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Using abstract accessor instead of random access file #137

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0dda32a
Added an abstraction layer to avoid directly supplying and using file…
Aug 12, 2017
580acf5
Increased test coverage.
Aug 12, 2017
08d935c
Merge remote-tracking branch 'origin/master' into using-abstract-acce…
Aug 12, 2017
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6 changes: 6 additions & 0 deletions pom.xml
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Original file line number Diff line number Diff line change
Expand Up @@ -49,6 +49,12 @@
<version>4.12</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>nl.jqno.equalsverifier</groupId>
<artifactId>equalsverifier</artifactId>
<version>2.3.2</version>
<scope>test</scope>
</dependency>
</dependencies>

<build>
Expand Down
43 changes: 43 additions & 0 deletions src/main/java/com/mpatric/mp3agic/FileInputSource.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,43 @@
package com.mpatric.mp3agic;

import java.io.IOException;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.util.concurrent.TimeUnit;

public class FileInputSource implements InputSource {

private final Path path;

public FileInputSource(Path path) {
this.path = path;
}

@Override
public String getResourceName() {
return path.toString();
}

@Override
public boolean isReadable() {
return Files.exists(path) && Files.isReadable(path);
}

@Override
public long getLastModified() throws IOException {
return Files.getLastModifiedTime(path).to(TimeUnit.MILLISECONDS);
}

@Override
public long getLength() throws IOException {
return Files.size(path);
}

@Override
public SeekableByteChannel openChannel(OpenOption... options) throws IOException {
return Files.newByteChannel(path, options);
}

}
36 changes: 20 additions & 16 deletions src/main/java/com/mpatric/mp3agic/FileWrapper.java
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Original file line number Diff line number Diff line change
Expand Up @@ -3,53 +3,57 @@
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.Files;
import java.nio.file.OpenOption;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.concurrent.TimeUnit;

public class FileWrapper {

protected Path path;
protected long length;
protected InputSource inputSource;
protected long lastModified;

protected FileWrapper() {
}

public FileWrapper(String filename) throws IOException {
this.path = Paths.get(filename);
if (filename == null) throw new IllegalArgumentException("filename must not be null");
this.inputSource = new FileInputSource(Paths.get(filename));
init();
}

public FileWrapper(File file) throws IOException {
if (file == null) throw new NullPointerException();
this.path = Paths.get(file.getPath());
if (file == null) throw new IllegalArgumentException("file must not be null");
this.inputSource = new FileInputSource(Paths.get(file.getPath()));
init();
}

public FileWrapper(Path path) throws IOException {
if (path == null) throw new NullPointerException();
this.path = path;
if (path == null) throw new IllegalArgumentException("path must not be null");
this.inputSource = new FileInputSource(path);
init();
}

private void init() throws IOException {
if (!Files.exists(path)) throw new FileNotFoundException("File not found " + path);
if (!Files.isReadable(path)) throw new IOException("File not readable");
length = Files.size(path);
lastModified = Files.getLastModifiedTime(path).to(TimeUnit.MILLISECONDS);
public FileWrapper(InputSource inputSource) throws IOException {
if (inputSource == null) throw new IllegalArgumentException("inputSource must not be null");
this.inputSource = inputSource;
init();
}

public String getFilename() {
return path.toString();
private void init() throws IOException {
if (!inputSource.isReadable()) throw new FileNotFoundException("File could not be found or is not readable " +
inputSource.getResourceName());
lastModified = inputSource.getLastModified();
}

public long getLength() {
return length;
public String getFilename() {
return inputSource.getResourceName();
}

public long getLastModified() {
return lastModified;
}

}
55 changes: 11 additions & 44 deletions src/main/java/com/mpatric/mp3agic/ID3v1Tag.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,7 @@

import java.io.UnsupportedEncodingException;
import java.util.Arrays;
import java.util.Objects;

public class ID3v1Tag implements ID3v1 {

Expand Down Expand Up @@ -227,16 +228,7 @@ public void setComment(String comment) {

@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + ((album == null) ? 0 : album.hashCode());
result = prime * result + ((artist == null) ? 0 : artist.hashCode());
result = prime * result + ((comment == null) ? 0 : comment.hashCode());
result = prime * result + genre;
result = prime * result + ((title == null) ? 0 : title.hashCode());
result = prime * result + ((track == null) ? 0 : track.hashCode());
result = prime * result + ((year == null) ? 0 : year.hashCode());
return result;
return Objects.hash(album, artist, comment, genre, title, track, year);
}

@Override
Expand All @@ -247,39 +239,14 @@ public boolean equals(Object obj) {
return false;
if (getClass() != obj.getClass())
return false;
ID3v1Tag other = (ID3v1Tag) obj;
if (album == null) {
if (other.album != null)
return false;
} else if (!album.equals(other.album))
return false;
if (artist == null) {
if (other.artist != null)
return false;
} else if (!artist.equals(other.artist))
return false;
if (comment == null) {
if (other.comment != null)
return false;
} else if (!comment.equals(other.comment))
return false;
if (genre != other.genre)
return false;
if (title == null) {
if (other.title != null)
return false;
} else if (!title.equals(other.title))
return false;
if (track == null) {
if (other.track != null)
return false;
} else if (!track.equals(other.track))
return false;
if (year == null) {
if (other.year != null)
return false;
} else if (!year.equals(other.year))
return false;
return true;
final ID3v1Tag other = (ID3v1Tag) obj;
return
Objects.equals(album, other.album) &&
Objects.equals(artist, other.artist) &&
Objects.equals(comment, other.comment) &&
Objects.equals(genre, other.genre) &&
Objects.equals(title, other.title) &&
Objects.equals(track, other.track) &&
Objects.equals(year, other.year);
}
}
35 changes: 35 additions & 0 deletions src/main/java/com/mpatric/mp3agic/InputSource.java
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Original file line number Diff line number Diff line change
@@ -0,0 +1,35 @@
package com.mpatric.mp3agic;

import java.io.IOException;
import java.nio.channels.SeekableByteChannel;
import java.nio.file.OpenOption;

public interface InputSource {

/**
* Retrieves a value that identifies this resource.
* Can be a URL or a file name, for example.
*/
String getResourceName();

/**
* Tells if the resource is valid and readable.
*/
boolean isReadable();

/**
* Retrieves the last modification time of the resource.
*/
long getLastModified() throws IOException;

/**
* Retrieves the length of the resource in bytes.
*/
long getLength() throws IOException;

/**
* Opens a channel to read the resource.
*/
SeekableByteChannel openChannel(OpenOption... options) throws IOException;

}
39 changes: 22 additions & 17 deletions src/main/java/com/mpatric/mp3agic/Mp3File.java
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Original file line number Diff line number Diff line change
Expand Up @@ -84,13 +84,18 @@ public Mp3File(Path path, int bufferLength, boolean scanFile) throws IOException
init(bufferLength, scanFile);
}

public Mp3File(InputSource inputSource, int bufferLength, boolean scanFile) throws IOException, UnsupportedTagException, InvalidDataException {
super(inputSource);
init(bufferLength, scanFile);
}

private void init(int bufferLength, boolean scanFile) throws IOException, UnsupportedTagException, InvalidDataException {
if (bufferLength < MINIMUM_BUFFER_LENGTH + 1) throw new IllegalArgumentException("Buffer too small");

this.bufferLength = bufferLength;
this.scanFile = scanFile;

try (SeekableByteChannel seekableByteChannel = Files.newByteChannel(path, StandardOpenOption.READ)) {
try (SeekableByteChannel seekableByteChannel = inputSource.openChannel(StandardOpenOption.READ)) {
initId3v1Tag(seekableByteChannel);
scanFile(seekableByteChannel);
if (startOffset < 0) {
Expand Down Expand Up @@ -146,7 +151,7 @@ private void scanFile(SeekableByteChannel seekableByteChannel) throws IOExceptio
}
lastOffset = startOffset;
}
offset = scanBlock(bytes, bytesRead, fileOffset, offset);
offset = scanBlock(bytes, bytesRead, fileOffset, offset, seekableByteChannel.size());
fileOffset += offset;
seekableByteChannel.position(fileOffset);
break;
Expand Down Expand Up @@ -204,12 +209,12 @@ private int scanBlockForStart(byte[] bytes, int bytesRead, int absoluteOffset, i
return offset;
}

private int scanBlock(byte[] bytes, int bytesRead, int absoluteOffset, int offset) throws InvalidDataException {
private int scanBlock(byte[] bytes, int bytesRead, int absoluteOffset, int offset, long size) throws InvalidDataException {
while (offset < bytesRead - MINIMUM_BUFFER_LENGTH) {
MpegFrame frame = new MpegFrame(bytes[offset], bytes[offset + 1], bytes[offset + 2], bytes[offset + 3]);
sanityCheckFrame(frame, absoluteOffset + offset);
sanityCheckFrame(frame, absoluteOffset + offset, size);
int newEndOffset = absoluteOffset + offset + frame.getLengthInBytes() - 1;
if (newEndOffset < maxEndOffset()) {
if (newEndOffset < maxEndOffset(size)) {
endOffset = absoluteOffset + offset + frame.getLengthInBytes() - 1;
frameCount++;
addBitrate(frame.getBitrate());
Expand All @@ -221,8 +226,8 @@ private int scanBlock(byte[] bytes, int bytesRead, int absoluteOffset, int offse
return offset;
}

private int maxEndOffset() {
int maxEndOffset = (int) getLength();
private int maxEndOffset(long size) {
int maxEndOffset = (int) size;
if (hasId3v1Tag()) maxEndOffset -= ID3v1Tag.TAG_LENGTH;
return maxEndOffset;
}
Expand All @@ -249,11 +254,11 @@ private boolean isXingFrame(byte[] bytes, int offset) {
return false;
}

private void sanityCheckFrame(MpegFrame frame, int offset) throws InvalidDataException {
private void sanityCheckFrame(MpegFrame frame, int offset, long size) throws InvalidDataException {
if (sampleRate != frame.getSampleRate()) throw new InvalidDataException("Inconsistent frame header");
if (!layer.equals(frame.getLayer())) throw new InvalidDataException("Inconsistent frame header");
if (!version.equals(frame.getVersion())) throw new InvalidDataException("Inconsistent frame header");
if (offset + frame.getLengthInBytes() > getLength())
if (offset + frame.getLengthInBytes() > size)
throw new InvalidDataException("Frame would extend beyond end of file");
}

Expand All @@ -270,7 +275,7 @@ private void addBitrate(int bitrate) {

private void initId3v1Tag(SeekableByteChannel seekableByteChannel) throws IOException {
ByteBuffer byteBuffer = ByteBuffer.allocate(ID3v1Tag.TAG_LENGTH);
seekableByteChannel.position(getLength() - ID3v1Tag.TAG_LENGTH);
seekableByteChannel.position(seekableByteChannel.size() - ID3v1Tag.TAG_LENGTH);
byteBuffer.clear();
int bytesRead = seekableByteChannel.read(byteBuffer);
if (bytesRead < ID3v1Tag.TAG_LENGTH) throw new IOException("Not enough bytes read");
Expand Down Expand Up @@ -302,7 +307,7 @@ private void initId3v2Tag(SeekableByteChannel seekableByteChannel) throws IOExce
}

private void initCustomTag(SeekableByteChannel seekableByteChannel) throws IOException {
int bufferLength = (int) (getLength() - (endOffset + 1));
int bufferLength = (int) (seekableByteChannel.size() - (endOffset + 1));
if (hasId3v1Tag()) bufferLength -= ID3v1Tag.TAG_LENGTH;
if (bufferLength <= 0) {
customTag = null;
Expand Down Expand Up @@ -442,10 +447,13 @@ public void removeCustomTag() {
}

public void save(String newFilename) throws IOException, NotSupportedException {
if (path.toAbsolutePath().compareTo(Paths.get(newFilename).toAbsolutePath()) == 0) {
final Path originalPath = Paths.get(inputSource.getResourceName()).toAbsolutePath();
final Path newPath = Paths.get(newFilename).toAbsolutePath();
if (originalPath.compareTo(newPath) == 0) {
throw new IllegalArgumentException("Save filename same as source filename");
}
try (SeekableByteChannel saveFile = Files.newByteChannel(Paths.get(newFilename), EnumSet.of(StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE))) {
try (SeekableByteChannel saveFile = Files.newByteChannel(newPath,
EnumSet.of(StandardOpenOption.CREATE, StandardOpenOption.TRUNCATE_EXISTING, StandardOpenOption.WRITE))) {
if (hasId3v2Tag()) {
ByteBuffer byteBuffer = ByteBuffer.wrap(id3v2Tag.toBytes());
byteBuffer.rewind();
Expand All @@ -471,9 +479,8 @@ private void saveMpegFrames(SeekableByteChannel saveFile) throws IOException {
if (filePos < 0) filePos = startOffset;
if (filePos < 0) return;
if (endOffset < filePos) return;
SeekableByteChannel seekableByteChannel = Files.newByteChannel(path, StandardOpenOption.READ);
ByteBuffer byteBuffer = ByteBuffer.allocate(bufferLength);
try {
try (SeekableByteChannel seekableByteChannel = inputSource.openChannel(StandardOpenOption.READ)) {
seekableByteChannel.position(filePos);
while (true) {
byteBuffer.clear();
Expand All @@ -489,8 +496,6 @@ private void saveMpegFrames(SeekableByteChannel saveFile) throws IOException {
break;
}
}
} finally {
seekableByteChannel.close();
}
}
}
13 changes: 5 additions & 8 deletions src/main/java/com/mpatric/mp3agic/MutableInteger.java
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Original file line number Diff line number Diff line change
@@ -1,5 +1,7 @@
package com.mpatric.mp3agic;

import java.util.Objects;

public class MutableInteger {

private int value;
Expand All @@ -22,10 +24,7 @@ public void setValue(int value) {

@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result + value;
return result;
return Objects.hash(value);
}

@Override
Expand All @@ -36,9 +35,7 @@ public boolean equals(Object obj) {
return false;
if (getClass() != obj.getClass())
return false;
MutableInteger other = (MutableInteger) obj;
if (value != other.value)
return false;
return true;
final MutableInteger other = (MutableInteger) obj;
return Objects.equals(value, other.value);
}
}
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