1 files changed, 119 insertions, 0 deletions
diff --git a/libs/minikin/HbFaceCache.cpp b/libs/minikin/HbFaceCache.cpp
new file mode 100644
index 0000000..fde2fa8
--- /dev/null
+++ b/libs/minikin/HbFaceCache.cpp
@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "Minikin"
+
+#include "HbFaceCache.h"
+
+#include <hb.h>
+#include <utils/LruCache.h>
+
+#include <minikin/MinikinFont.h>
+#include "MinikinInternal.h"
+
+namespace android {
+
+static hb_blob_t* referenceTable(hb_face_t* face, hb_tag_t tag, void* userData) {
+    MinikinFont* font = reinterpret_cast<MinikinFont*>(userData);
+    size_t length = 0;
+    bool ok = font->GetTable(tag, NULL, &length);
+    if (!ok) {
+        return 0;
+    }
+    char* buffer = reinterpret_cast<char*>(malloc(length));
+    if (!buffer) {
+        return 0;
+    }
+    ok = font->GetTable(tag, reinterpret_cast<uint8_t*>(buffer), &length);
+#ifdef VERBOSE_DEBUG
+    ALOGD("referenceTable %c%c%c%c length=%d %d",
+        (tag >>24)&0xff, (tag>>16)&0xff, (tag>>8)&0xff, tag&0xff, length, ok);
+#endif
+    if (!ok) {
+        free(buffer);
+        return 0;
+    }
+    return hb_blob_create(const_cast<char*>(buffer), length,
+            HB_MEMORY_MODE_WRITABLE, buffer, free);
+}
+
+static unsigned int disabledDecomposeCompatibility(
+        hb_unicode_funcs_t*, hb_codepoint_t, hb_codepoint_t*, void*) {
+    return 0;
+}
+
+class HbFaceCache : private OnEntryRemoved<int32_t, hb_face_t*> {
+public:
+    HbFaceCache() : mCache(kMaxEntries) {
+        mCache.setOnEntryRemovedListener(this);
+    }
+
+    // callback for OnEntryRemoved
+    void operator()(int32_t& key, hb_face_t*& value) {
+        hb_face_destroy(value);
+    }
+
+    hb_face_t* get(int32_t fontId) {
+        return mCache.get(fontId);
+    }
+
+    void put(int32_t fontId, hb_face_t* face) {
+        mCache.put(fontId, face);
+    }
+
+    void clear() {
+        mCache.clear();
+    }
+
+private:
+    static const size_t kMaxEntries = 100;
+
+    LruCache<int32_t, hb_face_t*> mCache;
+};
+
+HbFaceCache* getFaceCacheLocked() {
+    assertMinikinLocked();
+    static HbFaceCache* cache = nullptr;
+    if (cache == nullptr) {
+        cache = new HbFaceCache();
+    }
+    return cache;
+}
+
+void purgeHbFaceCacheLocked() {
+    assertMinikinLocked();
+    getFaceCacheLocked()->clear();
+}
+
+hb_face_t* getHbFaceLocked(MinikinFont* minikinFont) {
+    assertMinikinLocked();
+    if (minikinFont == nullptr) {
+        return nullptr;
+    }
+
+    HbFaceCache* faceCache = getFaceCacheLocked();
+    const int32_t fontId = minikinFont->GetUniqueId();
+    hb_face_t* face = faceCache->get(fontId);
+    if (face != nullptr) {
+        return face;
+    }
+
+    face = hb_face_create_for_tables(referenceTable, minikinFont, nullptr);
+    faceCache->put(fontId, face);
+    return face;
+}
+
+}  // namespace android