Support streaming of compressed assets > 1 megabyte

Compressed assets larger than one megabyte are now decompressed on demand
rather than being decompressed in their entirety and held in memory.  Reading
the data in order is relatively efficient, as is seeking forward in the stream.
Seeking backwards is supported, but requires reprocessing the compressed data
from the beginning, so is very inefficient.

In addition, the size limit on compressed assets has been eliminated.

Change-Id: I6e68247957e6c53e7e8ba70d12764695f1723bad

1 files changed, 104 insertions, 0 deletions

diff --git a/tests/LargeAssetTest/src/com/android/largeassettest/LargeAssetTest.java b/tests/LargeAssetTest/src/com/android/largeassettest/LargeAssetTest.java
new file mode 100644
index 0000000..e3a9cf4
--- /dev/null
+++ b/tests/LargeAssetTest/src/com/android/largeassettest/LargeAssetTest.java
@@ -0,0 +1,104 @@
+/*
+ * Copyright (C) 2006 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 com.android.largeassettest;
+
+import android.app.Activity;
+import android.content.Context;
+import android.content.res.AssetManager;
+import android.os.AsyncTask;
+import android.os.Bundle;
+import android.util.Log;
+import android.view.View;
+import android.widget.Button;
+import android.widget.TextView;
+
+import java.io.InputStream;
+import java.io.IOException;
+
+/**
+ * Skeleton to test large-asset handling.  The asset in question is one million
+ * four-byte integers, in ascending numeric order.
+ */
+public class LargeAssetTest extends Activity {
+    Button mValidateButton;
+    TextView mResultText;
+    Validator mValidateThread;
+
+    @Override
+    protected void onCreate(Bundle icicle) {
+        super.onCreate(icicle);
+        setContentView(R.layout.lat);
+
+        mResultText = (TextView) findViewById(R.id.result);
+        mValidateButton = (Button) findViewById(R.id.validate);
+
+        mValidateButton.setOnClickListener(mClickListener);
+    }
+
+    View.OnClickListener mClickListener = new View.OnClickListener() {
+        public void onClick(View v) {
+            mValidateButton.setEnabled(false);
+            mValidateThread = new Validator();
+            mValidateThread.execute(LargeAssetTest.this.getAssets());
+        }
+    };
+
+    /**
+     * Validation happens in a separate thread
+     */
+    class Validator extends AsyncTask<AssetManager, Integer, Boolean> {
+        static final String TAG = "Validator";
+
+        @Override
+        protected Boolean doInBackground(AssetManager... params) {
+            AssetManager am = params[0];
+            try {
+                InputStream is = am.open("million-ints", AssetManager.ACCESS_STREAMING);
+                byte[] buf = new byte[4];
+
+                for (int i = 0; i < 1000000; i++) {
+                    int num = is.read(buf, 0, 4);
+                    if (num != 4) {
+                        Log.e(TAG, "Wanted 4 bytes but read " + num);
+                        return false;
+                    }
+                    // the byte array is stored in the asset in little-endian order
+                    int value = (buf[3] << 24) + ((buf[2] & 0xFF) << 16)
+                            + ((buf[1] & 0xFF) << 8) + (buf[0] & 0xFF);
+                    if (value != i) {
+                        Log.e(TAG, "Mismatch: index " + i + " : value " + value);
+                        return false;
+                    }
+                }
+
+                is.close();
+            } catch (IOException e) {
+                Log.w(TAG, "Couldn't open asset", e);
+                return false;
+            }
+            Log.i(TAG, "Finished, reporting valid");
+            return true;
+        }
+
+        @Override
+        protected void onPostExecute(Boolean result) {
+            CharSequence text = (result) ? "Valid!" : "NOT VALID";
+            mResultText.setText(text);
+            mValidateButton.setEnabled(true);
+        }
+    }
+}