Fix some m_instVar instances in wtf/

third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp

Index: third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp
diff --git a/third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp b/third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp
index a9e61cbbd96e36e82527c2296ad646322fe0954b..595bc04296ef7bd5741dafb35bd525954e864db4 100644
--- a/third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp
+++ b/third_party/WebKit/Source/platform/wtf/text/StringImpl.cpp
@@ -41,15 +41,6 @@
 #include <algorithm>
 #include <memory>
 
-#ifdef STRING_STATS
-#include "platform/wtf/DataLog.h"
-#include "platform/wtf/HashMap.h"
-#include "platform/wtf/HashSet.h"
-#include "platform/wtf/RefCounted.h"
-#include "platform/wtf/ThreadingPrimitives.h"
-#include <unistd.h>
-#endif
-
 using namespace std;
 
 namespace WTF {
@@ -67,231 +58,6 @@ static_assert(sizeof(StringImpl) <= 3 * sizeof(int),
               "StringImpl should stay small");
 #endif
 
-#ifdef STRING_STATS

[dcheng, 2017/05/03 19:44:40]

Hmm... FWIW, the last time I asked about removing this, several people were in
favor of retaining it:
https://groups.google.com/a/chromium.org/forum/#!topic/blink-dev/aZSxBxs8_10

So maybe it'd be nice to keep it around for a bit longer... if no one rebases
this code in, say, 6 or 12 months, then I'd say it's probably safe to remove?

-
-static Mutex& statsMutex() {
-  DEFINE_STATIC_LOCAL(Mutex, mutex, ());
-  return mutex;
-}
-
-static HashSet<void*>& liveStrings() {
-  // Notice that we can't use HashSet<StringImpl*> because then HashSet would
-  // dedup identical strings.
-  DEFINE_STATIC_LOCAL(HashSet<void*>, strings, ());
-  return strings;
-}
-
-void addStringForStats(StringImpl* string) {
-  MutexLocker locker(statsMutex());
-  liveStrings().add(string);
-}
-
-void removeStringForStats(StringImpl* string) {
-  MutexLocker locker(statsMutex());
-  liveStrings().remove(string);
-}
-
-static void fillWithSnippet(const StringImpl* string, Vector<char>& snippet) {
-  const unsigned kMaxSnippetLength = 64;
-  snippet.clear();
-
-  size_t expectedLength = std::min(string->length(), kMaxSnippetLength);
-  if (expectedLength == kMaxSnippetLength)
-    expectedLength += 3;  // For the "...".
-  ++expectedLength;       // For the terminating '\0'.
-  snippet.reserveCapacity(expectedLength);
-
-  size_t i;
-  for (i = 0; i < string->length() && i < kMaxSnippetLength; ++i) {
-    UChar c = (*string)[i];
-    if (IsASCIIPrintable(c))
-      snippet.append(c);
-    else
-      snippet.append('?');
-  }
-  if (i < string->length()) {
-    snippet.append('.');
-    snippet.append('.');
-    snippet.append('.');
-  }
-  snippet.append('\0');
-}
-
-static bool isUnnecessarilyWide(const StringImpl* string) {
-  if (string->is8Bit())
-    return false;
-  UChar c = 0;
-  for (unsigned i = 0; i < string->length(); ++i)
-    c |= (*string)[i] >> 8;
-  return !c;
-}
-
-class PerStringStats : public RefCounted<PerStringStats> {
- public:
-  static PassRefPtr<PerStringStats> create() {
-    return adoptRef(new PerStringStats);
-  }
-
-  void add(const StringImpl* string) {
-    ++m_numberOfCopies;
-    if (!m_length) {
-      m_length = string->length();
-      fillWithSnippet(string, m_snippet);
-    }
-    if (string->isAtomic())
-      ++m_numberOfAtomicCopies;
-    if (isUnnecessarilyWide(string))
-      m_unnecessarilyWide = true;
-  }
-
-  size_t totalCharacters() const { return m_numberOfCopies * m_length; }
-
-  void print() {
-    const char* status = "ok";
-    if (m_unnecessarilyWide)
-      status = "16";
-    dataLogF("%8u copies (%s) of length %8u %s\n", m_numberOfCopies, status,
-             m_length, m_snippet.data());
-  }
-
-  bool m_unnecessarilyWide;
-  unsigned m_numberOfCopies;
-  unsigned m_length;
-  unsigned m_numberOfAtomicCopies;
-  Vector<char> m_snippet;
-
- private:
-  PerStringStats()
-      : m_unnecessarilyWide(false),
-        m_numberOfCopies(0),
-        m_length(0),
-        m_numberOfAtomicCopies(0) {}
-};
-
-bool operator<(const RefPtr<PerStringStats>& a,
-               const RefPtr<PerStringStats>& b) {
-  if (a->m_unnecessarilyWide != b->m_unnecessarilyWide)
-    return !a->m_unnecessarilyWide && b->m_unnecessarilyWide;
-  if (a->totalCharacters() != b->totalCharacters())
-    return a->totalCharacters() < b->totalCharacters();
-  if (a->m_numberOfCopies != b->m_numberOfCopies)
-    return a->m_numberOfCopies < b->m_numberOfCopies;
-  if (a->m_length != b->m_length)
-    return a->m_length < b->m_length;
-  return a->m_numberOfAtomicCopies < b->m_numberOfAtomicCopies;
-}
-
-static void printLiveStringStats(void*) {
-  MutexLocker locker(statsMutex());
-  HashSet<void*>& strings = liveStrings();
-
-  HashMap<StringImpl*, RefPtr<PerStringStats>> stats;
-  for (HashSet<void*>::iterator iter = strings.begin(); iter != strings.end();
-       ++iter) {
-    StringImpl* string = static_cast<StringImpl*>(*iter);
-    HashMap<StringImpl*, RefPtr<PerStringStats>>::iterator entry =
-        stats.find(string);
-    RefPtr<PerStringStats> value =
-        entry == stats.end() ? RefPtr<PerStringStats>(PerStringStats::create())
-                             : entry->value;
-    value->add(string);
-    stats.set(string, value.release());
-  }
-
-  Vector<RefPtr<PerStringStats>> all;
-  for (HashMap<StringImpl*, RefPtr<PerStringStats>>::iterator iter =
-           stats.begin();
-       iter != stats.end(); ++iter)
-    all.append(iter->value);
-
-  std::sort(all.begin(), all.end());
-  std::reverse(all.begin(), all.end());
-  for (size_t i = 0; i < 20 && i < all.size(); ++i)
-    all[i]->print();
-}
-
-StringStats StringImpl::m_stringStats;
-
-unsigned StringStats::s_stringRemovesTillPrintStats =
-    StringStats::s_printStringStatsFrequency;
-
-void StringStats::removeString(StringImpl* string) {
-  unsigned length = string->length();
-  --m_totalNumberStrings;
-
-  if (string->is8Bit()) {
-    --m_number8BitStrings;
-    m_total8BitData -= length;
-  } else {
-    --m_number16BitStrings;
-    m_total16BitData -= length;
-  }
-
-  if (!--s_stringRemovesTillPrintStats) {
-    s_stringRemovesTillPrintStats = s_printStringStatsFrequency;
-    printStats();
-  }
-}
-
-void StringStats::printStats() {
-  dataLogF("String stats for process id %d:\n", getpid());
-
-  unsigned long long totalNumberCharacters = m_total8BitData + m_total16BitData;
-  double percent8Bit =
-      m_totalNumberStrings
-          ? ((double)m_number8BitStrings * 100) / (double)m_totalNumberStrings
-          : 0.0;
-  double average8bitLength =
-      m_number8BitStrings
-          ? (double)m_total8BitData / (double)m_number8BitStrings
-          : 0.0;
-  dataLogF(
-      "%8u (%5.2f%%) 8 bit        %12llu chars  %12llu bytes  avg length "
-      "%6.1f\n",
-      m_number8BitStrings, percent8Bit, m_total8BitData, m_total8BitData,
-      average8bitLength);
-
-  double percent16Bit =
-      m_totalNumberStrings
-          ? ((double)m_number16BitStrings * 100) / (double)m_totalNumberStrings
-          : 0.0;
-  double average16bitLength =
-      m_number16BitStrings
-          ? (double)m_total16BitData / (double)m_number16BitStrings
-          : 0.0;
-  dataLogF(
-      "%8u (%5.2f%%) 16 bit       %12llu chars  %12llu bytes  avg length "
-      "%6.1f\n",
-      m_number16BitStrings, percent16Bit, m_total16BitData,
-      m_total16BitData * 2, average16bitLength);
-
-  double averageLength =
-      m_totalNumberStrings
-          ? (double)totalNumberCharacters / (double)m_totalNumberStrings
-          : 0.0;
-  unsigned long long totalDataBytes = m_total8BitData + m_total16BitData * 2;
-  dataLogF(
-      "%8u Total                 %12llu chars  %12llu bytes  avg length "
-      "%6.1f\n",
-      m_totalNumberStrings, totalNumberCharacters, totalDataBytes,
-      averageLength);
-  unsigned long long totalSavedBytes = m_total8BitData;
-  double percentSavings = totalSavedBytes
-                              ? ((double)totalSavedBytes * 100) /
-                                    (double)(totalDataBytes + totalSavedBytes)
-                              : 0.0;
-  dataLogF("         Total savings %12llu bytes (%5.2f%%)\n", totalSavedBytes,
-           percentSavings);
-
-  unsigned totalOverhead = m_totalNumberStrings * sizeof(StringImpl);
-  double overheadPercent = (double)totalOverhead / (double)totalDataBytes * 100;
-  dataLogF("         StringImpl overheader: %8u (%5.2f%%)\n", totalOverhead,
-           overheadPercent);
-
-  internal::callOnMainThread(&printLiveStringStats, nullptr);
-}
-#endif
-
 void* StringImpl::operator new(size_t size) {
   DCHECK_EQ(size, sizeof(StringImpl));
   return Partitions::BufferMalloc(size, "WTF::StringImpl");
@@ -304,8 +70,6 @@ void StringImpl::operator delete(void* ptr) {
 inline StringImpl::~StringImpl() {
   DCHECK(!IsStatic());
 
-  STRING_STATS_REMOVE_STRING(this);
-
   if (IsAtomic())
     AtomicStringTable::Instance().Remove(this);
 }