Add AB Update support

Change-Id: Iff38cb41b84566e1a1bf3a29bb631a5994ce6a14

src/eu/chainfire/opendelta/ABUpdate.java

@@ -0,0 +1,154 @@
+/*
+ * Copyright (C) 2017 The LineageOS 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 eu.chainfire.opendelta;
+
+import android.os.UpdateEngine;
+import android.os.UpdateEngineCallback;
+import android.util.Log;
+
+import java.util.Enumeration;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipFile;
+
+import java.io.BufferedReader;
+import java.io.File;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.InputStreamReader;
+import java.util.ArrayList;
+import java.util.List;
+
+class ABUpdate {
+
+    private static final String TAG = "ABUpdateInstaller";
+
+    private static boolean sIsInstallingUpdate;
+
+    private static final String PAYLOAD_BIN_PATH = "payload.bin";
+    private static final String PAYLOAD_PROPERTIES_PATH = "payload_properties.txt";
+
+    private final String zipPath;
+
+    private UpdaterListener mUpdateListener;
+
+    private final UpdateEngineCallback mUpdateEngineCallback = new UpdateEngineCallback() {
+        @Override
+        public void onStatusUpdate(int status, float percent) {
+            int progress = Math.round(percent * 100);
+            mUpdateListener.progressUpdate(progress);
+            mUpdateListener.notifyUpdateStatusChange(status);
+        }
+
+        @Override
+        public void onPayloadApplicationComplete(int errorCode) {
+           sIsInstallingUpdate = false;
+           mUpdateListener.progressUpdate(100);
+           mUpdateListener.notifyUpdateComplete(errorCode);
+        }
+    };
+
+    static synchronized boolean start(String zipPath, UpdaterListener listener) {
+        if (sIsInstallingUpdate) {
+            return false;
+        }
+        ABUpdate installer = new ABUpdate(zipPath, listener);
+        sIsInstallingUpdate = installer.startUpdate();
+        return sIsInstallingUpdate;
+    }
+
+    static synchronized boolean isInstallingUpdate() {
+        return sIsInstallingUpdate;
+    }
+
+    private ABUpdate(String zipPath, UpdaterListener listener) {
+        this.zipPath = zipPath;
+        this.mUpdateListener = listener;
+    }
+
+    private boolean startUpdate() {
+        File file = new File(zipPath);
+        if (!file.exists()) {
+            Log.e(TAG, "The given update doesn't exist");
+            return false;
+        }
+
+        long offset;
+        String[] headerKeyValuePairs;
+        try {
+            ZipFile zipFile = new ZipFile(file);
+            offset = getZipEntryOffset(zipFile, PAYLOAD_BIN_PATH);
+            ZipEntry payloadPropEntry = zipFile.getEntry(PAYLOAD_PROPERTIES_PATH);
+            try (InputStream is = zipFile.getInputStream(payloadPropEntry);
+                 InputStreamReader isr = new InputStreamReader(is);
+                 BufferedReader br = new BufferedReader(isr)) {
+                List<String> lines = new ArrayList<>();
+                for (String line; (line = br.readLine()) != null;) {
+                    lines.add(line);
+                }
+                headerKeyValuePairs = new String[lines.size()];
+                headerKeyValuePairs = lines.toArray(headerKeyValuePairs);
+            }
+            zipFile.close();
+        } catch (IOException | IllegalArgumentException e) {
+            Log.e(TAG, "Could not prepare " + file, e);
+            return false;
+        }
+
+        UpdateEngine updateEngine = new UpdateEngine();
+        updateEngine.bind(mUpdateEngineCallback);
+        String zipFileUri = "file://" + file.getAbsolutePath();
+        updateEngine.applyPayload(zipFileUri, offset, 0, headerKeyValuePairs);
+
+        return true;
+    }
+
+    static boolean isABUpdate(ZipFile zipFile) {
+        return zipFile.getEntry(PAYLOAD_BIN_PATH) != null &&
+                zipFile.getEntry(PAYLOAD_PROPERTIES_PATH) != null;
+    }
+
+    /**
+     * Get the offset to the compressed data of a file inside the given zip
+     *
+     * @param zipFile input zip file
+     * @param entryPath full path of the entry
+     * @return the offset of the compressed, or -1 if not found
+     * @throws IOException
+     * @throws IllegalArgumentException if the given entry is not found
+     */
+    public static long getZipEntryOffset(ZipFile zipFile, String entryPath)
+            throws IOException {
+        // Each entry has an header of (30 + n + m) bytes
+        // 'n' is the length of the file name
+        // 'm' is the length of the extra field
+        final int FIXED_HEADER_SIZE = 30;
+        Enumeration<? extends ZipEntry> zipEntries = zipFile.entries();
+        long offset = 0;
+        while (zipEntries.hasMoreElements()) {
+            ZipEntry entry = zipEntries.nextElement();
+            int n = entry.getName().length();
+            int m = entry.getExtra() == null ? 0 : entry.getExtra().length;
+            int headerSize = FIXED_HEADER_SIZE + n + m;
+            offset += headerSize;
+            if (entry.getName().equals(entryPath)) {
+                return offset;
+            }
+            offset += entry.getCompressedSize();
+        }
+        Log.e(TAG, "Entry " + entryPath + " not found");
+        throw new IllegalArgumentException("The given entry was not found");
+    }
+}