| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.hdfs.server.namenode; |
| |
| import java.util.Arrays; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.NoSuchElementException; |
| |
| import com.google.common.collect.ImmutableList; |
| import org.apache.commons.logging.Log; |
| import org.apache.commons.logging.LogFactory; |
| import org.apache.hadoop.fs.Path; |
| import org.apache.hadoop.fs.UnresolvedLinkException; |
| import org.apache.hadoop.hdfs.DFSUtil; |
| import org.apache.hadoop.hdfs.protocol.HdfsConstants; |
| import org.apache.hadoop.hdfs.protocol.UnresolvedPathException; |
| import org.apache.hadoop.hdfs.server.common.HdfsServerConstants; |
| import org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature; |
| import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot; |
| |
| import com.google.common.base.Preconditions; |
| |
| import static org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.CURRENT_STATE_ID; |
| import static org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.ID_INTEGER_COMPARATOR; |
| |
| /** |
| * Contains INodes information resolved from a given path. |
| */ |
| public class INodesInPath { |
| public static final Log LOG = LogFactory.getLog(INodesInPath.class); |
| |
| /** |
| * @return true if path component is {@link HdfsConstants#DOT_SNAPSHOT_DIR} |
| */ |
| private static boolean isDotSnapshotDir(byte[] pathComponent) { |
| return pathComponent != null && |
| Arrays.equals(HdfsServerConstants.DOT_SNAPSHOT_DIR_BYTES, pathComponent); |
| } |
| |
| static INodesInPath fromINode(INode inode) { |
| int depth = 0, index; |
| INode tmp = inode; |
| while (tmp != null) { |
| depth++; |
| tmp = tmp.getParent(); |
| } |
| final byte[][] path = new byte[depth][]; |
| final INode[] inodes = new INode[depth]; |
| tmp = inode; |
| index = depth; |
| while (tmp != null) { |
| index--; |
| path[index] = tmp.getKey(); |
| inodes[index] = tmp; |
| tmp = tmp.getParent(); |
| } |
| return new INodesInPath(inodes, path); |
| } |
| |
| /** |
| * Given some components, create a path name. |
| * @param components The path components |
| * @param start index |
| * @param end index |
| * @return concatenated path |
| */ |
| private static String constructPath(byte[][] components, int start, int end) { |
| StringBuilder buf = new StringBuilder(); |
| for (int i = start; i < end; i++) { |
| buf.append(DFSUtil.bytes2String(components[i])); |
| if (i < end - 1) { |
| buf.append(Path.SEPARATOR); |
| } |
| } |
| return buf.toString(); |
| } |
| |
| /** |
| * Retrieve existing INodes from a path. For non-snapshot path, |
| * the number of INodes is equal to the number of path components. For |
| * snapshot path (e.g., /foo/.snapshot/s1/bar), the number of INodes is |
| * (number_of_path_components - 1). |
| * |
| * An UnresolvedPathException is always thrown when an intermediate path |
| * component refers to a symbolic link. If the final path component refers |
| * to a symbolic link then an UnresolvedPathException is only thrown if |
| * resolveLink is true. |
| * |
| * <p> |
| * Example: <br> |
| * Given the path /c1/c2/c3 where only /c1/c2 exists, resulting in the |
| * following path components: ["","c1","c2","c3"] |
| * |
| * <p> |
| * <code>getExistingPathINodes(["","c1","c2"])</code> should fill |
| * the array with [rootINode,c1,c2], <br> |
| * <code>getExistingPathINodes(["","c1","c2","c3"])</code> should |
| * fill the array with [rootINode,c1,c2,null] |
| * |
| * @param startingDir the starting directory |
| * @param components array of path component name |
| * @param resolveLink indicates whether UnresolvedLinkException should |
| * be thrown when the path refers to a symbolic link. |
| * @return the specified number of existing INodes in the path |
| */ |
| static INodesInPath resolve(final INodeDirectory startingDir, |
| final byte[][] components, final boolean resolveLink) |
| throws UnresolvedLinkException { |
| Preconditions.checkArgument(startingDir.compareTo(components[0]) == 0); |
| |
| INode curNode = startingDir; |
| int count = 0; |
| int inodeNum = 0; |
| INode[] inodes = new INode[components.length]; |
| boolean isSnapshot = false; |
| int snapshotId = CURRENT_STATE_ID; |
| |
| while (count < components.length && curNode != null) { |
| final boolean lastComp = (count == components.length - 1); |
| inodes[inodeNum++] = curNode; |
| final boolean isRef = curNode.isReference(); |
| final boolean isDir = curNode.isDirectory(); |
| final INodeDirectory dir = isDir? curNode.asDirectory(): null; |
| if (!isRef && isDir && dir.isWithSnapshot()) { |
| //if the path is a non-snapshot path, update the latest snapshot. |
| if (!isSnapshot && shouldUpdateLatestId( |
| dir.getDirectoryWithSnapshotFeature().getLastSnapshotId(), |
| snapshotId)) { |
| snapshotId = dir.getDirectoryWithSnapshotFeature().getLastSnapshotId(); |
| } |
| } else if (isRef && isDir && !lastComp) { |
| // If the curNode is a reference node, need to check its dstSnapshot: |
| // 1. if the existing snapshot is no later than the dstSnapshot (which |
| // is the latest snapshot in dst before the rename), the changes |
| // should be recorded in previous snapshots (belonging to src). |
| // 2. however, if the ref node is already the last component, we still |
| // need to know the latest snapshot among the ref node's ancestors, |
| // in case of processing a deletion operation. Thus we do not overwrite |
| // the latest snapshot if lastComp is true. In case of the operation is |
| // a modification operation, we do a similar check in corresponding |
| // recordModification method. |
| if (!isSnapshot) { |
| int dstSnapshotId = curNode.asReference().getDstSnapshotId(); |
| if (snapshotId == CURRENT_STATE_ID || // no snapshot in dst tree of rename |
| (dstSnapshotId != CURRENT_STATE_ID && |
| dstSnapshotId >= snapshotId)) { // the above scenario |
| int lastSnapshot = CURRENT_STATE_ID; |
| DirectoryWithSnapshotFeature sf; |
| if (curNode.isDirectory() && |
| (sf = curNode.asDirectory().getDirectoryWithSnapshotFeature()) != null) { |
| lastSnapshot = sf.getLastSnapshotId(); |
| } |
| snapshotId = lastSnapshot; |
| } |
| } |
| } |
| if (curNode.isSymlink() && (!lastComp || resolveLink)) { |
| final String path = constructPath(components, 0, components.length); |
| final String preceding = constructPath(components, 0, count); |
| final String remainder = |
| constructPath(components, count + 1, components.length); |
| final String link = DFSUtil.bytes2String(components[count]); |
| final String target = curNode.asSymlink().getSymlinkString(); |
| if (LOG.isDebugEnabled()) { |
| LOG.debug("UnresolvedPathException " + |
| " path: " + path + " preceding: " + preceding + |
| " count: " + count + " link: " + link + " target: " + target + |
| " remainder: " + remainder); |
| } |
| throw new UnresolvedPathException(path, preceding, remainder, target); |
| } |
| if (lastComp || !isDir) { |
| break; |
| } |
| final byte[] childName = components[count + 1]; |
| |
| // check if the next byte[] in components is for ".snapshot" |
| if (isDotSnapshotDir(childName) && dir.isSnapshottable()) { |
| // skip the ".snapshot" in components |
| count++; |
| isSnapshot = true; |
| // check if ".snapshot" is the last element of components |
| if (count == components.length - 1) { |
| break; |
| } |
| // Resolve snapshot root |
| final Snapshot s = dir.getSnapshot(components[count + 1]); |
| if (s == null) { |
| curNode = null; // snapshot not found |
| } else { |
| curNode = s.getRoot(); |
| snapshotId = s.getId(); |
| } |
| } else { |
| // normal case, and also for resolving file/dir under snapshot root |
| curNode = dir.getChild(childName, |
| isSnapshot ? snapshotId : CURRENT_STATE_ID); |
| } |
| count++; |
| } |
| if (isSnapshot && !isDotSnapshotDir(components[components.length - 1])) { |
| // for snapshot path shrink the inode array. however, for path ending with |
| // .snapshot, still keep last the null inode in the array |
| INode[] newNodes = new INode[components.length - 1]; |
| System.arraycopy(inodes, 0, newNodes, 0, newNodes.length); |
| inodes = newNodes; |
| } |
| return new INodesInPath(inodes, components, isSnapshot, snapshotId); |
| } |
| |
| private static boolean shouldUpdateLatestId(int sid, int snapshotId) { |
| return snapshotId == CURRENT_STATE_ID || (sid != CURRENT_STATE_ID && |
| ID_INTEGER_COMPARATOR.compare(snapshotId, sid) < 0); |
| } |
| |
| /** |
| * Replace an inode of the given INodesInPath in the given position. We do a |
| * deep copy of the INode array. |
| * @param pos the position of the replacement |
| * @param inode the new inode |
| * @return a new INodesInPath instance |
| */ |
| public static INodesInPath replace(INodesInPath iip, int pos, INode inode) { |
| Preconditions.checkArgument(iip.length() > 0 && pos > 0 // no for root |
| && pos < iip.length()); |
| if (iip.getINode(pos) == null) { |
| Preconditions.checkState(iip.getINode(pos - 1) != null); |
| } |
| INode[] inodes = new INode[iip.inodes.length]; |
| System.arraycopy(iip.inodes, 0, inodes, 0, inodes.length); |
| inodes[pos] = inode; |
| return new INodesInPath(inodes, iip.path, iip.isSnapshot, iip.snapshotId); |
| } |
| |
| /** |
| * Extend a given INodesInPath with a child INode. The child INode will be |
| * appended to the end of the new INodesInPath. |
| */ |
| public static INodesInPath append(INodesInPath iip, INode child, |
| byte[] childName) { |
| Preconditions.checkArgument(!iip.isSnapshot && iip.length() > 0); |
| Preconditions.checkArgument(iip.getLastINode() != null && iip |
| .getLastINode().isDirectory()); |
| INode[] inodes = new INode[iip.length() + 1]; |
| System.arraycopy(iip.inodes, 0, inodes, 0, inodes.length - 1); |
| inodes[inodes.length - 1] = child; |
| byte[][] path = new byte[iip.path.length + 1][]; |
| System.arraycopy(iip.path, 0, path, 0, path.length - 1); |
| path[path.length - 1] = childName; |
| return new INodesInPath(inodes, path, false, iip.snapshotId); |
| } |
| |
| private final byte[][] path; |
| /** |
| * Array with the specified number of INodes resolved for a given path. |
| */ |
| private final INode[] inodes; |
| /** |
| * true if this path corresponds to a snapshot |
| */ |
| private final boolean isSnapshot; |
| /** |
| * For snapshot paths, it is the id of the snapshot; or |
| * {@link Snapshot#CURRENT_STATE_ID} if the snapshot does not exist. For |
| * non-snapshot paths, it is the id of the latest snapshot found in the path; |
| * or {@link Snapshot#CURRENT_STATE_ID} if no snapshot is found. |
| */ |
| private final int snapshotId; |
| |
| private INodesInPath(INode[] inodes, byte[][] path, boolean isSnapshot, |
| int snapshotId) { |
| Preconditions.checkArgument(inodes != null && path != null); |
| this.inodes = inodes; |
| this.path = path; |
| this.isSnapshot = isSnapshot; |
| this.snapshotId = snapshotId; |
| } |
| |
| private INodesInPath(INode[] inodes, byte[][] path) { |
| this(inodes, path, false, CURRENT_STATE_ID); |
| } |
| |
| /** |
| * For non-snapshot paths, return the latest snapshot id found in the path. |
| */ |
| public int getLatestSnapshotId() { |
| Preconditions.checkState(!isSnapshot); |
| return snapshotId; |
| } |
| |
| /** |
| * For snapshot paths, return the id of the snapshot specified in the path. |
| * For non-snapshot paths, return {@link Snapshot#CURRENT_STATE_ID}. |
| */ |
| public int getPathSnapshotId() { |
| return isSnapshot ? snapshotId : CURRENT_STATE_ID; |
| } |
| |
| /** |
| * @return the i-th inode if i >= 0; |
| * otherwise, i < 0, return the (length + i)-th inode. |
| */ |
| public INode getINode(int i) { |
| if (inodes == null || inodes.length == 0) { |
| throw new NoSuchElementException("inodes is null or empty"); |
| } |
| int index = i >= 0 ? i : inodes.length + i; |
| if (index < inodes.length && index >= 0) { |
| return inodes[index]; |
| } else { |
| throw new NoSuchElementException("inodes.length == " + inodes.length); |
| } |
| } |
| |
| /** @return the last inode. */ |
| public INode getLastINode() { |
| return getINode(-1); |
| } |
| |
| byte[] getLastLocalName() { |
| return path[path.length - 1]; |
| } |
| |
| public byte[][] getPathComponents() { |
| return path; |
| } |
| |
| /** @return the full path in string form */ |
| public String getPath() { |
| return DFSUtil.byteArray2PathString(path); |
| } |
| |
| public String getParentPath() { |
| return getPath(path.length - 1); |
| } |
| |
| public String getPath(int pos) { |
| return DFSUtil.byteArray2PathString(path, 0, pos); |
| } |
| |
| /** |
| * @param offset start endpoint (inclusive) |
| * @param length number of path components |
| * @return sub-list of the path |
| */ |
| public List<String> getPath(int offset, int length) { |
| Preconditions.checkArgument(offset >= 0 && length >= 0 && offset + length |
| <= path.length); |
| ImmutableList.Builder<String> components = ImmutableList.builder(); |
| for (int i = offset; i < offset + length; i++) { |
| components.add(DFSUtil.bytes2String(path[i])); |
| } |
| return components.build(); |
| } |
| |
| public int length() { |
| return inodes.length; |
| } |
| |
| public List<INode> getReadOnlyINodes() { |
| return Collections.unmodifiableList(Arrays.asList(inodes)); |
| } |
| |
| public INode[] getINodesArray() { |
| INode[] retArr = new INode[inodes.length]; |
| System.arraycopy(inodes, 0, retArr, 0, inodes.length); |
| return retArr; |
| } |
| |
| /** |
| * @param length number of ancestral INodes in the returned INodesInPath |
| * instance |
| * @return the INodesInPath instance containing ancestral INodes. Note that |
| * this method only handles non-snapshot paths. |
| */ |
| private INodesInPath getAncestorINodesInPath(int length) { |
| Preconditions.checkArgument(length >= 0 && length < inodes.length); |
| Preconditions.checkState(!isSnapshot()); |
| final INode[] anodes = new INode[length]; |
| final byte[][] apath = new byte[length][]; |
| System.arraycopy(this.inodes, 0, anodes, 0, length); |
| System.arraycopy(this.path, 0, apath, 0, length); |
| return new INodesInPath(anodes, apath, false, snapshotId); |
| } |
| |
| /** |
| * @return an INodesInPath instance containing all the INodes in the parent |
| * path. We do a deep copy here. |
| */ |
| public INodesInPath getParentINodesInPath() { |
| return inodes.length > 1 ? getAncestorINodesInPath(inodes.length - 1) : |
| null; |
| } |
| |
| /** |
| * @return a new INodesInPath instance that only contains exisitng INodes. |
| * Note that this method only handles non-snapshot paths. |
| */ |
| public INodesInPath getExistingINodes() { |
| Preconditions.checkState(!isSnapshot()); |
| int i = 0; |
| for (; i < inodes.length; i++) { |
| if (inodes[i] == null) { |
| break; |
| } |
| } |
| INode[] existing = new INode[i]; |
| byte[][] existingPath = new byte[i][]; |
| System.arraycopy(inodes, 0, existing, 0, i); |
| System.arraycopy(path, 0, existingPath, 0, i); |
| return new INodesInPath(existing, existingPath, false, snapshotId); |
| } |
| |
| /** |
| * @return isSnapshot true for a snapshot path |
| */ |
| boolean isSnapshot() { |
| return this.isSnapshot; |
| } |
| |
| private static String toString(INode inode) { |
| return inode == null? null: inode.getLocalName(); |
| } |
| |
| @Override |
| public String toString() { |
| return toString(true); |
| } |
| |
| private String toString(boolean vaildateObject) { |
| if (vaildateObject) { |
| validate(); |
| } |
| |
| final StringBuilder b = new StringBuilder(getClass().getSimpleName()) |
| .append(": path = ").append(DFSUtil.byteArray2PathString(path)) |
| .append("\n inodes = "); |
| if (inodes == null) { |
| b.append("null"); |
| } else if (inodes.length == 0) { |
| b.append("[]"); |
| } else { |
| b.append("[").append(toString(inodes[0])); |
| for(int i = 1; i < inodes.length; i++) { |
| b.append(", ").append(toString(inodes[i])); |
| } |
| b.append("], length=").append(inodes.length); |
| } |
| b.append("\n isSnapshot = ").append(isSnapshot) |
| .append("\n snapshotId = ").append(snapshotId); |
| return b.toString(); |
| } |
| |
| void validate() { |
| // check parent up to snapshotRootIndex if this is a snapshot path |
| int i = 0; |
| if (inodes[i] != null) { |
| for(i++; i < inodes.length && inodes[i] != null; i++) { |
| final INodeDirectory parent_i = inodes[i].getParent(); |
| final INodeDirectory parent_i_1 = inodes[i-1].getParent(); |
| if (parent_i != inodes[i-1] && |
| (parent_i_1 == null || !parent_i_1.isSnapshottable() |
| || parent_i != parent_i_1)) { |
| throw new AssertionError( |
| "inodes[" + i + "].getParent() != inodes[" + (i-1) |
| + "]\n inodes[" + i + "]=" + inodes[i].toDetailString() |
| + "\n inodes[" + (i-1) + "]=" + inodes[i-1].toDetailString() |
| + "\n this=" + toString(false)); |
| } |
| } |
| } |
| if (i != inodes.length) { |
| throw new AssertionError("i = " + i + " != " + inodes.length |
| + ", this=" + toString(false)); |
| } |
| } |
| } |