Support for binary decompression of dynamic patches. (flutter#7777)

ci/licenses.sh

@@ -42,7 +42,7 @@ fi
 
 echo "Checking license count in licenses_flutter..."
 actualLicenseCount=`tail -n 1 flutter/ci/licenses_golden/licenses_flutter | tr -dc '0-9'`
-expectedLicenseCount=2 # When changing this number: Update the error message below as well describing all expected license types.
+expectedLicenseCount=3 # When changing this number: Update the error message below as well describing all expected license types.
 
 if [ "$actualLicenseCount" -ne "$expectedLicenseCount" ]
 then

ci/licenses_golden/licenses_flutter

@@ -691,6 +691,40 @@ ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 ====================================================================================================
 
+====================================================================================================
+LIBRARY: engine
+ORIGIN: ../../../flutter/shell/platform/android/io/flutter/util/BSDiff.java + ../../../flutter/LICENSE
+TYPE: LicenseType.bsd
+FILE: ../../../flutter/shell/platform/android/io/flutter/util/BSDiff.java
+----------------------------------------------------------------------------------------------------
+Copyright 2003-2005 Colin Percival. All rights reserved.
+Copyright 2013 The Flutter Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without modification,
+are permitted provided that the following conditions are met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google Inc. nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+====================================================================================================
+
 ====================================================================================================
 LIBRARY: txt
 ORIGIN: ../../../flutter/third_party/txt/LICENSE
@@ -977,4 +1011,4 @@ 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.
 ====================================================================================================
-Total license count: 2
+Total license count: 3

shell/platform/android/BUILD.gn

@@ -149,6 +149,7 @@ java_library("flutter_shell_java") {
     "io/flutter/plugin/platform/PlatformViewsController.java",
     "io/flutter/plugin/platform/SingleViewPresentation.java",
     "io/flutter/plugin/platform/VirtualDisplayController.java",
+    "io/flutter/util/BSDiff.java",
     "io/flutter/util/PathUtils.java",
     "io/flutter/util/Preconditions.java",
     "io/flutter/util/Predicate.java",

shell/platform/android/io/flutter/util/BSDiff.java

@@ -0,0 +1,92 @@
+// Copyright 2003-2005 Colin Percival. All rights reserved.
+// Copyright 2013 The Flutter Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package io.flutter.util;
+
+import java.io.*;
+import java.util.zip.GZIPInputStream;
+
+/**
+ * This is a Java port of algorithm from Flutter framework bsdiff.dart.
+ * Note that this port uses 32-bit ints, which limits data size to 2GB.
+ **/
+public abstract class BSDiff {
+    public static byte[] bspatch(byte[] olddata, byte[] diffdata) throws IOException {
+        InputStream in = new ByteArrayInputStream(diffdata, 0, diffdata.length);
+        DataInputStream header = new DataInputStream(in);
+
+        byte[] magic = new byte[8];
+        header.read(magic);
+        if (!new String(magic).equals("BZDIFF40")) {
+            throw new IOException("Invalid magic");
+        }
+
+        int ctrllen = (int) header.readLong();
+        int datalen = (int) header.readLong();
+        int newsize = (int) header.readLong();
+        header.close();
+
+        in = new ByteArrayInputStream(diffdata, 0, diffdata.length);
+        in.skip(32);
+        DataInputStream cpf = new DataInputStream(new GZIPInputStream(in));
+
+        in = new ByteArrayInputStream(diffdata, 0, diffdata.length);
+        in.skip(32 + ctrllen);
+        InputStream dpf = new GZIPInputStream(in);
+
+        in = new ByteArrayInputStream(diffdata, 0, diffdata.length);
+        in.skip(32 + ctrllen + datalen);
+        InputStream epf = new GZIPInputStream(in);
+
+        byte[] newdata = new byte[newsize];
+
+	int oldpos = 0;
+        int newpos = 0;
+
+        while (newpos < newsize) {
+            int[] ctrl = new int[3];
+            for (int i = 0; i <= 2; i++) {
+                ctrl[i] = (int) cpf.readLong();
+            }
+            if (newpos + ctrl[0] > newsize) {
+                throw new IOException("Invalid ctrl[0]");
+            }
+
+            read(dpf, newdata, newpos, ctrl[0]);
+
+            for (int i = 0; i < ctrl[0]; i++) {
+                if ((oldpos + i >= 0) && (oldpos + i < olddata.length)) {
+                    newdata[newpos + i] += olddata[oldpos + i];
+                }
+            }
+
+            newpos += ctrl[0];
+            oldpos += ctrl[0];
+
+            if (newpos + ctrl[1] > newsize) {
+                throw new IOException("Invalid ctrl[0]");
+            }
+
+            read(epf, newdata, newpos, ctrl[1]);
+
+            newpos += ctrl[1];
+            oldpos += ctrl[2];
+        }
+
+        cpf.close();
+        dpf.close();
+        epf.close();
+
+        return newdata;
+    }
+
+    private static void read(InputStream in, byte[] buf, int off, int len) throws IOException {
+        for (int i, n = 0; n < len; n += i) {
+            if ((i = in.read(buf, off + n, len - n)) < 0) {
+                throw new IOException("Unexpected EOF");
+            }
+        }
+    }
+}

shell/platform/android/io/flutter/view/ResourceExtractor.java

@@ -11,6 +11,7 @@
 import android.os.AsyncTask;
 import android.os.Build;
 import android.util.Log;
+import io.flutter.util.BSDiff;
 import io.flutter.util.PathUtils;
 import org.json.JSONObject;
 
@@ -19,6 +20,7 @@
 import java.util.HashSet;
 import java.util.concurrent.CancellationException;
 import java.util.concurrent.ExecutionException;
+import java.util.zip.GZIPInputStream;
 import java.util.zip.ZipEntry;
 import java.util.zip.ZipFile;
 
@@ -29,8 +31,6 @@ class ResourceExtractor {
     private static final String TAG = "ResourceExtractor";
     private static final String TIMESTAMP_PREFIX = "res_timestamp-";
 
-    private static final int BUFFER_SIZE = 16 * 1024;
-
     @SuppressWarnings("deprecation")
     static long getVersionCode(PackageInfo packageInfo) {
         if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
@@ -177,7 +177,6 @@ private void deleteFiles() {
     private boolean extractAPK(File dataDir) {
         final AssetManager manager = mContext.getResources().getAssets();
 
-        byte[] buffer = null;
         for (String asset : mResources) {
             try {
                 final File output = new File(dataDir, asset);
@@ -190,19 +189,11 @@ private boolean extractAPK(File dataDir) {
 
                 try (InputStream is = manager.open(asset);
                      OutputStream os = new FileOutputStream(output)) {
-                    if (buffer == null) {
-                        buffer = new byte[BUFFER_SIZE];
-                    }
-
-                    int count = 0;
-                    while ((count = is.read(buffer, 0, BUFFER_SIZE)) != -1) {
-                        os.write(buffer, 0, count);
-                    }
-
-                    os.flush();
-                    Log.i(TAG, "Extracted baseline resource " + asset);
+                    copy(is, os);
                 }
 
+                Log.i(TAG, "Extracted baseline resource " + asset);
+
             } catch (FileNotFoundException fnfe) {
                 continue;
 
@@ -219,6 +210,8 @@ private boolean extractAPK(File dataDir) {
     /// Returns true if successfully unpacked update resources or if there is no update,
     /// otherwise deletes all resources and returns false.
     private boolean extractUpdate(File dataDir) {
+        final AssetManager manager = mContext.getResources().getAssets();
+
         ResourceUpdater resourceUpdater = FlutterMain.getResourceUpdater();
         if (resourceUpdater == null) {
             return true;
@@ -245,11 +238,15 @@ private boolean extractUpdate(File dataDir) {
             return false;
         }
 
-        byte[] buffer = null;
         for (String asset : mResources) {
+            boolean useDiff = false;
             ZipEntry entry = zipFile.getEntry(asset);
             if (entry == null) {
-                continue;
+                useDiff = true;
+                entry = zipFile.getEntry(asset + ".bzdiff40");
+                if (entry == null) {
+                    continue;
+                }
             }
 
             final File output = new File(dataDir, asset);
@@ -260,18 +257,29 @@ private boolean extractUpdate(File dataDir) {
                 output.getParentFile().mkdirs();
             }
 
-            try (InputStream is = zipFile.getInputStream(entry);
-                 OutputStream os = new FileOutputStream(output)) {
-                if (buffer == null) {
-                    buffer = new byte[BUFFER_SIZE];
-                }
+            try {
+                if (useDiff) {
+                    ByteArrayOutputStream diff = new ByteArrayOutputStream();
+                    try (InputStream is = zipFile.getInputStream(entry)) {
+                        copy(is, diff);
+                    }
+
+                    ByteArrayOutputStream orig = new ByteArrayOutputStream();
+                    try (InputStream is = manager.open(asset)) {
+                        copy(is, orig);
+                    }
+
+                    try (OutputStream os = new FileOutputStream(output)) {
+                        os.write(BSDiff.bspatch(orig.toByteArray(), diff.toByteArray()));
+                    }
 
-                int count = 0;
-                while ((count = is.read(buffer, 0, BUFFER_SIZE)) != -1) {
-                    os.write(buffer, 0, count);
+                } else {
+                    try (InputStream is = zipFile.getInputStream(entry);
+                         OutputStream os = new FileOutputStream(output)) {
+                        copy(is, os);
+                    }
                 }
 
-                os.flush();
                 Log.i(TAG, "Extracted override resource " + asset);
 
             } catch (FileNotFoundException fnfe) {
@@ -339,4 +347,11 @@ private String checkTimestamp(File dataDir) {
 
         return null;
     }
+
+    private static void copy(InputStream in, OutputStream out) throws IOException {
+        byte[] buf = new byte[16 * 1024];
+        for (int i; (i = in.read(buf)) >= 0; ) {
+            out.write(buf, 0, i);
+        }
+    }
 }