/// <summary>
/// Deserializes
/// </summary>
public static FileLocation Deserialize(BuildXLReader reader)
{
FileLocation result = default(FileLocation);
result.Path = reader.ReadString();
result.Hash = ContentHashingUtilities.CreateFrom(reader);
result.Length = reader.ReadInt32Compact();
result.Offset = reader.ReadInt64Compact();
return(result);
}
private static LoadResult TryLoadInternal(string fileContentTablePath, byte entryTimeToLive)
{
Contract.Requires(!string.IsNullOrWhiteSpace(fileContentTablePath));
Contract.Requires(entryTimeToLive > 0);
if (!FileUtilities.FileExistsNoFollow(fileContentTablePath))
{
return(LoadResult.FileNotFound(fileContentTablePath));
}
Stopwatch sw = Stopwatch.StartNew();
try
{
using (FileStream stream = FileUtilities.CreateFileStream(
fileContentTablePath,
FileMode.Open,
FileAccess.Read,
FileShare.Read | FileShare.Delete,
// Ok to evict the file from standby since the file will be overwritten and never reread from disk after this point.
FileOptions.SequentialScan))
{
try
{
Analysis.IgnoreResult(s_fileEnvelope.ReadHeader(stream));
}
catch (BuildXLException ex)
{
return(LoadResult.InvalidFormat(fileContentTablePath, ex.LogEventMessage, sw.ElapsedMilliseconds));
}
using (var reader = new BuildXLReader(debug: false, stream: stream, leaveOpen: true))
{
var loadedTable = new FileContentTable();
uint numberOfEntries = reader.ReadUInt32();
int hashLength = ContentHashingUtilities.HashInfo.ByteLength;
var hashBuffer = new byte[hashLength];
for (uint i = 0; i < numberOfEntries; i++)
{
// Key: Volume and file ID
var fileIdAndVolumeId = FileIdAndVolumeId.Deserialize(reader);
// Entry: USN, hash, length, time to live.
Usn usn = new Usn(reader.ReadUInt64());
int hashBytesRead = 0;
while (hashBytesRead != hashLength)
{
int thisRead = reader.Read(hashBuffer, hashBytesRead, hashLength - hashBytesRead);
if (thisRead == 0)
{
return(LoadResult.InvalidFormat(fileContentTablePath, "Unexpected end of stream", sw.ElapsedMilliseconds));
}
hashBytesRead += thisRead;
Contract.Assert(hashBytesRead <= hashLength);
}
long length = reader.ReadInt64();
byte thisEntryTimeToLive = reader.ReadByte();
if (thisEntryTimeToLive == 0)
{
return(LoadResult.InvalidFormat(fileContentTablePath, "TTL value must be positive", sw.ElapsedMilliseconds));
}
thisEntryTimeToLive = Math.Min(thisEntryTimeToLive, entryTimeToLive);
Contract.Assert(thisEntryTimeToLive > 0);
// We've loaded this entry just now and so clearly haven't used it yet. Tentatively decrement the TTL
// for the in-memory table; if the table is saved again without using this entry, the TTL will stay at this
// lower value.
thisEntryTimeToLive--;
var observedVersionAndHash = new Entry(usn, ContentHashingUtilities.CreateFrom(hashBuffer), length, thisEntryTimeToLive);
bool added = loadedTable.m_entries.TryAdd(fileIdAndVolumeId, observedVersionAndHash);
Contract.Assume(added);
}
loadedTable.Counters.AddToCounter(FileContentTableCounters.NumEntries, loadedTable.Count);
return(LoadResult.Success(fileContentTablePath, loadedTable, sw.ElapsedMilliseconds));
}
}
}
catch (Exception ex)
{
return(LoadResult.Exception(fileContentTablePath, ex, sw.ElapsedMilliseconds));
}
}
