Java tutorial
/* * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com> * Copyright (C) 2006-2008, Shawn O. Pearce <spearce@spearce.org> * 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.lib; import java.io.IOException; import java.io.OutputStream; /** * Constants describing various file modes recognized by GIT. * <p> * GIT uses a subset of the available UNIX file permission bits. The * <code>FileMode</code> class provides access to constants defining the modes * actually used by GIT. * </p> */ public abstract class FileMode { /** * Mask to apply to a file mode to obtain its type bits. * * @see #TYPE_TREE * @see #TYPE_SYMLINK * @see #TYPE_FILE * @see #TYPE_GITLINK * @see #TYPE_MISSING */ public static final int TYPE_MASK = 0170000; /** Bit pattern for {@link #TYPE_MASK} matching {@link #TREE}. */ public static final int TYPE_TREE = 0040000; /** Bit pattern for {@link #TYPE_MASK} matching {@link #SYMLINK}. */ public static final int TYPE_SYMLINK = 0120000; /** Bit pattern for {@link #TYPE_MASK} matching {@link #REGULAR_FILE}. */ public static final int TYPE_FILE = 0100000; /** Bit pattern for {@link #TYPE_MASK} matching {@link #GITLINK}. */ public static final int TYPE_GITLINK = 0160000; /** Bit pattern for {@link #TYPE_MASK} matching {@link #MISSING}. */ public static final int TYPE_MISSING = 0000000; /** * Mode indicating an entry is a tree (aka directory). */ public static final FileMode TREE = new FileMode(TYPE_TREE, Constants.OBJ_TREE) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return (modeBits & TYPE_MASK) == TYPE_TREE; } }; /** Mode indicating an entry is a symbolic link. */ public static final FileMode SYMLINK = new FileMode(TYPE_SYMLINK, Constants.OBJ_BLOB) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return (modeBits & TYPE_MASK) == TYPE_SYMLINK; } }; /** Mode indicating an entry is a non-executable file. */ public static final FileMode REGULAR_FILE = new FileMode(0100644, Constants.OBJ_BLOB) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return (modeBits & TYPE_MASK) == TYPE_FILE && (modeBits & 0111) == 0; } }; /** Mode indicating an entry is an executable file. */ public static final FileMode EXECUTABLE_FILE = new FileMode(0100755, Constants.OBJ_BLOB) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return (modeBits & TYPE_MASK) == TYPE_FILE && (modeBits & 0111) != 0; } }; /** Mode indicating an entry is a submodule commit in another repository. */ public static final FileMode GITLINK = new FileMode(TYPE_GITLINK, Constants.OBJ_COMMIT) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return (modeBits & TYPE_MASK) == TYPE_GITLINK; } }; /** Mode indicating an entry is missing during parallel walks. */ public static final FileMode MISSING = new FileMode(TYPE_MISSING, Constants.OBJ_BAD) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int modeBits) { return modeBits == 0; } }; /** * Convert a set of mode bits into a FileMode enumerated value. * * @param bits * the mode bits the caller has somehow obtained. * @return the FileMode instance that represents the given bits. */ public static final FileMode fromBits(int bits) { switch (bits & TYPE_MASK) { case TYPE_MISSING: if (bits == 0) return MISSING; break; case TYPE_TREE: return TREE; case TYPE_FILE: if ((bits & 0111) != 0) return EXECUTABLE_FILE; return REGULAR_FILE; case TYPE_SYMLINK: return SYMLINK; case TYPE_GITLINK: return GITLINK; } return new FileMode(bits, Constants.OBJ_BAD) { @Override @SuppressWarnings("NonOverridingEquals") public boolean equals(int a) { return bits == a; } }; } private final byte[] octalBytes; private final int modeBits; private final int objectType; private FileMode(int mode, int expType) { modeBits = mode; objectType = expType; if (mode != 0) { final byte[] tmp = new byte[10]; int p = tmp.length; while (mode != 0) { tmp[--p] = (byte) ('0' + (mode & 07)); mode >>= 3; } octalBytes = new byte[tmp.length - p]; for (int k = 0; k < octalBytes.length; k++) { octalBytes[k] = tmp[p + k]; } } else { octalBytes = new byte[] { '0' }; } } /** * Test a file mode for equality with this * {@link org.eclipse.jgit.lib.FileMode} object. * * @param modebits * a int. * @return true if the mode bits represent the same mode as this object */ @SuppressWarnings("NonOverridingEquals") public abstract boolean equals(int modebits); /** * Copy this mode as a sequence of octal US-ASCII bytes. * <p> * The mode is copied as a sequence of octal digits using the US-ASCII * character encoding. The sequence does not use a leading '0' prefix to * indicate octal notation. This method is suitable for generation of a mode * string within a GIT tree object. * </p> * * @param os * stream to copy the mode to. * @throws java.io.IOException * the stream encountered an error during the copy. */ public void copyTo(OutputStream os) throws IOException { os.write(octalBytes); } /** * Copy this mode as a sequence of octal US-ASCII bytes. * * The mode is copied as a sequence of octal digits using the US-ASCII * character encoding. The sequence does not use a leading '0' prefix to * indicate octal notation. This method is suitable for generation of a mode * string within a GIT tree object. * * @param buf * buffer to copy the mode to. * @param ptr * position within {@code buf} for first digit. */ public void copyTo(byte[] buf, int ptr) { System.arraycopy(octalBytes, 0, buf, ptr, octalBytes.length); } /** * Copy the number of bytes written by {@link #copyTo(OutputStream)}. * * @return the number of bytes written by {@link #copyTo(OutputStream)}. */ public int copyToLength() { return octalBytes.length; } /** * Get the object type that should appear for this type of mode. * <p> * See the object type constants in {@link org.eclipse.jgit.lib.Constants}. * * @return one of the well known object type constants. */ public int getObjectType() { return objectType; } /** * {@inheritDoc} * <p> * Format this mode as an octal string (for debugging only). */ @Override public String toString() { return Integer.toOctalString(modeBits); } /** * Get the mode bits as an integer. * * @return The mode bits as an integer. */ public int getBits() { return modeBits; } }