FileHeader.java
- /*
- * Copyright (C) 2008-2009, Google Inc. and others
- *
- * This program and the accompanying materials are made available under the
- * terms of the Eclipse Distribution License v. 1.0 which is available at
- * https://www.eclipse.org/org/documents/edl-v10.php.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
- package org.eclipse.jgit.patch;
- import static java.nio.charset.StandardCharsets.UTF_8;
- 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.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 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<HunkHeader> 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(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(byte[] b, int offset) {
- buf = b;
- startOffset = offset;
- changeType = ChangeType.MODIFY; // unless otherwise designated
- patchType = PatchType.UNIFIED;
- }
- int getParentCount() {
- return 1;
- }
- /**
- * Get the byte array holding this file's patch script.
- *
- * @return the byte array holding this file's patch script.
- */
- public byte[] getBuffer() {
- return buf;
- }
- /**
- * Get offset of the start of this file's script in {@link #getBuffer()}.
- *
- * @return offset of the start of this file's script in
- * {@link #getBuffer()}.
- */
- public int getStartOffset() {
- return startOffset;
- }
- /**
- * Get offset one past the end of the file script.
- *
- * @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.
- * <p>
- * The default character encoding
- * ({@link java.nio.charset.StandardCharsets#UTF_8}) 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 = UTF_8;
- }
- 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 (HunkHeader h : getHunks())
- h.extractFileLines(r, files, offsets);
- return r.toString();
- }
- private static boolean trySimpleConversion(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(Charset[] csGuess) {
- final TemporaryBuffer[] tmp = new TemporaryBuffer[getParentCount() + 1];
- try {
- for (int i = 0; i < tmp.length; i++)
- tmp[i] = new TemporaryBuffer.Heap(Integer.MAX_VALUE);
- for (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 = UTF_8;
- }
- r[i] = RawParseUtils.decode(cs, tmp[i].toByteArray());
- }
- return r;
- } catch (IOException ioe) {
- throw new RuntimeException(JGitText.get().cannotConvertScriptToText, ioe);
- }
- }
- /**
- * Get style of patch used to modify this file.
- *
- * @return style of patch used to modify this file.
- */
- public PatchType getPatchType() {
- return patchType;
- }
- /**
- * Whether this patch modifies metadata about a file
- *
- * @return {@code true} if this patch modifies metadata about a file .
- */
- public boolean hasMetaDataChanges() {
- return changeType != ChangeType.MODIFY || newMode != oldMode;
- }
- /**
- * Get hunks altering this file; in order of appearance in patch
- *
- * @return hunks altering this file; in order of appearance in patch.
- */
- public List<? extends HunkHeader> getHunks() {
- if (hunks == null)
- return Collections.emptyList();
- return hunks;
- }
- void addHunk(HunkHeader h) {
- if (h.getFileHeader() != this)
- throw new IllegalArgumentException(JGitText.get().hunkBelongsToAnotherFile);
- if (hunks == null)
- hunks = new ArrayList<>();
- hunks.add(h);
- }
- HunkHeader newHunkHeader(int offset) {
- return new HunkHeader(this, offset);
- }
- /**
- * Get the new-image delta/literal if this is a
- * {@link PatchType#GIT_BINARY}.
- *
- * @return the new-image delta/literal if this is a
- * {@link PatchType#GIT_BINARY}.
- */
- public BinaryHunk getForwardBinaryHunk() {
- return forwardBinaryHunk;
- }
- /**
- * Get the old-image delta/literal if this is a
- * {@link PatchType#GIT_BINARY}.
- *
- * @return the old-image delta/literal if this is a
- * {@link PatchType#GIT_BINARY}.
- */
- public BinaryHunk getReverseBinaryHunk() {
- return reverseBinaryHunk;
- }
- /**
- * Convert to a list describing the content edits performed on this file.
- *
- * @return a list describing the content edits performed on this file.
- */
- public EditList toEditList() {
- final EditList r = new EditList();
- for (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, 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(UTF_8, 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, 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, int eol) {
- oldPath = p1(parseName(oldPath, ptr + OLD_NAME.length, eol));
- if (oldPath == DEV_NULL)
- changeType = ChangeType.ADD;
- }
- void parseNewName(int ptr, int eol) {
- newPath = p1(parseName(newPath, ptr + NEW_NAME.length, eol));
- if (newPath == DEV_NULL)
- changeType = ChangeType.DELETE;
- }
- void parseNewFileMode(int ptr, int eol) {
- oldMode = FileMode.MISSING;
- newMode = parseFileMode(ptr + NEW_FILE_MODE.length, eol);
- changeType = ChangeType.ADD;
- }
- int parseTraditionalHeaders(int ptr, 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(String expect, int ptr, 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(UTF_8, 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, int end) {
- int tmp = 0;
- while (ptr < end - 1) {
- tmp <<= 3;
- tmp += buf[ptr++] - '0';
- }
- return FileMode.fromBits(tmp);
- }
- void parseIndexLine(int ptr, 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 (
- * <code>buf.length</code>) 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(byte[] buf, int start, 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;
- }
- }