Add mojo interface to load hyphenation dictionaries on Android

third_party/WebKit/Source/platform/text/hyphenation/HyphenationMinikin.cpp

+// Copyright 2016 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 "platform/text/Hyphenation.h"
+
+#include "base/files/file.h"
+#include "base/files/memory_mapped_file.h"
+#include "base/metrics/histogram.h"
+#include "base/timer/elapsed_timer.h"
+#include "mojo/public/cpp/system/platform_handle.h"
+#include "public/platform/Platform.h"
+#include "public/platform/ServiceRegistry.h"
+#include "public/platform/modules/hyphenation/hyphenation.mojom-blink.h"
+
+namespace blink {
+
+class HyphenationMinikin : public Hyphenation {
+public:
+    bool openDictionary(const AtomicString& locale);
+
+    size_t lastHyphenLocation(const StringView& text, size_t beforeIndex) const override;
+
+private:
+    static base::PlatformFile openDictionaryFile(const AtomicString& locale);
+
+    base::MemoryMappedFile m_file;
+};
+
+static const mojom::blink::HyphenationPtr& getService()
+{
+    DEFINE_STATIC_LOCAL(mojom::blink::HyphenationPtr, service, ());
+    if (service.is_bound())

[dcheng, 2016/07/13 02:56:29]

I have a question about this pattern:
https://groups.google.com/a/chromium.org/forum/#!topic/chromium-mojo/40iQ0dKWfVM

[kojii, 2016/07/13 05:02:29]

Thanks for asking in the group. I tried a different pattern in PS17, but will
change to "if (!service)" in the next patch.

[dcheng, 2016/07/13 12:08:58]

Nod, either way is fine with me.

+        return service;
+
+    Platform::current()->serviceRegistry()->connectToRemoteService(
+        mojo::GetProxy(&service));
+    return service;
+}
+
+base::PlatformFile HyphenationMinikin::openDictionaryFile(const AtomicString& locale)
+{
+    const mojom::blink::HyphenationPtr& service = getService();
+    mojo::ScopedHandle handle;
+    base::ElapsedTimer timer;
+    service->OpenDictionary(locale, &handle);
+    UMA_HISTOGRAM_TIMES("Hyphenation.Open", timer.Elapsed());
+    if (!handle.is_valid())
+        return base::kInvalidPlatformFile;
+
+    base::PlatformFile file;
+    MojoResult result = mojo::UnwrapPlatformFile(std::move(handle), &file);
+    if (result != MOJO_RESULT_OK) {
+        DLOG(ERROR) << "UnwrapPlatformFile failed";
+        return base::kInvalidPlatformFile;
+    }
+    return file;
+}
+
+bool HyphenationMinikin::openDictionary(const AtomicString& locale)
+{
+    base::PlatformFile file = openDictionaryFile(locale);
+    if (file == base::kInvalidPlatformFile)
+        return false;
+    if (!m_file.Initialize(base::File(file))) {
+        DLOG(ERROR) << "mmap failed";
+        return false;
+    }
+
+    // TODO(kojii): Create dictionary from m_file when Minikin is ready.
+
+    return true;
+}
+
+size_t HyphenationMinikin::lastHyphenLocation(const StringView& text, size_t beforeIndex) const
+{
+    // TODO(kojii): Call minikin using the dictionary when Minikin is ready.
+    return 0;
+}
+
+PassRefPtr<Hyphenation> Hyphenation::platformGetHyphenation(const AtomicString& locale)
+{
+    RefPtr<HyphenationMinikin> hyphenation(adoptRef(new HyphenationMinikin));
+    if (!hyphenation->openDictionary(locale))
+        return nullptr;
+    return hyphenation.release();
+}
+
+} // namespace blink