hyper.momitor.util.etcd.HMEtcdClientImpl.java Source code

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Here is the source code for hyper.momitor.util.etcd.HMEtcdClientImpl.java

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/*
 * Copyright 2013 Diwaker Gupta
 *
 * 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 hyper.momitor.util.etcd;

import java.io.IOException;
import java.io.InputStreamReader;
import java.util.Map;

import com.fasterxml.jackson.databind.DeserializationFeature;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.common.base.Charsets;
import com.google.common.base.Optional;
import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.common.collect.ImmutableMap;
import com.google.common.io.CharStreams;

import retrofit.ErrorHandler;
import retrofit.RestAdapter;
import retrofit.RetrofitError;
import retrofit.client.Client;
import retrofit.converter.JacksonConverter;

final class HMEtcdClientImpl implements HMEtcdClient {
    private static final ObjectMapper objectMapper = new ObjectMapper()
            .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
    private final HMEtcdApi etcd;

    HMEtcdClientImpl(final Optional<Client> client, final String server) {
        RestAdapter.Builder builder = new RestAdapter.Builder().setConverter(new JacksonConverter(objectMapper))
                .setEndpoint(server).setErrorHandler(new EtcdErrorHandler());
        if (client.isPresent()) {
            builder.setClient(client.get());
        }
        etcd = builder.build().create(HMEtcdApi.class);
    }

    @Override
    public String version() throws HMEtcdException {
        try (InputStreamReader reader = new InputStreamReader(etcd.version().getBody().in(), Charsets.UTF_8)) {
            return CharStreams.toString(reader);
        } catch (IOException e) {
            return "ERROR: " + e.getMessage();
        }
    }

    @Override
    public String get(final String key) throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(key));
        return etcd.get(key).getNode().getValue();
    }

    @Override
    public void set(final String key, final String value) throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(key));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(value));
        etcd.set(key, value, null, null, null);
    }

    @Override
    public void set(final String key, final String value, final int ttl) throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(key));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(value));
        Preconditions.checkArgument(ttl > 0);
        etcd.set(key, value, ttl, null, null);
    }

    @Override
    public void delete(final String key) throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(key));
        etcd.delete(key);
    }

    @Override
    public Map<String, String> list(final String path) throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(path));
        ImmutableMap.Builder<String, String> builder = ImmutableMap.builder();
        if (etcd.get(path).getNode().getNodes() != null) {
            for (HMEtcdResponse.Node node : etcd.get(path).getNode().getNodes()) {
                builder.put(node.getKey(), node.getValue());
            }
        }
        return builder.build();
    }

    @Override
    public void compareAndSwap(final String key, final String oldValue, final String newValue)
            throws HMEtcdException {
        Preconditions.checkArgument(!Strings.isNullOrEmpty(key));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(oldValue));
        Preconditions.checkArgument(!Strings.isNullOrEmpty(newValue));
        Preconditions.checkArgument(!oldValue.equals(newValue));

        HMEtcdResponse response = etcd.set(key, newValue, null, null, oldValue);
        response.getNode().getValue();
    }

    private static final class EtcdErrorHandler implements ErrorHandler {
        @Override
        public Throwable handleError(final RetrofitError cause) {
            if (cause.getResponse() == null) {
                return cause;
            }
            return (HMEtcdException) cause.getBodyAs(HMEtcdException.class);
        }
    }
}