| 1 | /** |
| 2 | * |
| 3 | * Copyright (C) 2011 Cloud Conscious, LLC. <info@cloudconscious.com> |
| 4 | * |
| 5 | * ==================================================================== |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | * ==================================================================== |
| 18 | */ |
| 19 | package org.jclouds.location.functions; |
| 20 | |
| 21 | import static com.google.common.base.Preconditions.checkArgument; |
| 22 | import static com.google.common.base.Preconditions.checkNotNull; |
| 23 | import static com.google.common.base.Preconditions.checkState; |
| 24 | |
| 25 | import java.net.URI; |
| 26 | import java.util.Map; |
| 27 | |
| 28 | import javax.annotation.Nullable; |
| 29 | import javax.inject.Inject; |
| 30 | import javax.inject.Singleton; |
| 31 | |
| 32 | import org.jclouds.location.Provider; |
| 33 | import org.jclouds.location.Region; |
| 34 | |
| 35 | import com.google.common.base.Function; |
| 36 | |
| 37 | /** |
| 38 | * If a mapping of regions to endpoints exists, return a uri corresponding to the name of the region |
| 39 | * (passed argument). Otherwise, return the default location. |
| 40 | * |
| 41 | * @author Adrian Cole |
| 42 | */ |
| 43 | @Singleton |
| 44 | public class RegionToEndpointOrProviderIfNull implements Function<Object, URI> { |
| 45 | private final URI defaultUri; |
| 46 | private final String defaultProvider; |
| 47 | private final Map<String, URI> regionToEndpoint; |
| 48 | |
| 49 | @Inject |
| 50 | public RegionToEndpointOrProviderIfNull(@Provider URI defaultUri, @Provider String defaultProvider, |
| 51 | @Nullable @Region Map<String, URI> regionToEndpoint) { |
| 52 | this.defaultUri = checkNotNull(defaultUri, "defaultUri"); |
| 53 | this.defaultProvider = checkNotNull(defaultProvider, "defaultProvider"); |
| 54 | this.regionToEndpoint = regionToEndpoint; |
| 55 | } |
| 56 | |
| 57 | @Override |
| 58 | public URI apply(@Nullable Object from) { |
| 59 | if (from == null || from.equals(defaultProvider)) |
| 60 | return defaultUri; |
| 61 | checkState(from.equals(defaultProvider) || regionToEndpoint != null, "requested location " + from |
| 62 | + ", but only the default location " + defaultProvider + " is configured"); |
| 63 | checkArgument(from.equals(defaultProvider) || (regionToEndpoint != null && regionToEndpoint.containsKey(from)), |
| 64 | "requested location %s, which is not in the configured locations: %s", from, regionToEndpoint); |
| 65 | return regionToEndpoint.get(from); |
| 66 | } |
| 67 | } |