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/*
* 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 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.nio.file.Files;
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}. */
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 (PackageFiles.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 (PackageFiles.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();
}
/**
* Creates a {@link PayloadSpec} for streaming update.
*/
public static PayloadSpec forStreaming(String updateUrl,
long offset,
long size,
File propertiesFile) throws IOException {
return PayloadSpec.newBuilder()
.url(updateUrl)
.offset(offset)
.size(size)
.properties(Files.readAllLines(propertiesFile.toPath()))
.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() {}
}
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