress, out physicalAddress);
}
}
}
if (logicalAddress < hlog.HeadAddress && logicalAddress != Constants.kInvalidAddress)
{
return(false);
}
return(true);
}
private void AsyncGetFromDiskCallback(
uint errorCode,
uint numBytes,
NativeOverlapped *overlap)
{
if (errorCode != 0)
{
Trace.TraceError("OverlappedStream GetQueuedCompletionStatus error: {0}", errorCode);
}
var result = (AsyncGetFromDiskResult <AsyncIOContext>)Overlapped.Unpack(overlap).AsyncResult;
Interlocked.Decrement(ref numPendingReads);
var ctx = result.context;
var record = ctx.record.GetValidPointer();
if (Layout.HasTotalRecord(record, ctx.record.available_bytes, out int requiredBytes))
{
//We have the complete record.
if (RetrievedObjects(record, ctx))
{
if (Key.Equals((Key *)ctx.key, Layout.GetKey((long)record)))
{
//The keys are same, so I/O is complete
// ctx.record = result.record;
ctx.callbackQueue.Add(ctx);
}
else
{
var oldAddress = ctx.logicalAddress;
//keys are not same. I/O is not complete
ctx.logicalAddress = ((RecordInfo *)record)->PreviousAddress;
if (ctx.logicalAddress != Constants.kInvalidAddress)
{
// Delete key, value, record
if (Key.HasObjectsToSerialize())
{
var physicalAddress = (long)ctx.record.GetValidPointer();
Key.Free(Layout.GetKey(physicalAddress));
}
if (Value.HasObjectsToSerialize())
{
var physicalAddress = (long)ctx.record.GetValidPointer();
Value.Free(Layout.GetValue(physicalAddress));
}
ctx.record.Return();
ctx.record = ctx.objBuffer = default(SectorAlignedMemory);
AsyncGetFromDisk(ctx.logicalAddress, requiredBytes, AsyncGetFromDiskCallback, ctx);
}
else
{
ctx.callbackQueue.Add(ctx);
}
}
}
}
else
{
ctx.record.Return();
AsyncGetFromDisk(ctx.logicalAddress, requiredBytes, AsyncGetFromDiskCallback, ctx);
}
Overlapped.Free(overlap);
}
protected void AsyncGetFromDiskCallback(
uint errorCode,
uint numBytes,
NativeOverlapped *overlap)
{
//Debugger.Break();
var result = (AsyncGetFromDiskResult <AsyncIOContext>)Overlapped.Unpack(overlap).AsyncResult;
try
{
if (errorCode != 0)
{
Trace.TraceError("OverlappedStream GetQueuedCompletionStatus error: {0}", errorCode);
}
}
catch (Exception ex)
{
Trace.TraceError("Completion Callback error, {0}", ex.Message);
}
finally
{
Interlocked.Decrement(ref numPendingReads);
var ctx = result.context;
var record = ctx.record.GetValidPointer();
if (Layout.HasTotalRecord(record, ctx.record.available_bytes, out int requiredBytes))
{
//We have the complete record.
if (RetrievedObjects(record, ctx))
{
if (Key.Equals(ctx.key, Layout.GetKey((long)record)))
{
//The keys are same, so I/O is complete
// ctx.record = result.record;
ctx.callbackQueue.Add(ctx);
}
else
{
var oldAddress = ctx.logicalAddress;
//keys are not same. I/O is not complete
ctx.logicalAddress = ((RecordInfo *)record)->PreviousAddress;
if (ctx.logicalAddress != Constants.kInvalidAddress)
{
// Delete key, value, record
if (Key.HasObjectsToSerialize())
{
var physicalAddress = (long)ctx.record.GetValidPointer();
Key.Free(Layout.GetKey(physicalAddress));
}
if (Value.HasObjectsToSerialize())
{
var physicalAddress = (long)ctx.record.GetValidPointer();
Value.Free(Layout.GetValue(physicalAddress));
}
ctx.record.Return();
AsyncGetFromDisk(ctx.logicalAddress, requiredBytes, AsyncGetFromDiskCallback, ctx);
}
else
{
//Console.WriteLine("Lookup Address = " + oldAddress);
//Console.WriteLine("RecordInfo: " + RecordInfo.ToString((RecordInfo*)record));
// Console.WriteLine("Record not found. Looking for: " + ctx.key->value + " found: " + Layout.GetKey((long)record)->value + " req bytes: " + requiredBytes);
ctx.callbackQueue.Add(ctx);
}
}
}
}
else
{
ctx.record.Return();
AsyncGetFromDisk(ctx.logicalAddress, requiredBytes, AsyncGetFromDiskCallback, ctx);
}
Overlapped.Free(overlap);
}
}