Reverting 19963.

Review URL: http://codereview.chromium.org/149208

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@19968 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 130 insertions, 0 deletions

diff --git a/webkit/port/bindings/v8/v8_binding.cpp b/webkit/port/bindings/v8/v8_binding.cpp
new file mode 100644
index 0000000..616d7b2
--- /dev/null
+++ b/webkit/port/bindings/v8/v8_binding.cpp
@@ -0,0 +1,130 @@
+// Copyright (c) 2006-2008 The Chromium 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 "v8_binding.h"
+
+#include "AtomicString.h"
+#include "CString.h"
+#include "MathExtras.h"
+#include "PlatformString.h"
+#include "StringBuffer.h"
+
+#include <v8.h>
+
+namespace WebCore {
+
+// WebCoreStringResource is a helper class for v8ExternalString. It is used
+// to manage the life-cycle of the underlying buffer of the external string.
+class WebCoreStringResource: public v8::String::ExternalStringResource {
+ public:
+  explicit WebCoreStringResource(const String& str)
+      : impl_(str.impl()) { }
+
+  virtual ~WebCoreStringResource() {}
+
+  const uint16_t* data() const {
+    return reinterpret_cast<const uint16_t*>(impl_.characters());
+  }
+
+  size_t length() const { return impl_.length(); }
+
+  String webcore_string() { return impl_; }
+
+ private:
+  // A shallow copy of the string.
+  // Keeps the string buffer alive until the V8 engine garbage collects it.
+  String impl_;
+};
+
+
+String v8StringToWebCoreString(
+    v8::Handle<v8::String> v8_str, bool externalize) {
+  WebCoreStringResource* str_resource = static_cast<WebCoreStringResource*>(
+      v8_str->GetExternalStringResource());
+  if (str_resource) {
+    return str_resource->webcore_string();
+  }
+
+  int length = v8_str->Length();
+  if (length == 0) {
+    // Avoid trying to morph empty strings, as they do not have enough room to
+    // contain the external reference.
+    return StringImpl::empty();
+  }
+
+  UChar* buffer;
+  String result = String::createUninitialized(length, buffer);
+  v8_str->Write(reinterpret_cast<uint16_t*>(buffer), 0, length);
+
+  if (externalize) {
+    WebCoreStringResource* resource = new WebCoreStringResource(result);
+    if (!v8_str->MakeExternal(resource)) {
+      // In case of a failure delete the external resource as it was not used.
+      delete resource;
+    }
+  }
+  return result;
+}
+
+
+String v8ValueToWebCoreString(v8::Handle<v8::Value> obj) {
+  if (obj->IsString()) {
+    v8::Handle<v8::String> v8_str = v8::Handle<v8::String>::Cast(obj);
+    String webCoreString = v8StringToWebCoreString(v8_str, true);
+    return webCoreString;
+  } else if (obj->IsInt32()) {
+    int value = obj->Int32Value();
+    // Most numbers used are <= 100. Even if they aren't used
+    // there's very little in using the space.
+    const int kLowNumbers = 100;
+    static AtomicString lowNumbers[kLowNumbers + 1];
+    String webCoreString;
+    if (0 <= value && value <= kLowNumbers) {
+      webCoreString = lowNumbers[value];
+      if (!webCoreString) {
+        AtomicString valueString = AtomicString(String::number(value));
+        lowNumbers[value] = valueString;
+        webCoreString = valueString;
+      }
+    } else {
+      webCoreString = String::number(value);
+    }
+    return webCoreString;
+  } else {
+    v8::TryCatch block;
+    v8::Handle<v8::String> v8_str = obj->ToString();
+    // Check for empty handles to handle the case where an exception
+    // is thrown as part of invoking toString on the object.
+    if (v8_str.IsEmpty())
+      return StringImpl::empty();
+    return v8StringToWebCoreString(v8_str, false);
+  }
+}
+
+
+AtomicString v8StringToAtomicWebCoreString(v8::Handle<v8::String> v8_str) {
+  String str = v8StringToWebCoreString(v8_str, true);
+  return AtomicString(str);
+}
+
+
+AtomicString v8ValueToAtomicWebCoreString(v8::Handle<v8::Value> v8_str) {
+  String str = v8ValueToWebCoreString(v8_str);
+  return AtomicString(str);
+}
+
+
+v8::Handle<v8::String> v8String(const String& str) {
+  if (!str.length())
+    return v8::String::Empty();
+  return v8::String::NewExternal(new WebCoreStringResource(str));
+}
+
+v8::Local<v8::String> v8ExternalString(const String& str) {
+  if (!str.length())
+    return v8::String::Empty();
+  return v8::String::NewExternal(new WebCoreStringResource(str));
+}
+
+}  // namespace WebCore