java/src/main/com/google/appengine/api/labs/modules/ModulesServiceImpl.java

   1 package com.google.appengine.api.labs.modules;
   2
   3 import com.google.appengine.api.labs.modules.ModulesServicePb.GetDefaultVersionRequest;
   4 import com.google.appengine.api.labs.modules.ModulesServicePb.GetDefaultVersionResponse;
   5 import com.google.appengine.api.labs.modules.ModulesServicePb.GetHostnameRequest;
   6 import com.google.appengine.api.labs.modules.ModulesServicePb.GetHostnameResponse;
   7 import com.google.appengine.api.labs.modules.ModulesServicePb.GetModulesRequest;
   8 import com.google.appengine.api.labs.modules.ModulesServicePb.GetModulesResponse;
   9 import com.google.appengine.api.labs.modules.ModulesServicePb.GetNumInstancesRequest;
  10 import com.google.appengine.api.labs.modules.ModulesServicePb.GetNumInstancesResponse;
  11 import com.google.appengine.api.labs.modules.ModulesServicePb.GetVersionsRequest;
  12 import com.google.appengine.api.labs.modules.ModulesServicePb.GetVersionsResponse;
  13 import com.google.appengine.api.labs.modules.ModulesServicePb.ModulesServiceError.ErrorCode;
  14 import com.google.appengine.api.labs.modules.ModulesServicePb.SetNumInstancesRequest;
  15 import com.google.appengine.api.labs.modules.ModulesServicePb.StartModuleRequest;
  16 import com.google.appengine.api.labs.modules.ModulesServicePb.StartModuleResponse;
  17 import com.google.appengine.api.labs.modules.ModulesServicePb.StopModuleRequest;
  18 import com.google.appengine.api.labs.modules.ModulesServicePb.StopModuleResponse;
  19 import com.google.apphosting.api.ApiProxy;
  20 import com.google.apphosting.api.ApiProxy.Environment;
  21 import com.google.common.base.Pair;
  22 import com.google.common.base.Splitter;
  23 import com.google.common.collect.Sets;
  24 import com.google.protobuf.InvalidProtocolBufferException;
  25 import com.google.protobuf.Message;
  26
  27 import java.util.List;
  28 import java.util.Map;
  29 import java.util.Set;
  30
  31 class ModulesServiceImpl implements ModulesService {
  32   protected static final String PACKAGE = "modules";
  33
  34   /**
  35    * Environment attribute key where the instance id is stored.
  36    *
  37    * @see ModulesService#getCurrentInstanceId()
  38    */
  39   private static final String INSTANCE_ID_ENV_ATTRIBUTE = "com.google.appengine.instance.id";
  40
  41   private Pair<String, String> getCurrentModuleAndVersion() {
  42     Environment env = ApiProxy.getCurrentEnvironment();
  43     String majorVersion = Splitter.on('.').split(env.getVersionId()).iterator().next();
  44     if (majorVersion.contains(":")) {
  45       List<String> result = Splitter.on(':').splitToList(majorVersion);
  46       return Pair.of(result.get(0), result.get(1));
  47     } else {
  48       return Pair.of("default", majorVersion);
  49     }
  50   }
  51
  52   @Override
  53   public String getCurrentModule() {
  54     return getCurrentModuleAndVersion().first;
  55   }
  56
  57   @Override
  58   public String getCurrentVersion() {
  59     return getCurrentModuleAndVersion().second;
  60   }
  61
  62   private static Map<String, Object> getThreadLocalAttributes() {
  63     return ApiProxy.getCurrentEnvironment().getAttributes();
  64   }
  65
  66   @Override
  67   public String getCurrentInstanceId() {
  68     Map<String, Object> env = getThreadLocalAttributes();
  69     if (!env.containsKey(INSTANCE_ID_ENV_ATTRIBUTE)) {
  70       throw new ModulesException("No valid instance id for this instance.");
  71     }
  72     String instanceId = (String) getThreadLocalAttributes().get(INSTANCE_ID_ENV_ATTRIBUTE);
  73     if (instanceId == null) {
  74       throw new ModulesException("No valid instance id for this instance.");
  75     }
  76     return instanceId;
  77   }
  78
  79   private static void makeSyncCall(String method, Message.Builder request, Message.Builder response)
  80       throws ModulesException {
  81     byte[] responseBytes;
  82     try {
  83       responseBytes = ApiProxy.makeSyncCall(PACKAGE, method, request.build().toByteArray());
  84       response.mergeFrom(responseBytes);
  85     } catch (ApiProxy.ApplicationException e) {
  86       switch(ErrorCode.valueOf(e.getApplicationError())) {
  87         case INVALID_MODULE:
  88           throw new InvalidModuleException("Given module is not known.");
  89         case INVALID_VERSION:
  90           throw new InvalidVersionException("Given module version is not known.");
  91         case INVALID_INSTANCES:
  92           throw new InvalidInstanceException("Given instances value is invalid.");
  93         case UNEXPECTED_STATE:
  94           if (method.equals("StartModule")) {
  95             throw new ModuleAlreadyStartedException("Given module version is already started.");
  96           } else if (method.equals("StopModule")) {
  97             throw new ModuleAlreadyStoppedException("Given module version is already stopped.");
  98           }
  99         default:
 100           throw new ModulesException("Unknown error occurred.");
 101       }
 102     } catch (InvalidProtocolBufferException e) {
 103       throw new RuntimeException("Internal logic error: Response PB could not be parsed.", e);
 104     }
 105   }
 106
 107   @Override
 108   public Set<String> getModules() {
 109     GetModulesResponse.Builder response = GetModulesResponse.newBuilder();
 110     makeSyncCall("GetModules", GetModulesRequest.newBuilder(), response);
 111     return Sets.newHashSet(response.getModuleList());
 112   }
 113
 114   @Override
 115   public Set<String> getVersions(String module) {
 116     GetVersionsRequest.Builder request = GetVersionsRequest.newBuilder();
 117     request.setModule(module);
 118     GetVersionsResponse.Builder response = GetVersionsResponse.newBuilder();
 119     makeSyncCall("GetVersions", request, response);
 120     return Sets.newHashSet(response.getVersionList());
 121   }
 122
 123   @Override
 124   public String getDefaultVersion(String module) {
 125     GetDefaultVersionRequest.Builder request = GetDefaultVersionRequest.newBuilder();
 126     request.setModule(module);
 127     GetDefaultVersionResponse.Builder response = GetDefaultVersionResponse.newBuilder();
 128     makeSyncCall("GetDefaultVersion", request, response);
 129     return response.getVersion();
 130   }
 131
 132   @Override
 133   public long getNumInstances(String module, String version) {
 134     GetNumInstancesRequest.Builder request = GetNumInstancesRequest.newBuilder();
 135     request.setModule(module);
 136     request.setVersion(version);
 137     GetNumInstancesResponse.Builder response = GetNumInstancesResponse.newBuilder();
 138     makeSyncCall("GetNumInstances", request, response);
 139     return response.getInstances();
 140   }
 141
 142   @Override
 143   public void setNumInstances(String module, String version, long instances) {
 144     SetNumInstancesRequest.Builder request = SetNumInstancesRequest.newBuilder();
 145     request.setModule(module);
 146     request.setVersion(version);
 147     request.setInstances(instances);
 148     makeSyncCall("SetNumInstances", request, SetNumInstancesRequest.newBuilder());
 149   }
 150
 151   @Override
 152   public void startModule(String module, String version) {
 153     StartModuleRequest.Builder request = StartModuleRequest.newBuilder();
 154     request.setModule(module);
 155     request.setVersion(version);
 156     makeSyncCall("StartModule", request, StartModuleResponse.newBuilder());
 157   }
 158
 159   @Override
 160   public void stopModule(String module, String version) {
 161     StopModuleRequest.Builder request = StopModuleRequest.newBuilder();
 162     request.setModule(module);
 163     request.setVersion(version);
 164     makeSyncCall("StopModule", request, StopModuleResponse.newBuilder());
 165   }
 166
 167   private String getHostname(GetHostnameRequest.Builder request) {
 168     GetHostnameResponse.Builder response = GetHostnameResponse.newBuilder();
 169     makeSyncCall("GetHostname", request, response);
 170     return response.getHostname();
 171   }
 172
 173   private GetHostnameRequest.Builder newGetHostnameRequestBuilder(String module, String version) {
 174     GetHostnameRequest.Builder builder = GetHostnameRequest.newBuilder();
 175     if (module != null) {
 176       builder.setModule(module);
 177     }
 178     if (version != null) {
 179       builder.setVersion(version);
 180     }
 181     return builder;
 182   }
 183
 184   @Override
 185   public String getModuleHostname(String module, String version) {
 186     GetHostnameRequest.Builder requestBuilder = newGetHostnameRequestBuilder(module, version);
 187     return getHostname(requestBuilder);
 188   }
 189
 190   @Override
 191   public String getModuleHostname(String module, String version, int instance) {
 192     GetHostnameRequest.Builder requestBuilder = newGetHostnameRequestBuilder(module, version);
 193     requestBuilder.setInstance(Integer.toString(instance));
 194     return getHostname(requestBuilder);
 195   }
 196
 197   ModulesServiceImpl() { }
 198 }