public Result Initialize(SubStorage tableStorage)
{
// Read and verify the bucket tree header.
// note: skip init
var header = new BucketTree.Header();
Result rc = tableStorage.Read(0, SpanHelpers.AsByteSpan(ref header));
if (rc.IsFailure())
{
return(rc);
}
rc = header.Verify();
if (rc.IsFailure())
{
return(rc);
}
// Determine extents.
long nodeStorageSize = QueryNodeStorageSize(header.EntryCount);
long entryStorageSize = QueryEntryStorageSize(header.EntryCount);
long nodeStorageOffset = QueryHeaderStorageSize();
long entryStorageOffset = nodeStorageOffset + nodeStorageSize;
// Initialize.
var nodeStorage = new SubStorage(tableStorage, nodeStorageOffset, nodeStorageSize);
var entryStorage = new SubStorage(tableStorage, entryStorageOffset, entryStorageSize);
return(Initialize(nodeStorage, entryStorage, header.EntryCount));
}
public Result Initialize(SubStorage nodeStorage, SubStorage entryStorage, int nodeSize, int entrySize,
int entryCount)
{
Assert.AssertTrue(entrySize >= sizeof(long));
Assert.AssertTrue(nodeSize >= entrySize + Unsafe.SizeOf <NodeHeader>());
Assert.AssertTrue(NodeSizeMin <= nodeSize && nodeSize <= NodeSizeMax);
Assert.AssertTrue(Utilities.IsPowerOfTwo(nodeSize));
Assert.AssertTrue(!IsInitialized());
// Ensure valid entry count.
if (entryCount <= 0)
{
return(ResultFs.InvalidArgument.Log());
}
// Allocate node.
if (!_nodeL1.Allocate(nodeSize))
{
return(ResultFs.BufferAllocationFailed.Log());
}
bool needFree = true;
try
{
// Read node.
Result rc = nodeStorage.Read(0, _nodeL1.GetBuffer());
if (rc.IsFailure())
{
return(rc);
}
// Verify node.
rc = _nodeL1.GetHeader().Verify(0, nodeSize, sizeof(long));
if (rc.IsFailure())
{
return(rc);
}
// Validate offsets.
int offsetCount = GetOffsetCount(nodeSize);
int entrySetCount = GetEntrySetCount(nodeSize, entrySize, entryCount);
BucketTreeNode <long> node = _nodeL1.GetNode <long>();
long startOffset;
if (offsetCount < entrySetCount && node.GetCount() < offsetCount)
{
startOffset = node.GetL2BeginOffset();
}
else
{
startOffset = node.GetBeginOffset();
}
long endOffset = node.GetEndOffset();
if (startOffset < 0 || startOffset > node.GetBeginOffset() || startOffset >= endOffset)
{
return(ResultFs.InvalidBucketTreeEntryOffset.Log());
}
NodeStorage = nodeStorage;
EntryStorage = entryStorage;
NodeSize = nodeSize;
EntrySize = entrySize;
OffsetCount = offsetCount;
EntrySetCount = entrySetCount;
StartOffset = startOffset;
EndOffset = endOffset;
needFree = false;
return(Result.Success);
}
finally
{
if (needFree)
{
_nodeL1.Free();
}
}
}