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-rw-r--r--netwerk/cache2/CacheFileUtils.cpp667
1 files changed, 667 insertions, 0 deletions
diff --git a/netwerk/cache2/CacheFileUtils.cpp b/netwerk/cache2/CacheFileUtils.cpp
new file mode 100644
index 0000000000..1e158f394a
--- /dev/null
+++ b/netwerk/cache2/CacheFileUtils.cpp
@@ -0,0 +1,667 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "CacheIndex.h"
+#include "CacheLog.h"
+#include "CacheFileUtils.h"
+#include "CacheObserver.h"
+#include "LoadContextInfo.h"
+#include "mozilla/Tokenizer.h"
+#include "mozilla/Telemetry.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include <algorithm>
+#include "mozilla/Unused.h"
+
+namespace mozilla::net::CacheFileUtils {
+
+// This designates the format for the "alt-data" metadata.
+// When the format changes we need to update the version.
+static uint32_t const kAltDataVersion = 1;
+const char* kAltDataKey = "alt-data";
+
+namespace {
+
+/**
+ * A simple recursive descent parser for the mapping key.
+ */
+class KeyParser : protected Tokenizer {
+ public:
+ explicit KeyParser(nsACString const& aInput)
+ : Tokenizer(aInput),
+ isAnonymous(false)
+ // Initialize the cache key to a zero length by default
+ ,
+ lastTag(0) {}
+
+ private:
+ // Results
+ OriginAttributes originAttribs;
+ bool isAnonymous;
+ nsCString idEnhance;
+ nsDependentCSubstring cacheKey;
+
+ // Keeps the last tag name, used for alphabetical sort checking
+ char lastTag;
+
+ // Classifier for the 'tag' character valid range.
+ // Explicitly using unsigned char as 127 is -1 when signed and it would only
+ // produce a warning.
+ static bool TagChar(const char aChar) {
+ unsigned char c = static_cast<unsigned char>(aChar);
+ return c >= ' ' && c <= '\x7f';
+ }
+
+ bool ParseTags() {
+ // Expects to be at the tag name or at the end
+ if (CheckEOF()) {
+ return true;
+ }
+
+ char tag;
+ if (!ReadChar(&TagChar, &tag)) {
+ return false;
+ }
+
+ // Check the alphabetical order, hard-fail on disobedience
+ if (!(lastTag < tag || tag == ':')) {
+ return false;
+ }
+ lastTag = tag;
+
+ switch (tag) {
+ case ':':
+ // last possible tag, when present there is the cacheKey following,
+ // not terminated with ',' and no need to unescape.
+ cacheKey.Rebind(mCursor, mEnd - mCursor);
+ return true;
+ case 'O': {
+ nsAutoCString originSuffix;
+ if (!ParseValue(&originSuffix) ||
+ !originAttribs.PopulateFromSuffix(originSuffix)) {
+ return false;
+ }
+ break;
+ }
+ case 'p':
+ originAttribs.SyncAttributesWithPrivateBrowsing(true);
+ break;
+ case 'b':
+ // Leaving to be able to read and understand oldformatted entries
+ originAttribs.mInIsolatedMozBrowser = true;
+ break;
+ case 'a':
+ isAnonymous = true;
+ break;
+ case 'i': {
+ // Leaving to be able to read and understand oldformatted entries
+ uint32_t deprecatedAppId = 0;
+ if (!ReadInteger(&deprecatedAppId)) {
+ return false; // not a valid 32-bit integer
+ }
+ break;
+ }
+ case '~':
+ if (!ParseValue(&idEnhance)) {
+ return false;
+ }
+ break;
+ default:
+ if (!ParseValue()) { // skip any tag values, optional
+ return false;
+ }
+ break;
+ }
+
+ // We expect a comma after every tag
+ if (!CheckChar(',')) {
+ return false;
+ }
+
+ // Recurse to the next tag
+ return ParseTags();
+ }
+
+ bool ParseValue(nsACString* result = nullptr) {
+ // If at the end, fail since we expect a comma ; value may be empty tho
+ if (CheckEOF()) {
+ return false;
+ }
+
+ Token t;
+ while (Next(t)) {
+ if (!Token::Char(',').Equals(t)) {
+ if (result) {
+ result->Append(t.Fragment());
+ }
+ continue;
+ }
+
+ if (CheckChar(',')) {
+ // Two commas in a row, escaping
+ if (result) {
+ result->Append(',');
+ }
+ continue;
+ }
+
+ // We must give the comma back since the upper calls expect it
+ Rollback();
+ return true;
+ }
+
+ return false;
+ }
+
+ public:
+ already_AddRefed<LoadContextInfo> Parse() {
+ RefPtr<LoadContextInfo> info;
+ if (ParseTags()) {
+ info = GetLoadContextInfo(isAnonymous, originAttribs);
+ }
+
+ return info.forget();
+ }
+
+ void URISpec(nsACString& result) { result.Assign(cacheKey); }
+
+ void IdEnhance(nsACString& result) { result.Assign(idEnhance); }
+};
+
+} // namespace
+
+already_AddRefed<nsILoadContextInfo> ParseKey(const nsACString& aKey,
+ nsACString* aIdEnhance,
+ nsACString* aURISpec) {
+ KeyParser parser(aKey);
+ RefPtr<LoadContextInfo> info = parser.Parse();
+
+ if (info) {
+ if (aIdEnhance) parser.IdEnhance(*aIdEnhance);
+ if (aURISpec) parser.URISpec(*aURISpec);
+ }
+
+ return info.forget();
+}
+
+void AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString& _retval) {
+ /**
+ * This key is used to salt file hashes. When form of the key is changed
+ * cache entries will fail to find on disk.
+ *
+ * IMPORTANT NOTE:
+ * Keep the attributes list sorted according their ASCII code.
+ */
+
+ if (!aInfo) {
+ return;
+ }
+
+ OriginAttributes const* oa = aInfo->OriginAttributesPtr();
+ nsAutoCString suffix;
+ oa->CreateSuffix(suffix);
+ if (!suffix.IsEmpty()) {
+ AppendTagWithValue(_retval, 'O', suffix);
+ }
+
+ if (aInfo->IsAnonymous()) {
+ _retval.AppendLiteral("a,");
+ }
+
+ if (aInfo->IsPrivate()) {
+ _retval.AppendLiteral("p,");
+ }
+}
+
+void AppendTagWithValue(nsACString& aTarget, char const aTag,
+ const nsACString& aValue) {
+ aTarget.Append(aTag);
+
+ // First check the value string to save some memory copying
+ // for cases we don't need to escape at all (most likely).
+ if (!aValue.IsEmpty()) {
+ if (!aValue.Contains(',')) {
+ // No need to escape
+ aTarget.Append(aValue);
+ } else {
+ nsAutoCString escapedValue(aValue);
+ escapedValue.ReplaceSubstring(","_ns, ",,"_ns);
+ aTarget.Append(escapedValue);
+ }
+ }
+
+ aTarget.Append(',');
+}
+
+nsresult KeyMatchesLoadContextInfo(const nsACString& aKey,
+ nsILoadContextInfo* aInfo, bool* _retval) {
+ nsCOMPtr<nsILoadContextInfo> info = ParseKey(aKey);
+
+ if (!info) {
+ return NS_ERROR_FAILURE;
+ }
+
+ *_retval = info->Equals(aInfo);
+ return NS_OK;
+}
+
+ValidityPair::ValidityPair(uint32_t aOffset, uint32_t aLen)
+ : mOffset(aOffset), mLen(aLen) {}
+
+bool ValidityPair::CanBeMerged(const ValidityPair& aOther) const {
+ // The pairs can be merged into a single one if the start of one of the pairs
+ // is placed anywhere in the validity interval of other pair or exactly after
+ // its end.
+ return IsInOrFollows(aOther.mOffset) || aOther.IsInOrFollows(mOffset);
+}
+
+bool ValidityPair::IsInOrFollows(uint32_t aOffset) const {
+ return mOffset <= aOffset && mOffset + mLen >= aOffset;
+}
+
+bool ValidityPair::LessThan(const ValidityPair& aOther) const {
+ if (mOffset < aOther.mOffset) {
+ return true;
+ }
+
+ if (mOffset == aOther.mOffset && mLen < aOther.mLen) {
+ return true;
+ }
+
+ return false;
+}
+
+void ValidityPair::Merge(const ValidityPair& aOther) {
+ MOZ_ASSERT(CanBeMerged(aOther));
+
+ uint32_t offset = std::min(mOffset, aOther.mOffset);
+ uint32_t end = std::max(mOffset + mLen, aOther.mOffset + aOther.mLen);
+
+ mOffset = offset;
+ mLen = end - offset;
+}
+
+void ValidityMap::Log() const {
+ LOG(("ValidityMap::Log() - number of pairs: %zu", mMap.Length()));
+ for (uint32_t i = 0; i < mMap.Length(); i++) {
+ LOG((" (%u, %u)", mMap[i].Offset() + 0, mMap[i].Len() + 0));
+ }
+}
+
+uint32_t ValidityMap::Length() const { return mMap.Length(); }
+
+void ValidityMap::AddPair(uint32_t aOffset, uint32_t aLen) {
+ ValidityPair pair(aOffset, aLen);
+
+ if (mMap.Length() == 0) {
+ mMap.AppendElement(pair);
+ return;
+ }
+
+ // Find out where to place this pair into the map, it can overlap only with
+ // one preceding pair and all subsequent pairs.
+ uint32_t pos = 0;
+ for (pos = mMap.Length(); pos > 0;) {
+ --pos;
+
+ if (mMap[pos].LessThan(pair)) {
+ // The new pair should be either inserted after pos or merged with it.
+ if (mMap[pos].CanBeMerged(pair)) {
+ // Merge with the preceding pair
+ mMap[pos].Merge(pair);
+ } else {
+ // They don't overlap, element must be placed after pos element
+ ++pos;
+ if (pos == mMap.Length()) {
+ mMap.AppendElement(pair);
+ } else {
+ mMap.InsertElementAt(pos, pair);
+ }
+ }
+
+ break;
+ }
+
+ if (pos == 0) {
+ // The new pair should be placed in front of all existing pairs.
+ mMap.InsertElementAt(0, pair);
+ }
+ }
+
+ // pos now points to merged or inserted pair, check whether it overlaps with
+ // subsequent pairs.
+ while (pos + 1 < mMap.Length()) {
+ if (mMap[pos].CanBeMerged(mMap[pos + 1])) {
+ mMap[pos].Merge(mMap[pos + 1]);
+ mMap.RemoveElementAt(pos + 1);
+ } else {
+ break;
+ }
+ }
+}
+
+void ValidityMap::Clear() { mMap.Clear(); }
+
+size_t ValidityMap::SizeOfExcludingThis(
+ mozilla::MallocSizeOf mallocSizeOf) const {
+ return mMap.ShallowSizeOfExcludingThis(mallocSizeOf);
+}
+
+ValidityPair& ValidityMap::operator[](uint32_t aIdx) {
+ return mMap.ElementAt(aIdx);
+}
+
+StaticMutex DetailedCacheHitTelemetry::sLock;
+uint32_t DetailedCacheHitTelemetry::sRecordCnt = 0;
+DetailedCacheHitTelemetry::HitRate
+ DetailedCacheHitTelemetry::sHRStats[kNumOfRanges];
+
+DetailedCacheHitTelemetry::HitRate::HitRate() { Reset(); }
+
+void DetailedCacheHitTelemetry::HitRate::AddRecord(ERecType aType) {
+ if (aType == HIT) {
+ ++mHitCnt;
+ } else {
+ ++mMissCnt;
+ }
+}
+
+uint32_t DetailedCacheHitTelemetry::HitRate::GetHitRateBucket(
+ uint32_t aNumOfBuckets) const {
+ uint32_t bucketIdx = (aNumOfBuckets * mHitCnt) / (mHitCnt + mMissCnt);
+ if (bucketIdx ==
+ aNumOfBuckets) { // make sure 100% falls into the last bucket
+ --bucketIdx;
+ }
+
+ return bucketIdx;
+}
+
+uint32_t DetailedCacheHitTelemetry::HitRate::Count() {
+ return mHitCnt + mMissCnt;
+}
+
+void DetailedCacheHitTelemetry::HitRate::Reset() {
+ mHitCnt = 0;
+ mMissCnt = 0;
+}
+
+// static
+void DetailedCacheHitTelemetry::AddRecord(ERecType aType,
+ TimeStamp aLoadStart) {
+ bool isUpToDate = false;
+ CacheIndex::IsUpToDate(&isUpToDate);
+ if (!isUpToDate) {
+ // Ignore the record when the entry file count might be incorrect
+ return;
+ }
+
+ uint32_t entryCount;
+ nsresult rv = CacheIndex::GetEntryFileCount(&entryCount);
+ if (NS_FAILED(rv)) {
+ return;
+ }
+
+ uint32_t rangeIdx = entryCount / kRangeSize;
+ if (rangeIdx >= kNumOfRanges) { // The last range has no upper limit.
+ rangeIdx = kNumOfRanges - 1;
+ }
+
+ uint32_t hitMissValue = 2 * rangeIdx; // 2 values per range
+ if (aType == MISS) { // The order is HIT, MISS
+ ++hitMissValue;
+ }
+
+ StaticMutexAutoLock lock(sLock);
+
+ if (aType == MISS) {
+ mozilla::Telemetry::AccumulateTimeDelta(
+ mozilla::Telemetry::NETWORK_CACHE_V2_MISS_TIME_MS, aLoadStart);
+ } else {
+ mozilla::Telemetry::AccumulateTimeDelta(
+ mozilla::Telemetry::NETWORK_CACHE_V2_HIT_TIME_MS, aLoadStart);
+ }
+
+ Telemetry::Accumulate(Telemetry::NETWORK_CACHE_HIT_MISS_STAT_PER_CACHE_SIZE,
+ hitMissValue);
+
+ sHRStats[rangeIdx].AddRecord(aType);
+ ++sRecordCnt;
+
+ if (sRecordCnt < kTotalSamplesReportLimit) {
+ return;
+ }
+
+ sRecordCnt = 0;
+
+ for (uint32_t i = 0; i < kNumOfRanges; ++i) {
+ if (sHRStats[i].Count() >= kHitRateSamplesReportLimit) {
+ // The telemetry enums are grouped by buckets as follows:
+ // Telemetry value : 0,1,2,3, ... ,19,20,21,22, ... ,398,399
+ // Hit rate bucket : 0,0,0,0, ... , 0, 1, 1, 1, ... , 19, 19
+ // Cache size range: 0,1,2,3, ... ,19, 0, 1, 2, ... , 18, 19
+ uint32_t bucketOffset =
+ sHRStats[i].GetHitRateBucket(kHitRateBuckets) * kNumOfRanges;
+
+ Telemetry::Accumulate(Telemetry::NETWORK_CACHE_HIT_RATE_PER_CACHE_SIZE,
+ bucketOffset + i);
+ sHRStats[i].Reset();
+ }
+ }
+}
+
+StaticMutex CachePerfStats::sLock;
+CachePerfStats::PerfData CachePerfStats::sData[CachePerfStats::LAST];
+uint32_t CachePerfStats::sCacheSlowCnt = 0;
+uint32_t CachePerfStats::sCacheNotSlowCnt = 0;
+
+CachePerfStats::MMA::MMA(uint32_t aTotalWeight, bool aFilter)
+ : mSum(0), mSumSq(0), mCnt(0), mWeight(aTotalWeight), mFilter(aFilter) {}
+
+void CachePerfStats::MMA::AddValue(uint32_t aValue) {
+ if (mFilter) {
+ // Filter high spikes
+ uint32_t avg = GetAverage();
+ uint32_t stddev = GetStdDev();
+ uint32_t maxdiff = avg + (3 * stddev);
+ if (avg && aValue > avg + maxdiff) {
+ return;
+ }
+ }
+
+ if (mCnt < mWeight) {
+ // Compute arithmetic average until we have at least mWeight values
+ CheckedInt<uint64_t> newSumSq = CheckedInt<uint64_t>(aValue) * aValue;
+ newSumSq += mSumSq;
+ if (!newSumSq.isValid()) {
+ return; // ignore this value
+ }
+ mSumSq = newSumSq.value();
+ mSum += aValue;
+ ++mCnt;
+ } else {
+ CheckedInt<uint64_t> newSumSq = mSumSq - mSumSq / mCnt;
+ newSumSq += static_cast<uint64_t>(aValue) * aValue;
+ if (!newSumSq.isValid()) {
+ return; // ignore this value
+ }
+ mSumSq = newSumSq.value();
+
+ // Compute modified moving average for more values:
+ // newAvg = ((weight - 1) * oldAvg + newValue) / weight
+ mSum -= GetAverage();
+ mSum += aValue;
+ }
+}
+
+uint32_t CachePerfStats::MMA::GetAverage() {
+ if (mCnt == 0) {
+ return 0;
+ }
+
+ return mSum / mCnt;
+}
+
+uint32_t CachePerfStats::MMA::GetStdDev() {
+ if (mCnt == 0) {
+ return 0;
+ }
+
+ uint32_t avg = GetAverage();
+ uint64_t avgSq = static_cast<uint64_t>(avg) * avg;
+ uint64_t variance = mSumSq / mCnt;
+ if (variance < avgSq) {
+ // Due to rounding error when using integer data type, it can happen that
+ // average of squares of the values is smaller than square of the average
+ // of the values. In this case fix mSumSq.
+ variance = avgSq;
+ mSumSq = variance * mCnt;
+ }
+
+ variance -= avgSq;
+ return sqrt(static_cast<double>(variance));
+}
+
+CachePerfStats::PerfData::PerfData()
+ : mFilteredAvg(50, true), mShortAvg(3, false) {}
+
+void CachePerfStats::PerfData::AddValue(uint32_t aValue, bool aShortOnly) {
+ if (!aShortOnly) {
+ mFilteredAvg.AddValue(aValue);
+ }
+ mShortAvg.AddValue(aValue);
+}
+
+uint32_t CachePerfStats::PerfData::GetAverage(bool aFiltered) {
+ return aFiltered ? mFilteredAvg.GetAverage() : mShortAvg.GetAverage();
+}
+
+uint32_t CachePerfStats::PerfData::GetStdDev(bool aFiltered) {
+ return aFiltered ? mFilteredAvg.GetStdDev() : mShortAvg.GetStdDev();
+}
+
+// static
+void CachePerfStats::AddValue(EDataType aType, uint32_t aValue,
+ bool aShortOnly) {
+ StaticMutexAutoLock lock(sLock);
+ sData[aType].AddValue(aValue, aShortOnly);
+}
+
+// static
+uint32_t CachePerfStats::GetAverage(EDataType aType, bool aFiltered) {
+ StaticMutexAutoLock lock(sLock);
+ return sData[aType].GetAverage(aFiltered);
+}
+
+// static
+uint32_t CachePerfStats::GetStdDev(EDataType aType, bool aFiltered) {
+ StaticMutexAutoLock lock(sLock);
+ return sData[aType].GetStdDev(aFiltered);
+}
+
+// static
+bool CachePerfStats::IsCacheSlow() {
+ StaticMutexAutoLock lock(sLock);
+
+ // Compare mShortAvg with mFilteredAvg to find out whether cache is getting
+ // slower. Use only data about single IO operations because ENTRY_OPEN can be
+ // affected by more factors than a slow disk.
+ for (uint32_t i = 0; i < ENTRY_OPEN; ++i) {
+ if (i == IO_WRITE) {
+ // Skip this data type. IsCacheSlow is used for determining cache slowness
+ // when opening entries. Writes have low priority and it's normal that
+ // they are delayed a lot, but this doesn't necessarily affect opening
+ // cache entries.
+ continue;
+ }
+
+ uint32_t avgLong = sData[i].GetAverage(true);
+ if (avgLong == 0) {
+ // We have no perf data yet, skip this data type.
+ continue;
+ }
+ uint32_t avgShort = sData[i].GetAverage(false);
+ uint32_t stddevLong = sData[i].GetStdDev(true);
+ uint32_t maxdiff = avgLong + (3 * stddevLong);
+
+ if (avgShort > avgLong + maxdiff) {
+ LOG(
+ ("CachePerfStats::IsCacheSlow() - result is slow based on perf "
+ "type %u [avgShort=%u, avgLong=%u, stddevLong=%u]",
+ i, avgShort, avgLong, stddevLong));
+ ++sCacheSlowCnt;
+ return true;
+ }
+ }
+
+ ++sCacheNotSlowCnt;
+ return false;
+}
+
+// static
+void CachePerfStats::GetSlowStats(uint32_t* aSlow, uint32_t* aNotSlow) {
+ StaticMutexAutoLock lock(sLock);
+ *aSlow = sCacheSlowCnt;
+ *aNotSlow = sCacheNotSlowCnt;
+}
+
+void FreeBuffer(void* aBuf) {
+#ifndef NS_FREE_PERMANENT_DATA
+ if (CacheObserver::ShuttingDown()) {
+ return;
+ }
+#endif
+
+ free(aBuf);
+}
+
+nsresult ParseAlternativeDataInfo(const char* aInfo, int64_t* _offset,
+ nsACString* _type) {
+ // The format is: "1;12345,javascript/binary"
+ // <version>;<offset>,<type>
+ mozilla::Tokenizer p(aInfo, nullptr, "/");
+ uint32_t altDataVersion = 0;
+ int64_t altDataOffset = -1;
+
+ // The metadata format has a wrong version number.
+ if (!p.ReadInteger(&altDataVersion) || altDataVersion != kAltDataVersion) {
+ LOG(
+ ("ParseAlternativeDataInfo() - altDataVersion=%u, "
+ "expectedVersion=%u",
+ altDataVersion, kAltDataVersion));
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+
+ if (!p.CheckChar(';') || !p.ReadInteger(&altDataOffset) ||
+ !p.CheckChar(',')) {
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+
+ // The requested alt-data representation is not available
+ if (altDataOffset < 0) {
+ return NS_ERROR_NOT_AVAILABLE;
+ }
+
+ if (_offset) {
+ *_offset = altDataOffset;
+ }
+
+ if (_type) {
+ mozilla::Unused << p.ReadUntil(Tokenizer::Token::EndOfFile(), *_type);
+ }
+
+ return NS_OK;
+}
+
+void BuildAlternativeDataInfo(const char* aInfo, int64_t aOffset,
+ nsACString& _retval) {
+ _retval.Truncate();
+ _retval.AppendInt(kAltDataVersion);
+ _retval.Append(';');
+ _retval.AppendInt(aOffset);
+ _retval.Append(',');
+ _retval.Append(aInfo);
+}
+
+} // namespace mozilla::net::CacheFileUtils