/// <summary>
/// Gets the file corresponding to the given CasHash and checks
/// to see if the file contents hash to the same CasHash value
/// </summary>
/// <param name="originalCasHash">CasHash value to check</param>
/// <param name="errors">Where any cache errors found get stored</param>
private async Task RehashContentsAsync(CasHash originalCasHash, ConcurrentDictionary <CacheError, int> errors)
{
if (originalCasHash.Equals(CasHash.NoItem))
{
// No need to rehash the NoItem cas hash
return;
}
Possible <StreamWithLength, Failure> possibleStream = await m_readOnlySession.GetStreamAsync(originalCasHash);
if (!possibleStream.Succeeded)
{
errors.TryAdd(new CacheError(CacheErrorType.CasHashError, "CasHash " + originalCasHash + " not found in CAS"), 0);
return;
}
using (StreamWithLength stream = possibleStream.Result)
{
ContentHash contentHash = await ContentHashingUtilities.HashContentStreamAsync(stream);
Hash newHash = new Hash(contentHash);
CasHash newCasHash = new CasHash(newHash);
if (!originalCasHash.Equals(newCasHash))
{
errors.TryAdd(new CacheError(CacheErrorType.CasHashError, "The data of CasHash " + originalCasHash + " has been altered in the CAS"), 0);
}
}
}
/// <summary>
/// Attempts to pin the specified CasHash. Returns true if the
/// pinning succeeds.
/// </summary>
/// <param name="casHash">CasHash value to attempt to pin</param>
private async Task <bool> AttemptToPinAsync(CasHash casHash)
{
if (casHash.Equals(CasHash.NoItem))
{
return(true);
}
Possible <string, Failure> pinAttempt = await m_readOnlySession.PinToCasAsync(casHash);
return(pinAttempt.Succeeded);
}
public async Task <Possible <ValidateContentStatus, Failure> > ValidateContentAsync(CasHash hash, UrgencyHint urgencyHint, Guid activityId)
{
Contract.Requires(!IsClosed);
using (var counter = m_counters.ValidateSessionCounter())
{
using (var eventing = new ValidateContentActivity(BasicFilesystemCache.EventSource, activityId, this))
{
eventing.Start(hash, urgencyHint);
if (CasHash.NoItem.Equals(hash))
{
return(eventing.Returns(counter.Ok()));
}
string path = m_cache.ToPath(hash);
try
{
// We don't use ProduceStream as this operation does not pin or cause pinning
// and we want to have FileShare.Delete in case we need to delete this entry
// due to it being corrupt. This way there is no race as to which file is
// being deleted - it will be the one that was just determined to be corrupt.
using (Stream fileData = await m_cache.ContendedOpenStreamAsync(path, FileMode.Open, FileAccess.Read, FileShare.Read | FileShare.Delete, useAsync: true, handlePendingDelete: true))
{
// Size of the file
counter.FileSize(fileData.Length);
CasHash contentHash = new CasHash(await ContentHashingUtilities.HashContentStreamAsync(fileData));
if (contentHash.Equals(hash))
{
return(eventing.Returns(counter.Ok()));
}
// Remove it from pinned as it is being removed
int junk;
m_pinnedToCas.TryRemove(hash, out junk);
// Now, we try to remediate - This is a simple delete attempt with any error
// saying that we could not delete it
try
{
File.Delete(path);
eventing.Write(CacheActivity.CriticalDataOptions, new { RemovedCorruptedEntry = path });
return(eventing.Returns(counter.Remediated()));
}
catch (Exception e)
{
// Could not delete it (for what ever reason)
eventing.Write(CacheActivity.CriticalDataOptions, new { FailedToRemovedCorruptedEntry = path, Reason = e.Message });
// The file failed to be deleted, so we need to say that it is still there
return(eventing.Returns(counter.Invalid()));
}
}
}
catch (FileNotFoundException)
{
// Not found (either type) is the same as Remediated
return(eventing.Returns(counter.Remediated()));
}
catch (DirectoryNotFoundException)
{
// Not found (either type) is the same as Remediated
return(eventing.Returns(counter.Remediated()));
}
catch (Exception e)
{
// Other errors are reported as a failure to produce a stream of the data
return(eventing.Returns(new ProduceStreamFailure(CacheId, hash, e)));
}
}
}
}
/// <summary>
/// Check the input list against the regex
/// </summary>
/// <param name="weak">The weak fingerprint (for logging on failure)</param>
/// <param name="casElement">The CasElement of the strong fingerprint</param>
/// <param name="hashElement">The hashElement of the strong fingerprint (for logging on failure)</param>
/// <param name="urgencyHint">Pass-through</param>
/// <param name="activityId">Pass-through activityId</param>
/// <returns>false if the check was not performed, true if the checks were performed, failure if the regex checks failed</returns>
/// <remarks>
/// This will attempt to validate the CAS stored input list against the regex rules
/// </remarks>
private async Task <Possible <bool, Failure> > CheckInputList(WeakFingerprintHash weak, CasHash casElement, Hash hashElement, UrgencyHint urgencyHint, Guid activityId)
{
// If we either have no CasHash item or we have no regex to check, just return false
// (that we did nothing)
if (casElement.Equals(CasHash.NoItem) || ((Cache.MustIncludeRegex == null) && (Cache.MustNotIncludeRegex == null)))
{
return(false);
}
// mustInclude start out false if we need to check for mustInclude
// Once we get a mustInclude match we no longer need to check.
// If we have no mustInclude regex, we set it to true such that
// we don't bother checking it
bool mustInclude = Cache.MustIncludeRegex == null;
// This is just to make a faster check for the MustNotinclude
// case. If we have the regex then we must check each entry
// but in many cases we don't have the regex so let this be a quick out.
bool checkMustNot = Cache.MustNotIncludeRegex != null;
// Try to get the observed inputs from the CasHash given
var possibleStream = await GetStreamAsync(casElement, urgencyHint, activityId);
if (!possibleStream.Succeeded)
{
// If we could not get a stream to the CasEntery in the fingerprint.
return(new InputListFilterFailure(Cache.CacheId, weak, casElement, hashElement, "Failed to get stream of CasElement"));
}
// Deserialize the contents of the path set.
using (possibleStream.Result)
{
PathTable pathTable = new PathTable();
BuildXLReader reader = new BuildXLReader(false, possibleStream.Result, true);
var maybePathSet = ObservedPathSet.TryDeserialize(pathTable, reader);
if (maybePathSet.Succeeded)
{
// Deserialization was successful
foreach (ObservedPathEntry entry in maybePathSet.Result.Paths)
{
string filepath = entry.Path.ToString(pathTable);
// Have we seen a must-have entry yet? If not check if this is one
// that way once we found one we want we stop checking this regex
if (!mustInclude)
{
mustInclude = Cache.MustIncludeRegex.IsMatch(filepath);
}
// Now, if we are looking for a must not include, we just check for that
// and if it matches we fail
if (checkMustNot)
{
if (Cache.MustNotIncludeRegex.IsMatch(filepath))
{
return(new InputListFilterFailure(Cache.CacheId, weak, casElement, hashElement, string.Format(CultureInfo.InvariantCulture, "Failed due to a MustNotInclude file: {0}", filepath)));
}
}
}
}
else
{
return(new InputListFilterFailure(Cache.CacheId, weak, casElement, hashElement, "Failed to deserialize observed inputs"));
}
}
if (!mustInclude)
{
return(new InputListFilterFailure(Cache.CacheId, weak, casElement, hashElement, "Failed due to not including at least one MustInclude file"));
}
return(true);
}
/// <summary>
/// Analyzes counts and churn of fingerprints, input lists, and optionally
/// content sizes of sessions in the cache.
/// </summary>
/// <param name="sessionNameRegex">Acts as a filter for which sessions to include in the analysis.</param>
/// <param name="analyzeContent">When true, analysis will include content sizing for each session.</param>
/// <returns>SessionChurnInfo object for every session analyzed</returns>
public IEnumerable <SessionChurnInfo> Analyze(Regex sessionNameRegex, bool analyzeContent)
{
Contract.Assume(sessionNameRegex != null);
m_numSessions = 0;
m_numSessionsAnalyzed = 0;
// Used to store every unique strong fingerprint for all sessions
HashSet <StrongFingerprint> allStrongFingerprints = new HashSet <StrongFingerprint>();
// Used to store strong fingerprints for a given session
HashSet <StrongFingerprint> sessionStrongFingerprints = new HashSet <StrongFingerprint>();
HashSet <WeakFingerprintHash> allWeakFingerprints = new HashSet <WeakFingerprintHash>();
// Used to store every unique cas element for all sessions
HashSet <CasHash> allCasHashes = new HashSet <CasHash>();
// Used to store every unique cas entry for all sessions
HashSet <CasHash> allCasEntries = new HashSet <CasHash>();
IEnumerable <Task <string> > unorderedSessionNames = m_cache.EnumerateCompletedSessions();
IOrderedEnumerable <string> orderedSessionNames = unorderedSessionNames.Select(stringTask => stringTask.Result)
.Where((sessionName) =>
{
m_numSessions++;
if (sessionNameRegex.IsMatch(sessionName))
{
m_numSessionsAnalyzed++;
return(true);
}
else
{
return(false);
}
})
.OrderBy(sessionName => sessionName);
// Dictionary of CAS entry sizes
Dictionary <CasHash, long> contentSizeTable = new Dictionary <CasHash, long>();
// Analyze each session in order
foreach (string sessionName in orderedSessionNames)
{
Console.Error.WriteLine("Analyzing session {0}", sessionName);
// Initialize counters for the current session
int totalNumberStrongFingerprints = 0;
int numberUniqueWeakFingerprints = 0;
int numberUniqueStrongFingerprints = 0;
int numberUniqueCasHashesOverTime = 0;
int numberCasHashNoItemsForSession = 0;
int contentErrors = 0;
// Clear the set of strong fingerprints in this next session.
sessionStrongFingerprints.Clear();
// Contains every unique cas hash for the current session
HashSet <CasHash> sessionCasHashes = new HashSet <CasHash>();
IEnumerable <Task <StrongFingerprint> > strongFingerprints = m_cache.EnumerateSessionStrongFingerprints(sessionName).Result;
// Analyze each strong fingerprint
foreach (Task <StrongFingerprint> strongFingerprintTask in strongFingerprints.OutOfOrderTasks())
{
totalNumberStrongFingerprints++;
StrongFingerprint strongFingerprint = strongFingerprintTask.Result;
sessionStrongFingerprints.Add(strongFingerprint);
// Check if strong fingerprint has never been seen before
if (allStrongFingerprints.Add(strongFingerprint))
{
// New strong fingerprint so increment counter and add to collection
numberUniqueStrongFingerprints++;
}
if (allWeakFingerprints.Add(strongFingerprint.WeakFingerprint))
{
numberUniqueWeakFingerprints++;
}
CasHash casElement = strongFingerprint.CasElement;
// Check if the cas hash is the special no item value
if (casElement.Equals(CasHash.NoItem))
{
numberCasHashNoItemsForSession++;
}
// Collect unique CAS elements in the session
sessionCasHashes.Add(casElement);
// Check if cas hash has never been seen before for the whole cache
if (allCasHashes.Add(casElement))
{
numberUniqueCasHashesOverTime++;
}
}
SessionContentInfo sessionContentInfo = null;
if (analyzeContent)
{
// Contains every unique cash entry hash for the current session
var sessionCasEntries = new HashSet <CasHash>();
// Accumulate all the CasEntries for the session
foreach (var task in m_session.GetCacheEntries(sessionStrongFingerprints).OutOfOrderTasks(32))
{
var possibleCasEntries = task.Result;
if (possibleCasEntries.Succeeded)
{
var casEntries = possibleCasEntries.Result;
sessionCasEntries.UnionWith(casEntries);
}
else
{
Console.Error.WriteLine("Unable to get CasEntries: {0}", possibleCasEntries.Failure.DescribeIncludingInnerFailures());
++contentErrors;
}
}
// Retrieve the content size for each new CasEntry.
foreach (var task in m_session.GetContentSizes(sessionCasEntries.Except(allCasEntries)).OutOfOrderTasks(32))
{
var tuple = task.Result;
contentSizeTable[tuple.Item1] = tuple.Item2;
}
// Accumulate the size of content we've already seen.
long totalContentSize = 0;
long newContentSize = 0;
var newContentCount = 0;
foreach (var e in sessionCasEntries)
{
long length;
if (contentSizeTable.TryGetValue(e, out length))
{
if (ValidContentSize(length))
{
totalContentSize += length;
if (!allCasEntries.Contains(e))
{
newContentSize += length;
newContentCount += 1;
allCasEntries.Add(e);
}
}
else
{
Console.Error.WriteLine("Unable to find content length ({0}) for {1}", (ContentError)length, e);
++contentErrors;
}
}
else
{
#pragma warning disable CA2201 // Do not raise reserved exception types
throw new ApplicationException($"No content length for {e}");
#pragma warning restore CA2201 // Do not raise reserved exception types
}
}
sessionContentInfo = new SessionContentInfo(
sessionCasEntries.Count,
totalContentSize,
newContentCount,
newContentSize,
contentErrors);
}
// Aggregate the counters and return the session's data
SessionStrongFingerprintChurnInfo sessionStrongFingerprintChurnInfo =
new SessionStrongFingerprintChurnInfo(totalNumberStrongFingerprints, numberUniqueStrongFingerprints, numberUniqueWeakFingerprints);
SessionInputListChurnInfo sessionInputListChurnInfo =
new SessionInputListChurnInfo(totalNumberStrongFingerprints, sessionCasHashes.Count, numberUniqueCasHashesOverTime, numberCasHashNoItemsForSession);
yield return(new SessionChurnInfo(sessionName, sessionStrongFingerprintChurnInfo, sessionInputListChurnInfo, sessionContentInfo));
}
}
private ContentBreakdownInfo AnalyzeSession(string name)
{
var casEntries = new HashSet <CasHash>();
var casElements = new HashSet <CasHash>();
var sfpSet = new HashSet <StrongFingerprint>();
var casElementSizeTable = new Dictionary <CasHash, long>();
var casEntrySizeTable = new Dictionary <CasHash, long>();
int countSFP = 0;
int contentErrors = 0;
// Enumerate strong fingerprints for the session...
IEnumerable <Task <StrongFingerprint> > strongFingerprints = m_cache.EnumerateSessionStrongFingerprints(name).Result;
// ...and for each, accumulate the input lists as part of the info we'll report.
foreach (Task <StrongFingerprint> strongFingerprintTask in strongFingerprints.OutOfOrderTasks())
{
++countSFP;
StrongFingerprint sfp = strongFingerprintTask.Result;
// Grab the observed input list.
CasHash casElement = sfp.CasElement;
if (!casElement.Equals(CasHash.NoItem))
{
casElements.Add(casElement);
}
// Remember the SFP for the content scan below, so we're not doing this enumeration twice.
sfpSet.Add(sfp);
}
// Now query the content for the SFPs in the session
foreach (var task in m_session.GetCacheEntries(sfpSet).OutOfOrderTasks())
{
var possibleCasEntries = task.Result;
if (possibleCasEntries.Succeeded)
{
casEntries.UnionWith(possibleCasEntries.Result);
}
else
{
Console.Error.WriteLine("Unable to get CasEntries: {0}", possibleCasEntries.Failure.DescribeIncludingInnerFailures());
++contentErrors;
}
}
// With all the CAS entries in hand, get the sizes...
foreach (var task in m_session.GetContentSizes(casEntries.Except(casEntrySizeTable.Keys)).OutOfOrderTasks())
{
var tuple = task.Result;
casEntrySizeTable[tuple.Item1] = tuple.Item2;
}
// Get the sizes of the input lists.
foreach (var task in m_session.GetContentSizes(casElements.Except(casElementSizeTable.Keys)).OutOfOrderTasks())
{
var tuple = task.Result;
casElementSizeTable[tuple.Item1] = tuple.Item2;
}
return(new ContentBreakdownInfo(name, casElementSizeTable, casEntrySizeTable));
}
