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more optimizations

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git-svn-id: https://only.mawhrin.net/repos/FBReaderJ/trunk@899 6a642e6f-84f6-412e-ac94-c4a38d5a04b0
This commit is contained in:
Nikolay Pultsin 2009-03-27 08:19:19 +00:00
parent d68eebf52f
commit a1b19524a4
8 changed files with 145 additions and 112 deletions
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135
src/org/amse/ys/zip/ZipFile.java
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@ -4,18 +4,16 @@ import java.io.*;
import java.util.Collection;
import java.util.Queue;
import java.util.LinkedList;
import java.util.TreeMap;
import java.util.LinkedHashMap;
public class ZipFile {
public final class ZipFile {
private final String myFileName;
private final TreeMap<String,LocalFileHeader> myFileHeaders = new TreeMap<String,LocalFileHeader>();
private final MyBufferedInputStream myBaseStream;
private final LinkedHashMap<String,LocalFileHeader> myFileHeaders = new LinkedHashMap<String,LocalFileHeader>();
private boolean myAllFilesAreRead;
public ZipFile(String fileName) throws IOException {
public ZipFile(String fileName) {
myFileName = fileName;
myBaseStream = new MyBufferedInputStream(myFileName);
}
public Collection<LocalFileHeader> headers() {
@ -27,27 +25,27 @@ public class ZipFile {
return myFileHeaders.values();
}
private boolean readFileHeader(String fileToFind) throws IOException {
int version2extract = myBaseStream.read2Bytes();
int generalFlag = myBaseStream.read2Bytes();
int compressionMethod = myBaseStream.read2Bytes();
myBaseStream.skip(8);
private boolean readFileHeader(MyBufferedInputStream baseStream, String fileToFind) throws IOException {
int version2extract = baseStream.read2Bytes();
int generalFlag = baseStream.read2Bytes();
int compressionMethod = baseStream.read2Bytes();
baseStream.skip(8);
int compressedSize = myBaseStream.read4Bytes();
int uncompressedSize = myBaseStream.read4Bytes();
int fileNameSize = myBaseStream.read2Bytes();
int extraField = myBaseStream.read2Bytes();
int compressedSize = baseStream.read4Bytes();
int uncompressedSize = baseStream.read4Bytes();
int fileNameSize = baseStream.read2Bytes();
int extraField = baseStream.read2Bytes();
final String fileName = myBaseStream.readString(fileNameSize);
myBaseStream.skip(extraField);
final String fileName = baseStream.readString(fileNameSize);
baseStream.skip(extraField);
LocalFileHeader header = new LocalFileHeader(version2extract, generalFlag,
compressionMethod, compressedSize, uncompressedSize,
myBaseStream.offset(), fileName);
baseStream.offset(), fileName);
myFileHeaders.put(fileName, header);
if (header.sizeIsKnown()) {
myBaseStream.skip(compressedSize);
baseStream.skip(compressedSize);
} else {
findAndReadDescriptor(header);
findAndReadDescriptor(baseStream, header);
}
return fileName.equals(fileToFind);
}
@ -58,47 +56,51 @@ public class ZipFile {
}
myAllFilesAreRead = true;
myBaseStream.reset();
MyBufferedInputStream baseStream = getBaseStream();
baseStream.setPosition(0);
myFileHeaders.clear();
while (true) {
int header = myBaseStream.read4Bytes();
if (header != LocalFileHeader.FILE_HEADER_SIGNATURE) {
if (header == LocalFileHeader.FOLDER_HEADER_SIGNATURE) {
break; // central directory, no more files
} else {
throw new WrongZipFormatException(
"readHeaders. Wrong signature found = " + header
+ " at position " + myBaseStream.offset());
try {
while (true) {
int header = baseStream.read4Bytes();
if (header != LocalFileHeader.FILE_HEADER_SIGNATURE) {
if (header == LocalFileHeader.FOLDER_HEADER_SIGNATURE) {
break; // central directory, no more files
} else {
throw new WrongZipFormatException(
"readHeaders. Wrong signature found = " + header
+ " at position " + baseStream.offset());
}
}
readFileHeader(baseStream, null);
}
readFileHeader(null);
}
myBaseStream.reset();
} finally {
storeBaseStream(baseStream);
}
}
/**
* Finds descriptor of the last header and installs sizes of files
*/
private void findAndReadDescriptor(LocalFileHeader header) throws IOException {
private void findAndReadDescriptor(MyBufferedInputStream baseStream, LocalFileHeader header) throws IOException {
while (true) {
int signature = 0;
do {
int nextByte = myBaseStream.read();
int nextByte = baseStream.read();
if (nextByte < 0) {
throw new IOException(
"readFileHeaders. Unexpected end of file when looking for DataDescriptor");
}
signature = ((signature << 8) & (0x0FFFFFFFF)) + (byte) nextByte;
} while (signature != LocalFileHeader.DATA_DESCRIPTOR_SIGNATURE);
myBaseStream.skip(4);
int compressedSize = myBaseStream.read4Bytes();
int uncompressedSize = myBaseStream.read4Bytes();
if ((myBaseStream.offset() - header.OffsetOfLocalData - 16) == compressedSize) {
baseStream.skip(4);
int compressedSize = baseStream.read4Bytes();
int uncompressedSize = baseStream.read4Bytes();
if ((baseStream.offset() - header.OffsetOfLocalData - 16) == compressedSize) {
header.setSizes(compressedSize, uncompressedSize);
break;
} else {
myBaseStream.backSkip(12);
baseStream.backSkip(12);
continue;
}
}
@ -110,12 +112,13 @@ public class ZipFile {
myStoredStreams.add(baseStream);
}
synchronized private ZipInputStream createZipInputStream(LocalFileHeader header) throws IOException, WrongZipFormatException {
MyBufferedInputStream baseStream =
myStoredStreams.isEmpty() ?
new MyBufferedInputStream(myFileName) :
myStoredStreams.poll();
return new ZipInputStream(this, baseStream, header);
synchronized MyBufferedInputStream getBaseStream() throws IOException {
MyBufferedInputStream baseStream = myStoredStreams.poll();
return (baseStream != null) ? baseStream : new MyBufferedInputStream(myFileName);
}
private ZipInputStream createZipInputStream(LocalFileHeader header) throws IOException, WrongZipFormatException {
return new ZipInputStream(this, header);
}
public InputStream getInputStream(String entryName) throws IOException {
@ -133,25 +136,31 @@ public class ZipFile {
}
}
// ready to read fileheader
do {
int signature = myBaseStream.read4Bytes();
if (signature != LocalFileHeader.FILE_HEADER_SIGNATURE) {
if (signature == LocalFileHeader.FOLDER_HEADER_SIGNATURE) {
break; // central directory, no more files
} else {
throw new IOException(
"Wrong signature " + signature
+ " found at position " + myBaseStream.offset());
MyBufferedInputStream baseStream = getBaseStream();
baseStream.setPosition(0);
try {
do {
int signature = baseStream.read4Bytes();
if (signature != LocalFileHeader.FILE_HEADER_SIGNATURE) {
if (signature == LocalFileHeader.FOLDER_HEADER_SIGNATURE) {
break; // central directory, no more files
} else {
throw new IOException(
"Wrong signature " + signature
+ " found at position " + baseStream.offset());
}
}
} while (!readFileHeader(baseStream, entryName));
LocalFileHeader header = myFileHeaders.get(entryName);
if (header != null) {
try {
return createZipInputStream(header);
} catch (WrongZipFormatException e) {
}
}
} while (!readFileHeader(entryName));
LocalFileHeader header = myFileHeaders.get(entryName);
if (header != null) {
try {
return createZipInputStream(header);
} catch (WrongZipFormatException e) {
}
}
} finally {
storeBaseStream(baseStream);
}
return null;
}
}