Introduce InputMethodSubtypeArray for memory efficient IPCs

This CL introduces InputMethodSubtypeArray which compresses
multiple instances of InputMethodSubtype to reduce the risk
of TransactionTooLargeException during IPCs.

There are some IMEs which rapidly adding new subtypes into
their supported language list. One problem here is that each
instance of InputMethodInfo internally owns the list of
supported subtypes. Basically it requires additional
200 ~ 300 bytes for each subtype when InputMethodInfo is
transffered via IPCs. We should keep the size less than
100 KB in typical scenario.

With this CL, the list of InputMethodSubtype is marshalled
with GZIP compression. Approximately one InputMethodInfo is
marshalled within 10 KB even when it has 100 subtypes.

No negative performance impact is observed so far. The cost of
decompression seems to be compensated by another optimization
in this CL. Actually marshalling cost is reduced with this CL
by caching the compressed data on demand.

BUG: 12954290
Change-Id: Ibb2940fcc02f3b3b51ba6bbe127d646fd7de7c45

2 files changed, 78 insertions, 1 deletions

diff --git a/core/tests/inputmethodtests/run_core_inputmethod_test.sh b/core/tests/inputmethodtests/run_core_inputmethod_test.sh
index 5e123ec..b0b119b 100755
--- a/core/tests/inputmethodtests/run_core_inputmethod_test.sh
+++ b/core/tests/inputmethodtests/run_core_inputmethod_test.sh
@@ -21,4 +21,4 @@ if [[ $rebuild == true ]]; then
   $COMMAND
 fi
 
-adb shell am instrument -w -e class android.os.InputMethodTest com.android.frameworks.coretests.inputmethod/android.test.InstrumentationTestRunner
+adb shell am instrument -w -e class android.os.InputMethodTest,android.os.InputMethodSubtypeArrayTest com.android.frameworks.coretests.inputmethod/android.test.InstrumentationTestRunner
diff --git a/core/tests/inputmethodtests/src/android/os/InputMethodSubtypeArrayTest.java b/core/tests/inputmethodtests/src/android/os/InputMethodSubtypeArrayTest.java
new file mode 100644
index 0000000..1e0a919
--- /dev/null
+++ b/core/tests/inputmethodtests/src/android/os/InputMethodSubtypeArrayTest.java
@@ -0,0 +1,77 @@
+/*
+ * Copyright (C) 2014 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.
+ */
+
+package android.os;
+
+import android.test.InstrumentationTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+import android.view.inputmethod.InputMethodSubtype;
+import android.view.inputmethod.InputMethodSubtypeArray;
+import android.view.inputmethod.InputMethodSubtype.InputMethodSubtypeBuilder;
+
+import java.util.ArrayList;
+
+public class InputMethodSubtypeArrayTest extends InstrumentationTestCase {
+    @SmallTest
+    public void testInstanciate() throws Exception {
+        final ArrayList<InputMethodSubtype> subtypes = new ArrayList<InputMethodSubtype>();
+        subtypes.add(createDummySubtype(0, "en_US"));
+        subtypes.add(createDummySubtype(1, "en_US"));
+        subtypes.add(createDummySubtype(2, "ja_JP"));
+
+        final InputMethodSubtypeArray array = new InputMethodSubtypeArray(subtypes);
+        assertEquals(subtypes.size(), array.getCount());
+        assertEquals(subtypes.get(0), array.get(0));
+        assertEquals(subtypes.get(1), array.get(1));
+        assertEquals(subtypes.get(2), array.get(2));
+
+        final InputMethodSubtypeArray clonedArray = cloneViaParcel(array);
+        assertEquals(subtypes.size(), clonedArray.getCount());
+        assertEquals(subtypes.get(0), clonedArray.get(0));
+        assertEquals(subtypes.get(1), clonedArray.get(1));
+        assertEquals(subtypes.get(2), clonedArray.get(2));
+
+        final InputMethodSubtypeArray clonedClonedArray = cloneViaParcel(clonedArray);
+        assertEquals(clonedArray.getCount(), clonedClonedArray.getCount());
+        assertEquals(clonedArray.get(0), clonedClonedArray.get(0));
+        assertEquals(clonedArray.get(1), clonedClonedArray.get(1));
+        assertEquals(clonedArray.get(2), clonedClonedArray.get(2));
+    }
+
+    InputMethodSubtypeArray cloneViaParcel(final InputMethodSubtypeArray original) {
+        Parcel parcel = null;
+        try {
+            parcel = Parcel.obtain();
+            original.writeToParcel(parcel);
+            parcel.setDataPosition(0);
+            return new InputMethodSubtypeArray(parcel);
+        } finally {
+            if (parcel != null) {
+                parcel.recycle();
+            }
+        }
+    }
+
+    private static InputMethodSubtype createDummySubtype(final int id, final String locale) {
+        final InputMethodSubtypeBuilder builder = new InputMethodSubtypeBuilder();
+        return builder.setSubtypeNameResId(0)
+                .setSubtypeIconResId(0)
+                .setSubtypeId(id)
+                .setSubtypeLocale(locale)
+                .setIsAsciiCapable(true)
+                .build();
+    }
+}