src/codegen/compilation-cache.cc - v8/v8 - Git at Google

 // Copyright 2011 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 #include "src/codegen/compilation-cache.h"

 #include "src/codegen/script-details.h"
 #include "src/common/globals.h"
 #include "src/heap/factory.h"
 #include "src/logging/counters.h"
 #include "src/logging/log.h"
 #include "src/objects/compilation-cache-table-inl.h"
 #include "src/objects/objects-inl.h"
 #include "src/objects/slots.h"
 #include "src/objects/visitors.h"
 #include "src/utils/ostreams.h"

 namespace v8 {
 namespace internal {

 // The number of generations for each sub cache.
 static const int kRegExpGenerations = 2;

 // Initial size of each compilation cache table allocated.
 static const int kInitialCacheSize = 64;

 CompilationCache::CompilationCache(Isolate* isolate)
     : isolate_(isolate),
       script_(isolate),
       eval_global_(isolate),
       eval_contextual_(isolate),
       reg_exp_(isolate, kRegExpGenerations),
       enabled_script_and_eval_(true) {
   CompilationSubCache* subcaches[kSubCacheCount] = {
       &script_, &eval_global_, &eval_contextual_, &reg_exp_};
   for (int i = 0; i < kSubCacheCount; ++i) {
     subcaches_[i] = subcaches[i];
   }
 }

 Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) {
   DCHECK_LT(generation, generations());
   Handle<CompilationCacheTable> result;
   if (tables_[generation].IsUndefined(isolate())) {
     result = CompilationCacheTable::New(isolate(), kInitialCacheSize);
     tables_[generation] = *result;
   } else {
     CompilationCacheTable table =
         CompilationCacheTable::cast(tables_[generation]);
     result = Handle<CompilationCacheTable>(table, isolate());
   }
   return result;
 }

 // static
 void CompilationSubCache::AgeByGeneration(CompilationSubCache* c) {
   DCHECK_GT(c->generations(), 1);

   // Age the generations implicitly killing off the oldest.
   for (int i = c->generations() - 1; i > 0; i--) {
     c->tables_[i] = c->tables_[i - 1];
   }

   // Set the first generation as unborn.
   c->tables_[0] = ReadOnlyRoots(c->isolate()).undefined_value();
 }

 // static
 void CompilationSubCache::AgeCustom(CompilationSubCache* c) {
   DCHECK_EQ(c->generations(), 1);
   if (c->tables_[0].IsUndefined(c->isolate())) return;
   CompilationCacheTable::cast(c->tables_[0]).Age(c->isolate());
 }

 void CompilationCacheScript::Age() {
   if (FLAG_isolate_script_cache_ageing) AgeCustom(this);
 }
 void CompilationCacheEval::Age() { AgeCustom(this); }
 void CompilationCacheRegExp::Age() { AgeByGeneration(this); }

 void CompilationSubCache::Iterate(RootVisitor* v) {
   v->VisitRootPointers(Root::kCompilationCache, nullptr,
                        FullObjectSlot(&tables_[0]),
                        FullObjectSlot(&tables_[generations()]));
 }

 void CompilationSubCache::Clear() {
   MemsetPointer(reinterpret_cast<Address*>(tables_),
                 ReadOnlyRoots(isolate()).undefined_value().ptr(),
                 generations());
 }

 void CompilationSubCache::Remove(Handle<SharedFunctionInfo> function_info) {
   // Probe the script generation tables. Make sure not to leak handles
   // into the caller's handle scope.
   {
     HandleScope scope(isolate());
     for (int generation = 0; generation < generations(); generation++) {
       Handle<CompilationCacheTable> table = GetTable(generation);
       table->Remove(*function_info);
     }
   }
 }

 CompilationCacheScript::CompilationCacheScript(Isolate* isolate)
     : CompilationSubCache(isolate, 1) {}

 namespace {

 // We only re-use a cached function for some script source code if the
 // script originates from the same place. This is to avoid issues
 // when reporting errors, etc.
 bool HasOrigin(Isolate* isolate, Handle<SharedFunctionInfo> function_info,
                const ScriptDetails& script_details) {
   Handle<Script> script =
       Handle<Script>(Script::cast(function_info->script()), isolate);
   // If the script name isn't set, the boilerplate script should have
   // an undefined name to have the same origin.
   Handle<Object> name;
   if (!script_details.name_obj.ToHandle(&name)) {
     return script->name().IsUndefined(isolate);
   }
   // Do the fast bailout checks first.
   if (script_details.line_offset != script->line_offset()) return false;
   if (script_details.column_offset != script->column_offset()) return false;
   // Check that both names are strings. If not, no match.
   if (!name->IsString() || !script->name().IsString()) return false;
   // Are the origin_options same?
   if (script_details.origin_options.Flags() !=
       script->origin_options().Flags()) {
     return false;
   }
   // Compare the two name strings for equality.
   if (!String::Equals(isolate, Handle<String>::cast(name),
                       Handle<String>(String::cast(script->name()), isolate))) {
     return false;
   }

   // TODO(cbruni, chromium:1244145): Remove once migrated to the context
   Handle<Object> maybe_host_defined_options;
   if (!script_details.host_defined_options.ToHandle(
           &maybe_host_defined_options)) {
     maybe_host_defined_options = isolate->factory()->empty_fixed_array();
   }
   Handle<FixedArray> host_defined_options =
       Handle<FixedArray>::cast(maybe_host_defined_options);
   Handle<FixedArray> script_options(
       FixedArray::cast(script->host_defined_options()), isolate);
   int length = host_defined_options->length();
   if (length != script_options->length()) return false;

   for (int i = 0; i < length; i++) {
     // host-defined options is a v8::PrimitiveArray.
     DCHECK(host_defined_options->get(i).IsPrimitive());
     DCHECK(script_options->get(i).IsPrimitive());
     if (!host_defined_options->get(i).StrictEquals(script_options->get(i))) {
       return false;
     }
   }
   return true;
 }
 }  // namespace

 // TODO(245): Need to allow identical code from different contexts to
 // be cached in the same script generation. Currently the first use
 // will be cached, but subsequent code from different source / line
 // won't.
 MaybeHandle<SharedFunctionInfo> CompilationCacheScript::Lookup(
     Handle<String> source, const ScriptDetails& script_details,
     LanguageMode language_mode) {
   MaybeHandle<SharedFunctionInfo> result;

   // Probe the script generation tables. Make sure not to leak handles
   // into the caller's handle scope.
   {
     HandleScope scope(isolate());
     const int generation = 0;
     DCHECK_EQ(generations(), 1);
     Handle<CompilationCacheTable> table = GetTable(generation);
     MaybeHandle<SharedFunctionInfo> probe = CompilationCacheTable::LookupScript(
         table, source, language_mode, isolate());
     Handle<SharedFunctionInfo> function_info;
     if (probe.ToHandle(&function_info)) {
       // Break when we've found a suitable shared function info that
       // matches the origin.
       if (HasOrigin(isolate(), function_info, script_details)) {
         result = scope.CloseAndEscape(function_info);
       }
     }
   }

   // Once outside the manacles of the handle scope, we need to recheck
   // to see if we actually found a cached script. If so, we return a
   // handle created in the caller's handle scope.
   Handle<SharedFunctionInfo> function_info;
   if (result.ToHandle(&function_info)) {
     // Since HasOrigin can allocate, we need to protect the SharedFunctionInfo
     // with handles during the call.
     DCHECK(HasOrigin(isolate(), function_info, script_details));
     isolate()->counters()->compilation_cache_hits()->Increment();
     LOG(isolate(), CompilationCacheEvent("hit", "script", *function_info));
   } else {
     isolate()->counters()->compilation_cache_misses()->Increment();
   }
   return result;
 }

 void CompilationCacheScript::Put(Handle<String> source,
                                  LanguageMode language_mode,
                                  Handle<SharedFunctionInfo> function_info) {
   HandleScope scope(isolate());
   Handle<CompilationCacheTable> table = GetFirstTable();
   SetFirstTable(CompilationCacheTable::PutScript(table, source, language_mode,
                                                  function_info, isolate()));
 }

 InfoCellPair CompilationCacheEval::Lookup(Handle<String> source,
                                           Handle<SharedFunctionInfo> outer_info,
                                           Handle<Context> native_context,
                                           LanguageMode language_mode,
                                           int position) {
   HandleScope scope(isolate());
   // Make sure not to leak the table into the surrounding handle
   // scope. Otherwise, we risk keeping old tables around even after
   // having cleared the cache.
   InfoCellPair result;
   const int generation = 0;
   DCHECK_EQ(generations(), 1);
   Handle<CompilationCacheTable> table = GetTable(generation);
   result = CompilationCacheTable::LookupEval(
       table, source, outer_info, native_context, language_mode, position);
   if (result.has_shared()) {
     isolate()->counters()->compilation_cache_hits()->Increment();
   } else {
     isolate()->counters()->compilation_cache_misses()->Increment();
   }
   return result;
 }

 void CompilationCacheEval::Put(Handle<String> source,
                                Handle<SharedFunctionInfo> outer_info,
                                Handle<SharedFunctionInfo> function_info,
                                Handle<Context> native_context,
                                Handle<FeedbackCell> feedback_cell,
                                int position) {
   HandleScope scope(isolate());
   Handle<CompilationCacheTable> table = GetFirstTable();
   table =
       CompilationCacheTable::PutEval(table, source, outer_info, function_info,
                                      native_context, feedback_cell, position);
   SetFirstTable(table);
 }

 MaybeHandle<FixedArray> CompilationCacheRegExp::Lookup(Handle<String> source,
                                                        JSRegExp::Flags flags) {
   HandleScope scope(isolate());
   // Make sure not to leak the table into the surrounding handle
   // scope. Otherwise, we risk keeping old tables around even after
   // having cleared the cache.
   Handle<Object> result = isolate()->factory()->undefined_value();
   int generation;
   for (generation = 0; generation < generations(); generation++) {
     Handle<CompilationCacheTable> table = GetTable(generation);
     result = table->LookupRegExp(source, flags);
     if (result->IsFixedArray()) break;
   }
   if (result->IsFixedArray()) {
     Handle<FixedArray> data = Handle<FixedArray>::cast(result);
     if (generation != 0) {
       Put(source, flags, data);
     }
     isolate()->counters()->compilation_cache_hits()->Increment();
     return scope.CloseAndEscape(data);
   } else {
     isolate()->counters()->compilation_cache_misses()->Increment();
     return MaybeHandle<FixedArray>();
   }
 }

 void CompilationCacheRegExp::Put(Handle<String> source, JSRegExp::Flags flags,
                                  Handle<FixedArray> data) {
   HandleScope scope(isolate());
   Handle<CompilationCacheTable> table = GetFirstTable();
   SetFirstTable(
       CompilationCacheTable::PutRegExp(isolate(), table, source, flags, data));
 }

 void CompilationCache::Remove(Handle<SharedFunctionInfo> function_info) {
   if (!IsEnabledScriptAndEval()) return;

   eval_global_.Remove(function_info);
   eval_contextual_.Remove(function_info);
   script_.Remove(function_info);
 }

 MaybeHandle<SharedFunctionInfo> CompilationCache::LookupScript(
     Handle<String> source, const ScriptDetails& script_details,
     LanguageMode language_mode) {
   if (!IsEnabledScriptAndEval()) return MaybeHandle<SharedFunctionInfo>();
   return script_.Lookup(source, script_details, language_mode);
 }

 InfoCellPair CompilationCache::LookupEval(Handle<String> source,
                                           Handle<SharedFunctionInfo> outer_info,
                                           Handle<Context> context,
                                           LanguageMode language_mode,
                                           int position) {
   InfoCellPair result;
   if (!IsEnabledScriptAndEval()) return result;

   const char* cache_type;

   if (context->IsNativeContext()) {
     result = eval_global_.Lookup(source, outer_info, context, language_mode,
                                  position);
     cache_type = "eval-global";

   } else {
     DCHECK_NE(position, kNoSourcePosition);
     Handle<Context> native_context(context->native_context(), isolate());
     result = eval_contextual_.Lookup(source, outer_info, native_context,
                                      language_mode, position);
     cache_type = "eval-contextual";
   }

   if (result.has_shared()) {
     LOG(isolate(), CompilationCacheEvent("hit", cache_type, result.shared()));
   }

   return result;
 }

 MaybeHandle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
                                                        JSRegExp::Flags flags) {
   return reg_exp_.Lookup(source, flags);
 }

 void CompilationCache::PutScript(Handle<String> source,
                                  LanguageMode language_mode,
                                  Handle<SharedFunctionInfo> function_info) {
   if (!IsEnabledScriptAndEval()) return;
   LOG(isolate(), CompilationCacheEvent("put", "script", *function_info));

   script_.Put(source, language_mode, function_info);
 }

 void CompilationCache::PutEval(Handle<String> source,
                                Handle<SharedFunctionInfo> outer_info,
                                Handle<Context> context,
                                Handle<SharedFunctionInfo> function_info,
                                Handle<FeedbackCell> feedback_cell,
                                int position) {
   if (!IsEnabledScriptAndEval()) return;

   const char* cache_type;
   HandleScope scope(isolate());
   if (context->IsNativeContext()) {
     eval_global_.Put(source, outer_info, function_info, context, feedback_cell,
                      position);
     cache_type = "eval-global";
   } else {
     DCHECK_NE(position, kNoSourcePosition);
     Handle<Context> native_context(context->native_context(), isolate());
     eval_contextual_.Put(source, outer_info, function_info, native_context,
                          feedback_cell, position);
     cache_type = "eval-contextual";
   }
   LOG(isolate(), CompilationCacheEvent("put", cache_type, *function_info));
 }

 void CompilationCache::PutRegExp(Handle<String> source, JSRegExp::Flags flags,
                                  Handle<FixedArray> data) {
   reg_exp_.Put(source, flags, data);
 }

 void CompilationCache::Clear() {
   for (int i = 0; i < kSubCacheCount; i++) {
     subcaches_[i]->Clear();
   }
 }

 void CompilationCache::Iterate(RootVisitor* v) {
   for (int i = 0; i < kSubCacheCount; i++) {
     subcaches_[i]->Iterate(v);
   }
 }

 void CompilationCache::MarkCompactPrologue() {
   for (int i = 0; i < kSubCacheCount; i++) {
     subcaches_[i]->Age();
   }
 }

 void CompilationCache::EnableScriptAndEval() {
   enabled_script_and_eval_ = true;
 }

 void CompilationCache::DisableScriptAndEval() {
   enabled_script_and_eval_ = false;
   Clear();
 }

 }  // namespace internal
 }  // namespace v8
	// Copyright 2011 the V8 project authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	#include "src/codegen/compilation-cache.h"

	#include "src/codegen/script-details.h"
	#include "src/common/globals.h"
	#include "src/heap/factory.h"
	#include "src/logging/counters.h"
	#include "src/logging/log.h"
	#include "src/objects/compilation-cache-table-inl.h"
	#include "src/objects/objects-inl.h"
	#include "src/objects/slots.h"
	#include "src/objects/visitors.h"
	#include "src/utils/ostreams.h"

	namespace v8 {
	namespace internal {

	// The number of generations for each sub cache.
	static const int kRegExpGenerations = 2;

	// Initial size of each compilation cache table allocated.
	static const int kInitialCacheSize = 64;

	CompilationCache::CompilationCache(Isolate* isolate)
	: isolate_(isolate),
	script_(isolate),
	eval_global_(isolate),
	eval_contextual_(isolate),
	reg_exp_(isolate, kRegExpGenerations),
	enabled_script_and_eval_(true) {
	CompilationSubCache* subcaches[kSubCacheCount] = {
	&script_, &eval_global_, &eval_contextual_, &reg_exp_};
	for (int i = 0; i < kSubCacheCount; ++i) {
	subcaches_[i] = subcaches[i];
	}
	}

	Handle<CompilationCacheTable> CompilationSubCache::GetTable(int generation) {
	DCHECK_LT(generation, generations());
	Handle<CompilationCacheTable> result;
	if (tables_[generation].IsUndefined(isolate())) {
	result = CompilationCacheTable::New(isolate(), kInitialCacheSize);
	tables_[generation] = *result;
	} else {
	CompilationCacheTable table =
	CompilationCacheTable::cast(tables_[generation]);
	result = Handle<CompilationCacheTable>(table, isolate());
	}
	return result;
	}

	// static
	void CompilationSubCache::AgeByGeneration(CompilationSubCache* c) {
	DCHECK_GT(c->generations(), 1);

	// Age the generations implicitly killing off the oldest.
	for (int i = c->generations() - 1; i > 0; i--) {
	c->tables_[i] = c->tables_[i - 1];
	}

	// Set the first generation as unborn.
	c->tables_[0] = ReadOnlyRoots(c->isolate()).undefined_value();
	}

	// static
	void CompilationSubCache::AgeCustom(CompilationSubCache* c) {
	DCHECK_EQ(c->generations(), 1);
	if (c->tables_[0].IsUndefined(c->isolate())) return;
	CompilationCacheTable::cast(c->tables_[0]).Age(c->isolate());
	}

	void CompilationCacheScript::Age() {
	if (FLAG_isolate_script_cache_ageing) AgeCustom(this);
	}
	void CompilationCacheEval::Age() { AgeCustom(this); }
	void CompilationCacheRegExp::Age() { AgeByGeneration(this); }

	void CompilationSubCache::Iterate(RootVisitor* v) {
	v->VisitRootPointers(Root::kCompilationCache, nullptr,
	FullObjectSlot(&tables_[0]),
	FullObjectSlot(&tables_[generations()]));
	}

	void CompilationSubCache::Clear() {
	MemsetPointer(reinterpret_cast<Address*>(tables_),
	ReadOnlyRoots(isolate()).undefined_value().ptr(),
	generations());
	}

	void CompilationSubCache::Remove(Handle<SharedFunctionInfo> function_info) {
	// Probe the script generation tables. Make sure not to leak handles
	// into the caller's handle scope.
	{
	HandleScope scope(isolate());
	for (int generation = 0; generation < generations(); generation++) {
	Handle<CompilationCacheTable> table = GetTable(generation);
	table->Remove(*function_info);
	}
	}
	}

	CompilationCacheScript::CompilationCacheScript(Isolate* isolate)
	: CompilationSubCache(isolate, 1) {}

	namespace {

	// We only re-use a cached function for some script source code if the
	// script originates from the same place. This is to avoid issues
	// when reporting errors, etc.
	bool HasOrigin(Isolate* isolate, Handle<SharedFunctionInfo> function_info,
	const ScriptDetails& script_details) {
	Handle<Script> script =
	Handle<Script>(Script::cast(function_info->script()), isolate);
	// If the script name isn't set, the boilerplate script should have
	// an undefined name to have the same origin.
	Handle<Object> name;
	if (!script_details.name_obj.ToHandle(&name)) {
	return script->name().IsUndefined(isolate);
	}
	// Do the fast bailout checks first.
	if (script_details.line_offset != script->line_offset()) return false;
	if (script_details.column_offset != script->column_offset()) return false;
	// Check that both names are strings. If not, no match.
	if (!name->IsString() \|\| !script->name().IsString()) return false;
	// Are the origin_options same?
	if (script_details.origin_options.Flags() !=
	script->origin_options().Flags()) {
	return false;
	}
	// Compare the two name strings for equality.
	if (!String::Equals(isolate, Handle<String>::cast(name),
	Handle<String>(String::cast(script->name()), isolate))) {
	return false;
	}

	// TODO(cbruni, chromium:1244145): Remove once migrated to the context
	Handle<Object> maybe_host_defined_options;
	if (!script_details.host_defined_options.ToHandle(
	&maybe_host_defined_options)) {
	maybe_host_defined_options = isolate->factory()->empty_fixed_array();
	}
	Handle<FixedArray> host_defined_options =
	Handle<FixedArray>::cast(maybe_host_defined_options);
	Handle<FixedArray> script_options(
	FixedArray::cast(script->host_defined_options()), isolate);
	int length = host_defined_options->length();
	if (length != script_options->length()) return false;

	for (int i = 0; i < length; i++) {
	// host-defined options is a v8::PrimitiveArray.
	DCHECK(host_defined_options->get(i).IsPrimitive());
	DCHECK(script_options->get(i).IsPrimitive());
	if (!host_defined_options->get(i).StrictEquals(script_options->get(i))) {
	return false;
	}
	}
	return true;
	}
	} // namespace

	// TODO(245): Need to allow identical code from different contexts to
	// be cached in the same script generation. Currently the first use
	// will be cached, but subsequent code from different source / line
	// won't.
	MaybeHandle<SharedFunctionInfo> CompilationCacheScript::Lookup(
	Handle<String> source, const ScriptDetails& script_details,
	LanguageMode language_mode) {
	MaybeHandle<SharedFunctionInfo> result;

	// Probe the script generation tables. Make sure not to leak handles
	// into the caller's handle scope.
	{
	HandleScope scope(isolate());
	const int generation = 0;
	DCHECK_EQ(generations(), 1);
	Handle<CompilationCacheTable> table = GetTable(generation);
	MaybeHandle<SharedFunctionInfo> probe = CompilationCacheTable::LookupScript(
	table, source, language_mode, isolate());
	Handle<SharedFunctionInfo> function_info;
	if (probe.ToHandle(&function_info)) {
	// Break when we've found a suitable shared function info that
	// matches the origin.
	if (HasOrigin(isolate(), function_info, script_details)) {
	result = scope.CloseAndEscape(function_info);
	}
	}
	}

	// Once outside the manacles of the handle scope, we need to recheck
	// to see if we actually found a cached script. If so, we return a
	// handle created in the caller's handle scope.
	Handle<SharedFunctionInfo> function_info;
	if (result.ToHandle(&function_info)) {
	// Since HasOrigin can allocate, we need to protect the SharedFunctionInfo
	// with handles during the call.
	DCHECK(HasOrigin(isolate(), function_info, script_details));
	isolate()->counters()->compilation_cache_hits()->Increment();
	LOG(isolate(), CompilationCacheEvent("hit", "script", *function_info));
	} else {
	isolate()->counters()->compilation_cache_misses()->Increment();
	}
	return result;
	}

	void CompilationCacheScript::Put(Handle<String> source,
	LanguageMode language_mode,
	Handle<SharedFunctionInfo> function_info) {
	HandleScope scope(isolate());
	Handle<CompilationCacheTable> table = GetFirstTable();
	SetFirstTable(CompilationCacheTable::PutScript(table, source, language_mode,
	function_info, isolate()));
	}

	InfoCellPair CompilationCacheEval::Lookup(Handle<String> source,
	Handle<SharedFunctionInfo> outer_info,
	Handle<Context> native_context,
	LanguageMode language_mode,
	int position) {
	HandleScope scope(isolate());
	// Make sure not to leak the table into the surrounding handle
	// scope. Otherwise, we risk keeping old tables around even after
	// having cleared the cache.
	InfoCellPair result;
	const int generation = 0;
	DCHECK_EQ(generations(), 1);
	Handle<CompilationCacheTable> table = GetTable(generation);
	result = CompilationCacheTable::LookupEval(
	table, source, outer_info, native_context, language_mode, position);
	if (result.has_shared()) {
	isolate()->counters()->compilation_cache_hits()->Increment();
	} else {
	isolate()->counters()->compilation_cache_misses()->Increment();
	}
	return result;
	}

	void CompilationCacheEval::Put(Handle<String> source,
	Handle<SharedFunctionInfo> outer_info,
	Handle<SharedFunctionInfo> function_info,
	Handle<Context> native_context,
	Handle<FeedbackCell> feedback_cell,
	int position) {
	HandleScope scope(isolate());
	Handle<CompilationCacheTable> table = GetFirstTable();
	table =
	CompilationCacheTable::PutEval(table, source, outer_info, function_info,
	native_context, feedback_cell, position);
	SetFirstTable(table);
	}

	MaybeHandle<FixedArray> CompilationCacheRegExp::Lookup(Handle<String> source,
	JSRegExp::Flags flags) {
	HandleScope scope(isolate());
	// Make sure not to leak the table into the surrounding handle
	// scope. Otherwise, we risk keeping old tables around even after
	// having cleared the cache.
	Handle<Object> result = isolate()->factory()->undefined_value();
	int generation;
	for (generation = 0; generation < generations(); generation++) {
	Handle<CompilationCacheTable> table = GetTable(generation);
	result = table->LookupRegExp(source, flags);
	if (result->IsFixedArray()) break;
	}
	if (result->IsFixedArray()) {
	Handle<FixedArray> data = Handle<FixedArray>::cast(result);
	if (generation != 0) {
	Put(source, flags, data);
	}
	isolate()->counters()->compilation_cache_hits()->Increment();
	return scope.CloseAndEscape(data);
	} else {
	isolate()->counters()->compilation_cache_misses()->Increment();
	return MaybeHandle<FixedArray>();
	}
	}

	void CompilationCacheRegExp::Put(Handle<String> source, JSRegExp::Flags flags,
	Handle<FixedArray> data) {
	HandleScope scope(isolate());
	Handle<CompilationCacheTable> table = GetFirstTable();
	SetFirstTable(
	CompilationCacheTable::PutRegExp(isolate(), table, source, flags, data));
	}

	void CompilationCache::Remove(Handle<SharedFunctionInfo> function_info) {
	if (!IsEnabledScriptAndEval()) return;

	eval_global_.Remove(function_info);
	eval_contextual_.Remove(function_info);
	script_.Remove(function_info);
	}

	MaybeHandle<SharedFunctionInfo> CompilationCache::LookupScript(
	Handle<String> source, const ScriptDetails& script_details,
	LanguageMode language_mode) {
	if (!IsEnabledScriptAndEval()) return MaybeHandle<SharedFunctionInfo>();
	return script_.Lookup(source, script_details, language_mode);
	}

	InfoCellPair CompilationCache::LookupEval(Handle<String> source,
	Handle<SharedFunctionInfo> outer_info,
	Handle<Context> context,
	LanguageMode language_mode,
	int position) {
	InfoCellPair result;
	if (!IsEnabledScriptAndEval()) return result;

	const char* cache_type;

	if (context->IsNativeContext()) {
	result = eval_global_.Lookup(source, outer_info, context, language_mode,
	position);
	cache_type = "eval-global";

	} else {
	DCHECK_NE(position, kNoSourcePosition);
	Handle<Context> native_context(context->native_context(), isolate());
	result = eval_contextual_.Lookup(source, outer_info, native_context,
	language_mode, position);
	cache_type = "eval-contextual";
	}

	if (result.has_shared()) {
	LOG(isolate(), CompilationCacheEvent("hit", cache_type, result.shared()));
	}

	return result;
	}

	MaybeHandle<FixedArray> CompilationCache::LookupRegExp(Handle<String> source,
	JSRegExp::Flags flags) {
	return reg_exp_.Lookup(source, flags);
	}

	void CompilationCache::PutScript(Handle<String> source,
	LanguageMode language_mode,
	Handle<SharedFunctionInfo> function_info) {
	if (!IsEnabledScriptAndEval()) return;
	LOG(isolate(), CompilationCacheEvent("put", "script", *function_info));

	script_.Put(source, language_mode, function_info);
	}

	void CompilationCache::PutEval(Handle<String> source,
	Handle<SharedFunctionInfo> outer_info,
	Handle<Context> context,
	Handle<SharedFunctionInfo> function_info,
	Handle<FeedbackCell> feedback_cell,
	int position) {
	if (!IsEnabledScriptAndEval()) return;

	const char* cache_type;
	HandleScope scope(isolate());
	if (context->IsNativeContext()) {
	eval_global_.Put(source, outer_info, function_info, context, feedback_cell,
	position);
	cache_type = "eval-global";
	} else {
	DCHECK_NE(position, kNoSourcePosition);
	Handle<Context> native_context(context->native_context(), isolate());
	eval_contextual_.Put(source, outer_info, function_info, native_context,
	feedback_cell, position);
	cache_type = "eval-contextual";
	}
	LOG(isolate(), CompilationCacheEvent("put", cache_type, *function_info));
	}

	void CompilationCache::PutRegExp(Handle<String> source, JSRegExp::Flags flags,
	Handle<FixedArray> data) {
	reg_exp_.Put(source, flags, data);
	}

	void CompilationCache::Clear() {
	for (int i = 0; i < kSubCacheCount; i++) {
	subcaches_[i]->Clear();
	}
	}

	void CompilationCache::Iterate(RootVisitor* v) {
	for (int i = 0; i < kSubCacheCount; i++) {
	subcaches_[i]->Iterate(v);
	}
	}

	void CompilationCache::MarkCompactPrologue() {
	for (int i = 0; i < kSubCacheCount; i++) {
	subcaches_[i]->Age();
	}
	}

	void CompilationCache::EnableScriptAndEval() {
	enabled_script_and_eval_ = true;
	}

	void CompilationCache::DisableScriptAndEval() {
	enabled_script_and_eval_ = false;
	Clear();
	}

	} // namespace internal
	} // namespace v8