org.apache.hadoop.hbase.security.access.Permission.java Source code

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Here is the source code for org.apache.hadoop.hbase.security.access.Permission.java

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/*
 * 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.hbase.security.access;

import com.google.common.collect.Maps;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.io.VersionedWritable;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.util.Arrays;
import java.util.Map;

/**
 * Base permissions instance representing the ability to perform a given set
 * of actions.
 *
 * @see TablePermission
 */
public class Permission extends VersionedWritable {
    protected static final byte VERSION = 0;

    public enum Action {
        READ('R'), WRITE('W'), EXEC('X'), CREATE('C'), ADMIN('A');

        private byte code;

        Action(char code) {
            this.code = (byte) code;
        }

        public byte code() {
            return code;
        }
    }

    private static final Log LOG = LogFactory.getLog(Permission.class);
    protected static final Map<Byte, Action> ACTION_BY_CODE = Maps.newHashMap();

    protected Action[] actions;

    static {
        for (Action a : Action.values()) {
            ACTION_BY_CODE.put(a.code(), a);
        }
    }

    /** Empty constructor for Writable implementation.  <b>Do not use.</b> */
    public Permission() {
        super();
    }

    public Permission(Action... assigned) {
        if (assigned != null && assigned.length > 0) {
            actions = Arrays.copyOf(assigned, assigned.length);
        }
    }

    public Permission(byte[] actionCodes) {
        if (actionCodes != null) {
            Action acts[] = new Action[actionCodes.length];
            int j = 0;
            for (int i = 0; i < actionCodes.length; i++) {
                byte b = actionCodes[i];
                Action a = ACTION_BY_CODE.get(b);
                if (a == null) {
                    LOG.error("Ignoring unknown action code '" + Bytes.toStringBinary(new byte[] { b }) + "'");
                    continue;
                }
                acts[j++] = a;
            }
            this.actions = Arrays.copyOf(acts, j);
        }
    }

    public Action[] getActions() {
        return actions;
    }

    public boolean implies(Action action) {
        if (this.actions != null) {
            for (Action a : this.actions) {
                if (a == action) {
                    return true;
                }
            }
        }

        return false;
    }

    @Override
    public boolean equals(Object obj) {
        if (!(obj instanceof Permission)) {
            return false;
        }
        Permission other = (Permission) obj;
        // check actions
        if (actions == null && other.getActions() == null) {
            return true;
        } else if (actions != null && other.getActions() != null) {
            Action[] otherActions = other.getActions();
            if (actions.length != otherActions.length) {
                return false;
            }

            outer: for (Action a : actions) {
                for (Action oa : otherActions) {
                    if (a == oa)
                        continue outer;
                }
                return false;
            }
            return true;
        }

        return false;
    }

    @Override
    public int hashCode() {
        final int prime = 37;
        int result = 23;
        for (Action a : actions) {
            result = prime * result + a.code();
        }
        return result;
    }

    public String toString() {
        StringBuilder str = new StringBuilder("[Permission: ").append("actions=");
        if (actions != null) {
            for (int i = 0; i < actions.length; i++) {
                if (i > 0)
                    str.append(",");
                if (actions[i] != null)
                    str.append(actions[i].toString());
                else
                    str.append("NULL");
            }
        }
        str.append("]");

        return str.toString();
    }

    /** @return the object version number */
    public byte getVersion() {
        return VERSION;
    }

    @Override
    public void readFields(DataInput in) throws IOException {
        super.readFields(in);
        int length = (int) in.readByte();
        if (length > 0) {
            actions = new Action[length];
            for (int i = 0; i < length; i++) {
                byte b = in.readByte();
                Action a = ACTION_BY_CODE.get(b);
                if (a == null) {
                    throw new IOException(
                            "Unknown action code '" + Bytes.toStringBinary(new byte[] { b }) + "' in input");
                }
                this.actions[i] = a;
            }
        } else {
            actions = new Action[0];
        }
    }

    @Override
    public void write(DataOutput out) throws IOException {
        super.write(out);
        out.writeByte(actions != null ? actions.length : 0);
        if (actions != null) {
            for (Action a : actions) {
                out.writeByte(a.code());
            }
        }
    }
}