| // Copyright 2017 JanusGraph Authors |
| // |
| // Licensed 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.janusgraph.diskstorage.hbase2; |
| |
| import org.apache.hadoop.hbase.util.VersionInfo; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class HBaseCompatLoader { |
| |
| private static final Logger log = LoggerFactory.getLogger(HBaseCompatLoader.class); |
| |
| private static final String DEFAULT_HBASE_COMPAT_VERSION = "1.2"; |
| |
| private static final String HBASE_VERSION_2_STRING = "2."; |
| |
| private static final String DEFAULT_HBASE_COMPAT_CLASS_NAME = |
| "org.janusgraph.diskstorage.hbase2.HBaseCompat2_0"; |
| |
| private static final String[] HBASE_SUPPORTED_VERSIONS = |
| new String[] { "0.98", "1.0", "1.1", "1.2", "1.3", "2.0" }; |
| |
| private static HBaseCompat cachedCompat; |
| |
| public synchronized static HBaseCompat getCompat(String classOverride) { |
| |
| if (null != cachedCompat) { |
| log.debug("Returning cached HBase compatibility layer: {}", cachedCompat); |
| return cachedCompat; |
| } |
| |
| HBaseCompat compat; |
| String className = null; |
| String classNameSource = null; |
| |
| if (null != classOverride) { |
| className = classOverride; |
| classNameSource = "from explicit configuration"; |
| } else { |
| String hbaseVersion = VersionInfo.getVersion(); |
| for (String supportedVersion : HBASE_SUPPORTED_VERSIONS) { |
| if (hbaseVersion.startsWith(supportedVersion + ".")) { |
| if (hbaseVersion.startsWith(HBASE_VERSION_2_STRING)) { |
| // All HBase 2.x maps to HBaseCompat2_0. |
| className = DEFAULT_HBASE_COMPAT_CLASS_NAME; |
| } |
| else { |
| className = "org.janusgraph.diskstorage.hbase2.HBaseCompat" + supportedVersion.replaceAll("\\.", "_"); |
| } |
| classNameSource = "supporting runtime HBase version " + hbaseVersion; |
| break; |
| } |
| } |
| if (null == className) { |
| log.info("The HBase version {} is not explicitly supported by JanusGraph. " + |
| "Loading JanusGraph's compatibility layer for its most recent supported HBase version ({})", |
| hbaseVersion, DEFAULT_HBASE_COMPAT_VERSION); |
| className = DEFAULT_HBASE_COMPAT_CLASS_NAME; |
| classNameSource = " by default"; |
| } |
| } |
| |
| final String errTemplate = " when instantiating HBase compatibility class " + className; |
| |
| try { |
| compat = (HBaseCompat)Class.forName(className).newInstance(); |
| log.info("Instantiated HBase compatibility layer {}: {}", classNameSource, compat.getClass().getCanonicalName()); |
| } catch (IllegalAccessException e) { |
| throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e); |
| } catch (InstantiationException e) { |
| throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e); |
| } catch (ClassNotFoundException e) { |
| throw new RuntimeException(e.getClass().getSimpleName() + errTemplate, e); |
| } |
| |
| return cachedCompat = compat; |
| } |
| } |