| // Copyright 2015 The Bazel Authors. All rights reserved. |
| // |
| // 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.google.devtools.build.zip; |
| |
| import com.google.devtools.build.zip.ZipFileEntry.Compression; |
| |
| import java.io.IOException; |
| import java.io.InputStream; |
| import java.util.zip.Inflater; |
| import java.util.zip.InflaterInputStream; |
| import java.util.zip.ZipException; |
| |
| /** An input stream for reading the file data of a ZIP file entry. */ |
| class ZipEntryInputStream extends InputStream { |
| private InputStream stream; |
| private long rem; |
| |
| /** |
| * Opens an input stream for reading at the beginning of the ZIP file entry's content. |
| * |
| * @param zipReader the backing ZIP reader for this InputStream |
| * @param zipEntry the ZIP file entry to open the input stream for |
| * @param raw if the entry should be opened for raw read mode |
| * @throws ZipException if a ZIP format error has occurred |
| * @throws IOException if an I/O error has occurred |
| */ |
| ZipEntryInputStream(ZipReader zipReader, ZipFileEntry zipEntry, boolean raw) |
| throws IOException { |
| stream = zipReader.getStreamAt(zipEntry.getLocalHeaderOffset()); |
| |
| byte[] fileHeader = new byte[LocalFileHeader.FIXED_DATA_SIZE]; |
| ZipUtil.readFully(stream, fileHeader); |
| |
| if (!ZipUtil.arrayStartsWith(fileHeader, |
| ZipUtil.intToLittleEndian(LocalFileHeader.SIGNATURE))) { |
| throw new ZipException(String.format("The file '%s' is not a correctly formatted zip file: " |
| + "Expected a File Header at file offset %d, but was not present.", |
| zipReader.getFilename(), zipEntry.getLocalHeaderOffset())); |
| } |
| |
| int nameLength = ZipUtil.getUnsignedShort(fileHeader, |
| LocalFileHeader.FILENAME_LENGTH_OFFSET); |
| int extraFieldLength = ZipUtil.getUnsignedShort(fileHeader, |
| LocalFileHeader.EXTRA_FIELD_LENGTH_OFFSET); |
| ZipUtil.readFully(stream, new byte[nameLength + extraFieldLength]); |
| if (raw) { |
| rem = zipEntry.getCompressedSize(); |
| } else { |
| rem = zipEntry.getSize(); |
| } |
| if (!raw && zipEntry.getMethod() == Compression.DEFLATED) { |
| stream = new InflaterInputStream(stream, new Inflater(true)); |
| } |
| } |
| |
| @Override public int available() throws IOException { |
| return (int) Math.min(rem, Integer.MAX_VALUE); |
| } |
| |
| @Override public void close() throws IOException { |
| } |
| |
| @Override public synchronized void mark(int readlimit) { |
| } |
| |
| @Override public boolean markSupported() { |
| return false; |
| } |
| |
| @Override public int read() throws IOException { |
| byte[] b = new byte[1]; |
| if (read(b, 0, 1) == 1) { |
| return b[0] & 0xff; |
| } else { |
| return -1; |
| } |
| } |
| |
| @Override public int read(byte[] b) throws IOException { |
| return read(b, 0, b.length); |
| } |
| |
| @Override public int read(byte[] b, int off, int len) throws IOException { |
| if (rem == 0) { |
| return -1; |
| } |
| if (len > rem) { |
| len = available(); |
| } |
| len = stream.read(b, off, len); |
| rem -= len; |
| return len; |
| } |
| |
| @Override public long skip(long n) throws IOException { |
| if (n > rem) { |
| n = rem; |
| } |
| n = stream.skip(n); |
| rem -= n; |
| return n; |
| } |
| |
| @Override public synchronized void reset() throws IOException { |
| throw new IOException("Reset is not supported on this type of stream."); |
| } |
| } |