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Diffstat (limited to 'updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java')
-rw-r--r-- | updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java b/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java new file mode 100644 index 000000000..43c8d75e2 --- /dev/null +++ b/updater_sample/src/com/example/android/systemupdatersample/util/PayloadSpecs.java @@ -0,0 +1,117 @@ +/* + * Copyright (C) 2018 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.example.android.systemupdatersample.util; + +import android.annotation.TargetApi; +import android.os.Build; + +import com.example.android.systemupdatersample.PayloadSpec; + +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.Arrays; +import java.util.Enumeration; +import java.util.List; +import java.util.zip.ZipEntry; +import java.util.zip.ZipFile; + +/** The helper class that creates {@link PayloadSpec}. */ +@TargetApi(Build.VERSION_CODES.N) +public final class PayloadSpecs { + + /** + * The payload PAYLOAD_ENTRY is stored in the zip package to comply with the Android OTA package + * format. We want to find out the offset of the entry, so that we can pass it over to the A/B + * updater without making an extra copy of the payload. + * + * <p>According to Android docs, the entries are listed in the order in which they appear in the + * zip file. So we enumerate the entries to identify the offset of the payload file. + * http://developer.android.com/reference/java/util/zip/ZipFile.html#entries() + */ + public static PayloadSpec forNonStreaming(File packageFile) throws IOException { + boolean payloadFound = false; + long payloadOffset = 0; + long payloadSize = 0; + + List<String> properties = new ArrayList<>(); + try (ZipFile zip = new ZipFile(packageFile)) { + Enumeration<? extends ZipEntry> entries = zip.entries(); + long offset = 0; + while (entries.hasMoreElements()) { + ZipEntry entry = entries.nextElement(); + String name = entry.getName(); + // Zip local file header has 30 bytes + filename + sizeof extra field. + // https://en.wikipedia.org/wiki/Zip_(file_format) + long extraSize = entry.getExtra() == null ? 0 : entry.getExtra().length; + offset += 30 + name.length() + extraSize; + + if (entry.isDirectory()) { + continue; + } + + long length = entry.getCompressedSize(); + if (PackagePropertyFiles.PAYLOAD_BINARY_FILE_NAME.equals(name)) { + if (entry.getMethod() != ZipEntry.STORED) { + throw new IOException("Invalid compression method."); + } + payloadFound = true; + payloadOffset = offset; + payloadSize = length; + } else if (PackagePropertyFiles.PAYLOAD_PROPERTIES_FILE_NAME.equals(name)) { + InputStream inputStream = zip.getInputStream(entry); + if (inputStream != null) { + BufferedReader br = new BufferedReader(new InputStreamReader(inputStream)); + String line; + while ((line = br.readLine()) != null) { + properties.add(line); + } + } + } + offset += length; + } + } + + if (!payloadFound) { + throw new IOException("Failed to find payload entry in the given package."); + } + return PayloadSpec.newBuilder() + .url("file://" + packageFile.getAbsolutePath()) + .offset(payloadOffset) + .size(payloadSize) + .properties(properties) + .build(); + } + + /** + * Converts an {@link PayloadSpec} to a string. + */ + public static String toString(PayloadSpec payloadSpec) { + return "<PayloadSpec url=" + payloadSpec.getUrl() + + ", offset=" + payloadSpec.getOffset() + + ", size=" + payloadSpec.getSize() + + ", properties=" + Arrays.toString( + payloadSpec.getProperties().toArray(new String[0])) + + ">"; + } + + private PayloadSpecs() {} + +} |