toolkit/components/telemetry/Telemetry.cpp
author Wes Kocher <wkocher@mozilla.com>
Wed, 07 Sep 2016 10:18:17 -0700
changeset 313071 1530103e032c225c93bf7ac8fc581ccbab898275
parent 313001 ce2a2dabb0421fa8fd375f4baff9c9eac15cf723
child 313851 a38442afa9317df51b8b47d1251efb851ff54a57
permissions -rw-r--r--
Backed out 17 changesets (bug 1277504, bug 1218577, bug 1218576) for ASAN bc2 failures a=backout Backed out changeset 62009556e4ad (bug 1218576) Backed out changeset 57f9849f0f8f (bug 1218576) Backed out changeset 9595c56c9db2 (bug 1277504) Backed out changeset 9d15ae92f2fa (bug 1218576) Backed out changeset ea7282078b05 (bug 1218576) Backed out changeset 848f4ef30978 (bug 1218576) Backed out changeset 1b6666eb3b81 (bug 1218576) Backed out changeset ce2a2dabb042 (bug 1218576) Backed out changeset 3caacb5c213b (bug 1218576) Backed out changeset c68fc5ad5ecf (bug 1218576) Backed out changeset 1678482b2fad (bug 1218576) Backed out changeset df28918fe236 (bug 1218576) Backed out changeset eb5dbe28ab20 (bug 1218576) Backed out changeset baf105cbe0c8 (bug 1218576) Backed out changeset 7fdd6b6ab594 (bug 1218576) Backed out changeset a0a4829d0ca0 (bug 1218577) Backed out changeset fc16cda7781b (bug 1218576)

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 <algorithm>

#include <fstream>

#include <prio.h>

#include "mozilla/dom/ToJSValue.h"
#include "mozilla/Atomics.h"
#include "mozilla/Attributes.h"
#include "mozilla/DebugOnly.h"
#include "mozilla/Likely.h"
#include "mozilla/MathAlgorithms.h"
#include "mozilla/Unused.h"

#include "base/pickle.h"
#include "nsIComponentManager.h"
#include "nsIServiceManager.h"
#include "nsThreadManager.h"
#include "nsCOMArray.h"
#include "nsCOMPtr.h"
#include "nsXPCOMPrivate.h"
#include "nsIXULAppInfo.h"
#include "nsVersionComparator.h"
#include "mozilla/MemoryReporting.h"
#include "mozilla/ModuleUtils.h"
#include "nsIXPConnect.h"
#include "mozilla/Services.h"
#include "jsapi.h"
#include "jsfriendapi.h"
#include "js/GCAPI.h"
#include "nsString.h"
#include "nsITelemetry.h"
#include "nsIFile.h"
#include "nsIFileStreams.h"
#include "nsIMemoryReporter.h"
#include "nsISeekableStream.h"
#include "Telemetry.h"
#include "TelemetryCommon.h"
#include "TelemetryHistogram.h"
#include "TelemetryScalar.h"
#include "WebrtcTelemetry.h"
#include "nsTHashtable.h"
#include "nsHashKeys.h"
#include "nsBaseHashtable.h"
#include "nsClassHashtable.h"
#include "nsXULAppAPI.h"
#include "nsReadableUtils.h"
#include "nsThreadUtils.h"
#if defined(XP_WIN)
#include "nsUnicharUtils.h"
#endif
#include "nsNetCID.h"
#include "nsNetUtil.h"
#include "nsJSUtils.h"
#include "nsReadableUtils.h"
#include "plstr.h"
#include "nsAppDirectoryServiceDefs.h"
#include "mozilla/BackgroundHangMonitor.h"
#include "mozilla/ThreadHangStats.h"
#include "mozilla/ProcessedStack.h"
#include "mozilla/Mutex.h"
#include "mozilla/FileUtils.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPtr.h"
#include "mozilla/IOInterposer.h"
#include "mozilla/PoisonIOInterposer.h"
#include "mozilla/StartupTimeline.h"
#include "mozilla/HangMonitor.h"
#if defined(MOZ_ENABLE_PROFILER_SPS)
#include "shared-libraries.h"
#endif

namespace {

using namespace mozilla;
using namespace mozilla::HangMonitor;
using Telemetry::Common::AutoHashtable;

// The maximum number of chrome hangs stacks that we're keeping.
const size_t kMaxChromeStacksKept = 50;
// The maximum depth of a single chrome hang stack.
const size_t kMaxChromeStackDepth = 50;

// This class is conceptually a list of ProcessedStack objects, but it represents them
// more efficiently by keeping a single global list of modules.
class CombinedStacks {
public:
  CombinedStacks() : mNextIndex(0) {}
  typedef std::vector<Telemetry::ProcessedStack::Frame> Stack;
  const Telemetry::ProcessedStack::Module& GetModule(unsigned aIndex) const;
  size_t GetModuleCount() const;
  const Stack& GetStack(unsigned aIndex) const;
  size_t AddStack(const Telemetry::ProcessedStack& aStack);
  size_t GetStackCount() const;
  size_t SizeOfExcludingThis() const;
private:
  std::vector<Telemetry::ProcessedStack::Module> mModules;
  // A circular buffer to hold the stacks.
  std::vector<Stack> mStacks;
  // The index of the next buffer element to write to in mStacks.
  size_t mNextIndex;
};

static JSObject *
CreateJSStackObject(JSContext *cx, const CombinedStacks &stacks);

size_t
CombinedStacks::GetModuleCount() const {
  return mModules.size();
}

const Telemetry::ProcessedStack::Module&
CombinedStacks::GetModule(unsigned aIndex) const {
  return mModules[aIndex];
}

size_t
CombinedStacks::AddStack(const Telemetry::ProcessedStack& aStack) {
  // Advance the indices of the circular queue holding the stacks.
  size_t index = mNextIndex++ % kMaxChromeStacksKept;
  // Grow the vector up to the maximum size, if needed.
  if (mStacks.size() < kMaxChromeStacksKept) {
    mStacks.resize(mStacks.size() + 1);
  }
  // Get a reference to the location holding the new stack.
  CombinedStacks::Stack& adjustedStack = mStacks[index];
  // If we're using an old stack to hold aStack, clear it.
  adjustedStack.clear();

  size_t stackSize = aStack.GetStackSize();
  for (size_t i = 0; i < stackSize; ++i) {
    const Telemetry::ProcessedStack::Frame& frame = aStack.GetFrame(i);
    uint16_t modIndex;
    if (frame.mModIndex == std::numeric_limits<uint16_t>::max()) {
      modIndex = frame.mModIndex;
    } else {
      const Telemetry::ProcessedStack::Module& module =
        aStack.GetModule(frame.mModIndex);
      std::vector<Telemetry::ProcessedStack::Module>::iterator modIterator =
        std::find(mModules.begin(), mModules.end(), module);
      if (modIterator == mModules.end()) {
        mModules.push_back(module);
        modIndex = mModules.size() - 1;
      } else {
        modIndex = modIterator - mModules.begin();
      }
    }
    Telemetry::ProcessedStack::Frame adjustedFrame = { frame.mOffset, modIndex };
    adjustedStack.push_back(adjustedFrame);
  }
  return index;
}

const CombinedStacks::Stack&
CombinedStacks::GetStack(unsigned aIndex) const {
  return mStacks[aIndex];
}

size_t
CombinedStacks::GetStackCount() const {
  return mStacks.size();
}

size_t
CombinedStacks::SizeOfExcludingThis() const {
  // This is a crude approximation. We would like to do something like
  // aMallocSizeOf(&mModules[0]), but on linux aMallocSizeOf will call
  // malloc_usable_size which is only safe on the pointers returned by malloc.
  // While it works on current libstdc++, it is better to be safe and not assume
  // that &vec[0] points to one. We could use a custom allocator, but
  // it doesn't seem worth it.
  size_t n = 0;
  n += mModules.capacity() * sizeof(Telemetry::ProcessedStack::Module);
  n += mStacks.capacity() * sizeof(Stack);
  for (std::vector<Stack>::const_iterator i = mStacks.begin(),
         e = mStacks.end(); i != e; ++i) {
    const Stack& s = *i;
    n += s.capacity() * sizeof(Telemetry::ProcessedStack::Frame);
  }
  return n;
}

// This utility function generates a string key that is used to index the annotations
// in a hash map from |HangReports::AddHang|.
nsresult
ComputeAnnotationsKey(const HangAnnotationsPtr& aAnnotations, nsAString& aKeyOut)
{
  UniquePtr<HangAnnotations::Enumerator> annotationsEnum = aAnnotations->GetEnumerator();
  if (!annotationsEnum) {
    return NS_ERROR_FAILURE;
  }

  // Append all the attributes to the key, to uniquely identify this annotation.
  nsAutoString  key;
  nsAutoString  value;
  while (annotationsEnum->Next(key, value)) {
    aKeyOut.Append(key);
    aKeyOut.Append(value);
  }

  return NS_OK;
}

class HangReports {
public:
  /**
   * This struct encapsulates information for an individual ChromeHang annotation.
   * mHangIndex is the index of the corresponding ChromeHang.
   */
  struct AnnotationInfo {
    AnnotationInfo(uint32_t aHangIndex,
                   HangAnnotationsPtr aAnnotations)
      : mAnnotations(Move(aAnnotations))
    {
      mHangIndices.AppendElement(aHangIndex);
    }
    AnnotationInfo(AnnotationInfo&& aOther)
      : mHangIndices(aOther.mHangIndices)
      , mAnnotations(Move(aOther.mAnnotations))
    {}
    ~AnnotationInfo() {}
    AnnotationInfo& operator=(AnnotationInfo&& aOther)
    {
      mHangIndices = aOther.mHangIndices;
      mAnnotations = Move(aOther.mAnnotations);
      return *this;
    }
    // To save memory, a single AnnotationInfo can be associated to multiple chrome
    // hangs. The following array holds the index of each related chrome hang.
    nsTArray<uint32_t> mHangIndices;
    HangAnnotationsPtr mAnnotations;

  private:
    // Force move constructor
    AnnotationInfo(const AnnotationInfo& aOther) = delete;
    void operator=(const AnnotationInfo& aOther) = delete;
  };
  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
  void AddHang(const Telemetry::ProcessedStack& aStack, uint32_t aDuration,
               int32_t aSystemUptime, int32_t aFirefoxUptime,
               HangAnnotationsPtr aAnnotations);
  void PruneStackReferences(const size_t aRemovedStackIndex);
  uint32_t GetDuration(unsigned aIndex) const;
  int32_t GetSystemUptime(unsigned aIndex) const;
  int32_t GetFirefoxUptime(unsigned aIndex) const;
  const nsClassHashtable<nsStringHashKey, AnnotationInfo>& GetAnnotationInfo() const;
  const CombinedStacks& GetStacks() const;
private:
  /**
   * This struct encapsulates the data for an individual ChromeHang, excluding
   * annotations.
   */
  struct HangInfo {
    // Hang duration (in seconds)
    uint32_t mDuration;
    // System uptime (in minutes) at the time of the hang
    int32_t mSystemUptime;
    // Firefox uptime (in minutes) at the time of the hang
    int32_t mFirefoxUptime;
  };
  std::vector<HangInfo> mHangInfo;
  nsClassHashtable<nsStringHashKey, AnnotationInfo> mAnnotationInfo;
  CombinedStacks mStacks;
};

void
HangReports::AddHang(const Telemetry::ProcessedStack& aStack,
                     uint32_t aDuration,
                     int32_t aSystemUptime,
                     int32_t aFirefoxUptime,
                     HangAnnotationsPtr aAnnotations) {
  // Append the new stack to the stack's circular queue.
  size_t hangIndex = mStacks.AddStack(aStack);
  // Append the hang info at the same index, in mHangInfo.
  HangInfo info = { aDuration, aSystemUptime, aFirefoxUptime };
  if (mHangInfo.size() < kMaxChromeStacksKept) {
    mHangInfo.push_back(info);
  } else {
    mHangInfo[hangIndex] = info;
    // Remove any reference to the stack overwritten in the circular queue
    // from the annotations.
    PruneStackReferences(hangIndex);
  }

  if (!aAnnotations) {
    return;
  }

  nsAutoString annotationsKey;
  // Generate a key to index aAnnotations in the hash map.
  nsresult rv = ComputeAnnotationsKey(aAnnotations, annotationsKey);
  if (NS_FAILED(rv)) {
    return;
  }

  AnnotationInfo* annotationsEntry = mAnnotationInfo.Get(annotationsKey);
  if (annotationsEntry) {
    // If the key is already in the hash map, append the index of the chrome hang
    // to its indices.
    annotationsEntry->mHangIndices.AppendElement(hangIndex);
    return;
  }

  // If the key was not found, add the annotations to the hash map.
  mAnnotationInfo.Put(annotationsKey, new AnnotationInfo(hangIndex, Move(aAnnotations)));
}

/**
 * This function removes links to discarded chrome hangs stacks and prunes unused
 * annotations.
 */
void
HangReports::PruneStackReferences(const size_t aRemovedStackIndex) {
  // We need to adjust the indices that link annotations to chrome hangs. Since we
  // removed a stack, we must remove all references to it and prune annotations
  // linked to no stacks.
  for (auto iter = mAnnotationInfo.Iter(); !iter.Done(); iter.Next()) {
    nsTArray<uint32_t>& stackIndices = iter.Data()->mHangIndices;
    size_t toRemove = stackIndices.NoIndex;
    for (size_t k = 0; k < stackIndices.Length(); k++) {
      // Is this index referencing the removed stack?
      if (stackIndices[k] == aRemovedStackIndex) {
        toRemove = k;
        break;
      }
    }

    // Remove the index referencing the old stack from the annotation.
    if (toRemove != stackIndices.NoIndex) {
      stackIndices.RemoveElementAt(toRemove);
    }

    // If this annotation no longer references any stack, drop it.
    if (!stackIndices.Length()) {
      iter.Remove();
    }
  }
}

size_t
HangReports::SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
  size_t n = 0;
  n += mStacks.SizeOfExcludingThis();
  // This is a crude approximation. See comment on
  // CombinedStacks::SizeOfExcludingThis.
  n += mHangInfo.capacity() * sizeof(HangInfo);
  n += mAnnotationInfo.ShallowSizeOfExcludingThis(aMallocSizeOf);
  n += mAnnotationInfo.Count() * sizeof(AnnotationInfo);
  for (auto iter = mAnnotationInfo.ConstIter(); !iter.Done(); iter.Next()) {
    n += iter.Key().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
    n += iter.Data()->mAnnotations->SizeOfIncludingThis(aMallocSizeOf);
  }
  return n;
}

const CombinedStacks&
HangReports::GetStacks() const {
  return mStacks;
}

uint32_t
HangReports::GetDuration(unsigned aIndex) const {
  return mHangInfo[aIndex].mDuration;
}

int32_t
HangReports::GetSystemUptime(unsigned aIndex) const {
  return mHangInfo[aIndex].mSystemUptime;
}

int32_t
HangReports::GetFirefoxUptime(unsigned aIndex) const {
  return mHangInfo[aIndex].mFirefoxUptime;
}

const nsClassHashtable<nsStringHashKey, HangReports::AnnotationInfo>&
HangReports::GetAnnotationInfo() const {
  return mAnnotationInfo;
}

/**
 * IOInterposeObserver recording statistics of main-thread I/O during execution,
 * aimed at consumption by TelemetryImpl
 */
class TelemetryIOInterposeObserver : public IOInterposeObserver
{
  /** File-level statistics structure */
  struct FileStats {
    FileStats()
      : creates(0)
      , reads(0)
      , writes(0)
      , fsyncs(0)
      , stats(0)
      , totalTime(0)
    {}
    uint32_t  creates;      /** Number of create/open operations */
    uint32_t  reads;        /** Number of read operations */
    uint32_t  writes;       /** Number of write operations */
    uint32_t  fsyncs;       /** Number of fsync operations */
    uint32_t  stats;        /** Number of stat operations */
    double    totalTime;    /** Accumulated duration of all operations */
  };

  struct SafeDir {
    SafeDir(const nsAString& aPath, const nsAString& aSubstName)
      : mPath(aPath)
      , mSubstName(aSubstName)
    {}
    size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
      return mPath.SizeOfExcludingThisIfUnshared(aMallocSizeOf) +
             mSubstName.SizeOfExcludingThisIfUnshared(aMallocSizeOf);
    }
    nsString  mPath;        /** Path to the directory */
    nsString  mSubstName;   /** Name to substitute with */
  };

public:
  explicit TelemetryIOInterposeObserver(nsIFile* aXreDir);

  /**
   * An implementation of Observe that records statistics of all
   * file IO operations.
   */
  void Observe(Observation& aOb);

  /**
   * Reflect recorded file IO statistics into Javascript
   */
  bool ReflectIntoJS(JSContext *cx, JS::Handle<JSObject*> rootObj);

  /**
   * Adds a path for inclusion in main thread I/O report.
   * @param aPath Directory path
   * @param aSubstName Name to substitute for aPath for privacy reasons
   */
  void AddPath(const nsAString& aPath, const nsAString& aSubstName);

  /**
   * Get size of hash table with file stats
   */
  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
    return aMallocSizeOf(this) + SizeOfExcludingThis(aMallocSizeOf);
  }

  size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const {
    size_t size = 0;
    size += mFileStats.ShallowSizeOfExcludingThis(aMallocSizeOf);
    for (auto iter = mFileStats.ConstIter(); !iter.Done(); iter.Next()) {
      size += iter.Get()->GetKey().SizeOfExcludingThisIfUnshared(aMallocSizeOf);
    }
    size += mSafeDirs.ShallowSizeOfExcludingThis(aMallocSizeOf);
    uint32_t safeDirsLen = mSafeDirs.Length();
    for (uint32_t i = 0; i < safeDirsLen; ++i) {
      size += mSafeDirs[i].SizeOfExcludingThis(aMallocSizeOf);
    }
    return size;
  }

private:
  enum Stage
  {
    STAGE_STARTUP = 0,
    STAGE_NORMAL,
    STAGE_SHUTDOWN,
    NUM_STAGES
  };
  static inline Stage NextStage(Stage aStage)
  {
    switch (aStage) {
      case STAGE_STARTUP:
        return STAGE_NORMAL;
      case STAGE_NORMAL:
        return STAGE_SHUTDOWN;
      case STAGE_SHUTDOWN:
        return STAGE_SHUTDOWN;
      default:
        return NUM_STAGES;
    }
  }

  struct FileStatsByStage
  {
    FileStats mStats[NUM_STAGES];
  };
  typedef nsBaseHashtableET<nsStringHashKey, FileStatsByStage> FileIOEntryType;

  // Statistics for each filename
  AutoHashtable<FileIOEntryType> mFileStats;
  // Container for whitelisted directories
  nsTArray<SafeDir> mSafeDirs;
  Stage             mCurStage;

  /**
   * Reflect a FileIOEntryType object to a Javascript property on obj with
   * filename as key containing array:
   * [totalTime, creates, reads, writes, fsyncs, stats]
   */
  static bool ReflectFileStats(FileIOEntryType* entry, JSContext *cx,
                               JS::Handle<JSObject*> obj);
};

TelemetryIOInterposeObserver::TelemetryIOInterposeObserver(nsIFile* aXreDir)
  : mCurStage(STAGE_STARTUP)
{
  nsAutoString xreDirPath;
  nsresult rv = aXreDir->GetPath(xreDirPath);
  if (NS_SUCCEEDED(rv)) {
    AddPath(xreDirPath, NS_LITERAL_STRING("{xre}"));
  }
}

void TelemetryIOInterposeObserver::AddPath(const nsAString& aPath,
                                           const nsAString& aSubstName)
{
  mSafeDirs.AppendElement(SafeDir(aPath, aSubstName));
}

// Threshold for reporting slow main-thread I/O (50 milliseconds).
const TimeDuration kTelemetryReportThreshold = TimeDuration::FromMilliseconds(50);

void TelemetryIOInterposeObserver::Observe(Observation& aOb)
{
  // We only report main-thread I/O
  if (!IsMainThread()) {
    return;
  }

  if (aOb.ObservedOperation() == OpNextStage) {
    mCurStage = NextStage(mCurStage);
    MOZ_ASSERT(mCurStage < NUM_STAGES);
    return;
  }

  if (aOb.Duration() < kTelemetryReportThreshold) {
    return;
  }

  // Get the filename
  const char16_t* filename = aOb.Filename();
 
  // Discard observations without filename
  if (!filename) {
    return;
  }

#if defined(XP_WIN)
  nsCaseInsensitiveStringComparator comparator;
#else
  nsDefaultStringComparator comparator;
#endif
  nsAutoString      processedName;
  nsDependentString filenameStr(filename);
  uint32_t safeDirsLen = mSafeDirs.Length();
  for (uint32_t i = 0; i < safeDirsLen; ++i) {
    if (StringBeginsWith(filenameStr, mSafeDirs[i].mPath, comparator)) {
      processedName = mSafeDirs[i].mSubstName;
      processedName += Substring(filenameStr, mSafeDirs[i].mPath.Length());
      break;
    }
  }

  if (processedName.IsEmpty()) {
    return;
  }

  // Create a new entry or retrieve the existing one
  FileIOEntryType* entry = mFileStats.PutEntry(processedName);
  if (entry) {
    FileStats& stats = entry->mData.mStats[mCurStage];
    // Update the statistics
    stats.totalTime += (double) aOb.Duration().ToMilliseconds();
    switch (aOb.ObservedOperation()) {
      case OpCreateOrOpen:
        stats.creates++;
        break;
      case OpRead:
        stats.reads++;
        break;
      case OpWrite:
        stats.writes++;
        break;
      case OpFSync:
        stats.fsyncs++;
        break;
      case OpStat:
        stats.stats++;
        break;
      default:
        break;
    }
  }
}

bool TelemetryIOInterposeObserver::ReflectFileStats(FileIOEntryType* entry,
                                                    JSContext *cx,
                                                    JS::Handle<JSObject*> obj)
{
  JS::AutoValueArray<NUM_STAGES> stages(cx);

  FileStatsByStage& statsByStage = entry->mData;
  for (int s = STAGE_STARTUP; s < NUM_STAGES; ++s) {
    FileStats& fileStats = statsByStage.mStats[s];

    if (fileStats.totalTime == 0 && fileStats.creates == 0 &&
        fileStats.reads == 0 && fileStats.writes == 0 &&
        fileStats.fsyncs == 0 && fileStats.stats == 0) {
      // Don't add an array that contains no information
      stages[s].setNull();
      continue;
    }

    // Array we want to report
    JS::AutoValueArray<6> stats(cx);
    stats[0].setNumber(fileStats.totalTime);
    stats[1].setNumber(fileStats.creates);
    stats[2].setNumber(fileStats.reads);
    stats[3].setNumber(fileStats.writes);
    stats[4].setNumber(fileStats.fsyncs);
    stats[5].setNumber(fileStats.stats);

    // Create jsStats as array of elements above
    JS::RootedObject jsStats(cx, JS_NewArrayObject(cx, stats));
    if (!jsStats) {
      continue;
    }

    stages[s].setObject(*jsStats);
  }

  JS::Rooted<JSObject*> jsEntry(cx, JS_NewArrayObject(cx, stages));
  if (!jsEntry) {
    return false;
  }

  // Add jsEntry to top-level dictionary
  const nsAString& key = entry->GetKey();
  return JS_DefineUCProperty(cx, obj, key.Data(), key.Length(),
                             jsEntry, JSPROP_ENUMERATE | JSPROP_READONLY);
}

bool TelemetryIOInterposeObserver::ReflectIntoJS(JSContext *cx,
                                                 JS::Handle<JSObject*> rootObj)
{
  return mFileStats.ReflectIntoJS(ReflectFileStats, cx, rootObj);
}

// This is not a member of TelemetryImpl because we want to record I/O during
// startup.
StaticAutoPtr<TelemetryIOInterposeObserver> sTelemetryIOObserver;

void
ClearIOReporting()
{
  if (!sTelemetryIOObserver) {
    return;
  }
  IOInterposer::Unregister(IOInterposeObserver::OpAllWithStaging,
                           sTelemetryIOObserver);
  sTelemetryIOObserver = nullptr;
}

class TelemetryImpl final
  : public nsITelemetry
  , public nsIMemoryReporter
{
  NS_DECL_THREADSAFE_ISUPPORTS
  NS_DECL_NSITELEMETRY
  NS_DECL_NSIMEMORYREPORTER

public:
  void InitMemoryReporter();

  static already_AddRefed<nsITelemetry> CreateTelemetryInstance();
  static void ShutdownTelemetry();
  static void RecordSlowStatement(const nsACString &sql, const nsACString &dbName,
                                  uint32_t delay);
#if defined(MOZ_ENABLE_PROFILER_SPS)
  static void RecordChromeHang(uint32_t aDuration,
                               Telemetry::ProcessedStack &aStack,
                               int32_t aSystemUptime,
                               int32_t aFirefoxUptime,
                               HangAnnotationsPtr aAnnotations);
#endif
  static void RecordThreadHangStats(Telemetry::ThreadHangStats& aStats);
  size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf);
  struct Stat {
    uint32_t hitCount;
    uint32_t totalTime;
  };
  struct StmtStats {
    struct Stat mainThread;
    struct Stat otherThreads;
  };
  typedef nsBaseHashtableET<nsCStringHashKey, StmtStats> SlowSQLEntryType;

  static void RecordIceCandidates(const uint32_t iceCandidateBitmask,
                                  const bool success,
                                  const bool loop);
private:
  TelemetryImpl();
  ~TelemetryImpl();

  static nsCString SanitizeSQL(const nsACString& sql);

  enum SanitizedState { Sanitized, Unsanitized };

  static void StoreSlowSQL(const nsACString &offender, uint32_t delay,
                           SanitizedState state);

  static bool ReflectMainThreadSQL(SlowSQLEntryType *entry, JSContext *cx,
                                   JS::Handle<JSObject*> obj);
  static bool ReflectOtherThreadsSQL(SlowSQLEntryType *entry, JSContext *cx,
                                     JS::Handle<JSObject*> obj);
  static bool ReflectSQL(const SlowSQLEntryType *entry, const Stat *stat,
                         JSContext *cx, JS::Handle<JSObject*> obj);

  bool AddSQLInfo(JSContext *cx, JS::Handle<JSObject*> rootObj, bool mainThread,
                  bool privateSQL);
  bool GetSQLStats(JSContext *cx, JS::MutableHandle<JS::Value> ret,
                   bool includePrivateSql);

  void ReadLateWritesStacks(nsIFile* aProfileDir);

  static TelemetryImpl *sTelemetry;
  AutoHashtable<SlowSQLEntryType> mPrivateSQL;
  AutoHashtable<SlowSQLEntryType> mSanitizedSQL;
  Mutex mHashMutex;
  HangReports mHangReports;
  Mutex mHangReportsMutex;
  // mThreadHangStats stores recorded, inactive thread hang stats
  Vector<Telemetry::ThreadHangStats> mThreadHangStats;
  Mutex mThreadHangStatsMutex;

  CombinedStacks mLateWritesStacks; // This is collected out of the main thread.
  bool mCachedTelemetryData;
  uint32_t mLastShutdownTime;
  uint32_t mFailedLockCount;
  nsCOMArray<nsIFetchTelemetryDataCallback> mCallbacks;
  friend class nsFetchTelemetryData;

  WebrtcTelemetry mWebrtcTelemetry;
};

TelemetryImpl*  TelemetryImpl::sTelemetry = nullptr;

MOZ_DEFINE_MALLOC_SIZE_OF(TelemetryMallocSizeOf)

NS_IMETHODIMP
TelemetryImpl::CollectReports(nsIHandleReportCallback* aHandleReport,
                              nsISupports* aData, bool aAnonymize)
{
  MOZ_COLLECT_REPORT(
    "explicit/telemetry", KIND_HEAP, UNITS_BYTES,
    SizeOfIncludingThis(TelemetryMallocSizeOf),
    "Memory used by the telemetry system.");

  return NS_OK;
}

void
InitHistogramRecordingEnabled()
{
  TelemetryHistogram::InitHistogramRecordingEnabled();
}

static uint32_t
ReadLastShutdownDuration(const char *filename) {
  FILE *f = fopen(filename, "r");
  if (!f) {
    return 0;
  }

  int shutdownTime;
  int r = fscanf(f, "%d\n", &shutdownTime);
  fclose(f);
  if (r != 1) {
    return 0;
  }

  return shutdownTime;
}

const int32_t kMaxFailedProfileLockFileSize = 10;

bool
GetFailedLockCount(nsIInputStream* inStream, uint32_t aCount,
                   unsigned int& result)
{
  nsAutoCString bufStr;
  nsresult rv;
  rv = NS_ReadInputStreamToString(inStream, bufStr, aCount);
  NS_ENSURE_SUCCESS(rv, false);
  result = bufStr.ToInteger(&rv);
  return NS_SUCCEEDED(rv) && result > 0;
}

nsresult
GetFailedProfileLockFile(nsIFile* *aFile, nsIFile* aProfileDir)
{
  NS_ENSURE_ARG_POINTER(aProfileDir);

  nsresult rv = aProfileDir->Clone(aFile);
  NS_ENSURE_SUCCESS(rv, rv);

  (*aFile)->AppendNative(NS_LITERAL_CSTRING("Telemetry.FailedProfileLocks.txt"));
  return NS_OK;
}

class nsFetchTelemetryData : public Runnable
{
public:
  nsFetchTelemetryData(const char* aShutdownTimeFilename,
                       nsIFile* aFailedProfileLockFile,
                       nsIFile* aProfileDir)
    : mShutdownTimeFilename(aShutdownTimeFilename),
      mFailedProfileLockFile(aFailedProfileLockFile),
      mTelemetry(TelemetryImpl::sTelemetry),
      mProfileDir(aProfileDir)
  {
  }

private:
  const char* mShutdownTimeFilename;
  nsCOMPtr<nsIFile> mFailedProfileLockFile;
  RefPtr<TelemetryImpl> mTelemetry;
  nsCOMPtr<nsIFile> mProfileDir;

public:
  void MainThread() {
    mTelemetry->mCachedTelemetryData = true;
    for (unsigned int i = 0, n = mTelemetry->mCallbacks.Count(); i < n; ++i) {
      mTelemetry->mCallbacks[i]->Complete();
    }
    mTelemetry->mCallbacks.Clear();
  }

  NS_IMETHOD Run() override {
    LoadFailedLockCount(mTelemetry->mFailedLockCount);
    mTelemetry->mLastShutdownTime = 
      ReadLastShutdownDuration(mShutdownTimeFilename);
    mTelemetry->ReadLateWritesStacks(mProfileDir);
    nsCOMPtr<nsIRunnable> e =
      NewRunnableMethod(this, &nsFetchTelemetryData::MainThread);
    NS_ENSURE_STATE(e);
    NS_DispatchToMainThread(e);
    return NS_OK;
  }

private:
  nsresult
  LoadFailedLockCount(uint32_t& failedLockCount)
  {
    failedLockCount = 0;
    int64_t fileSize = 0;
    nsresult rv = mFailedProfileLockFile->GetFileSize(&fileSize);
    if (NS_FAILED(rv)) {
      return rv;
    }
    NS_ENSURE_TRUE(fileSize <= kMaxFailedProfileLockFileSize,
                   NS_ERROR_UNEXPECTED);
    nsCOMPtr<nsIInputStream> inStream;
    rv = NS_NewLocalFileInputStream(getter_AddRefs(inStream),
                                    mFailedProfileLockFile,
                                    PR_RDONLY);
    NS_ENSURE_SUCCESS(rv, rv);
    NS_ENSURE_TRUE(GetFailedLockCount(inStream, fileSize, failedLockCount),
                   NS_ERROR_UNEXPECTED);
    inStream->Close();

    mFailedProfileLockFile->Remove(false);
    return NS_OK;
  }
};

static TimeStamp gRecordedShutdownStartTime;
static bool gAlreadyFreedShutdownTimeFileName = false;
static char *gRecordedShutdownTimeFileName = nullptr;

static char *
GetShutdownTimeFileName()
{
  if (gAlreadyFreedShutdownTimeFileName) {
    return nullptr;
  }

  if (!gRecordedShutdownTimeFileName) {
    nsCOMPtr<nsIFile> mozFile;
    NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR, getter_AddRefs(mozFile));
    if (!mozFile)
      return nullptr;

    mozFile->AppendNative(NS_LITERAL_CSTRING("Telemetry.ShutdownTime.txt"));
    nsAutoCString nativePath;
    nsresult rv = mozFile->GetNativePath(nativePath);
    if (!NS_SUCCEEDED(rv))
      return nullptr;

    gRecordedShutdownTimeFileName = PL_strdup(nativePath.get());
  }

  return gRecordedShutdownTimeFileName;
}

NS_IMETHODIMP
TelemetryImpl::GetLastShutdownDuration(uint32_t *aResult)
{
  // The user must call AsyncFetchTelemetryData first. We return zero instead of
  // reporting a failure so that the rest of telemetry can uniformly handle
  // the read not being available yet.
  if (!mCachedTelemetryData) {
    *aResult = 0;
    return NS_OK;
  }

  *aResult = mLastShutdownTime;
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::GetFailedProfileLockCount(uint32_t* aResult)
{
  // The user must call AsyncFetchTelemetryData first. We return zero instead of
  // reporting a failure so that the rest of telemetry can uniformly handle
  // the read not being available yet.
  if (!mCachedTelemetryData) {
    *aResult = 0;
    return NS_OK;
  }

  *aResult = mFailedLockCount;
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::AsyncFetchTelemetryData(nsIFetchTelemetryDataCallback *aCallback)
{
  // We have finished reading the data already, just call the callback.
  if (mCachedTelemetryData) {
    aCallback->Complete();
    return NS_OK;
  }

  // We already have a read request running, just remember the callback.
  if (mCallbacks.Count() != 0) {
    mCallbacks.AppendObject(aCallback);
    return NS_OK;
  }

  // We make this check so that GetShutdownTimeFileName() doesn't get
  // called; calling that function without telemetry enabled violates
  // assumptions that the write-the-shutdown-timestamp machinery makes.
  if (!Telemetry::CanRecordExtended()) {
    mCachedTelemetryData = true;
    aCallback->Complete();
    return NS_OK;
  }

  // Send the read to a background thread provided by the stream transport
  // service to avoid a read in the main thread.
  nsCOMPtr<nsIEventTarget> targetThread =
    do_GetService(NS_STREAMTRANSPORTSERVICE_CONTRACTID);
  if (!targetThread) {
    mCachedTelemetryData = true;
    aCallback->Complete();
    return NS_OK;
  }

  // We have to get the filename from the main thread.
  const char *shutdownTimeFilename = GetShutdownTimeFileName();
  if (!shutdownTimeFilename) {
    mCachedTelemetryData = true;
    aCallback->Complete();
    return NS_OK;
  }

  nsCOMPtr<nsIFile> profileDir;
  nsresult rv = NS_GetSpecialDirectory(NS_APP_USER_PROFILE_50_DIR,
                                       getter_AddRefs(profileDir));
  if (NS_FAILED(rv)) {
    mCachedTelemetryData = true;
    aCallback->Complete();
    return NS_OK;
  }

  nsCOMPtr<nsIFile> failedProfileLockFile;
  rv = GetFailedProfileLockFile(getter_AddRefs(failedProfileLockFile),
                                profileDir);
  if (NS_FAILED(rv)) {
    mCachedTelemetryData = true;
    aCallback->Complete();
    return NS_OK;
  }

  mCallbacks.AppendObject(aCallback);

  nsCOMPtr<nsIRunnable> event = new nsFetchTelemetryData(shutdownTimeFilename,
                                                         failedProfileLockFile,
                                                         profileDir);

  targetThread->Dispatch(event, NS_DISPATCH_NORMAL);
  return NS_OK;
}

TelemetryImpl::TelemetryImpl()
  : mHashMutex("Telemetry::mHashMutex")
  , mHangReportsMutex("Telemetry::mHangReportsMutex")
  , mThreadHangStatsMutex("Telemetry::mThreadHangStatsMutex")
  , mCachedTelemetryData(false)
  , mLastShutdownTime(0)
  , mFailedLockCount(0)
{
  // We expect TelemetryHistogram::InitializeGlobalState() to have been
  // called before we get to this point.
  MOZ_ASSERT(TelemetryHistogram::GlobalStateHasBeenInitialized());
}

TelemetryImpl::~TelemetryImpl() {
  UnregisterWeakMemoryReporter(this);
}

void
TelemetryImpl::InitMemoryReporter() {
  RegisterWeakMemoryReporter(this);
}

NS_IMETHODIMP
TelemetryImpl::NewKeyedHistogram(const nsACString &name, const nsACString &expiration, uint32_t histogramType,
                            uint32_t min, uint32_t max, uint32_t bucketCount, JSContext *cx,
                            uint8_t optArgCount, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::NewKeyedHistogram(name, expiration, histogramType,
                                               min, max, bucketCount,
                                               cx, optArgCount, ret);
}


bool
TelemetryImpl::ReflectSQL(const SlowSQLEntryType *entry,
                          const Stat *stat,
                          JSContext *cx,
                          JS::Handle<JSObject*> obj)
{
  if (stat->hitCount == 0)
    return true;

  const nsACString &sql = entry->GetKey();

  JS::Rooted<JSObject*> arrayObj(cx, JS_NewArrayObject(cx, 0));
  if (!arrayObj) {
    return false;
  }
  return (JS_DefineElement(cx, arrayObj, 0, stat->hitCount, JSPROP_ENUMERATE)
          && JS_DefineElement(cx, arrayObj, 1, stat->totalTime, JSPROP_ENUMERATE)
          && JS_DefineProperty(cx, obj, sql.BeginReading(), arrayObj,
                               JSPROP_ENUMERATE));
}

bool
TelemetryImpl::ReflectMainThreadSQL(SlowSQLEntryType *entry, JSContext *cx,
                                    JS::Handle<JSObject*> obj)
{
  return ReflectSQL(entry, &entry->mData.mainThread, cx, obj);
}

bool
TelemetryImpl::ReflectOtherThreadsSQL(SlowSQLEntryType *entry, JSContext *cx,
                                      JS::Handle<JSObject*> obj)
{
  return ReflectSQL(entry, &entry->mData.otherThreads, cx, obj);
}

bool
TelemetryImpl::AddSQLInfo(JSContext *cx, JS::Handle<JSObject*> rootObj, bool mainThread,
                          bool privateSQL)
{
  JS::Rooted<JSObject*> statsObj(cx, JS_NewPlainObject(cx));
  if (!statsObj)
    return false;

  AutoHashtable<SlowSQLEntryType>& sqlMap = (privateSQL ? mPrivateSQL : mSanitizedSQL);
  AutoHashtable<SlowSQLEntryType>::ReflectEntryFunc reflectFunction =
    (mainThread ? ReflectMainThreadSQL : ReflectOtherThreadsSQL);
  if (!sqlMap.ReflectIntoJS(reflectFunction, cx, statsObj)) {
    return false;
  }

  return JS_DefineProperty(cx, rootObj,
                           mainThread ? "mainThread" : "otherThreads",
                           statsObj, JSPROP_ENUMERATE);
}

NS_IMETHODIMP
TelemetryImpl::HistogramFrom(const nsACString &name, const nsACString &existing_name,
                             JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::HistogramFrom(name, existing_name, cx, ret);
}

NS_IMETHODIMP
TelemetryImpl::RegisterAddonHistogram(const nsACString &id,
                                      const nsACString &name,
                                      uint32_t histogramType,
                                      uint32_t min, uint32_t max,
                                      uint32_t bucketCount,
                                      uint8_t optArgCount)
{
  return TelemetryHistogram::RegisterAddonHistogram
            (id, name, histogramType, min, max, bucketCount, optArgCount);
}

NS_IMETHODIMP
TelemetryImpl::GetAddonHistogram(const nsACString &id, const nsACString &name,
                                 JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::GetAddonHistogram(id, name, cx, ret);
}

NS_IMETHODIMP
TelemetryImpl::UnregisterAddonHistograms(const nsACString &id)
{
  return TelemetryHistogram::UnregisterAddonHistograms(id);
}

NS_IMETHODIMP
TelemetryImpl::SetHistogramRecordingEnabled(const nsACString &id, bool aEnabled)
{
  return TelemetryHistogram::SetHistogramRecordingEnabled(id, aEnabled);
}

NS_IMETHODIMP
TelemetryImpl::GetHistogramSnapshots(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::CreateHistogramSnapshots(cx, ret, false, false);
}

NS_IMETHODIMP
TelemetryImpl::SnapshotSubsessionHistograms(bool clearSubsession,
                                            JSContext *cx,
                                            JS::MutableHandle<JS::Value> ret)
{
#if !defined(MOZ_WIDGET_GONK) && !defined(MOZ_WIDGET_ANDROID)
  return TelemetryHistogram::CreateHistogramSnapshots(cx, ret, true,
                                                      clearSubsession);
#else
  return NS_OK;
#endif
}

NS_IMETHODIMP
TelemetryImpl::GetAddonHistogramSnapshots(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::GetAddonHistogramSnapshots(cx, ret);
}

NS_IMETHODIMP
TelemetryImpl::GetKeyedHistogramSnapshots(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::GetKeyedHistogramSnapshots(cx, ret);
}

bool
TelemetryImpl::GetSQLStats(JSContext *cx, JS::MutableHandle<JS::Value> ret, bool includePrivateSql)
{
  JS::Rooted<JSObject*> root_obj(cx, JS_NewPlainObject(cx));
  if (!root_obj)
    return false;
  ret.setObject(*root_obj);

  MutexAutoLock hashMutex(mHashMutex);
  // Add info about slow SQL queries on the main thread
  if (!AddSQLInfo(cx, root_obj, true, includePrivateSql))
    return false;
  // Add info about slow SQL queries on other threads
  if (!AddSQLInfo(cx, root_obj, false, includePrivateSql))
    return false;

  return true;
}

NS_IMETHODIMP
TelemetryImpl::GetSlowSQL(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  if (GetSQLStats(cx, ret, false))
    return NS_OK;
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
TelemetryImpl::GetDebugSlowSQL(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  bool revealPrivateSql =
    Preferences::GetBool("toolkit.telemetry.debugSlowSql", false);
  if (GetSQLStats(cx, ret, revealPrivateSql))
    return NS_OK;
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
TelemetryImpl::GetWebrtcStats(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  if (mWebrtcTelemetry.GetWebrtcStats(cx, ret))
    return NS_OK;
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
TelemetryImpl::GetMaximalNumberOfConcurrentThreads(uint32_t *ret)
{
  *ret = nsThreadManager::get().GetHighestNumberOfThreads();
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::GetChromeHangs(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  MutexAutoLock hangReportMutex(mHangReportsMutex);

  const CombinedStacks& stacks = mHangReports.GetStacks();
  JS::Rooted<JSObject*> fullReportObj(cx, CreateJSStackObject(cx, stacks));
  if (!fullReportObj) {
    return NS_ERROR_FAILURE;
  }

  ret.setObject(*fullReportObj);

  JS::Rooted<JSObject*> durationArray(cx, JS_NewArrayObject(cx, 0));
  JS::Rooted<JSObject*> systemUptimeArray(cx, JS_NewArrayObject(cx, 0));
  JS::Rooted<JSObject*> firefoxUptimeArray(cx, JS_NewArrayObject(cx, 0));
  JS::Rooted<JSObject*> annotationsArray(cx, JS_NewArrayObject(cx, 0));
  if (!durationArray || !systemUptimeArray || !firefoxUptimeArray ||
      !annotationsArray) {
    return NS_ERROR_FAILURE;
  }

  bool ok = JS_DefineProperty(cx, fullReportObj, "durations",
                              durationArray, JSPROP_ENUMERATE);
  if (!ok) {
    return NS_ERROR_FAILURE;
  }

  ok = JS_DefineProperty(cx, fullReportObj, "systemUptime",
                         systemUptimeArray, JSPROP_ENUMERATE);
  if (!ok) {
    return NS_ERROR_FAILURE;
  }

  ok = JS_DefineProperty(cx, fullReportObj, "firefoxUptime",
                         firefoxUptimeArray, JSPROP_ENUMERATE);
  if (!ok) {
    return NS_ERROR_FAILURE;
  }

  ok = JS_DefineProperty(cx, fullReportObj, "annotations", annotationsArray,
                         JSPROP_ENUMERATE);
  if (!ok) {
    return NS_ERROR_FAILURE;
  }


  const size_t length = stacks.GetStackCount();
  for (size_t i = 0; i < length; ++i) {
    if (!JS_DefineElement(cx, durationArray, i, mHangReports.GetDuration(i),
                          JSPROP_ENUMERATE)) {
      return NS_ERROR_FAILURE;
    }
    if (!JS_DefineElement(cx, systemUptimeArray, i, mHangReports.GetSystemUptime(i),
                          JSPROP_ENUMERATE)) {
      return NS_ERROR_FAILURE;
    }
    if (!JS_DefineElement(cx, firefoxUptimeArray, i, mHangReports.GetFirefoxUptime(i),
                          JSPROP_ENUMERATE)) {
      return NS_ERROR_FAILURE;
    }

    size_t annotationIndex = 0;
    const nsClassHashtable<nsStringHashKey, HangReports::AnnotationInfo>& annotationInfo =
      mHangReports.GetAnnotationInfo();

    for (auto iter = annotationInfo.ConstIter(); !iter.Done(); iter.Next()) {
      const HangReports::AnnotationInfo* info = iter.Data();

      JS::Rooted<JSObject*> keyValueArray(cx, JS_NewArrayObject(cx, 0));
      if (!keyValueArray) {
        return NS_ERROR_FAILURE;
      }

      // Create an array containing all the indices of the chrome hangs relative to this
      // annotation.
      JS::Rooted<JS::Value> indicesArray(cx);
      if (!mozilla::dom::ToJSValue(cx, info->mHangIndices, &indicesArray)) {
        return NS_ERROR_OUT_OF_MEMORY;
      }

      // We're saving the annotation as [[indices], {annotation-data}], so add the indices
      // array as the first element of that structure.
      if (!JS_DefineElement(cx, keyValueArray, 0, indicesArray, JSPROP_ENUMERATE)) {
        return NS_ERROR_FAILURE;
      }

      // Create the annotations object...
      JS::Rooted<JSObject*> jsAnnotation(cx, JS_NewPlainObject(cx));
      if (!jsAnnotation) {
        return NS_ERROR_FAILURE;
      }
      UniquePtr<HangAnnotations::Enumerator> annotationsEnum =
        info->mAnnotations->GetEnumerator();
      if (!annotationsEnum) {
        return NS_ERROR_FAILURE;
      }

      // ... fill it with key:value pairs...
      nsAutoString key;
      nsAutoString value;
      while (annotationsEnum->Next(key, value)) {
        JS::RootedValue jsValue(cx);
        jsValue.setString(JS_NewUCStringCopyN(cx, value.get(), value.Length()));
        if (!JS_DefineUCProperty(cx, jsAnnotation, key.get(), key.Length(),
                                 jsValue, JSPROP_ENUMERATE)) {
          return NS_ERROR_FAILURE;
        }
      }

      // ... and append it after the indices array.
      if (!JS_DefineElement(cx, keyValueArray, 1, jsAnnotation, JSPROP_ENUMERATE)) {
        return NS_ERROR_FAILURE;
      }
      if (!JS_DefineElement(cx, annotationsArray, annotationIndex++,
                         keyValueArray, JSPROP_ENUMERATE)) {
        return NS_ERROR_FAILURE;
      }
    }
  }

  return NS_OK;
}

static JSObject *
CreateJSStackObject(JSContext *cx, const CombinedStacks &stacks) {
  JS::Rooted<JSObject*> ret(cx, JS_NewPlainObject(cx));
  if (!ret) {
    return nullptr;
  }

  JS::Rooted<JSObject*> moduleArray(cx, JS_NewArrayObject(cx, 0));
  if (!moduleArray) {
    return nullptr;
  }
  bool ok = JS_DefineProperty(cx, ret, "memoryMap", moduleArray,
                              JSPROP_ENUMERATE);
  if (!ok) {
    return nullptr;
  }

  const size_t moduleCount = stacks.GetModuleCount();
  for (size_t moduleIndex = 0; moduleIndex < moduleCount; ++moduleIndex) {
    // Current module
    const Telemetry::ProcessedStack::Module& module =
      stacks.GetModule(moduleIndex);

    JS::Rooted<JSObject*> moduleInfoArray(cx, JS_NewArrayObject(cx, 0));
    if (!moduleInfoArray) {
      return nullptr;
    }
    if (!JS_DefineElement(cx, moduleArray, moduleIndex, moduleInfoArray,
                          JSPROP_ENUMERATE)) {
      return nullptr;
    }

    unsigned index = 0;

    // Module name
    JS::Rooted<JSString*> str(cx, JS_NewStringCopyZ(cx, module.mName.c_str()));
    if (!str) {
      return nullptr;
    }
    if (!JS_DefineElement(cx, moduleInfoArray, index++, str, JSPROP_ENUMERATE)) {
      return nullptr;
    }

    // Module breakpad identifier
    JS::Rooted<JSString*> id(cx, JS_NewStringCopyZ(cx, module.mBreakpadId.c_str()));
    if (!id) {
      return nullptr;
    }
    if (!JS_DefineElement(cx, moduleInfoArray, index++, id, JSPROP_ENUMERATE)) {
      return nullptr;
    }
  }

  JS::Rooted<JSObject*> reportArray(cx, JS_NewArrayObject(cx, 0));
  if (!reportArray) {
    return nullptr;
  }
  ok = JS_DefineProperty(cx, ret, "stacks", reportArray, JSPROP_ENUMERATE);
  if (!ok) {
    return nullptr;
  }

  const size_t length = stacks.GetStackCount();
  for (size_t i = 0; i < length; ++i) {
    // Represent call stack PCs as (module index, offset) pairs.
    JS::Rooted<JSObject*> pcArray(cx, JS_NewArrayObject(cx, 0));
    if (!pcArray) {
      return nullptr;
    }

    if (!JS_DefineElement(cx, reportArray, i, pcArray, JSPROP_ENUMERATE)) {
      return nullptr;
    }

    const CombinedStacks::Stack& stack = stacks.GetStack(i);
    const uint32_t pcCount = stack.size();
    for (size_t pcIndex = 0; pcIndex < pcCount; ++pcIndex) {
      const Telemetry::ProcessedStack::Frame& frame = stack[pcIndex];
      JS::Rooted<JSObject*> framePair(cx, JS_NewArrayObject(cx, 0));
      if (!framePair) {
        return nullptr;
      }
      int modIndex = (std::numeric_limits<uint16_t>::max() == frame.mModIndex) ?
        -1 : frame.mModIndex;
      if (!JS_DefineElement(cx, framePair, 0, modIndex, JSPROP_ENUMERATE)) {
        return nullptr;
      }
      if (!JS_DefineElement(cx, framePair, 1, static_cast<double>(frame.mOffset),
                            JSPROP_ENUMERATE)) {
        return nullptr;
      }
      if (!JS_DefineElement(cx, pcArray, pcIndex, framePair, JSPROP_ENUMERATE)) {
        return nullptr;
      }
    }
  }

  return ret;
}

static bool
IsValidBreakpadId(const std::string &breakpadId) {
  if (breakpadId.size() < 33) {
    return false;
  }
  for (unsigned i = 0, n = breakpadId.size(); i < n; ++i) {
    char c = breakpadId[i];
    if ((c < '0' || c > '9') && (c < 'A' || c > 'F')) {
      return false;
    }
  }
  return true;
}

// Read a stack from the given file name. In case of any error, aStack is
// unchanged.
static void
ReadStack(const char *aFileName, Telemetry::ProcessedStack &aStack)
{
  std::ifstream file(aFileName);

  size_t numModules;
  file >> numModules;
  if (file.fail()) {
    return;
  }

  char newline = file.get();
  if (file.fail() || newline != '\n') {
    return;
  }

  Telemetry::ProcessedStack stack;
  for (size_t i = 0; i < numModules; ++i) {
    std::string breakpadId;
    file >> breakpadId;
    if (file.fail() || !IsValidBreakpadId(breakpadId)) {
      return;
    }

    char space = file.get();
    if (file.fail() || space != ' ') {
      return;
    }

    std::string moduleName;
    getline(file, moduleName);
    if (file.fail() || moduleName[0] == ' ') {
      return;
    }

    Telemetry::ProcessedStack::Module module = {
      moduleName,
      breakpadId
    };
    stack.AddModule(module);
  }

  size_t numFrames;
  file >> numFrames;
  if (file.fail()) {
    return;
  }

  newline = file.get();
  if (file.fail() || newline != '\n') {
    return;
  }

  for (size_t i = 0; i < numFrames; ++i) {
    uint16_t index;
    file >> index;
    uintptr_t offset;
    file >> std::hex >> offset >> std::dec;
    if (file.fail()) {
      return;
    }

    Telemetry::ProcessedStack::Frame frame = {
      offset,
      index
    };
    stack.AddFrame(frame);
  }

  aStack = stack;
}

static JSObject*
CreateJSTimeHistogram(JSContext* cx, const Telemetry::TimeHistogram& time)
{
  /* Create JS representation of TimeHistogram,
     in the format of Chromium-style histograms. */
  JS::RootedObject ret(cx, JS_NewPlainObject(cx));
  if (!ret) {
    return nullptr;
  }

  if (!JS_DefineProperty(cx, ret, "min", time.GetBucketMin(0),
                         JSPROP_ENUMERATE) ||
      !JS_DefineProperty(cx, ret, "max",
                         time.GetBucketMax(ArrayLength(time) - 1),
                         JSPROP_ENUMERATE) ||
      !JS_DefineProperty(cx, ret, "histogram_type",
                         nsITelemetry::HISTOGRAM_EXPONENTIAL,
                         JSPROP_ENUMERATE)) {
    return nullptr;
  }
  // TODO: calculate "sum"
  if (!JS_DefineProperty(cx, ret, "sum", 0, JSPROP_ENUMERATE)) {
    return nullptr;
  }

  JS::RootedObject ranges(
    cx, JS_NewArrayObject(cx, ArrayLength(time) + 1));
  JS::RootedObject counts(
    cx, JS_NewArrayObject(cx, ArrayLength(time) + 1));
  if (!ranges || !counts) {
    return nullptr;
  }
  /* In a Chromium-style histogram, the first bucket is an "under" bucket
     that represents all values below the histogram's range. */
  if (!JS_DefineElement(cx, ranges, 0, time.GetBucketMin(0), JSPROP_ENUMERATE) ||
      !JS_DefineElement(cx, counts, 0, 0, JSPROP_ENUMERATE)) {
    return nullptr;
  }
  for (size_t i = 0; i < ArrayLength(time); i++) {
    if (!JS_DefineElement(cx, ranges, i + 1, time.GetBucketMax(i),
                          JSPROP_ENUMERATE) ||
        !JS_DefineElement(cx, counts, i + 1, time[i], JSPROP_ENUMERATE)) {
      return nullptr;
    }
  }
  if (!JS_DefineProperty(cx, ret, "ranges", ranges, JSPROP_ENUMERATE) ||
      !JS_DefineProperty(cx, ret, "counts", counts, JSPROP_ENUMERATE)) {
    return nullptr;
  }
  return ret;
}

static JSObject*
CreateJSHangStack(JSContext* cx, const Telemetry::HangStack& stack)
{
  JS::RootedObject ret(cx, JS_NewArrayObject(cx, stack.length()));
  if (!ret) {
    return nullptr;
  }
  for (size_t i = 0; i < stack.length(); i++) {
    JS::RootedString string(cx, JS_NewStringCopyZ(cx, stack[i]));
    if (!JS_DefineElement(cx, ret, i, string, JSPROP_ENUMERATE)) {
      return nullptr;
    }
  }
  return ret;
}

static void
CreateJSHangAnnotations(JSContext* cx, const HangAnnotationsVector& annotations,
                        JS::MutableHandleObject returnedObject)
{
  JS::RootedObject annotationsArray(cx, JS_NewArrayObject(cx, 0));
  if (!annotationsArray) {
    returnedObject.set(nullptr);
    return;
  }
  // We keep track of the annotations we reported in this hash set, so we can
  // discard duplicated ones.
  nsTHashtable<nsStringHashKey> reportedAnnotations;
  size_t annotationIndex = 0;
  for (const HangAnnotationsPtr *i = annotations.begin(), *e = annotations.end();
       i != e; ++i) {
    JS::RootedObject jsAnnotation(cx, JS_NewPlainObject(cx));
    if (!jsAnnotation) {
      continue;
    }
    const HangAnnotationsPtr& curAnnotations = *i;
    // Build a key to index the current annotations in our hash set.
    nsAutoString annotationsKey;
    nsresult rv = ComputeAnnotationsKey(curAnnotations, annotationsKey);
    if (NS_FAILED(rv)) {
      continue;
    }
    // Check if the annotations are in the set. If that's the case, don't double report.
    if (reportedAnnotations.GetEntry(annotationsKey)) {
      continue;
    }
    // If not, report them.
    reportedAnnotations.PutEntry(annotationsKey);
    UniquePtr<HangAnnotations::Enumerator> annotationsEnum =
      curAnnotations->GetEnumerator();
    if (!annotationsEnum) {
      continue;
    }
    nsAutoString key;
    nsAutoString value;
    while (annotationsEnum->Next(key, value)) {
      JS::RootedValue jsValue(cx);
      jsValue.setString(JS_NewUCStringCopyN(cx, value.get(), value.Length()));
      if (!JS_DefineUCProperty(cx, jsAnnotation, key.get(), key.Length(),
                               jsValue, JSPROP_ENUMERATE)) {
        returnedObject.set(nullptr);
        return;
      }
    }
    if (!JS_SetElement(cx, annotationsArray, annotationIndex, jsAnnotation)) {
      continue;
    }
    ++annotationIndex;
  }
  // Return the array using a |MutableHandleObject| to avoid triggering a false
  // positive rooting issue in the hazard analysis build.
  returnedObject.set(annotationsArray);
}

static JSObject*
CreateJSHangHistogram(JSContext* cx, const Telemetry::HangHistogram& hang)
{
  JS::RootedObject ret(cx, JS_NewPlainObject(cx));
  if (!ret) {
    return nullptr;
  }

  JS::RootedObject stack(cx, CreateJSHangStack(cx, hang.GetStack()));
  JS::RootedObject time(cx, CreateJSTimeHistogram(cx, hang));
  auto& hangAnnotations = hang.GetAnnotations();
  JS::RootedObject annotations(cx);
  CreateJSHangAnnotations(cx, hangAnnotations, &annotations);

  if (!stack ||
      !time ||
      !annotations ||
      !JS_DefineProperty(cx, ret, "stack", stack, JSPROP_ENUMERATE) ||
      !JS_DefineProperty(cx, ret, "histogram", time, JSPROP_ENUMERATE) ||
      (!hangAnnotations.empty() && // <-- Only define annotations when nonempty
        !JS_DefineProperty(cx, ret, "annotations", annotations, JSPROP_ENUMERATE))) {
    return nullptr;
  }

  if (!hang.GetNativeStack().empty()) {
    JS::RootedObject native(cx, CreateJSHangStack(cx, hang.GetNativeStack()));
    if (!native ||
        !JS_DefineProperty(cx, ret, "nativeStack", native, JSPROP_ENUMERATE)) {
      return nullptr;
    }
  }
  return ret;
}

static JSObject*
CreateJSThreadHangStats(JSContext* cx, const Telemetry::ThreadHangStats& thread)
{
  JS::RootedObject ret(cx, JS_NewPlainObject(cx));
  if (!ret) {
    return nullptr;
  }
  JS::RootedString name(cx, JS_NewStringCopyZ(cx, thread.GetName()));
  if (!name ||
      !JS_DefineProperty(cx, ret, "name", name, JSPROP_ENUMERATE)) {
    return nullptr;
  }

  JS::RootedObject activity(cx, CreateJSTimeHistogram(cx, thread.mActivity));
  if (!activity ||
      !JS_DefineProperty(cx, ret, "activity", activity, JSPROP_ENUMERATE)) {
    return nullptr;
  }

  JS::RootedObject hangs(cx, JS_NewArrayObject(cx, 0));
  if (!hangs) {
    return nullptr;
  }
  for (size_t i = 0; i < thread.mHangs.length(); i++) {
    JS::RootedObject obj(cx, CreateJSHangHistogram(cx, thread.mHangs[i]));
    if (!JS_DefineElement(cx, hangs, i, obj, JSPROP_ENUMERATE)) {
      return nullptr;
    }
  }
  if (!JS_DefineProperty(cx, ret, "hangs", hangs, JSPROP_ENUMERATE)) {
    return nullptr;
  }

  return ret;
}

NS_IMETHODIMP
TelemetryImpl::GetThreadHangStats(JSContext* cx, JS::MutableHandle<JS::Value> ret)
{
  JS::RootedObject retObj(cx, JS_NewArrayObject(cx, 0));
  if (!retObj) {
    return NS_ERROR_FAILURE;
  }
  size_t threadIndex = 0;

  if (!BackgroundHangMonitor::IsDisabled()) {
    /* First add active threads; we need to hold |iter| (and its lock)
       throughout this method to avoid a race condition where a thread can
       be recorded twice if the thread is destroyed while this method is
       running */
    BackgroundHangMonitor::ThreadHangStatsIterator iter;
    for (Telemetry::ThreadHangStats* histogram = iter.GetNext();
         histogram; histogram = iter.GetNext()) {
      JS::RootedObject obj(cx, CreateJSThreadHangStats(cx, *histogram));
      if (!JS_DefineElement(cx, retObj, threadIndex++, obj, JSPROP_ENUMERATE)) {
        return NS_ERROR_FAILURE;
      }
    }
  }

  // Add saved threads next
  MutexAutoLock autoLock(mThreadHangStatsMutex);
  for (size_t i = 0; i < mThreadHangStats.length(); i++) {
    JS::RootedObject obj(cx,
      CreateJSThreadHangStats(cx, mThreadHangStats[i]));
    if (!JS_DefineElement(cx, retObj, threadIndex++, obj, JSPROP_ENUMERATE)) {
      return NS_ERROR_FAILURE;
    }
  }
  ret.setObject(*retObj);
  return NS_OK;
}

void
TelemetryImpl::ReadLateWritesStacks(nsIFile* aProfileDir)
{
  nsAutoCString nativePath;
  nsresult rv = aProfileDir->GetNativePath(nativePath);
  if (NS_FAILED(rv)) {
    return;
  }

  const char *name = nativePath.get();
  PRDir *dir = PR_OpenDir(name);
  if (!dir) {
    return;
  }

  PRDirEntry *ent;
  const char *prefix = "Telemetry.LateWriteFinal-";
  unsigned int prefixLen = strlen(prefix);
  while ((ent = PR_ReadDir(dir, PR_SKIP_NONE))) {
    if (strncmp(prefix, ent->name, prefixLen) != 0) {
      continue;
    }

    nsAutoCString stackNativePath = nativePath;
    stackNativePath += XPCOM_FILE_PATH_SEPARATOR;
    stackNativePath += nsDependentCString(ent->name);

    Telemetry::ProcessedStack stack;
    ReadStack(stackNativePath.get(), stack);
    if (stack.GetStackSize() != 0) {
      mLateWritesStacks.AddStack(stack);
    }
    // Delete the file so that we don't report it again on the next run.
    PR_Delete(stackNativePath.get());
  }
  PR_CloseDir(dir);
}

NS_IMETHODIMP
TelemetryImpl::GetLateWrites(JSContext *cx, JS::MutableHandle<JS::Value> ret)
{
  // The user must call AsyncReadTelemetryData first. We return an empty list
  // instead of reporting a failure so that the rest of telemetry can uniformly
  // handle the read not being available yet.

  // FIXME: we allocate the js object again and again in the getter. We should
  // figure out a way to cache it. In order to do that we have to call
  // JS_AddNamedObjectRoot. A natural place to do so is in the TelemetryImpl
  // constructor, but it is not clear how to get a JSContext in there.
  // Another option would be to call it in here when we first call
  // CreateJSStackObject, but we would still need to figure out where to call
  // JS_RemoveObjectRoot. Would it be ok to never call JS_RemoveObjectRoot
  // and just set the pointer to nullptr is the telemetry destructor?

  JSObject *report;
  if (!mCachedTelemetryData) {
    CombinedStacks empty;
    report = CreateJSStackObject(cx, empty);
  } else {
    report = CreateJSStackObject(cx, mLateWritesStacks);
  }

  if (report == nullptr) {
    return NS_ERROR_FAILURE;
  }

  ret.setObject(*report);
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::RegisteredHistograms(uint32_t aDataset, uint32_t *aCount,
                                    char*** aHistograms)
{
  return
    TelemetryHistogram::RegisteredHistograms(aDataset, aCount, aHistograms);
}

NS_IMETHODIMP
TelemetryImpl::RegisteredKeyedHistograms(uint32_t aDataset, uint32_t *aCount,
                                         char*** aHistograms)
{
  return
    TelemetryHistogram::RegisteredKeyedHistograms(aDataset, aCount,
                                                  aHistograms);
}

NS_IMETHODIMP
TelemetryImpl::GetHistogramById(const nsACString &name, JSContext *cx,
                                JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::GetHistogramById(name, cx, ret);
}

NS_IMETHODIMP
TelemetryImpl::GetKeyedHistogramById(const nsACString &name, JSContext *cx,
                                     JS::MutableHandle<JS::Value> ret)
{
  return TelemetryHistogram::GetKeyedHistogramById(name, cx, ret);
}

/**
 * Indicates if Telemetry can record base data (FHR data). This is true if the
 * FHR data reporting service or self-support are enabled.
 *
 * In the unlikely event that adding a new base probe is needed, please check the data
 * collection wiki at https://wiki.mozilla.org/Firefox/Data_Collection and talk to the
 * Telemetry team.
 */
NS_IMETHODIMP
TelemetryImpl::GetCanRecordBase(bool *ret) {
  *ret = TelemetryHistogram::CanRecordBase();
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::SetCanRecordBase(bool canRecord) {
  TelemetryHistogram::SetCanRecordBase(canRecord);
  TelemetryScalar::SetCanRecordBase(canRecord);
  return NS_OK;
}

/**
 * Indicates if Telemetry is allowed to record extended data. Returns false if the user
 * hasn't opted into "extended Telemetry" on the Release channel, when the user has
 * explicitly opted out of Telemetry on Nightly/Aurora/Beta or if manually set to false
 * during tests.
 * If the returned value is false, gathering of extended telemetry statistics is disabled.
 */
NS_IMETHODIMP
TelemetryImpl::GetCanRecordExtended(bool *ret) {
  *ret = TelemetryHistogram::CanRecordExtended();
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::SetCanRecordExtended(bool canRecord) {
  TelemetryHistogram::SetCanRecordExtended(canRecord);
  TelemetryScalar::SetCanRecordExtended(canRecord);
  return NS_OK;
}


NS_IMETHODIMP
TelemetryImpl::GetIsOfficialTelemetry(bool *ret) {
#if defined(MOZILLA_OFFICIAL) && defined(MOZ_TELEMETRY_REPORTING) && !defined(DEBUG)
  *ret = true;
#else
  *ret = false;
#endif
  return NS_OK;
}

already_AddRefed<nsITelemetry>
TelemetryImpl::CreateTelemetryInstance()
{
  MOZ_ASSERT(sTelemetry == nullptr, "CreateTelemetryInstance may only be called once, via GetService()");

  // First, initialize the TelemetryHistogram and TelemetryScalar global states.
  TelemetryHistogram::InitializeGlobalState(
                        XRE_IsParentProcess() || XRE_IsContentProcess(),
                        XRE_IsParentProcess() || XRE_IsContentProcess());

  // Only record scalars from the parent process.
  TelemetryScalar::InitializeGlobalState(XRE_IsParentProcess(), XRE_IsParentProcess());

  // Now, create and initialize the Telemetry global state.
  sTelemetry = new TelemetryImpl();

  // AddRef for the local reference
  NS_ADDREF(sTelemetry);
  // AddRef for the caller
  nsCOMPtr<nsITelemetry> ret = sTelemetry;

  sTelemetry->InitMemoryReporter();
  InitHistogramRecordingEnabled(); // requires sTelemetry to exist

  return ret.forget();
}

void
TelemetryImpl::ShutdownTelemetry()
{
  // No point in collecting IO beyond this point
  ClearIOReporting();
  NS_IF_RELEASE(sTelemetry);

  // Lastly, de-initialise the TelemetryHistogram and TelemetryScalar global states,
  // so as to release any heap storage that would otherwise be kept alive by it.
  TelemetryHistogram::DeInitializeGlobalState();
  TelemetryScalar::DeInitializeGlobalState();
}

void
TelemetryImpl::StoreSlowSQL(const nsACString &sql, uint32_t delay,
                            SanitizedState state)
{
  AutoHashtable<SlowSQLEntryType>* slowSQLMap = nullptr;
  if (state == Sanitized)
    slowSQLMap = &(sTelemetry->mSanitizedSQL);
  else
    slowSQLMap = &(sTelemetry->mPrivateSQL);

  MutexAutoLock hashMutex(sTelemetry->mHashMutex);

  SlowSQLEntryType *entry = slowSQLMap->GetEntry(sql);
  if (!entry) {
    entry = slowSQLMap->PutEntry(sql);
    if (MOZ_UNLIKELY(!entry))
      return;
    entry->mData.mainThread.hitCount = 0;
    entry->mData.mainThread.totalTime = 0;
    entry->mData.otherThreads.hitCount = 0;
    entry->mData.otherThreads.totalTime = 0;
  }

  if (NS_IsMainThread()) {
    entry->mData.mainThread.hitCount++;
    entry->mData.mainThread.totalTime += delay;
  } else {
    entry->mData.otherThreads.hitCount++;
    entry->mData.otherThreads.totalTime += delay;
  }
}

/**
 * This method replaces string literals in SQL strings with the word :private
 *
 * States used in this state machine:
 *
 * NORMAL:
 *  - This is the active state when not iterating over a string literal or
 *  comment
 *
 * SINGLE_QUOTE:
 *  - Defined here: http://www.sqlite.org/lang_expr.html
 *  - This state represents iterating over a string literal opened with
 *  a single quote.
 *  - A single quote within the string can be encoded by putting 2 single quotes
 *  in a row, e.g. 'This literal contains an escaped quote '''
 *  - Any double quotes found within a single-quoted literal are ignored
 *  - This state covers BLOB literals, e.g. X'ABC123'
 *  - The string literal and the enclosing quotes will be replaced with
 *  the text :private
 *
 * DOUBLE_QUOTE:
 *  - Same rules as the SINGLE_QUOTE state.
 *  - According to http://www.sqlite.org/lang_keywords.html,
 *  SQLite interprets text in double quotes as an identifier unless it's used in
 *  a context where it cannot be resolved to an identifier and a string literal
 *  is allowed. This method removes text in double-quotes for safety.
 *
 *  DASH_COMMENT:
 *  - http://www.sqlite.org/lang_comment.html
 *  - A dash comment starts with two dashes in a row,
 *  e.g. DROP TABLE foo -- a comment
 *  - Any text following two dashes in a row is interpreted as a comment until
 *  end of input or a newline character
 *  - Any quotes found within the comment are ignored and no replacements made
 *
 *  C_STYLE_COMMENT:
 *  - http://www.sqlite.org/lang_comment.html
 *  - A C-style comment starts with a forward slash and an asterisk, and ends
 *  with an asterisk and a forward slash
 *  - Any text following comment start is interpreted as a comment up to end of
 *  input or comment end
 *  - Any quotes found within the comment are ignored and no replacements made
 */
nsCString
TelemetryImpl::SanitizeSQL(const nsACString &sql) {
  nsCString output;
  int length = sql.Length();

  typedef enum {
    NORMAL,
    SINGLE_QUOTE,
    DOUBLE_QUOTE,
    DASH_COMMENT,
    C_STYLE_COMMENT,
  } State;

  State state = NORMAL;
  int fragmentStart = 0;
  for (int i = 0; i < length; i++) {
    char character = sql[i];
    char nextCharacter = (i + 1 < length) ? sql[i + 1] : '\0';

    switch (character) {
      case '\'':
      case '"':
        if (state == NORMAL) {
          state = (character == '\'') ? SINGLE_QUOTE : DOUBLE_QUOTE;
          output += nsDependentCSubstring(sql, fragmentStart, i - fragmentStart);
          output += ":private";
          fragmentStart = -1;
        } else if ((state == SINGLE_QUOTE && character == '\'') ||
                   (state == DOUBLE_QUOTE && character == '"')) {
          if (nextCharacter == character) {
            // Two consecutive quotes within a string literal are a single escaped quote
            i++;
          } else {
            state = NORMAL;
            fragmentStart = i + 1;
          }
        }
        break;
      case '-':
        if (state == NORMAL) {
          if (nextCharacter == '-') {
            state = DASH_COMMENT;
            i++;
          }
        }
        break;
      case '\n':
        if (state == DASH_COMMENT) {
          state = NORMAL;
        }
        break;
      case '/':
        if (state == NORMAL) {
          if (nextCharacter == '*') {
            state = C_STYLE_COMMENT;
            i++;
          }
        }
        break;
      case '*':
        if (state == C_STYLE_COMMENT) {
          if (nextCharacter == '/') {
            state = NORMAL;
          }
        }
        break;
      default:
        continue;
    }
  }

  if ((fragmentStart >= 0) && fragmentStart < length)
    output += nsDependentCSubstring(sql, fragmentStart, length - fragmentStart);

  return output;
}

// A whitelist mechanism to prevent Telemetry reporting on Addon & Thunderbird
// DBs.
struct TrackedDBEntry
{
  const char* mName;
  const uint32_t mNameLength;

  // This struct isn't meant to be used beyond the static arrays below.
  constexpr
  TrackedDBEntry(const char* aName, uint32_t aNameLength)
    : mName(aName)
    , mNameLength(aNameLength)
  { }

  TrackedDBEntry() = delete;
  TrackedDBEntry(TrackedDBEntry&) = delete;
};

#define TRACKEDDB_ENTRY(_name) { _name, (sizeof(_name) - 1) }

// A whitelist of database names. If the database name exactly matches one of
// these then its SQL statements will always be recorded.
static constexpr TrackedDBEntry kTrackedDBs[] = {
  // IndexedDB for about:home, see aboutHome.js
  TRACKEDDB_ENTRY("818200132aebmoouht.sqlite"),
  TRACKEDDB_ENTRY("addons.sqlite"),
  TRACKEDDB_ENTRY("content-prefs.sqlite"),
  TRACKEDDB_ENTRY("cookies.sqlite"),
  TRACKEDDB_ENTRY("downloads.sqlite"),
  TRACKEDDB_ENTRY("extensions.sqlite"),
  TRACKEDDB_ENTRY("formhistory.sqlite"),
  TRACKEDDB_ENTRY("index.sqlite"),
  TRACKEDDB_ENTRY("netpredictions.sqlite"),
  TRACKEDDB_ENTRY("permissions.sqlite"),
  TRACKEDDB_ENTRY("places.sqlite"),
  TRACKEDDB_ENTRY("reading-list.sqlite"),
  TRACKEDDB_ENTRY("search.sqlite"),
  TRACKEDDB_ENTRY("signons.sqlite"),
  TRACKEDDB_ENTRY("urlclassifier3.sqlite"),
  TRACKEDDB_ENTRY("webappsstore.sqlite")
};

// A whitelist of database name prefixes. If the database name begins with
// one of these prefixes then its SQL statements will always be recorded.
static const TrackedDBEntry kTrackedDBPrefixes[] = {
  TRACKEDDB_ENTRY("indexedDB-")
};

#undef TRACKEDDB_ENTRY

// Slow SQL statements will be automatically
// trimmed to kMaxSlowStatementLength characters.
// This limit doesn't include the ellipsis and DB name,
// that are appended at the end of the stored statement.
const uint32_t kMaxSlowStatementLength = 1000;

void
TelemetryImpl::RecordSlowStatement(const nsACString &sql,
                                   const nsACString &dbName,
                                   uint32_t delay)
{
  MOZ_ASSERT(!sql.IsEmpty());
  MOZ_ASSERT(!dbName.IsEmpty());

  if (!sTelemetry || !TelemetryHistogram::CanRecordExtended())
    return;

  bool recordStatement = false;

  for (const TrackedDBEntry& nameEntry : kTrackedDBs) {
    MOZ_ASSERT(nameEntry.mNameLength);
    const nsDependentCString name(nameEntry.mName, nameEntry.mNameLength);
    if (dbName == name) {
      recordStatement = true;
      break;
    }
  }

  if (!recordStatement) {
    for (const TrackedDBEntry& prefixEntry : kTrackedDBPrefixes) {
      MOZ_ASSERT(prefixEntry.mNameLength);
      const nsDependentCString prefix(prefixEntry.mName,
                                      prefixEntry.mNameLength);
      if (StringBeginsWith(dbName, prefix)) {
        recordStatement = true;
        break;
      }
    }
  }

  if (recordStatement) {
    nsAutoCString sanitizedSQL(SanitizeSQL(sql));
    if (sanitizedSQL.Length() > kMaxSlowStatementLength) {
      sanitizedSQL.SetLength(kMaxSlowStatementLength);
      sanitizedSQL += "...";
    }
    sanitizedSQL.AppendPrintf(" /* %s */", nsPromiseFlatCString(dbName).get());
    StoreSlowSQL(sanitizedSQL, delay, Sanitized);
  } else {
    // Report aggregate DB-level statistics for addon DBs
    nsAutoCString aggregate;
    aggregate.AppendPrintf("Untracked SQL for %s",
                           nsPromiseFlatCString(dbName).get());
    StoreSlowSQL(aggregate, delay, Sanitized);
  }

  nsAutoCString fullSQL;
  fullSQL.AppendPrintf("%s /* %s */",
                       nsPromiseFlatCString(sql).get(),
                       nsPromiseFlatCString(dbName).get());
  StoreSlowSQL(fullSQL, delay, Unsanitized);
}

void
TelemetryImpl::RecordIceCandidates(const uint32_t iceCandidateBitmask,
                                   const bool success, const bool loop)
{
  if (!sTelemetry || !TelemetryHistogram::CanRecordExtended())
    return;

  sTelemetry->mWebrtcTelemetry.RecordIceCandidateMask(iceCandidateBitmask, success, loop);
}

#if defined(MOZ_ENABLE_PROFILER_SPS)
void
TelemetryImpl::RecordChromeHang(uint32_t aDuration,
                                Telemetry::ProcessedStack &aStack,
                                int32_t aSystemUptime,
                                int32_t aFirefoxUptime,
                                HangAnnotationsPtr aAnnotations)
{
  if (!sTelemetry || !TelemetryHistogram::CanRecordExtended())
    return;

  HangAnnotationsPtr annotations;
  // We only pass aAnnotations if it is not empty.
  if (aAnnotations && !aAnnotations->IsEmpty()) {
    annotations = Move(aAnnotations);
  }

  MutexAutoLock hangReportMutex(sTelemetry->mHangReportsMutex);

  sTelemetry->mHangReports.AddHang(aStack, aDuration,
                                   aSystemUptime, aFirefoxUptime,
                                   Move(annotations));
}
#endif

void
TelemetryImpl::RecordThreadHangStats(Telemetry::ThreadHangStats& aStats)
{
  if (!sTelemetry || !TelemetryHistogram::CanRecordExtended())
    return;

  MutexAutoLock autoLock(sTelemetry->mThreadHangStatsMutex);

  // Ignore OOM.
  mozilla::Unused << sTelemetry->mThreadHangStats.append(Move(aStats));
}

NS_IMPL_ISUPPORTS(TelemetryImpl, nsITelemetry, nsIMemoryReporter)
NS_GENERIC_FACTORY_SINGLETON_CONSTRUCTOR(nsITelemetry, TelemetryImpl::CreateTelemetryInstance)

#define NS_TELEMETRY_CID \
  {0xaea477f2, 0xb3a2, 0x469c, {0xaa, 0x29, 0x0a, 0x82, 0xd1, 0x32, 0xb8, 0x29}}
NS_DEFINE_NAMED_CID(NS_TELEMETRY_CID);

const Module::CIDEntry kTelemetryCIDs[] = {
  { &kNS_TELEMETRY_CID, false, nullptr, nsITelemetryConstructor },
  { nullptr }
};

const Module::ContractIDEntry kTelemetryContracts[] = {
  { "@mozilla.org/base/telemetry;1", &kNS_TELEMETRY_CID },
  { nullptr }
};

const Module kTelemetryModule = {
  Module::kVersion,
  kTelemetryCIDs,
  kTelemetryContracts,
  nullptr,
  nullptr,
  nullptr,
  TelemetryImpl::ShutdownTelemetry
};

NS_IMETHODIMP
TelemetryImpl::GetFileIOReports(JSContext *cx, JS::MutableHandleValue ret)
{
  if (sTelemetryIOObserver) {
    JS::Rooted<JSObject*> obj(cx, JS_NewPlainObject(cx));
    if (!obj) {
      return NS_ERROR_FAILURE;
    }

    if (!sTelemetryIOObserver->ReflectIntoJS(cx, obj)) {
      return NS_ERROR_FAILURE;
    }
    ret.setObject(*obj);
    return NS_OK;
  }
  ret.setNull();
  return NS_OK;
}

NS_IMETHODIMP
TelemetryImpl::MsSinceProcessStart(double* aResult)
{
  bool error;
  *aResult = (TimeStamp::NowLoRes() -
              TimeStamp::ProcessCreation(error)).ToMilliseconds();
  if (error) {
    return NS_ERROR_NOT_AVAILABLE;
  }
  return NS_OK;
}

// Telemetry Scalars IDL Implementation

NS_IMETHODIMP
TelemetryImpl::ScalarAdd(const nsACString& aName, JS::HandleValue aVal, JSContext* aCx)
{
  return TelemetryScalar::Add(aName, aVal, aCx);
}

NS_IMETHODIMP
TelemetryImpl::ScalarSet(const nsACString& aName, JS::HandleValue aVal, JSContext* aCx)
{
  return TelemetryScalar::Set(aName, aVal, aCx);
}

NS_IMETHODIMP
TelemetryImpl::ScalarSetMaximum(const nsACString& aName, JS::HandleValue aVal, JSContext* aCx)
{
  return TelemetryScalar::SetMaximum(aName, aVal, aCx);
}

NS_IMETHODIMP
TelemetryImpl::SnapshotScalars(unsigned int aDataset, bool aClearScalars, JSContext* aCx,
                               uint8_t optional_argc, JS::MutableHandleValue aResult)
{
  return TelemetryScalar::CreateSnapshots(aDataset, aClearScalars, aCx, optional_argc, aResult);
}

NS_IMETHODIMP
TelemetryImpl::ClearScalars()
{
  TelemetryScalar::ClearScalars();
  return NS_OK;
}

size_t
TelemetryImpl::SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf)
{
  size_t n = aMallocSizeOf(this);

  // Ignore the hashtables in mAddonMap; they are not significant.
  n += TelemetryHistogram::GetMapShallowSizesOfExcludingThis(aMallocSizeOf);
  n += TelemetryScalar::GetMapShallowSizesOfExcludingThis(aMallocSizeOf);
  n += mWebrtcTelemetry.SizeOfExcludingThis(aMallocSizeOf);
  { // Scope for mHashMutex lock
    MutexAutoLock lock(mHashMutex);
    n += mPrivateSQL.SizeOfExcludingThis(aMallocSizeOf);
    n += mSanitizedSQL.SizeOfExcludingThis(aMallocSizeOf);
  }
  { // Scope for mHangReportsMutex lock
    MutexAutoLock lock(mHangReportsMutex);
    n += mHangReports.SizeOfExcludingThis(aMallocSizeOf);
  }
  { // Scope for mThreadHangStatsMutex lock
    MutexAutoLock lock(mThreadHangStatsMutex);
    n += mThreadHangStats.sizeOfExcludingThis(aMallocSizeOf);
  }

  // It's a bit gross that we measure this other stuff that lives outside of
  // TelemetryImpl... oh well.
  if (sTelemetryIOObserver) {
    n += sTelemetryIOObserver->SizeOfIncludingThis(aMallocSizeOf);
  }

  n += TelemetryHistogram::GetHistogramSizesofIncludingThis(aMallocSizeOf);
  n += TelemetryScalar::GetScalarSizesOfIncludingThis(aMallocSizeOf);

  return n;
}

struct StackFrame
{
  uintptr_t mPC;      // The program counter at this position in the call stack.
  uint16_t mIndex;    // The number of this frame in the call stack.
  uint16_t mModIndex; // The index of module that has this program counter.
};

#ifdef MOZ_ENABLE_PROFILER_SPS
static bool CompareByPC(const StackFrame &a, const StackFrame &b)
{
  return a.mPC < b.mPC;
}

static bool CompareByIndex(const StackFrame &a, const StackFrame &b)
{
  return a.mIndex < b.mIndex;
}
#endif

} // namespace


////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// EXTERNALLY VISIBLE FUNCTIONS in no name space
// These are NOT listed in Telemetry.h

NSMODULE_DEFN(nsTelemetryModule) = &kTelemetryModule;

/**
 * The XRE_TelemetryAdd function is to be used by embedding applications
 * that can't use mozilla::Telemetry::Accumulate() directly.
 */
void
XRE_TelemetryAccumulate(int aID, uint32_t aSample)
{
  mozilla::Telemetry::Accumulate((mozilla::Telemetry::ID) aID, aSample);
}


////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// EXTERNALLY VISIBLE FUNCTIONS in mozilla::
// These are NOT listed in Telemetry.h

namespace mozilla {

void
RecordShutdownStartTimeStamp() {
#ifdef DEBUG
  // FIXME: this function should only be called once, since it should be called
  // at the earliest point we *know* we are shutting down. Unfortunately
  // this assert has been firing. Given that if we are called multiple times
  // we just keep the last timestamp, the assert is commented for now.
  static bool recorded = false;
  //  MOZ_ASSERT(!recorded);
  (void)recorded; // Silence unused-var warnings (remove when assert re-enabled)
  recorded = true;
#endif

  if (!Telemetry::CanRecordExtended())
    return;

  gRecordedShutdownStartTime = TimeStamp::Now();

  GetShutdownTimeFileName();
}

void
RecordShutdownEndTimeStamp() {
  if (!gRecordedShutdownTimeFileName || gAlreadyFreedShutdownTimeFileName)
    return;

  nsCString name(gRecordedShutdownTimeFileName);
  PL_strfree(gRecordedShutdownTimeFileName);
  gRecordedShutdownTimeFileName = nullptr;
  gAlreadyFreedShutdownTimeFileName = true;

  if (gRecordedShutdownStartTime.IsNull()) {
    // If |CanRecordExtended()| is true before |AsyncFetchTelemetryData| is called and
    // then disabled before shutdown, |RecordShutdownStartTimeStamp| will bail out and
    // we will end up with a null |gRecordedShutdownStartTime| here. This can happen
    // during tests.
    return;
  }

  nsCString tmpName = name;
  tmpName += ".tmp";
  FILE *f = fopen(tmpName.get(), "w");
  if (!f)
    return;
  // On a normal release build this should be called just before
  // calling _exit, but on a debug build or when the user forces a full
  // shutdown this is called as late as possible, so we have to
  // white list this write as write poisoning will be enabled.
  MozillaRegisterDebugFILE(f);

  TimeStamp now = TimeStamp::Now();
  MOZ_ASSERT(now >= gRecordedShutdownStartTime);
  TimeDuration diff = now - gRecordedShutdownStartTime;
  uint32_t diff2 = diff.ToMilliseconds();
  int written = fprintf(f, "%d\n", diff2);
  MozillaUnRegisterDebugFILE(f);
  int rv = fclose(f);
  if (written < 0 || rv != 0) {
    PR_Delete(tmpName.get());
    return;
  }
  PR_Delete(name.get());
  PR_Rename(tmpName.get(), name.get());
}

} // namespace mozilla


////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// EXTERNALLY VISIBLE FUNCTIONS in mozilla::Telemetry::
// These are NOT listed in Telemetry.h

namespace mozilla {
namespace Telemetry {

ProcessedStack::ProcessedStack()
{
}

size_t ProcessedStack::GetStackSize() const
{
  return mStack.size();
}

size_t ProcessedStack::GetNumModules() const
{
  return mModules.size();
}

bool ProcessedStack::Module::operator==(const Module& aOther) const {
  return  mName == aOther.mName &&
    mBreakpadId == aOther.mBreakpadId;
}

const ProcessedStack::Frame &ProcessedStack::GetFrame(unsigned aIndex) const
{
  MOZ_ASSERT(aIndex < mStack.size());
  return mStack[aIndex];
}

void ProcessedStack::AddFrame(const Frame &aFrame)
{
  mStack.push_back(aFrame);
}

const ProcessedStack::Module &ProcessedStack::GetModule(unsigned aIndex) const
{
  MOZ_ASSERT(aIndex < mModules.size());
  return mModules[aIndex];
}

void ProcessedStack::AddModule(const Module &aModule)
{
  mModules.push_back(aModule);
}

void ProcessedStack::Clear() {
  mModules.clear();
  mStack.clear();
}

ProcessedStack
GetStackAndModules(const std::vector<uintptr_t>& aPCs)
{
  std::vector<StackFrame> rawStack;
  auto stackEnd = aPCs.begin() + std::min(aPCs.size(), kMaxChromeStackDepth);
  for (auto i = aPCs.begin(); i != stackEnd; ++i) {
    uintptr_t aPC = *i;
    StackFrame Frame = {aPC, static_cast<uint16_t>(rawStack.size()),
                        std::numeric_limits<uint16_t>::max()};
    rawStack.push_back(Frame);
  }

#ifdef MOZ_ENABLE_PROFILER_SPS
  // Remove all modules not referenced by a PC on the stack
  std::sort(rawStack.begin(), rawStack.end(), CompareByPC);

  size_t moduleIndex = 0;
  size_t stackIndex = 0;
  size_t stackSize = rawStack.size();

  SharedLibraryInfo rawModules = SharedLibraryInfo::GetInfoForSelf();
  rawModules.SortByAddress();

  while (moduleIndex < rawModules.GetSize()) {
    const SharedLibrary& module = rawModules.GetEntry(moduleIndex);
    uintptr_t moduleStart = module.GetStart();
    uintptr_t moduleEnd = module.GetEnd() - 1;
    // the interval is [moduleStart, moduleEnd)

    bool moduleReferenced = false;
    for (;stackIndex < stackSize; ++stackIndex) {
      uintptr_t pc = rawStack[stackIndex].mPC;
      if (pc >= moduleEnd)
        break;

      if (pc >= moduleStart) {
        // If the current PC is within the current module, mark
        // module as used
        moduleReferenced = true;
        rawStack[stackIndex].mPC -= moduleStart;
        rawStack[stackIndex].mModIndex = moduleIndex;
      } else {
        // PC does not belong to any module. It is probably from
        // the JIT. Use a fixed mPC so that we don't get different
        // stacks on different runs.
        rawStack[stackIndex].mPC =
          std::numeric_limits<uintptr_t>::max();
      }
    }

    if (moduleReferenced) {
      ++moduleIndex;
    } else {
      // Remove module if no PCs within its address range
      rawModules.RemoveEntries(moduleIndex, moduleIndex + 1);
    }
  }

  for (;stackIndex < stackSize; ++stackIndex) {
    // These PCs are past the last module.
    rawStack[stackIndex].mPC = std::numeric_limits<uintptr_t>::max();
  }

  std::sort(rawStack.begin(), rawStack.end(), CompareByIndex);
#endif

  // Copy the information to the return value.
  ProcessedStack Ret;
  for (std::vector<StackFrame>::iterator i = rawStack.begin(),
         e = rawStack.end(); i != e; ++i) {
    const StackFrame &rawFrame = *i;
    mozilla::Telemetry::ProcessedStack::Frame frame = { rawFrame.mPC, rawFrame.mModIndex };
    Ret.AddFrame(frame);
  }

#ifdef MOZ_ENABLE_PROFILER_SPS
  for (unsigned i = 0, n = rawModules.GetSize(); i != n; ++i) {
    const SharedLibrary &info = rawModules.GetEntry(i);
    const std::string &name = info.GetName();
    std::string basename = name;
#ifdef XP_MACOSX
    // FIXME: We want to use just the basename as the libname, but the
    // current profiler addon needs the full path name, so we compute the
    // basename in here.
    size_t pos = name.rfind('/');
    if (pos != std::string::npos) {
      basename = name.substr(pos + 1);
    }
#endif
    mozilla::Telemetry::ProcessedStack::Module module = {
      basename,
      info.GetBreakpadId()
    };
    Ret.AddModule(module);
  }
#endif

  return Ret;
}

void
TimeHistogram::Add(PRIntervalTime aTime)
{
  uint32_t timeMs = PR_IntervalToMilliseconds(aTime);
  size_t index = mozilla::FloorLog2(timeMs);
  operator[](index)++;
}

const char*
HangStack::InfallibleAppendViaBuffer(const char* aText, size_t aLength)
{
  MOZ_ASSERT(this->canAppendWithoutRealloc(1));
  // Include null-terminator in length count.
  MOZ_ASSERT(mBuffer.canAppendWithoutRealloc(aLength + 1));

  const char* const entry = mBuffer.end();
  mBuffer.infallibleAppend(aText, aLength);
  mBuffer.infallibleAppend('\0'); // Explicitly append null-terminator
  this->infallibleAppend(entry);
  return entry;
}

const char*
HangStack::AppendViaBuffer(const char* aText, size_t aLength)
{
  if (!this->reserve(this->length() + 1)) {
    return nullptr;
  }

  // Keep track of the previous buffer in case we need to adjust pointers later.
  const char* const prevStart = mBuffer.begin();
  const char* const prevEnd = mBuffer.end();

  // Include null-terminator in length count.
  if (!mBuffer.reserve(mBuffer.length() + aLength + 1)) {
    return nullptr;
  }

  if (prevStart != mBuffer.begin()) {
    // The buffer has moved; we have to adjust pointers in the stack.
    for (const char** entry = this->begin(); entry != this->end(); entry++) {
      if (*entry >= prevStart && *entry < prevEnd) {
        // Move from old buffer to new buffer.
        *entry += mBuffer.begin() - prevStart;
      }
    }
  }

  return InfallibleAppendViaBuffer(aText, aLength);
}

uint32_t
HangHistogram::GetHash(const HangStack& aStack)
{
  uint32_t hash = 0;
  for (const char* const* label = aStack.begin();
       label != aStack.end(); label++) {
    /* If the string is within our buffer, we need to hash its content.
       Otherwise, the string is statically allocated, and we only need
       to hash the pointer instead of the content. */
    if (aStack.IsInBuffer(*label)) {
      hash = AddToHash(hash, HashString(*label));
    } else {
      hash = AddToHash(hash, *label);
    }
  }
  return hash;
}

bool
HangHistogram::operator==(const HangHistogram& aOther) const
{
  if (mHash != aOther.mHash) {
    return false;
  }
  if (mStack.length() != aOther.mStack.length()) {
    return false;
  }
  return mStack == aOther.mStack;
}

} // namespace Telemetry
} // namespace mozilla


////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
//
// EXTERNALLY VISIBLE FUNCTIONS in mozilla::Telemetry::
// These are listed in Telemetry.h

namespace mozilla {
namespace Telemetry {

// The external API for controlling recording state
void
SetHistogramRecordingEnabled(ID aID, bool aEnabled)
{
  TelemetryHistogram::SetHistogramRecordingEnabled(aID, aEnabled);
}

void
Accumulate(ID aHistogram, uint32_t aSample)
{
  TelemetryHistogram::Accumulate(aHistogram, aSample);
}

void
Accumulate(ID aID, const nsCString& aKey, uint32_t aSample)
{
  TelemetryHistogram::Accumulate(aID, aKey, aSample);
}

void
Accumulate(const char* name, uint32_t sample)
{
  TelemetryHistogram::Accumulate(name, sample);
}

void
Accumulate(const char *name, const nsCString& key, uint32_t sample)
{
  TelemetryHistogram::Accumulate(name, key, sample);
}

void
AccumulateCategorical(ID id, const nsCString& label)
{
  TelemetryHistogram::AccumulateCategorical(id, label);
}

void
AccumulateTimeDelta(ID aHistogram, TimeStamp start, TimeStamp end)
{
  Accumulate(aHistogram,
             static_cast<uint32_t>((end - start).ToMilliseconds()));
}

void
ClearHistogram(ID aId)
{
  TelemetryHistogram::ClearHistogram(aId);
}

const char*
GetHistogramName(ID id)
{
  return TelemetryHistogram::GetHistogramName(id);
}

bool
CanRecordBase()
{
  return TelemetryHistogram::CanRecordBase();
}

bool
CanRecordExtended()
{
  return TelemetryHistogram::CanRecordExtended();
}

void
RecordSlowSQLStatement(const nsACString &statement,
                       const nsACString &dbName,
                       uint32_t delay)
{
  TelemetryImpl::RecordSlowStatement(statement, dbName, delay);
}

void
RecordWebrtcIceCandidates(const uint32_t iceCandidateBitmask,
                          const bool success, const bool loop)
{
  TelemetryImpl::RecordIceCandidates(iceCandidateBitmask, success, loop);
}

void Init()
{
  // Make the service manager hold a long-lived reference to the service
  nsCOMPtr<nsITelemetry> telemetryService =
    do_GetService("@mozilla.org/base/telemetry;1");
  MOZ_ASSERT(telemetryService);
}

#if defined(MOZ_ENABLE_PROFILER_SPS)
void RecordChromeHang(uint32_t duration,
                      ProcessedStack &aStack,
                      int32_t aSystemUptime,
                      int32_t aFirefoxUptime,
                      HangAnnotationsPtr aAnnotations)
{
  TelemetryImpl::RecordChromeHang(duration, aStack,
                                  aSystemUptime, aFirefoxUptime,
                                  Move(aAnnotations));
}
#endif

void RecordThreadHangStats(ThreadHangStats& aStats)
{
  TelemetryImpl::RecordThreadHangStats(aStats);
}


void
WriteFailedProfileLock(nsIFile* aProfileDir)
{
  nsCOMPtr<nsIFile> file;
  nsresult rv = GetFailedProfileLockFile(getter_AddRefs(file), aProfileDir);
  NS_ENSURE_SUCCESS_VOID(rv);
  int64_t fileSize = 0;
  rv = file->GetFileSize(&fileSize);
  // It's expected that the file might not exist yet
  if (NS_FAILED(rv) && rv != NS_ERROR_FILE_NOT_FOUND) {
    return;
  }
  nsCOMPtr<nsIFileStream> fileStream;
  rv = NS_NewLocalFileStream(getter_AddRefs(fileStream), file,
                             PR_RDWR | PR_CREATE_FILE, 0640);
  NS_ENSURE_SUCCESS_VOID(rv);
  NS_ENSURE_TRUE_VOID(fileSize <= kMaxFailedProfileLockFileSize);
  unsigned int failedLockCount = 0;
  if (fileSize > 0) {
    nsCOMPtr<nsIInputStream> inStream = do_QueryInterface(fileStream);
    NS_ENSURE_TRUE_VOID(inStream);
    if (!GetFailedLockCount(inStream, fileSize, failedLockCount)) {
      failedLockCount = 0;
    }
  }
  ++failedLockCount;
  nsAutoCString bufStr;
  bufStr.AppendInt(static_cast<int>(failedLockCount));
  nsCOMPtr<nsISeekableStream> seekStream = do_QueryInterface(fileStream);
  NS_ENSURE_TRUE_VOID(seekStream);
  // If we read in an existing failed lock count, we need to reset the file ptr
  if (fileSize > 0) {
    rv = seekStream->Seek(nsISeekableStream::NS_SEEK_SET, 0);
    NS_ENSURE_SUCCESS_VOID(rv);
  }
  nsCOMPtr<nsIOutputStream> outStream = do_QueryInterface(fileStream);
  uint32_t bytesLeft = bufStr.Length();
  const char* bytes = bufStr.get();
  do {
    uint32_t written = 0;
    rv = outStream->Write(bytes, bytesLeft, &written);
    if (NS_FAILED(rv)) {
      break;
    }
    bytes += written;
    bytesLeft -= written;
  } while (bytesLeft > 0);
  seekStream->SetEOF();
}

void
InitIOReporting(nsIFile* aXreDir)
{
  // Never initialize twice
  if (sTelemetryIOObserver) {
    return;
  }

  sTelemetryIOObserver = new TelemetryIOInterposeObserver(aXreDir);
  IOInterposer::Register(IOInterposeObserver::OpAllWithStaging,
                         sTelemetryIOObserver);
}

void
SetProfileDir(nsIFile* aProfD)
{
  if (!sTelemetryIOObserver || !aProfD) {
    return;
  }
  nsAutoString profDirPath;
  nsresult rv = aProfD->GetPath(profDirPath);
  if (NS_FAILED(rv)) {
    return;
  }
  sTelemetryIOObserver->AddPath(profDirPath, NS_LITERAL_STRING("{profile}"));
}

void CreateStatisticsRecorder()
{
  TelemetryHistogram::CreateStatisticsRecorder();
}

void DestroyStatisticsRecorder()
{
  TelemetryHistogram::DestroyStatisticsRecorder();
}

// Scalar API C++ Endpoints

/**
 * Adds the value to the given scalar.
 *
 * @param aId The scalar enum id.
 * @param aValue The unsigned value to add to the scalar.
 */
void
ScalarAdd(mozilla::Telemetry::ScalarID aId, uint32_t aVal)
{
  TelemetryScalar::Add(aId, aVal);
}

/**
 * Sets the scalar to the given value.
 *
 * @param aId The scalar enum id.
 * @param aValue The numeric, unsigned value to set the scalar to.
 */
void
ScalarSet(mozilla::Telemetry::ScalarID aId, uint32_t aVal)
{
  TelemetryScalar::Set(aId, aVal);
}

/**
 * Sets the scalar to the given value.
 *
 * @param aId The scalar enum id.
 * @param aValue The string value to set the scalar to.
 */
void
ScalarSet(mozilla::Telemetry::ScalarID aId, const nsAString& aVal)
{
  TelemetryScalar::Set(aId, aVal);
}

/**
 * Sets the scalar to the maximum of the current and the passed value.
 *
 * @param aId The scalar enum id.
 * @param aValue The unsigned value to set the scalar to.
 */
void
ScalarSetMaximum(mozilla::Telemetry::ScalarID aId, uint32_t aVal)
{
  TelemetryScalar::SetMaximum(aId, aVal);
}

} // namespace Telemetry
} // namespace mozilla