private static int GetBitCount(int entryCount)
{
var result = checked (entryCount * 64);
Contract.AssertDebug(IsValidBitCount(result));
return(result);
}
/// <summary>
/// Rounds up the given bit count as needed to an allowable size for a <see cref="BitSet"/>
/// (i.e., the returned value satisfies <see cref="IsValidBitCount"/>)
/// </summary>
public static int RoundToValidBitCount(int unroundedBitCount)
{
var result = checked (unroundedBitCount + 63) & ~63;
Contract.AssertDebug(IsValidBitCount(result));
return(result);
}
/// <summary>
/// Renders this object to a string which when parsed with <see cref="Parse(string)"/>
/// returns a <see cref="FileContentInfo"/> object that is equal to this object.
///
/// The format of the rendered value is $"{Hash}_{Length}".
/// </summary>
public string Render()
{
Func <string, object, string> propertyRenderer = (name, value) =>
{
var valueStr = value.ToString();
Contract.AssertDebug(
!valueStr.Contains(RenderSeparator),
I($"Rendered value of the '{name}' property ('{valueStr}') must not contain the designated separator string ('{RenderSeparator}')"));
return(valueStr);
};
string hashStr = propertyRenderer(nameof(Hash), Hash);
string lengthStr = propertyRenderer(nameof(RawLength), m_length);
return(I($"{hashStr}{RenderSeparator}{lengthStr}"));
}
/// <summary>
/// Splits the current instance into a smaller instances
/// </summary>
public IReadOnlyList <ContentLocationEventData> Split(long maxEstimatedSize)
{
// First, need to compute the number of hashes that will fit into maxEstimatedSize.
var maxHashCount = MaxContentHashesCount(maxEstimatedSize);
// Then we need to split the instance into a sequence of instances.
var hashes = ContentHashes.Split(maxHashCount).ToList();
var result = new List <ContentLocationEventData>(hashes.Count);
Contract.Assert(hashes.Sum(c => c.Count) == ContentHashes.Count);
switch (this)
{
case AddContentLocationEventData addContentLocationEventData:
var contentSizes = addContentLocationEventData.ContentSizes.Split(maxHashCount).ToList();
Contract.Assert(hashes.Count == contentSizes.Count);
result.AddRange(hashes.Select((t, index) => new AddContentLocationEventData(Sender, t, contentSizes[index], addContentLocationEventData.Touch)));
break;
case RemoveContentLocationEventData _:
result.AddRange(hashes.Select(t => new RemoveContentLocationEventData(Sender, t)));
break;
case TouchContentLocationEventData touchContentLocationEventData:
result.AddRange(hashes.Select(t => new TouchContentLocationEventData(Sender, t, touchContentLocationEventData.AccessTime)));
break;
}
Contract.AssertDebug(result.TrueForAll(v => v.EstimateSerializedInstanceSize() < maxEstimatedSize));
return(result);
int MaxContentHashesCount(long estimatedSize)
{
switch (this)
{
case AddContentLocationEventData _:
return((int)(estimatedSize - SerializedSizeBase) / (ShortHash.SerializedLength + sizeof(long)));
default:
return((int)(estimatedSize - SerializedSizeBase) / (ShortHash.SerializedLength));
}
}
}
/// <inheritdoc />
protected override byte[] HashFinal()
{
Contract.AssertDebug(_buffer != null);
// Here, either the buffer has data, or there were no blocks.
// Flush out buffer
if (_currentOffset != 0)
{
var blockHash = HashBlock(_buffer, _currentOffset);
return(_rollingId.Finalize(blockHash).Bytes);
}
// if there are no blocks add an empty block
var emptyBlockHash = HashBlock(new byte[] { }, 0);
return(_rollingId.Finalize(emptyBlockHash).Bytes);
}
/// <summary>
/// Records a <see cref="ContentHash" /> for the given file handle. This hash mapping will be persisted to disk if the
/// table is saved with <see cref="SaveAsync" />. The given file handle should be opened with at most Read sharing
/// (having the handle should ensure the file is not being written).
/// This returns a <see cref="VersionedFileIdentityAndContentInfo"/>:
/// - The identity has the kind <see cref="VersionedFileIdentity.IdentityKind.StrongUsn"/> if a USN-based identity was successfully established;
/// the identity may have kind <see cref="VersionedFileIdentity.IdentityKind.Anonymous"/> if such an identity was unavailable.
/// - Regardless, the contained <see cref="FileContentInfo"/> contains the actual length of the stream corresponding to <paramref name="hash"/>.
/// </summary>
/// <remarks>
/// An overload taking a file path is intentionally not provided. This should be called after hashing or writing a file,
/// but before closing the handle. This way, there is no race between establishing the file's hash, some unrelated writer,
/// and recording its file version (e.g., USN) to hash mapping.
/// Note that this results in a small amount of I/O (e.g., on Windows, a file open and USN query), but never hashes the file or reads its contents.
/// The <paramref name="strict"/> corresponds to the <c>flush</c> parameter of <see cref="VersionedFileIdentity.TryEstablishStrong"/>
/// </remarks>
public VersionedFileIdentityAndContentInfo RecordContentHash(
FileStream stream,
ContentHash hash,
bool?strict = default)
{
Contract.Requires(stream != null);
strict = strict ?? stream.CanWrite;
Contract.AssertDebug(stream.SafeFileHandle != null && stream.Name != null);
long length = stream.Length;
VersionedFileIdentity identity = RecordContentHash(
stream.Name,
stream.SafeFileHandle,
hash,
length,
strict: strict);
return(new VersionedFileIdentityAndContentInfo(identity, new FileContentInfo(hash, length)));
}
/// <inheritdoc />
protected override void HashCore(byte[] array, int ibStart, int cbSize)
{
Contract.AssertDebug(_buffer != null);
while (cbSize > 0)
{
if (_currentOffset == _buffer.Length)
{
var blockHash = HashBlock(_buffer, _buffer.Length);
_rollingId.Update(blockHash);
_currentOffset = 0;
}
int bytesToCopy = Math.Min(cbSize, _buffer.Length - _currentOffset);
Buffer.BlockCopy(array, ibStart, _buffer, _currentOffset, bytesToCopy);
_currentOffset += bytesToCopy;
ibStart += bytesToCopy;
cbSize -= bytesToCopy;
}
}
private static bool RangeIncidentNodesAndIntersect(
IReadonlyDirectedGraph graph,
RangedNodeSet walkFromNodes,
Func <IReadonlyDirectedGraph, NodeId, IEnumerable <Edge> > getEdges,
Func <NodeId, NodeId, bool> validateEdgeTopoProperty,
NodeRange incidentNodeFilter,
RangedNodeSet intersectWith,
bool skipOutOfOrderNodes,
out NodeRange range,
out NodeId intersection)
{
// Note that initially, currentMin > currentMax so NodeRange.CreatePossiblyEmpty
// would return an empty range. We return an empty range iff no nodes pass incidentNodeFilter below.
uint currentMin = NodeId.MaxValue;
uint currentMax = NodeId.MinValue;
foreach (NodeId existingNode in walkFromNodes)
{
IEnumerable <Edge> edges = getEdges(graph, existingNode);
foreach (Edge edge in edges)
{
NodeId other = edge.OtherNode;
if (!validateEdgeTopoProperty(existingNode, other))
{
if (skipOutOfOrderNodes)
{
continue;
}
throw new BuildXLException(I($"Topological order violated due to an edge between nodes {existingNode} and {other}"));
}
if (!incidentNodeFilter.Contains(other))
{
continue;
}
if (other.Value > currentMax)
{
currentMax = edge.OtherNode.Value;
Contract.AssertDebug(currentMax <= NodeId.MaxValue && currentMax >= NodeId.MinValue);
}
if (other.Value < currentMin)
{
currentMin = edge.OtherNode.Value;
Contract.AssertDebug(currentMin <= NodeId.MaxValue && currentMin >= NodeId.MinValue);
}
if (intersectWith.Contains(other))
{
intersection = other;
Contract.AssertDebug(currentMin <= NodeId.MaxValue && currentMin >= NodeId.MinValue);
Contract.AssertDebug(currentMax <= NodeId.MaxValue && currentMax >= NodeId.MinValue);
range = NodeRange.CreatePossiblyEmpty(new NodeId(currentMin), new NodeId(currentMax));
return(true);
}
}
}
intersection = NodeId.Invalid;
Contract.AssertDebug(currentMin <= NodeId.MaxValue && currentMin >= NodeId.MinValue);
Contract.AssertDebug(currentMax <= NodeId.MaxValue && currentMax >= NodeId.MinValue);
range = NodeRange.CreatePossiblyEmpty(new NodeId(currentMin), new NodeId(currentMax));
return(false);
}