/// <summary>
/// Analyzes the cache miss for a specific pip.
/// </summary>
public static CacheMissAnalysisDetailAndResult AnalyzeCacheMiss(
PipCacheMissInfo missInfo,
Func <PipRecordingSession> oldSessionFunc,
Func <PipRecordingSession> newSessionFunc,
CacheMissDiffFormat diffFormat)
{
Contract.Requires(oldSessionFunc != null);
Contract.Requires(newSessionFunc != null);
var cacheMissType = missInfo.CacheMissType.ToString();
var cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType);
switch (missInfo.CacheMissType)
{
// Fingerprint miss.
case PipCacheMissType.MissForDescriptorsDueToAugmentedWeakFingerprints:
case PipCacheMissType.MissForDescriptorsDueToWeakFingerprints:
case PipCacheMissType.MissForDescriptorsDueToStrongFingerprints:
// Compute the pip unique output hash to use as the primary lookup key for fingerprint store entries
cacheMissAnalysisDetailAndResult = AnalyzeFingerprints(oldSessionFunc, newSessionFunc, diffFormat, cacheMissType);
break;
// We had a weak and strong fingerprint match, but couldn't retrieve correct data from the cache
case PipCacheMissType.MissForCacheEntry:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.DataMiss, "Cache entry missing from the cache.");
break;
case PipCacheMissType.MissForProcessMetadata:
case PipCacheMissType.MissForProcessMetadataFromHistoricMetadata:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.DataMiss, "MetaData missing from the cache.");
break;
case PipCacheMissType.MissForProcessOutputContent:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.OutputMiss, "Outputs missing from the cache.", new JObject(new JProperty("MissingOutputs", missInfo.MissedOutputs)));
break;
case PipCacheMissType.MissDueToInvalidDescriptors:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.InvalidDescriptors, "Cache returned invalid data.");
break;
case PipCacheMissType.MissForDescriptorsDueToArtificialMissOptions:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.ArtificialMiss, "Cache miss artificially forced by user.");
break;
case PipCacheMissType.Hit:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.NoMiss, "Pip was a cache hit.");
break;
case PipCacheMissType.Invalid:
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.Invalid, "No valid changes or cache issues were detected to cause process execution, but a process still executed.");
break;
default:
break;
}
return(cacheMissAnalysisDetailAndResult);
}
private static CacheMissAnalysisDetailAndResult AnalyzeFingerprints(
Func <PipRecordingSession> oldSessionFunc,
Func <PipRecordingSession> newSessionFunc,
CacheMissDiffFormat diffFormat,
string cacheMissType)
{
var cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType);
// While a PipRecordingSession is in scope, any pip information retrieved from the fingerprint store is
// automatically written out to per-pip files.
using (var oldPipSession = oldSessionFunc())
using (var newPipSession = newSessionFunc())
{
if (!oldPipSession.EntryExists)
{
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.MissingFromOldBuild, $"No fingerprint computation data found from old build. This may be the first execution where pip outputs were stored to the cache. {RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching}");
// Write to just the old pip file
WriteLine(RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching, oldPipSession.PipWriter);
WriteLine(string.Empty, oldPipSession.PipWriter);
return(cacheMissAnalysisDetailAndResult);
}
if (!newPipSession.EntryExists)
{
// Cases:
// 1. ScheduleProcessNotStoredToCacheDueToFileMonitoringViolations
// 2. ScheduleProcessNotStoredDueToMissingOutputs
// 3. ScheduleProcessNotStoredToWarningsUnderWarnAsError
// 4. ScheduleProcessNotStoredToCacheDueToInherentUncacheability
cacheMissAnalysisDetailAndResult = new CacheMissAnalysisDetailAndResult(cacheMissType, CacheMissAnalysisResult.MissingFromNewBuild, $"No fingerprint computation data found from new build. {RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching}");
// Write to just the new pip file
WriteLine(RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching, newPipSession.PipWriter);
WriteLine(string.Empty, newPipSession.PipWriter);
return(cacheMissAnalysisDetailAndResult);
}
if (oldPipSession.FormattedSemiStableHash != newPipSession.FormattedSemiStableHash)
{
cacheMissAnalysisDetailAndResult.Detail.ReasonFromAnalysis = "SemiStableHashs of the builds are different.";
// Make trivial json so the print looks like the rest of the diff
if (diffFormat == CacheMissDiffFormat.CustomJsonDiff)
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("SemiStableHash",
new JObject(
new JProperty("Old", oldPipSession.FormattedSemiStableHash),
new JProperty("New", newPipSession.FormattedSemiStableHash)));
}
else
{
var oldNode = new JsonNode
{
Name = RepeatedStrings.FormattedSemiStableHashChanged
};
oldNode.Values.Add(oldPipSession.FormattedSemiStableHash);
var newNode = new JsonNode
{
Name = RepeatedStrings.FormattedSemiStableHashChanged
};
newNode.Values.Add(newPipSession.FormattedSemiStableHash);
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("SemiStableHash", JsonTree.PrintTreeDiff(oldNode, newNode));
}
}
// Diff based off the actual fingerprints instead of the PipCacheMissType
// The actual miss type can mismatch the reason from analysis, since cache miss analyzer is a best effort approach.
// There are several circumstances that fingerprintstore doesn't not match the real cache for pip's cache lookup.
// 1. Fingerprint store used for cache miss analysis is load at the beginning of the build and store at the end of the build,
// while cache entries in cache is store and retrieve during the build. There is a chance that the entry of a pip retrieved
// in cache look up time is not the same entry in the fingerprint store for analysis.
// Example: PipA executes in three builds in sequence Build1, Build2, Build3. Build1 finished before Build2 and Build3 starts.
// So, the fingerprint store created/updated in Build1 get stored in cache.
// Then Build2 and Build 3 starts and load the fingerprint store for cache miss analysis.
// PipA in Build2 finished execution and get stored in cache.
// PipB in Build3 started to execute. It get cache miss.
// Its actual cache miss type is from the cache look up result. In this example is the result compare to PipA in Build2.
// However, the cache miss analysis result is a comparison between PipA in Build1 and PipA in Build3.
// So, the ActualMissType can mismatch ReasonFromAnalysis.
// 2. Not all builds contribute to cache enable cache miss analysis, so the fingerprint store doesn't not have a full collection of entry from all builds.
if (oldPipSession.WeakFingerprint != newPipSession.WeakFingerprint)
{
cacheMissAnalysisDetailAndResult.Detail.ReasonFromAnalysis = "WeakFingerprints of the builds are different.";
if (diffFormat == CacheMissDiffFormat.CustomJsonDiff)
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("WeakFingerprintMismatchResult", oldPipSession.DiffWeakFingerprint(newPipSession));
}
else
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("WeakFingerprintMismatchResult", PrintTreeDiff(oldPipSession.GetWeakFingerprintTree(), newPipSession.GetWeakFingerprintTree(), oldPipSession));
}
cacheMissAnalysisDetailAndResult.Result = CacheMissAnalysisResult.WeakFingerprintMismatch;
}
else if (oldPipSession.PathSetHash != newPipSession.PathSetHash)
{
cacheMissAnalysisDetailAndResult.Detail.ReasonFromAnalysis = "PathSets of the builds are different.";
if (diffFormat == CacheMissDiffFormat.CustomJsonDiff)
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("PathSetMismatchResult", oldPipSession.DiffPathSet(newPipSession));
}
else
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("PathSetMismatchResult", PrintTreeDiff(oldPipSession.GetStrongFingerprintTree(), newPipSession.GetStrongFingerprintTree(), oldPipSession));
}
cacheMissAnalysisDetailAndResult.Result = CacheMissAnalysisResult.PathSetHashMismatch;
}
else if (oldPipSession.StrongFingerprint != newPipSession.StrongFingerprint)
{
cacheMissAnalysisDetailAndResult.Detail.ReasonFromAnalysis = "StrongFingerprints of the builds are different.";
if (diffFormat == CacheMissDiffFormat.CustomJsonDiff)
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("StrongFingerprintMismatchResult", oldPipSession.DiffStrongFingerprint(newPipSession));
}
else
{
cacheMissAnalysisDetailAndResult.Detail.AddPropertyToCacheMissInfo("StrongFingerprintMismatchResult", PrintTreeDiff(oldPipSession.GetStrongFingerprintTree(), newPipSession.GetStrongFingerprintTree(), oldPipSession));
}
cacheMissAnalysisDetailAndResult.Result = CacheMissAnalysisResult.StrongFingerprintMismatch;
}
else
{
cacheMissAnalysisDetailAndResult.Detail.ReasonFromAnalysis = $"The fingerprints from both builds matched and no cache retrieval errors occurred. {RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching}";
WriteLine(RepeatedStrings.DisallowedFileAccessesOrPipFailuresPreventCaching, oldPipSession.PipWriter, newPipSession.PipWriter);
cacheMissAnalysisDetailAndResult.Result = CacheMissAnalysisResult.UncacheablePip;
}
}
return(cacheMissAnalysisDetailAndResult);
}
