http://www.eclipse.org/jgit//org.eclipse.jgit: Repository access and algorithms (Eclipse JGit Project)
  • Eclipse Distribution License (New BSD License)
  • Andrey Loskutov
  • Christian Halstrick
  • Dave Borowitz
  • David Pursehouse
  • Gunnar Wagenknecht
  • Jonathan Nieder
  • Jonathan Tan
  • Matthias Sohn
  • Sasa Zivkov
  • Terry Parker
  • Thomas Wolf 
/*
 * Copyright (C) 2009, Google Inc.
 * Copyright (C) 2008-2009, Johannes E. Schindelin <johannes.schindelin@gmx.de>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.diff;

import java.io.EOFException;
import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;

import org.eclipse.jgit.errors.BinaryBlobException;
import org.eclipse.jgit.errors.LargeObjectException;
import org.eclipse.jgit.lib.ObjectLoader;
import org.eclipse.jgit.util.IO;
import org.eclipse.jgit.util.IntList;
import org.eclipse.jgit.util.RawParseUtils;


A Sequence supporting UNIX formatted text in byte[] format.


Elements of the sequence are the lines of the file, as delimited by the UNIX
newline character ('\n'). The file content is treated as 8 bit binary text,
with no assumptions or requirements on character encoding.


Note that the first line of the file is element 0, as defined by the Sequence
interface API. Traditionally in a text editor a patch file the first line is
line number 1. Callers may need to subtract 1 prior to invoking methods if
they are converting from "line number" to "element index".

/**
 * A Sequence supporting UNIX formatted text in byte[] format.
 * <p>
 * Elements of the sequence are the lines of the file, as delimited by the UNIX
 * newline character ('\n'). The file content is treated as 8 bit binary text,
 * with no assumptions or requirements on character encoding.
 * <p>
 * Note that the first line of the file is element 0, as defined by the Sequence
 * interface API. Traditionally in a text editor a patch file the first line is
 * line number 1. Callers may need to subtract 1 prior to invoking methods if
 * they are converting from "line number" to "element index".
 */
public class RawText extends Sequence {
	
A RawText of length 0 
/** A RawText of length 0 */
	public static final RawText EMPTY_TEXT = new RawText(new byte[0]);

	
Number of bytes to check for heuristics in isBinary(byte[]) 
/** Number of bytes to check for heuristics in {@link #isBinary(byte[])} */
	static final int FIRST_FEW_BYTES = 8000;

	
The file content for this sequence. 
/** The file content for this sequence. */
	protected final byte[] content;

	
Map of line number to starting position within content. 
/** Map of line number to starting position within {@link #content}. */
	protected final IntList lines;

	
Create a new sequence from an existing content byte array.


The entire array (indexes 0 through length-1) is used as the content.

Params:
  • input – 
           the content array. The object retains a reference to this
           array, so it should be immutable.
/**
	 * Create a new sequence from an existing content byte array.
	 * <p>
	 * The entire array (indexes 0 through length-1) is used as the content.
	 *
	 * @param input
	 *            the content array. The object retains a reference to this
	 *            array, so it should be immutable.
	 */
	public RawText(byte[] input) {
		this(input, RawParseUtils.lineMap(input, 0, input.length));
	}

	
Create a new sequence from the existing content byte array and the line
map indicating line boundaries.

Params:
  • input – 
           the content array. The object retains a reference to this
           array, so it should be immutable.
  • lineMap –  an array with 1-based offsets for the start of each line. The first and last entries should be Integer.MIN_VALUE and an offset one past the end of the last line, respectively.
Since:5.0
/**
	 * Create a new sequence from the existing content byte array and the line
	 * map indicating line boundaries.
	 *
	 * @param input
	 *            the content array. The object retains a reference to this
	 *            array, so it should be immutable.
	 * @param lineMap
	 *            an array with 1-based offsets for the start of each line.
	 *            The first and last entries should be {@link Integer#MIN_VALUE}
	 *            and an offset one past the end of the last line, respectively.
	 * @since 5.0
	 */
	public RawText(byte[] input, IntList lineMap) {
		content = input;
		lines = lineMap;
	}

	
Create a new sequence from a file.


The entire file contents are used.

Params:
  • file – 
           the text file.
Throws:
  • IOException – 
            if Exceptions occur while reading the file
/**
	 * Create a new sequence from a file.
	 * <p>
	 * The entire file contents are used.
	 *
	 * @param file
	 *            the text file.
	 * @throws java.io.IOException
	 *             if Exceptions occur while reading the file
	 */
	public RawText(File file) throws IOException {
		this(IO.readFully(file));
	}

	
Returns:the raw, unprocessed content read.
Since:4.11
/**
	 * @return the raw, unprocessed content read.
	 * @since 4.11
	 */
	public byte[] getRawContent() {
		return content;
	}

	/** @return total number of items in the sequence. */
	
{@inheritDoc} 
/** {@inheritDoc} */
	@Override
	public int size() {
		// The line map is always 2 entries larger than the number of lines in
		// the file. Index 0 is padded out/unused. The last index is the total
		// length of the buffer, and acts as a sentinel.
		//
		return lines.size() - 2;
	}

	
Write a specific line to the output stream, without its trailing LF.


The specified line is copied as-is, with no character encoding
translation performed.


If the specified line ends with an LF ('\n'), the LF is not
copied. It is up to the caller to write the LF, if desired, between
output lines.

Params:
  • out – 
           stream to copy the line data onto.
  • i – 
           index of the line to extract. Note this is 0-based, so line
           number 1 is actually index 0.
Throws:
/**
	 * Write a specific line to the output stream, without its trailing LF.
	 * <p>
	 * The specified line is copied as-is, with no character encoding
	 * translation performed.
	 * <p>
	 * If the specified line ends with an LF ('\n'), the LF is <b>not</b>
	 * copied. It is up to the caller to write the LF, if desired, between
	 * output lines.
	 *
	 * @param out
	 *            stream to copy the line data onto.
	 * @param i
	 *            index of the line to extract. Note this is 0-based, so line
	 *            number 1 is actually index 0.
	 * @throws java.io.IOException
	 *             the stream write operation failed.
	 */
	public void writeLine(OutputStream out, int i)
			throws IOException {
		int start = getStart(i);
		int end = getEnd(i);
		if (content[end - 1] == '\n')
			end--;
		out.write(content, start, end - start);
	}

	
Determine if the file ends with a LF ('\n').

Returns:true if the last line has an LF; false otherwise.
/**
	 * Determine if the file ends with a LF ('\n').
	 *
	 * @return true if the last line has an LF; false otherwise.
	 */
	public boolean isMissingNewlineAtEnd() {
		final int end = lines.get(lines.size() - 1);
		if (end == 0)
			return true;
		return content[end - 1] != '\n';
	}

	
Get the text for a single line.

Params:
  • i – 
           index of the line to extract. Note this is 0-based, so line
           number 1 is actually index 0.
Returns:the text for the line, without a trailing LF.
/**
	 * Get the text for a single line.
	 *
	 * @param i
	 *            index of the line to extract. Note this is 0-based, so line
	 *            number 1 is actually index 0.
	 * @return the text for the line, without a trailing LF.
	 */
	public String getString(int i) {
		return getString(i, i + 1, true);
	}

	
Get the text for a region of lines.

Params:
  • begin – 
           index of the first line to extract. Note this is 0-based, so
           line number 1 is actually index 0.
  • end – 
           index of one past the last line to extract.
  • dropLF – 
           if true the trailing LF ('\n') of the last returned line is
           dropped, if present.
Returns:the text for lines [begin, end).
/**
	 * Get the text for a region of lines.
	 *
	 * @param begin
	 *            index of the first line to extract. Note this is 0-based, so
	 *            line number 1 is actually index 0.
	 * @param end
	 *            index of one past the last line to extract.
	 * @param dropLF
	 *            if true the trailing LF ('\n') of the last returned line is
	 *            dropped, if present.
	 * @return the text for lines {@code [begin, end)}.
	 */
	public String getString(int begin, int end, boolean dropLF) {
		if (begin == end)
			return ""; //$NON-NLS-1$

		int s = getStart(begin);
		int e = getEnd(end - 1);
		if (dropLF && content[e - 1] == '\n')
			e--;
		return decode(s, e);
	}

	
Decode a region of the text into a String.
The default implementation of this method tries to guess the character
set by considering UTF-8, the platform default, and falling back on
ISO-8859-1 if neither of those can correctly decode the region given.

Params:
  • start – 
           first byte of the content to decode.
  • end – 
           one past the last byte of the content to decode.
Returns:the region [start, end) decoded as a String.
/**
	 * Decode a region of the text into a String.
	 *
	 * The default implementation of this method tries to guess the character
	 * set by considering UTF-8, the platform default, and falling back on
	 * ISO-8859-1 if neither of those can correctly decode the region given.
	 *
	 * @param start
	 *            first byte of the content to decode.
	 * @param end
	 *            one past the last byte of the content to decode.
	 * @return the region {@code [start, end)} decoded as a String.
	 */
	protected String decode(int start, int end) {
		return RawParseUtils.decode(content, start, end);
	}

	private int getStart(int i) {
		return lines.get(i + 1);
	}

	private int getEnd(int i) {
		return lines.get(i + 2);
	}

	
Determine heuristically whether a byte array represents binary (as
opposed to text) content.

Params:
  • raw – 
           the raw file content.
Returns:true if raw is likely to be a binary file, false otherwise
/**
	 * Determine heuristically whether a byte array represents binary (as
	 * opposed to text) content.
	 *
	 * @param raw
	 *            the raw file content.
	 * @return true if raw is likely to be a binary file, false otherwise
	 */
	public static boolean isBinary(byte[] raw) {
		return isBinary(raw, raw.length);
	}

	
Determine heuristically whether the bytes contained in a stream
represents binary (as opposed to text) content.
Note: Do not further use this stream after having called this method! The
stream may not be fully read and will be left at an unknown position
after consuming an unknown number of bytes. The caller is responsible for
closing the stream.

Params:
  • raw – 
           input stream containing the raw file content.
Throws:
Returns:true if raw is likely to be a binary file, false otherwise
/**
	 * Determine heuristically whether the bytes contained in a stream
	 * represents binary (as opposed to text) content.
	 *
	 * Note: Do not further use this stream after having called this method! The
	 * stream may not be fully read and will be left at an unknown position
	 * after consuming an unknown number of bytes. The caller is responsible for
	 * closing the stream.
	 *
	 * @param raw
	 *            input stream containing the raw file content.
	 * @return true if raw is likely to be a binary file, false otherwise
	 * @throws java.io.IOException
	 *             if input stream could not be read
	 */
	public static boolean isBinary(InputStream raw) throws IOException {
		final byte[] buffer = new byte[FIRST_FEW_BYTES];
		int cnt = 0;
		while (cnt < buffer.length) {
			final int n = raw.read(buffer, cnt, buffer.length - cnt);
			if (n == -1)
				break;
			cnt += n;
		}
		return isBinary(buffer, cnt);
	}

	
Determine heuristically whether a byte array represents binary (as
opposed to text) content.

Params:
  • raw – 
           the raw file content.
  • length –  number of bytes in raw to evaluate. This should be raw.length unless raw was over-allocated by the caller.
Returns:true if raw is likely to be a binary file, false otherwise
/**
	 * Determine heuristically whether a byte array represents binary (as
	 * opposed to text) content.
	 *
	 * @param raw
	 *            the raw file content.
	 * @param length
	 *            number of bytes in {@code raw} to evaluate. This should be
	 *            {@code raw.length} unless {@code raw} was over-allocated by
	 *            the caller.
	 * @return true if raw is likely to be a binary file, false otherwise
	 */
	public static boolean isBinary(byte[] raw, int length) {
		// Same heuristic as C Git
		if (length > FIRST_FEW_BYTES)
			length = FIRST_FEW_BYTES;
		for (int ptr = 0; ptr < length; ptr++)
			if (raw[ptr] == '\0')
				return true;

		return false;
	}

	
Determine heuristically whether a byte array represents text content
using CR-LF as line separator.

Params:
  • raw – 
           the raw file content.
Returns:true if raw is likely to be CR-LF delimited text, false otherwise
Since:5.3
/**
	 * Determine heuristically whether a byte array represents text content
	 * using CR-LF as line separator.
	 *
	 * @param raw
	 *            the raw file content.
	 * @return {@code true} if raw is likely to be CR-LF delimited text,
	 *         {@code false} otherwise
	 * @since 5.3
	 */
	public static boolean isCrLfText(byte[] raw) {
		return isCrLfText(raw, raw.length);
	}

	
Determine heuristically whether the bytes contained in a stream represent
text content using CR-LF as line separator.
Note: Do not further use this stream after having called this method! The
stream may not be fully read and will be left at an unknown position
after consuming an unknown number of bytes. The caller is responsible for
closing the stream.

Params:
  • raw – 
           input stream containing the raw file content.
Throws:
Returns:true if raw is likely to be CR-LF delimited text, false otherwise
Since:5.3
/**
	 * Determine heuristically whether the bytes contained in a stream represent
	 * text content using CR-LF as line separator.
	 *
	 * Note: Do not further use this stream after having called this method! The
	 * stream may not be fully read and will be left at an unknown position
	 * after consuming an unknown number of bytes. The caller is responsible for
	 * closing the stream.
	 *
	 * @param raw
	 *            input stream containing the raw file content.
	 * @return {@code true} if raw is likely to be CR-LF delimited text,
	 *         {@code false} otherwise
	 * @throws java.io.IOException
	 *             if input stream could not be read
	 * @since 5.3
	 */
	public static boolean isCrLfText(InputStream raw) throws IOException {
		byte[] buffer = new byte[FIRST_FEW_BYTES];
		int cnt = 0;
		while (cnt < buffer.length) {
			int n = raw.read(buffer, cnt, buffer.length - cnt);
			if (n == -1) {
				break;
			}
			cnt += n;
		}
		return isCrLfText(buffer, cnt);
	}

	
Determine heuristically whether a byte array represents text content
using CR-LF as line separator.

Params:
  • raw – 
           the raw file content.
  • length –  number of bytes in raw to evaluate.
Returns:true if raw is likely to be CR-LF delimited text, false otherwise
Since:5.3
/**
	 * Determine heuristically whether a byte array represents text content
	 * using CR-LF as line separator.
	 *
	 * @param raw
	 *            the raw file content.
	 * @param length
	 *            number of bytes in {@code raw} to evaluate.
	 * @return {@code true} if raw is likely to be CR-LF delimited text,
	 *         {@code false} otherwise
	 * @since 5.3
	 */
	public static boolean isCrLfText(byte[] raw, int length) {
		boolean has_crlf = false;
		for (int ptr = 0; ptr < length - 1; ptr++) {
			if (raw[ptr] == '\0') {
				return false; // binary
			} else if (raw[ptr] == '\r' && raw[ptr + 1] == '\n') {
				has_crlf = true;
			}
		}
		return has_crlf;
	}

	
Get the line delimiter for the first line.

Since:2.0
Returns:the line delimiter or null
/**
	 * Get the line delimiter for the first line.
	 *
	 * @since 2.0
	 * @return the line delimiter or <code>null</code>
	 */
	public String getLineDelimiter() {
		if (size() == 0)
			return null;
		int e = getEnd(0);
		if (content[e - 1] != '\n')
			return null;
		if (content.length > 1 && e > 1 && content[e - 2] == '\r')
			return "\r\n"; //$NON-NLS-1$
		else
			return "\n"; //$NON-NLS-1$
	}

	
Read a blob object into RawText, or throw BinaryBlobException if the blob
is binary.

Params:
  • ldr – 
           the ObjectLoader for the blob
  • threshold – 
           if the blob is larger than this size, it is always assumed to
           be binary.
Throws:
Since:4.10
Returns:the RawText representing the blob.
/**
	 * Read a blob object into RawText, or throw BinaryBlobException if the blob
	 * is binary.
	 *
	 * @param ldr
	 *            the ObjectLoader for the blob
	 * @param threshold
	 *            if the blob is larger than this size, it is always assumed to
	 *            be binary.
	 * @since 4.10
	 * @return the RawText representing the blob.
	 * @throws org.eclipse.jgit.errors.BinaryBlobException
	 *             if the blob contains binary data.
	 * @throws java.io.IOException
	 *             if the input could not be read.
	 */
	public static RawText load(ObjectLoader ldr, int threshold)
			throws IOException, BinaryBlobException {
		long sz = ldr.getSize();

		if (sz > threshold) {
			throw new BinaryBlobException();
		}

		if (sz <= FIRST_FEW_BYTES) {
			byte[] data = ldr.getCachedBytes(FIRST_FEW_BYTES);
			if (isBinary(data)) {
				throw new BinaryBlobException();
			}
			return new RawText(data);
		}

		byte[] head = new byte[FIRST_FEW_BYTES];
		try (InputStream stream = ldr.openStream()) {
			int off = 0;
			int left = head.length;
			while (left > 0) {
				int n = stream.read(head, off, left);
				if (n < 0) {
					throw new EOFException();
				}
				left -= n;

				while (n > 0) {
					if (head[off] == '\0') {
						throw new BinaryBlobException();
					}
					off++;
					n--;
				}
			}

			byte data[];
			try {
				data = new byte[(int)sz];
			} catch (OutOfMemoryError e) {
				throw new LargeObjectException.OutOfMemory(e);
			}

			System.arraycopy(head, 0, data, 0, head.length);
			IO.readFully(stream, data, off, (int) (sz-off));
			return new RawText(data, RawParseUtils.lineMapOrBinary(data, 0, (int) sz));
		}
	}
}