1 files changed, 238 insertions, 0 deletions
diff --git a/netwerk/cache2/CacheFileUtils.h b/netwerk/cache2/CacheFileUtils.h
new file mode 100644
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+++ b/netwerk/cache2/CacheFileUtils.h
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+/* 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/. */
+
+#ifndef CacheFileUtils__h__
+#define CacheFileUtils__h__
+
+#include "nsError.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsTArray.h"
+#include "mozilla/Mutex.h"
+#include "mozilla/StaticMutex.h"
+#include "mozilla/TimeStamp.h"
+
+class nsILoadContextInfo;
+
+namespace mozilla {
+namespace net {
+namespace CacheFileUtils {
+
+extern const char* kAltDataKey;
+
+already_AddRefed<nsILoadContextInfo> ParseKey(const nsACString& aKey,
+                                              nsACString* aIdEnhance = nullptr,
+                                              nsACString* aURISpec = nullptr);
+
+void AppendKeyPrefix(nsILoadContextInfo* aInfo, nsACString& _retval);
+
+void AppendTagWithValue(nsACString& aTarget, char const aTag,
+                        const nsACString& aValue);
+
+nsresult KeyMatchesLoadContextInfo(const nsACString& aKey,
+                                   nsILoadContextInfo* aInfo, bool* _retval);
+
+class ValidityPair {
+ public:
+  ValidityPair(uint32_t aOffset, uint32_t aLen);
+
+  ValidityPair& operator=(const ValidityPair& aOther) = default;
+
+  // Returns true when two pairs can be merged, i.e. they do overlap or the one
+  // ends exactly where the other begins.
+  bool CanBeMerged(const ValidityPair& aOther) const;
+
+  // Returns true when aOffset is placed anywhere in the validity interval or
+  // exactly after its end.
+  bool IsInOrFollows(uint32_t aOffset) const;
+
+  // Returns true when this pair has lower offset than the other pair. In case
+  // both pairs have the same offset it returns true when this pair has a
+  // shorter length.
+  bool LessThan(const ValidityPair& aOther) const;
+
+  // Merges two pair into one.
+  void Merge(const ValidityPair& aOther);
+
+  uint32_t Offset() const { return mOffset; }
+  uint32_t Len() const { return mLen; }
+
+ private:
+  uint32_t mOffset;
+  uint32_t mLen;
+};
+
+class ValidityMap {
+ public:
+  // Prints pairs in the map into log.
+  void Log() const;
+
+  // Returns number of pairs in the map.
+  uint32_t Length() const;
+
+  // Adds a new pair to the map. It keeps the pairs ordered and merges pairs
+  // when possible.
+  void AddPair(uint32_t aOffset, uint32_t aLen);
+
+  // Removes all pairs from the map.
+  void Clear();
+
+  size_t SizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf) const;
+
+  ValidityPair& operator[](uint32_t aIdx);
+
+ private:
+  nsTArray<ValidityPair> mMap;
+};
+
+class DetailedCacheHitTelemetry {
+ public:
+  enum ERecType { HIT = 0, MISS = 1 };
+
+  static void AddRecord(ERecType aType, TimeStamp aLoadStart);
+
+ private:
+  class HitRate {
+   public:
+    HitRate();
+
+    void AddRecord(ERecType aType);
+    // Returns the bucket index that the current hit rate falls into according
+    // to the given aNumOfBuckets.
+    uint32_t GetHitRateBucket(uint32_t aNumOfBuckets) const;
+    uint32_t Count();
+    void Reset();
+
+   private:
+    uint32_t mHitCnt = 0;
+    uint32_t mMissCnt = 0;
+  };
+
+  // Group the hits and misses statistics by cache files count ranges (0-5000,
+  // 5001-10000, ... , 95001- )
+  static const uint32_t kRangeSize = 5000;
+  static const uint32_t kNumOfRanges = 20;
+
+  // Use the same ranges to report an average hit rate. Report the hit rates
+  // (and reset the counters) every kTotalSamplesReportLimit samples.
+  static const uint32_t kTotalSamplesReportLimit = 1000;
+
+  // Report hit rate for a given cache size range only if it contains
+  // kHitRateSamplesReportLimit or more samples. This limit should avoid
+  // reporting a biased statistics.
+  static const uint32_t kHitRateSamplesReportLimit = 500;
+
+  // All hit rates are accumulated in a single telemetry probe, so to use
+  // a sane number of enumerated values the hit rate is divided into buckets
+  // instead of using a percent value. This constant defines number of buckets
+  // that we divide the hit rates into. I.e. we'll report ranges 0%-5%, 5%-10%,
+  // 10-%15%, ...
+  static const uint32_t kHitRateBuckets = 20;
+
+  // Protects sRecordCnt, sHRStats and Telemetry::Accumulated() calls.
+  static StaticMutex sLock;
+
+  // Counter of samples that is compared against kTotalSamplesReportLimit.
+  static uint32_t sRecordCnt MOZ_GUARDED_BY(sLock);
+
+  // Hit rate statistics for every cache size range.
+  static HitRate sHRStats[kNumOfRanges] MOZ_GUARDED_BY(sLock);
+};
+
+class CachePerfStats {
+ public:
+  // perfStatTypes in displayRcwnStats() in toolkit/content/aboutNetworking.js
+  // must match EDataType
+  enum EDataType {
+    IO_OPEN = 0,
+    IO_READ = 1,
+    IO_WRITE = 2,
+    ENTRY_OPEN = 3,
+    LAST = 4
+  };
+
+  static void AddValue(EDataType aType, uint32_t aValue, bool aShortOnly);
+  static uint32_t GetAverage(EDataType aType, bool aFiltered);
+  static uint32_t GetStdDev(EDataType aType, bool aFiltered);
+  static bool IsCacheSlow();
+  static void GetSlowStats(uint32_t* aSlow, uint32_t* aNotSlow);
+
+ private:
+  // This class computes average and standard deviation, it returns an
+  // arithmetic avg and stddev until total number of values reaches mWeight.
+  // Then it returns modified moving average computed as follows:
+  //
+  //   avg = (1-a)*avg + a*value
+  //   avgsq = (1-a)*avgsq + a*value^2
+  //   stddev = sqrt(avgsq - avg^2)
+  //
+  //   where
+  //       avgsq is an average of the square of the values
+  //       a = 1 / weight
+  class MMA {
+   public:
+    MMA(uint32_t aTotalWeight, bool aFilter);
+
+    void AddValue(uint32_t aValue);
+    uint32_t GetAverage();
+    uint32_t GetStdDev();
+
+   private:
+    uint64_t mSum;
+    uint64_t mSumSq;
+    uint32_t mCnt;
+    uint32_t mWeight;
+    bool mFilter;
+  };
+
+  class PerfData {
+   public:
+    PerfData();
+
+    void AddValue(uint32_t aValue, bool aShortOnly);
+    uint32_t GetAverage(bool aFiltered);
+    uint32_t GetStdDev(bool aFiltered);
+
+   private:
+    // Contains filtered data (i.e. times when we think the cache and disk was
+    // not busy) for a longer time.
+    MMA mFilteredAvg;
+
+    // Contains unfiltered average of few recent values.
+    MMA mShortAvg;
+  };
+
+  static StaticMutex sLock;
+
+  static PerfData sData[LAST] MOZ_GUARDED_BY(sLock);
+  static uint32_t sCacheSlowCnt MOZ_GUARDED_BY(sLock);
+  static uint32_t sCacheNotSlowCnt MOZ_GUARDED_BY(sLock);
+};
+
+void FreeBuffer(void* aBuf);
+
+nsresult ParseAlternativeDataInfo(const char* aInfo, int64_t* _offset,
+                                  nsACString* _type);
+
+void BuildAlternativeDataInfo(const char* aInfo, int64_t aOffset,
+                              nsACString& _retval);
+
+class CacheFileLock final {
+ public:
+  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(CacheFileLock)
+  CacheFileLock() = default;
+
+  mozilla::Mutex& Lock() MOZ_RETURN_CAPABILITY(mLock) { return mLock; }
+
+ private:
+  ~CacheFileLock() = default;
+
+  mozilla::Mutex mLock{"CacheFile.mLock"};
+};
+
+}  // namespace CacheFileUtils
+}  // namespace net
+}  // namespace mozilla
+
+#endif