org.eclipse.jgit.patch.FileHeader Maven / Gradle / Ivy
/*
* Copyright (C) 2008-2009, Google Inc.
* 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
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*
* - 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.
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package org.eclipse.jgit.patch;
import static org.eclipse.jgit.lib.Constants.encodeASCII;
import static org.eclipse.jgit.util.RawParseUtils.decode;
import static org.eclipse.jgit.util.RawParseUtils.decodeNoFallback;
import static org.eclipse.jgit.util.RawParseUtils.extractBinaryString;
import static org.eclipse.jgit.util.RawParseUtils.match;
import static org.eclipse.jgit.util.RawParseUtils.nextLF;
import static org.eclipse.jgit.util.RawParseUtils.parseBase10;
import java.io.IOException;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.text.MessageFormat;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import org.eclipse.jgit.diff.DiffEntry;
import org.eclipse.jgit.diff.EditList;
import org.eclipse.jgit.internal.JGitText;
import org.eclipse.jgit.lib.AbbreviatedObjectId;
import org.eclipse.jgit.lib.Constants;
import org.eclipse.jgit.lib.FileMode;
import org.eclipse.jgit.util.QuotedString;
import org.eclipse.jgit.util.RawParseUtils;
import org.eclipse.jgit.util.TemporaryBuffer;
/** Patch header describing an action for a single file path. */
public class FileHeader extends DiffEntry {
private static final byte[] OLD_MODE = encodeASCII("old mode "); //$NON-NLS-1$
private static final byte[] NEW_MODE = encodeASCII("new mode "); //$NON-NLS-1$
static final byte[] DELETED_FILE_MODE = encodeASCII("deleted file mode "); //$NON-NLS-1$
static final byte[] NEW_FILE_MODE = encodeASCII("new file mode "); //$NON-NLS-1$
private static final byte[] COPY_FROM = encodeASCII("copy from "); //$NON-NLS-1$
private static final byte[] COPY_TO = encodeASCII("copy to "); //$NON-NLS-1$
private static final byte[] RENAME_OLD = encodeASCII("rename old "); //$NON-NLS-1$
private static final byte[] RENAME_NEW = encodeASCII("rename new "); //$NON-NLS-1$
private static final byte[] RENAME_FROM = encodeASCII("rename from "); //$NON-NLS-1$
private static final byte[] RENAME_TO = encodeASCII("rename to "); //$NON-NLS-1$
private static final byte[] SIMILARITY_INDEX = encodeASCII("similarity index "); //$NON-NLS-1$
private static final byte[] DISSIMILARITY_INDEX = encodeASCII("dissimilarity index "); //$NON-NLS-1$
static final byte[] INDEX = encodeASCII("index "); //$NON-NLS-1$
static final byte[] OLD_NAME = encodeASCII("--- "); //$NON-NLS-1$
static final byte[] NEW_NAME = encodeASCII("+++ "); //$NON-NLS-1$
/** Type of patch used by this file. */
public static enum PatchType {
/** A traditional unified diff style patch of a text file. */
UNIFIED,
/** An empty patch with a message "Binary files ... differ" */
BINARY,
/** A Git binary patch, holding pre and post image deltas */
GIT_BINARY;
}
/** Buffer holding the patch data for this file. */
final byte[] buf;
/** Offset within {@link #buf} to the "diff ..." line. */
final int startOffset;
/** Position 1 past the end of this file within {@link #buf}. */
int endOffset;
/** Type of patch used to modify this file */
PatchType patchType;
/** The hunks of this file */
private List hunks;
/** If {@link #patchType} is {@link PatchType#GIT_BINARY}, the new image */
BinaryHunk forwardBinaryHunk;
/** If {@link #patchType} is {@link PatchType#GIT_BINARY}, the old image */
BinaryHunk reverseBinaryHunk;
/**
* Constructs a new FileHeader
*
* @param headerLines
* buffer holding the diff header for this file
* @param edits
* the edits for this file
* @param type
* the type of patch used to modify this file
*/
public FileHeader(final byte[] headerLines, EditList edits, PatchType type) {
this(headerLines, 0);
endOffset = headerLines.length;
int ptr = parseGitFileName(Patch.DIFF_GIT.length, headerLines.length);
parseGitHeaders(ptr, headerLines.length);
this.patchType = type;
addHunk(new HunkHeader(this, edits));
}
FileHeader(final byte[] b, final int offset) {
buf = b;
startOffset = offset;
changeType = ChangeType.MODIFY; // unless otherwise designated
patchType = PatchType.UNIFIED;
}
int getParentCount() {
return 1;
}
/** @return the byte array holding this file's patch script. */
public byte[] getBuffer() {
return buf;
}
/** @return offset the start of this file's script in {@link #getBuffer()}. */
public int getStartOffset() {
return startOffset;
}
/** @return offset one past the end of the file script. */
public int getEndOffset() {
return endOffset;
}
/**
* Convert the patch script for this file into a string.
*
* The default character encoding ({@link Constants#CHARSET}) is assumed for
* both the old and new files.
*
* @return the patch script, as a Unicode string.
*/
public String getScriptText() {
return getScriptText(null, null);
}
/**
* Convert the patch script for this file into a string.
*
* @param oldCharset
* hint character set to decode the old lines with.
* @param newCharset
* hint character set to decode the new lines with.
* @return the patch script, as a Unicode string.
*/
public String getScriptText(Charset oldCharset, Charset newCharset) {
return getScriptText(new Charset[] { oldCharset, newCharset });
}
String getScriptText(Charset[] charsetGuess) {
if (getHunks().isEmpty()) {
// If we have no hunks then we can safely assume the entire
// patch is a binary style patch, or a meta-data only style
// patch. Either way the encoding of the headers should be
// strictly 7-bit US-ASCII and the body is either 7-bit ASCII
// (due to the base 85 encoding used for a BinaryHunk) or is
// arbitrary noise we have chosen to ignore and not understand
// (e.g. the message "Binary files ... differ").
//
return extractBinaryString(buf, startOffset, endOffset);
}
if (charsetGuess != null && charsetGuess.length != getParentCount() + 1)
throw new IllegalArgumentException(MessageFormat.format(
JGitText.get().expectedCharacterEncodingGuesses,
Integer.valueOf(getParentCount() + 1)));
if (trySimpleConversion(charsetGuess)) {
Charset cs = charsetGuess != null ? charsetGuess[0] : null;
if (cs == null)
cs = Constants.CHARSET;
try {
return decodeNoFallback(cs, buf, startOffset, endOffset);
} catch (CharacterCodingException cee) {
// Try the much slower, more-memory intensive version which
// can handle a character set conversion patch.
}
}
final StringBuilder r = new StringBuilder(endOffset - startOffset);
// Always treat the headers as US-ASCII; Git file names are encoded
// in a C style escape if any character has the high-bit set.
//
final int hdrEnd = getHunks().get(0).getStartOffset();
for (int ptr = startOffset; ptr < hdrEnd;) {
final int eol = Math.min(hdrEnd, nextLF(buf, ptr));
r.append(extractBinaryString(buf, ptr, eol));
ptr = eol;
}
final String[] files = extractFileLines(charsetGuess);
final int[] offsets = new int[files.length];
for (final HunkHeader h : getHunks())
h.extractFileLines(r, files, offsets);
return r.toString();
}
private static boolean trySimpleConversion(final Charset[] charsetGuess) {
if (charsetGuess == null)
return true;
for (int i = 1; i < charsetGuess.length; i++) {
if (charsetGuess[i] != charsetGuess[0])
return false;
}
return true;
}
private String[] extractFileLines(final Charset[] csGuess) {
final TemporaryBuffer[] tmp = new TemporaryBuffer[getParentCount() + 1];
try {
for (int i = 0; i < tmp.length; i++)
tmp[i] = new TemporaryBuffer.LocalFile();
for (final HunkHeader h : getHunks())
h.extractFileLines(tmp);
final String[] r = new String[tmp.length];
for (int i = 0; i < tmp.length; i++) {
Charset cs = csGuess != null ? csGuess[i] : null;
if (cs == null)
cs = Constants.CHARSET;
r[i] = RawParseUtils.decode(cs, tmp[i].toByteArray());
}
return r;
} catch (IOException ioe) {
throw new RuntimeException(JGitText.get().cannotConvertScriptToText, ioe);
} finally {
for (final TemporaryBuffer b : tmp) {
if (b != null)
b.destroy();
}
}
}
/** @return style of patch used to modify this file */
public PatchType getPatchType() {
return patchType;
}
/** @return true if this patch modifies metadata about a file */
public boolean hasMetaDataChanges() {
return changeType != ChangeType.MODIFY || newMode != oldMode;
}
/** @return hunks altering this file; in order of appearance in patch */
public List getHunks() {
if (hunks == null)
return Collections.emptyList();
return hunks;
}
void addHunk(final HunkHeader h) {
if (h.getFileHeader() != this)
throw new IllegalArgumentException(JGitText.get().hunkBelongsToAnotherFile);
if (hunks == null)
hunks = new ArrayList();
hunks.add(h);
}
HunkHeader newHunkHeader(final int offset) {
return new HunkHeader(this, offset);
}
/** @return if a {@link PatchType#GIT_BINARY}, the new-image delta/literal */
public BinaryHunk getForwardBinaryHunk() {
return forwardBinaryHunk;
}
/** @return if a {@link PatchType#GIT_BINARY}, the old-image delta/literal */
public BinaryHunk getReverseBinaryHunk() {
return reverseBinaryHunk;
}
/** @return a list describing the content edits performed on this file. */
public EditList toEditList() {
final EditList r = new EditList();
for (final HunkHeader hunk : hunks)
r.addAll(hunk.toEditList());
return r;
}
/**
* Parse a "diff --git" or "diff --cc" line.
*
* @param ptr
* first character after the "diff --git " or "diff --cc " part.
* @param end
* one past the last position to parse.
* @return first character after the LF at the end of the line; -1 on error.
*/
int parseGitFileName(int ptr, final int end) {
final int eol = nextLF(buf, ptr);
final int bol = ptr;
if (eol >= end) {
return -1;
}
// buffer[ptr..eol] looks like "a/foo b/foo\n". After the first
// A regex to match this is "^[^/]+/(.*?) [^/+]+/\1\n$". There
// is only one way to split the line such that text to the left
// of the space matches the text to the right, excluding the part
// before the first slash.
//
final int aStart = nextLF(buf, ptr, '/');
if (aStart >= eol)
return eol;
while (ptr < eol) {
final int sp = nextLF(buf, ptr, ' ');
if (sp >= eol) {
// We can't split the header, it isn't valid.
// This may be OK if this is a rename patch.
//
return eol;
}
final int bStart = nextLF(buf, sp, '/');
if (bStart >= eol)
return eol;
// If buffer[aStart..sp - 1] = buffer[bStart..eol - 1]
// we have a valid split.
//
if (eq(aStart, sp - 1, bStart, eol - 1)) {
if (buf[bol] == '"') {
// We're a double quoted name. The region better end
// in a double quote too, and we need to decode the
// characters before reading the name.
//
if (buf[sp - 2] != '"') {
return eol;
}
oldPath = QuotedString.GIT_PATH.dequote(buf, bol, sp - 1);
oldPath = p1(oldPath);
} else {
oldPath = decode(Constants.CHARSET, buf, aStart, sp - 1);
}
newPath = oldPath;
return eol;
}
// This split wasn't correct. Move past the space and try
// another split as the space must be part of the file name.
//
ptr = sp;
}
return eol;
}
int parseGitHeaders(int ptr, final int end) {
while (ptr < end) {
final int eol = nextLF(buf, ptr);
if (isHunkHdr(buf, ptr, eol) >= 1) {
// First hunk header; break out and parse them later.
break;
} else if (match(buf, ptr, OLD_NAME) >= 0) {
parseOldName(ptr, eol);
} else if (match(buf, ptr, NEW_NAME) >= 0) {
parseNewName(ptr, eol);
} else if (match(buf, ptr, OLD_MODE) >= 0) {
oldMode = parseFileMode(ptr + OLD_MODE.length, eol);
} else if (match(buf, ptr, NEW_MODE) >= 0) {
newMode = parseFileMode(ptr + NEW_MODE.length, eol);
} else if (match(buf, ptr, DELETED_FILE_MODE) >= 0) {
oldMode = parseFileMode(ptr + DELETED_FILE_MODE.length, eol);
newMode = FileMode.MISSING;
changeType = ChangeType.DELETE;
} else if (match(buf, ptr, NEW_FILE_MODE) >= 0) {
parseNewFileMode(ptr, eol);
} else if (match(buf, ptr, COPY_FROM) >= 0) {
oldPath = parseName(oldPath, ptr + COPY_FROM.length, eol);
changeType = ChangeType.COPY;
} else if (match(buf, ptr, COPY_TO) >= 0) {
newPath = parseName(newPath, ptr + COPY_TO.length, eol);
changeType = ChangeType.COPY;
} else if (match(buf, ptr, RENAME_OLD) >= 0) {
oldPath = parseName(oldPath, ptr + RENAME_OLD.length, eol);
changeType = ChangeType.RENAME;
} else if (match(buf, ptr, RENAME_NEW) >= 0) {
newPath = parseName(newPath, ptr + RENAME_NEW.length, eol);
changeType = ChangeType.RENAME;
} else if (match(buf, ptr, RENAME_FROM) >= 0) {
oldPath = parseName(oldPath, ptr + RENAME_FROM.length, eol);
changeType = ChangeType.RENAME;
} else if (match(buf, ptr, RENAME_TO) >= 0) {
newPath = parseName(newPath, ptr + RENAME_TO.length, eol);
changeType = ChangeType.RENAME;
} else if (match(buf, ptr, SIMILARITY_INDEX) >= 0) {
score = parseBase10(buf, ptr + SIMILARITY_INDEX.length, null);
} else if (match(buf, ptr, DISSIMILARITY_INDEX) >= 0) {
score = parseBase10(buf, ptr + DISSIMILARITY_INDEX.length, null);
} else if (match(buf, ptr, INDEX) >= 0) {
parseIndexLine(ptr + INDEX.length, eol);
} else {
// Probably an empty patch (stat dirty).
break;
}
ptr = eol;
}
return ptr;
}
void parseOldName(int ptr, final int eol) {
oldPath = p1(parseName(oldPath, ptr + OLD_NAME.length, eol));
if (oldPath == DEV_NULL)
changeType = ChangeType.ADD;
}
void parseNewName(int ptr, final int eol) {
newPath = p1(parseName(newPath, ptr + NEW_NAME.length, eol));
if (newPath == DEV_NULL)
changeType = ChangeType.DELETE;
}
void parseNewFileMode(int ptr, final int eol) {
oldMode = FileMode.MISSING;
newMode = parseFileMode(ptr + NEW_FILE_MODE.length, eol);
changeType = ChangeType.ADD;
}
int parseTraditionalHeaders(int ptr, final int end) {
while (ptr < end) {
final int eol = nextLF(buf, ptr);
if (isHunkHdr(buf, ptr, eol) >= 1) {
// First hunk header; break out and parse them later.
break;
} else if (match(buf, ptr, OLD_NAME) >= 0) {
parseOldName(ptr, eol);
} else if (match(buf, ptr, NEW_NAME) >= 0) {
parseNewName(ptr, eol);
} else {
// Possibly an empty patch.
break;
}
ptr = eol;
}
return ptr;
}
private String parseName(final String expect, int ptr, final int end) {
if (ptr == end)
return expect;
String r;
if (buf[ptr] == '"') {
// New style GNU diff format
//
r = QuotedString.GIT_PATH.dequote(buf, ptr, end - 1);
} else {
// Older style GNU diff format, an optional tab ends the name.
//
int tab = end;
while (ptr < tab && buf[tab - 1] != '\t')
tab--;
if (ptr == tab)
tab = end;
r = decode(Constants.CHARSET, buf, ptr, tab - 1);
}
if (r.equals(DEV_NULL))
r = DEV_NULL;
return r;
}
private static String p1(final String r) {
final int s = r.indexOf('/');
return s > 0 ? r.substring(s + 1) : r;
}
FileMode parseFileMode(int ptr, final int end) {
int tmp = 0;
while (ptr < end - 1) {
tmp <<= 3;
tmp += buf[ptr++] - '0';
}
return FileMode.fromBits(tmp);
}
void parseIndexLine(int ptr, final int end) {
// "index $asha1..$bsha1[ $mode]" where $asha1 and $bsha1
// can be unique abbreviations
//
final int dot2 = nextLF(buf, ptr, '.');
final int mode = nextLF(buf, dot2, ' ');
oldId = AbbreviatedObjectId.fromString(buf, ptr, dot2 - 1);
newId = AbbreviatedObjectId.fromString(buf, dot2 + 1, mode - 1);
if (mode < end)
newMode = oldMode = parseFileMode(mode, end);
}
private boolean eq(int aPtr, int aEnd, int bPtr, int bEnd) {
if (aEnd - aPtr != bEnd - bPtr) {
return false;
}
while (aPtr < aEnd) {
if (buf[aPtr++] != buf[bPtr++])
return false;
}
return true;
}
/**
* Determine if this is a patch hunk header.
*
* @param buf
* the buffer to scan
* @param start
* first position in the buffer to evaluate
* @param end
* last position to consider; usually the end of the buffer (
* buf.length) or the first position on the next
* line. This is only used to avoid very long runs of '@' from
* killing the scan loop.
* @return the number of "ancestor revisions" in the hunk header. A
* traditional two-way diff ("@@ -...") returns 1; a combined diff
* for a 3 way-merge returns 3. If this is not a hunk header, 0 is
* returned instead.
*/
static int isHunkHdr(final byte[] buf, final int start, final int end) {
int ptr = start;
while (ptr < end && buf[ptr] == '@')
ptr++;
if (ptr - start < 2)
return 0;
if (ptr == end || buf[ptr++] != ' ')
return 0;
if (ptr == end || buf[ptr++] != '-')
return 0;
return (ptr - 3) - start;
}
}