ZipResourceFile

package com.android.vending.expansion.zipfile; /* * Copyright (C) 2012 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. */ import android.content.res.AssetFileDescriptor; import android.os.ParcelFileDescriptor; import android.util.Log; import java.io.EOFException; import java.io.File; import java.io.FileNotFoundException; import java.io.IOException; import java.io.InputStream; import java.io.RandomAccessFile; import java.nio.ByteBuffer; import java.nio.ByteOrder; import java.nio.MappedByteBuffer; import java.nio.channels.FileChannel; import java.util.Collection; import java.util.HashMap; import java.util.Vector; import java.util.zip.ZipEntry; import java.util.zip.ZipFile; public class ZipResourceFile { // // Read-only access to Zip archives, with minimal heap allocation. // static final String LOG_TAG = "zipro"; static final boolean LOGV = false; // 4-byte number static private int swapEndian(int i) { return ((i & 0xff) << 24) + ((i & 0xff00) << 8) + ((i & 0xff0000) >>> 8) + ((i >>> 24) & 0xff); } // 2-byte number static private int swapEndian(short i) { return ((i & 0x00FF) << 8 | (i & 0xFF00) >>> 8); } /* * Zip file constants. */ static final int kEOCDSignature = 0x06054b50; static final int kEOCDLen = 22; static final int kEOCDNumEntries = 8; // offset to #of entries in file static final int kEOCDSize = 12; // size of the central directory static final int kEOCDFileOffset = 16; // offset to central directory static final int kMaxCommentLen = 65535; // longest possible in ushort static final int kMaxEOCDSearch = (kMaxCommentLen + kEOCDLen); static final int kLFHSignature = 0x04034b50; static final int kLFHLen = 30; // excluding variable-len fields static final int kLFHNameLen = 26; // offset to filename length static final int kLFHExtraLen = 28; // offset to extra length static final int kCDESignature = 0x02014b50; static final int kCDELen = 46; // excluding variable-len fields static final int kCDEMethod = 10; // offset to compression method static final int kCDEModWhen = 12; // offset to modification timestamp static final int kCDECRC = 16; // offset to entry CRC static final int kCDECompLen = 20; // offset to compressed length static final int kCDEUncompLen = 24; // offset to uncompressed length static final int kCDENameLen = 28; // offset to filename length static final int kCDEExtraLen = 30; // offset to extra length static final int kCDECommentLen = 32; // offset to comment length static final int kCDELocalOffset = 42; // offset to local hdr static final int kCompressStored = 0; // no compression static final int kCompressDeflated = 8; // standard deflate /* * The values we return for ZipEntryRO use 0 as an invalid value, so we want * to adjust the hash table index by a fixed amount. Using a large value * helps insure that people don't mix & match arguments, e.g. to * findEntryByIndex(). */ static final int kZipEntryAdj = 10000; static public final class ZipEntryRO { public ZipEntryRO(final String zipFileName, final File file, final String fileName) { mFileName = fileName; mZipFileName = zipFileName; mFile = file; } public final File mFile; public final String mFileName; public final String mZipFileName; public long mLocalHdrOffset; // offset of local file header /* useful stuff from the directory entry */ public int mMethod; public long mWhenModified; public long mCRC32; public long mCompressedLength; public long mUncompressedLength; public long mOffset = -1; public void setOffsetFromFile(RandomAccessFile f, ByteBuffer buf) throws IOException { long localHdrOffset = mLocalHdrOffset; try { f.seek(localHdrOffset); f.readFully(buf.array()); if (buf.getInt(0) != kLFHSignature) { Log.w(LOG_TAG, "didn't find signature at start of lfh"); throw new IOException(); } int nameLen = buf.getShort(kLFHNameLen) & 0xFFFF; int extraLen = buf.getShort(kLFHExtraLen) & 0xFFFF; mOffset = localHdrOffset + kLFHLen + nameLen + extraLen; } catch (FileNotFoundException e) { e.printStackTrace(); } catch (IOException ioe) { ioe.printStackTrace(); } } /** * Calculates the offset of the start of the Zip file entry within the * Zip file. * * @return the offset, in bytes from the start of the file of the entry */ public long getOffset() { return mOffset; } /** * isUncompressed * * @return true if the file is stored in uncompressed form */ public boolean isUncompressed() { return mMethod == kCompressStored; } public AssetFileDescriptor getAssetFileDescriptor() { if (mMethod == kCompressStored) { ParcelFileDescriptor pfd; try { pfd = ParcelFileDescriptor.open(mFile, ParcelFileDescriptor.MODE_READ_ONLY); return new AssetFileDescriptor(pfd, getOffset(), mUncompressedLength); } catch (FileNotFoundException e) { // TODO Auto-generated catch block e.printStackTrace(); } } return null; } public String getZipFileName() { return mZipFileName; } public File getZipFile() { return mFile; } } private HashMap<String, ZipEntryRO> mHashMap = new HashMap<String, ZipEntryRO>(); /* for reading compressed files */ public HashMap<File, ZipFile> mZipFiles = new HashMap<File, ZipFile>(); public ZipResourceFile(String zipFileName) throws IOException { addPatchFile(zipFileName); } ZipEntryRO[] getEntriesAt(String path) { Vector<ZipEntryRO> zev = new Vector<ZipEntryRO>(); Collection<ZipEntryRO> values = mHashMap.values(); if (null == path) path = ""; int length = path.length(); for (ZipEntryRO ze : values) { if (ze.mFileName.startsWith(path)) { if (-1 == ze.mFileName.indexOf('/', length)) { zev.add(ze); } } } ZipEntryRO[] entries = new ZipEntryRO[zev.size()]; return zev.toArray(entries); } public ZipEntryRO[] getAllEntries() { Collection<ZipEntryRO> values = mHashMap.values(); return values.toArray(new ZipEntryRO[values.size()]); } /** * getAssetFileDescriptor allows for ZipResourceFile to directly feed * Android API's that want an fd, offset, and length such as the * MediaPlayer. It also allows for the class to be used in a content * provider that can feed video players. The file must be stored * (non-compressed) in the Zip file for this to work. * * @param assetPath * @return the asset file descriptor for the file, or null if the file isn't * pres