Optionally compress V8 code cache data with snappy.

Source/bindings/core/v8/V8ScriptRunner.cpp

 /*
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 19 matching lines @@
 #include "bindings/core/v8/ScriptStreamer.h"
 #include "bindings/core/v8/V8Binding.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8RecursionScope.h"
 #include "bindings/core/v8/V8ThrowException.h"
 #include "core/dom/ExecutionContext.h"
 #include "core/fetch/CachedMetadata.h"
 #include "core/fetch/ScriptResource.h"
 #include "platform/ScriptForbiddenScope.h"
 #include "platform/TraceEvent.h"
+#include "third_party/snappy/src/snappy.h"
 
 namespace blink {
 
 namespace {
 
 // In order to make sure all pending messages to be processed in
 // v8::Function::Call, we don't call handleMaxRecursionDepthExceeded
 // directly. Instead, we create a v8::Function of
 // throwStackOverflowException and call it.
 void throwStackOverflowException(const v8::FunctionCallbackInfo<v8::Value>& info)
 {
     V8ThrowException::throwRangeError(info.GetIsolate(), "Maximum call stack size exceeded.");
 }
 
 v8::Local<v8::Value> throwStackOverflowExceptionIfNeeded(v8::Isolate* isolate)
 {
     if (V8PerIsolateData::from(isolate)->isHandlingRecursionLevelError()) {
         // If we are already handling a recursion level error, we should
         // not invoke v8::Function::Call.
         return v8::Undefined(isolate);
     }
     V8PerIsolateData::from(isolate)->setIsHandlingRecursionLevelError(true);
     v8::Local<v8::Value> result = v8::Function::New(isolate, throwStackOverflowException)->Call(v8::Undefined(isolate), 0, 0);
     V8PerIsolateData::from(isolate)->setIsHandlingRecursionLevelError(false);
     return result;
 }
 
-v8::Local<v8::Script> compileAndProduceCache(v8::Isolate* isolate, v8::Handle<v8::String> code, v8::ScriptOrigin origin, ScriptResource* resource, v8::ScriptCompiler::CompileOptions options, unsigned cacheTag, Resource::MetadataCacheType cacheType)
+void writeToCache(ScriptResource* resource, unsigned cacheTag, Resource::MetadataCacheType cacheType, const v8::ScriptCompiler::CachedData* cachedData, bool compressed)
+{
+    const char* data = reinterpret_cast<const char*>(cachedData->data);
+    int length = cachedData->length;
+    std::string compressedOutput;
+    if (compressed) {
+        snappy::Compress(data, length, &compressedOutput);
+        data = compressedOutput.data();
+        length = compressedOutput.length();
+    }
+    resource->clearCachedMetadata();
+    resource->setCachedMetadata(
+        cacheTag,
+        data,
+        length,
+        cacheType);
+}
+
+v8::Local<v8::Script> compileAndProduceCache(v8::Isolate* isolate, v8::Handle<v8::String> code, v8::ScriptOrigin origin, ScriptResource* resource, v8::ScriptCompiler::CompileOptions options, unsigned cacheTag, Resource::MetadataCacheType cacheType, bool compressed)
 {
     v8::ScriptCompiler::Source source(code, origin);
     v8::Local<v8::Script> script = v8::ScriptCompiler::Compile(isolate, &source, options);
     const v8::ScriptCompiler::CachedData* cachedData = source.GetCachedData();
-    if (resource && cachedData) {
-        resource->clearCachedMetadata();
-        resource->setCachedMetadata(
-            cacheTag,
-            reinterpret_cast<const char*>(cachedData->data),
-            cachedData->length,
-            cacheType);
-    }
+    if (resource && cachedData)
+        writeToCache(resource, cacheTag, cacheType, cachedData, compressed);
     return script;
 }
 
-v8::Local<v8::Script> compileAndConsumeCache(v8::Isolate* isolate, v8::Handle<v8::String> code, v8::ScriptOrigin origin, ScriptResource* resource, v8::ScriptCompiler::CompileOptions options, unsigned cacheTag)
+v8::Local<v8::Script> compileAndConsumeCache(v8::Isolate* isolate, v8::Handle<v8::String> code, v8::ScriptOrigin origin, ScriptResource* resource, v8::ScriptCompiler::CompileOptions options, unsigned cacheTag, bool compressed)
 {
     // Consume existing cache data:
     CachedMetadata* cachedMetadata = resource->cachedMetadata(cacheTag);
+    const char* data = cachedMetadata->data();
+    int length = cachedMetadata->size();
+    std::string uncompressedOutput;
+    if (compressed) {
+        snappy::Uncompress(data, length, &uncompressedOutput);
+        data = uncompressedOutput.data();
+        length = uncompressedOutput.length();
+    }
     v8::ScriptCompiler::CachedData* cachedData = new v8::ScriptCompiler::CachedData(
-        reinterpret_cast<const uint8_t*>(cachedMetadata->data()),
-        cachedMetadata->size(),
+        reinterpret_cast<const uint8_t*>(data),
+        length,
         v8::ScriptCompiler::CachedData::BufferNotOwned);
     v8::ScriptCompiler::Source source(code, origin, cachedData);
     return v8::ScriptCompiler::Compile(isolate, &source, options);
 }
 
 } // namespace
 
 v8::Local<v8::Script> V8ScriptRunner::compileScript(const ScriptSourceCode& source, v8::Isolate* isolate, AccessControlStatus corsStatus, V8CacheOptions cacheOptions)
 {
     return compileScript(v8String(isolate, source.source()), source.url(), source.startPosition(), source.resource(), source.streamer(), isolate, corsStatus, cacheOptions);
 }
 
 v8::Local<v8::Script> V8ScriptRunner::compileScript(v8::Handle<v8::String> code, const String& fileName, const TextPosition& scriptStartPosition, ScriptResource* resource, ScriptStreamer* streamer, v8::Isolate* isolate, AccessControlStatus corsStatus, V8CacheOptions cacheOptions)
 {
     TRACE_EVENT1("v8", "v8.compile", "fileName", fileName.utf8());
     TRACE_EVENT_SCOPED_SAMPLING_STATE("v8", "V8Compile");
 
     // NOTE: For compatibility with WebCore, ScriptSourceCode's line starts at
     // 1, whereas v8 starts at 0.
     v8::Handle<v8::String> name = v8String(isolate, fileName);
     v8::Handle<v8::Integer> line = v8::Integer::New(isolate, scriptStartPosition.m_line.zeroBasedInt());
     v8::Handle<v8::Integer> column = v8::Integer::New(isolate, scriptStartPosition.m_column.zeroBasedInt());
     v8::Handle<v8::Boolean> isSharedCrossOrigin = corsStatus == SharableCrossOrigin ? v8::True(isolate) : v8::False(isolate);
     v8::ScriptOrigin origin(name, line, column, isSharedCrossOrigin);
 
     v8::Local<v8::Script> script;
     unsigned cacheTag = 0;
+    bool compressed = cacheOptions == V8CacheOptionsCodeCompressed;
     if (streamer) {
         // We don't stream scripts which don't have a Resource.
         ASSERT(resource);
         // Failed resources should never get this far.
         ASSERT(!resource->errorOccurred());
         ASSERT(streamer->isFinished());
         ASSERT(!streamer->streamingSuppressed());
         script = v8::ScriptCompiler::Compile(isolate, streamer->source(), code, origin);
         // Whether to produce the cached data or not is decided when the
         // streamer is started. Here we only need to get the data out.
         const v8::ScriptCompiler::CachedData* newCachedData = streamer->source()->GetCachedData();
         if (newCachedData) {
-            resource->clearCachedMetadata();
-            resource->setCachedMetadata(streamer->cachedDataType(), reinterpret_cast<const char*>(newCachedData->data), newCachedData->length, Resource::CacheLocally);
+            // TODO(yangguo,vogelheim): code cache should use Resource::SendToPlatform.
+            writeToCache(resource, streamer->cachedDataType(), Resource::CacheLocally, newCachedData, compressed);
         }
     } else if (!resource || !resource->url().protocolIsInHTTPFamily() || code->Length() < 1024) {
         v8::ScriptCompiler::Source source(code, origin);
         script = v8::ScriptCompiler::Compile(isolate, &source, v8::ScriptCompiler::kNoCompileOptions);
     } else {
+        Resource::MetadataCacheType cacheType = Resource::CacheLocally;
+        v8::ScriptCompiler::CompileOptions consumeOption = v8::ScriptCompiler::kConsumeParserCache;
+        v8::ScriptCompiler::CompileOptions produceOption = v8::ScriptCompiler::kProduceParserCache;
         switch (cacheOptions) {
+        case V8CacheOptionsOff:
+            // Use default.
+            cacheTag = tagForParserCache();
+            break;
         case V8CacheOptionsParse:
             cacheTag = tagForParserCache();
-            script = resource->cachedMetadata(cacheTag)
-                ? compileAndConsumeCache(isolate, code, origin, resource, v8::ScriptCompiler::kConsumeParserCache, cacheTag)
-                : compileAndProduceCache(isolate, code, origin, resource, v8::ScriptCompiler::kProduceParserCache, cacheTag, Resource::SendToPlatform);
+            cacheType = Resource::SendToPlatform;
+            consumeOption = v8::ScriptCompiler::kConsumeParserCache;
+            produceOption = v8::ScriptCompiler::kProduceParserCache;
             break;
+        case V8CacheOptionsCodeCompressed:
         case V8CacheOptionsCode:
             cacheTag = tagForCodeCache();
-            script = resource->cachedMetadata(cacheTag)
-                ? compileAndConsumeCache(isolate, code, origin, resource, v8::ScriptCompiler::kConsumeCodeCache, cacheTag)
-                : compileAndProduceCache(isolate, code, origin, resource, v8::ScriptCompiler::kProduceCodeCache, cacheTag, Resource::SendToPlatform);
-            break;
-        case V8CacheOptionsOff:
-            // Previous behaviour was to always generate an in-memory parser
-            // cache. We emulate this here.
-            // FIXME: Determine whether this should get its own setting, so we
-            //        can also have a true 'off'.
-            cacheTag = tagForParserCache();
-            script = resource->cachedMetadata(cacheTag)
-                ? compileAndConsumeCache(isolate, code, origin, resource, v8::ScriptCompiler::kConsumeParserCache, cacheTag)
-                : compileAndProduceCache(isolate, code, origin, resource, v8::ScriptCompiler::kProduceParserCache, cacheTag, Resource::CacheLocally);
+            cacheType = Resource::SendToPlatform;
+            consumeOption = v8::ScriptCompiler::kConsumeCodeCache;
+            produceOption = v8::ScriptCompiler::kProduceCodeCache;
             break;
         }
+        script = resource->cachedMetadata(cacheTag)
+            ? compileAndConsumeCache(isolate, code, origin, resource, consumeOption, cacheTag, compressed)
+            : compileAndProduceCache(isolate, code, origin, resource, produceOption, cacheTag, cacheType, compressed);
     }
     return script;
 }
 
 v8::Local<v8::Value> V8ScriptRunner::runCompiledScript(v8::Isolate* isolate, v8::Handle<v8::Script> script, ExecutionContext* context)
 {
     if (script.IsEmpty())
         return v8::Local<v8::Value>();
     TRACE_EVENT_SCOPED_SAMPLING_STATE("v8", "V8Execution");
     TRACE_EVENT1("v8", "v8.run", "fileName", TRACE_STR_COPY(*v8::String::Utf8Value(script->GetUnboundScript()->GetScriptName())));
@@ skipping 120 matching lines @@
 {
     return StringHash::hash(v8::V8::GetVersion()) * 2;
 }
 
 unsigned V8ScriptRunner::tagForCodeCache()
 {
     return StringHash::hash(v8::V8::GetVersion()) * 2 + 1;
 }
 
 } // namespace blink