java/src/main/com/google/appengine/tools/admin/AppYamlTranslator.java

   1 // Copyright 2008 Google Inc. All Rights Reserved.
   2
   3 package com.google.appengine.tools.admin;
   4
   5 import com.google.appengine.tools.info.Version;
   6 import com.google.apphosting.utils.config.AppEngineConfigException;
   7 import com.google.apphosting.utils.config.AppEngineWebXml;
   8 import com.google.apphosting.utils.config.AppEngineWebXml.AdminConsolePage;
   9 import com.google.apphosting.utils.config.AppEngineWebXml.ApiConfig;
  10 import com.google.apphosting.utils.config.AppEngineWebXml.ErrorHandler;
  11 import com.google.apphosting.utils.config.AppEngineWebXml.Pagespeed;
  12 import com.google.apphosting.utils.config.AppEngineWebXml.VmHealthCheck;
  13 import com.google.apphosting.utils.config.BackendsXml;
  14 import com.google.apphosting.utils.config.WebXml;
  15 import com.google.apphosting.utils.config.WebXml.SecurityConstraint;
  16 import com.google.apphosting.utils.glob.ConflictResolver;
  17 import com.google.apphosting.utils.glob.Glob;
  18 import com.google.apphosting.utils.glob.GlobFactory;
  19 import com.google.apphosting.utils.glob.GlobIntersector;
  20 import com.google.apphosting.utils.glob.LongestPatternConflictResolver;
  21 import com.google.common.collect.Maps;
  22
  23 import net.sourceforge.yamlbeans.YamlConfig;
  24 import net.sourceforge.yamlbeans.YamlException;
  25 import net.sourceforge.yamlbeans.YamlWriter;
  26
  27 import java.io.StringWriter;
  28 import java.util.ArrayList;
  29 import java.util.Collection;
  30 import java.util.Collections;
  31 import java.util.HashMap;
  32 import java.util.List;
  33 import java.util.Map;
  34 import java.util.Set;
  35
  36 /**
  37  * Generates {@code app.yaml} files suitable for uploading as part of
  38  * a Google App Engine application.
  39  *
  40  */
  41 public class AppYamlTranslator {
  42   private static final String NO_API_VERSION = "none";
  43
  44   private static final ConflictResolver RESOLVER =
  45       new LongestPatternConflictResolver();
  46
  47   private static final String DYNAMIC_PROPERTY = "dynamic";
  48   private static final String STATIC_PROPERTY = "static";
  49   private static final String WELCOME_FILES = "welcome";
  50   private static final String TRANSPORT_GUARANTEE_PROPERTY = "transportGuarantee";
  51   private static final String REQUIRED_ROLE_PROPERTY = "requiredRole";
  52   private static final String EXPIRATION_PROPERTY = "expiration";
  53   private static final String HTTP_HEADERS_PROPERTY = "http_headers";
  54   private static final String API_ENDPOINT_REGEX = "/_ah/spi/*";
  55
  56   private static final String[] PROPERTIES = new String[] {
  57     DYNAMIC_PROPERTY,
  58     STATIC_PROPERTY,
  59     WELCOME_FILES,
  60     TRANSPORT_GUARANTEE_PROPERTY,
  61     REQUIRED_ROLE_PROPERTY,
  62     EXPIRATION_PROPERTY,
  63   };
  64
  65   private static final int MAX_HANDLERS = 100;
  66
  67   private final AppEngineWebXml appEngineWebXml;
  68   private final WebXml webXml;
  69   private final BackendsXml backendsXml;
  70   private final String apiVersion;
  71   private final Set<String> staticFiles;
  72   private final String runtime;
  73   private final Version sdkVersion;
  74
  75   public AppYamlTranslator(AppEngineWebXml appEngineWebXml,
  76                            WebXml webXml,
  77                            BackendsXml backendsXml,
  78                            String apiVersion,
  79                            Set<String> staticFiles,
  80                            ApiConfig apiConfig,
  81                            String runtime,
  82                            Version sdkVersion) {
  83     this.appEngineWebXml = appEngineWebXml;
  84     this.webXml = webXml;
  85     this.backendsXml = backendsXml;
  86     this.apiVersion = apiVersion;
  87     this.staticFiles = staticFiles;
  88     this.runtime = runtime;
  89     this.sdkVersion = sdkVersion;
  90   }
  91
  92   public String getYaml() {
  93     StringBuilder builder = new StringBuilder();
  94     translateAppEngineWebXml(builder);
  95     translateApiVersion(builder);
  96     translateWebXml(builder);
  97     return builder.toString();
  98   }
  99
 100   private void appendIfNotNull(StringBuilder builder, String tag, Object value) {
 101     if (value != null) {
 102       builder.append(tag);
 103       builder.append(value);
 104       builder.append("\n");
 105     }
 106   }
 107
 108   private void translateAppEngineWebXml(StringBuilder builder) {
 109     builder.append("application: '" + appEngineWebXml.getAppId() + "'\n");
 110     builder.append("runtime: " + runtime + "\n");
 111     if (appEngineWebXml.getUseVm()) {
 112       builder.append("vm: True\n");
 113     }
 114
 115     if (appEngineWebXml.getSourceLanguage() != null) {
 116       builder.append("source_language: '" + appEngineWebXml.getSourceLanguage() + "'\n");
 117     }
 118
 119     if (appEngineWebXml.getMajorVersionId() != null) {
 120       builder.append("version: '" + appEngineWebXml.getMajorVersionId() + "'\n");
 121     }
 122
 123     if (appEngineWebXml.getModule() != null) {
 124       builder.append("module: '" + appEngineWebXml.getModule() + "'\n");
 125     }
 126
 127     if (appEngineWebXml.getInstanceClass() != null) {
 128       builder.append("instance_class: " + appEngineWebXml.getInstanceClass() + "\n");
 129     }
 130
 131     if (!appEngineWebXml.getAutomaticScaling().isEmpty()) {
 132       builder.append("automatic_scaling:\n");
 133       AppEngineWebXml.AutomaticScaling settings = appEngineWebXml.getAutomaticScaling();
 134       appendIfNotNull(builder, "  min_pending_latency: ", settings.getMinPendingLatency());
 135       appendIfNotNull(builder, "  max_pending_latency: ", settings.getMaxPendingLatency());
 136       appendIfNotNull(builder, "  min_idle_instances: ", settings.getMinIdleInstances());
 137       appendIfNotNull(builder, "  max_idle_instances: ", settings.getMaxIdleInstances());
 138       appendIfNotNull(builder, "  max_concurrent_requests: ", settings.getMaxConcurrentRequests());
 139     }
 140
 141     if (!appEngineWebXml.getManualScaling().isEmpty()) {
 142       builder.append("manual_scaling:\n");
 143       AppEngineWebXml.ManualScaling settings = appEngineWebXml.getManualScaling();
 144       builder.append("  instances: " + settings.getInstances() + "\n");
 145     }
 146
 147     if (!appEngineWebXml.getBasicScaling().isEmpty()) {
 148       builder.append("basic_scaling:\n");
 149       AppEngineWebXml.BasicScaling settings = appEngineWebXml.getBasicScaling();
 150       builder.append("  max_instances: " + settings.getMaxInstances() + "\n");
 151       appendIfNotNull(builder, "  idle_timeout: ", settings.getIdleTimeout());
 152     }
 153
 154     Collection<String> services = appEngineWebXml.getInboundServices();
 155     if (!services.isEmpty()) {
 156       builder.append("inbound_services:\n");
 157       for (String service : services) {
 158         builder.append("- " + service + "\n");
 159       }
 160     }
 161
 162     if (appEngineWebXml.getPrecompilationEnabled()) {
 163       builder.append("derived_file_type:\n");
 164       builder.append("- java_precompiled\n");
 165     }
 166
 167     if (appEngineWebXml.getThreadsafe()) {
 168       builder.append("threadsafe: True\n");
 169     }
 170
 171     if (appEngineWebXml.getAutoIdPolicy() != null) {
 172       builder.append("auto_id_policy: " + appEngineWebXml.getAutoIdPolicy() + "\n");
 173     } else {
 174       builder.append("auto_id_policy: default\n");
 175     }
 176
 177     if (appEngineWebXml.getCodeLock()) {
 178       builder.append("code_lock: True\n");
 179     }
 180
 181     List<AdminConsolePage> adminConsolePages = appEngineWebXml.getAdminConsolePages();
 182     if (!adminConsolePages.isEmpty()) {
 183       builder.append("admin_console:\n");
 184       builder.append("  pages:\n");
 185       for (AdminConsolePage page : adminConsolePages) {
 186         builder.append("  - name: " + page.getName() + "\n");
 187         builder.append("    url: " + page.getUrl() + "\n");
 188       }
 189     }
 190
 191     List<ErrorHandler> errorHandlers = appEngineWebXml.getErrorHandlers();
 192     if (!errorHandlers.isEmpty()) {
 193       builder.append("error_handlers:\n");
 194       for (ErrorHandler handler : errorHandlers) {
 195         String fileName = handler.getFile();
 196         if (!fileName.startsWith("/")) {
 197           fileName = "/" + fileName;
 198         }
 199         if (!staticFiles.contains("__static__" + fileName)) {
 200           throw new AppEngineConfigException("No static file found for error handler: "
 201               + fileName + ", out of " + staticFiles);
 202         }
 203         builder.append("- file: __static__" + fileName + "\n");
 204         if (handler.getErrorCode() != null) {
 205           builder.append("  error_code: " + handler.getErrorCode() + "\n");
 206         }
 207         String mimeType = webXml.getMimeTypeForPath(handler.getFile());
 208         if (mimeType != null) {
 209           builder.append("  mime_type: " + mimeType + "\n");
 210         }
 211       }
 212     }
 213
 214     if (backendsXml != null) {
 215       builder.append(backendsXml.toYaml());
 216     }
 217
 218     ApiConfig apiConfig = appEngineWebXml.getApiConfig();
 219     if (apiConfig != null) {
 220       builder.append("api_config:\n");
 221       builder.append("  url: " + apiConfig.getUrl() + "\n");
 222       builder.append("  script: unused\n");
 223     }
 224
 225     if (appEngineWebXml.getPagespeed() != null) {
 226       builder.append("pagespeed:\n");
 227       appendPagespeed(appEngineWebXml.getPagespeed(), builder, 2);
 228     }
 229
 230     if (appEngineWebXml.getUseVm()) {
 231       appendEnvVariables(appEngineWebXml.getEnvironmentVariables(), builder);
 232       appendVmSettings(appEngineWebXml.getVmSettings(), builder);
 233       appendVmHealthCheck(appEngineWebXml.getVmHealthCheck(), builder);
 234     }
 235   }
 236
 237   /**
 238    * Appends the given VM Settings as YAML to the given StringBuilder.
 239    *
 240    * @param vmSettings The vm settings map to append as YAML.
 241    * @param builder The StringBuilder to append to.
 242    */
 243   private void appendEnvVariables(Map<String, String> envVariables, StringBuilder builder) {
 244     if (envVariables.size() > 0) {
 245       builder.append("env_variables:\n");
 246       for (Map.Entry<String, String> envVariable : envVariables.entrySet()) {
 247         String k = envVariable.getKey();
 248         String v = envVariable.getValue();
 249         builder.append("  ").append(yamlQuote(k)).append(": ").append(yamlQuote(v)).append("\n");
 250       }
 251     }
 252   }
 253
 254   /**
 255    * Appends the given VM Settings as YAML to the given StringBuilder.
 256    *
 257    * @param vmSettings The vm settings map to append as YAML.
 258    * @param builder The StringBuilder to append to.
 259    */
 260   private void appendVmSettings(Map<String, String> vmSettings, StringBuilder builder) {
 261     builder.append("vm_settings:\n");
 262     if (vmSettings == null || !vmSettings.containsKey("image")) {
 263       if (sdkVersion != null && sdkVersion.getRelease() != null) {
 264         builder.append("  'image': " + yamlQuote(sdkVersion.getRelease()) + "\n");
 265       }
 266     }
 267     if (vmSettings != null) {
 268       for (Map.Entry<String, String> setting : vmSettings.entrySet()) {
 269         builder.append(
 270             "  " + yamlQuote(setting.getKey()) + ": " + yamlQuote(setting.getValue()) + "\n");
 271       }
 272     }
 273   }
 274
 275   private void appendVmHealthCheck(VmHealthCheck vmHealthCheck, StringBuilder builder) {
 276     builder.append("vm_health_check:\n");
 277     if (vmHealthCheck.getEnableHealthCheck()) {
 278       builder.append("  enable_health_check: True\n");
 279     } else {
 280       builder.append("  enable_health_check: False\n");
 281     }
 282
 283     appendIfNotNull(builder, "  check_interval_sec: ", vmHealthCheck.getCheckIntervalSec());
 284     appendIfNotNull(builder, "  timeout_sec: ", vmHealthCheck.getTimeoutSec());
 285     appendIfNotNull(builder, "  unhealthy_threshold: ", vmHealthCheck.getUnhealthyThreshold());
 286     appendIfNotNull(builder, "  healthy_threshold: ", vmHealthCheck.getHealthyThreshold());
 287     appendIfNotNull(builder, "  restart_threshold: ", vmHealthCheck.getRestartThreshold());
 288     appendIfNotNull(builder, "  host: ", vmHealthCheck.getHost());
 289   }
 290
 291   /**
 292    * Append the given Pagespeed node as YAML to the given StringBuilder.
 293    * @param pagespeed The Pagespeed instance to append as YAML.
 294    * @param builder The StringBuilder to append to.
 295    * @param indent The number of spaces to indent the pagespeed YAML.
 296    */
 297   public static void appendPagespeed(Pagespeed pagespeed, StringBuilder builder, int indent) {
 298     if (pagespeed != null && !pagespeed.isEmpty()) {
 299       Map<String, List<String>> config = Maps.newTreeMap();
 300       putListInMapIfNotEmpty(config, "url_blacklist", pagespeed.getUrlBlacklist());
 301       putListInMapIfNotEmpty(config, "domains_to_rewrite", pagespeed.getDomainsToRewrite());
 302       putListInMapIfNotEmpty(config, "enabled_rewriters", pagespeed.getEnabledRewriters());
 303       putListInMapIfNotEmpty(config, "disabled_rewriters", pagespeed.getDisabledRewriters());
 304       appendObjectAsYaml(builder, config, indent);
 305     }
 306   }
 307
 308   /**
 309    * Adds the list to the given map, using the specified name, if the list is non-null and not
 310    * empty.
 311    */
 312   private static void putListInMapIfNotEmpty(Map<String, List<String>> map, String name,
 313       List<String> values) {
 314     if (values != null && !values.isEmpty()) {
 315       map.put(name, values);
 316     }
 317   }
 318
 319   /**
 320    * Appends the given collection to the StringBuilder as YAML, indenting each emitted line by
 321    * numIndentSpaces.
 322    */
 323   private static void appendObjectAsYaml(
 324       StringBuilder builder, Object collection, int numIndentSpaces) {
 325     StringBuilder prefixBuilder = new StringBuilder();
 326     for (int i = 0; i < numIndentSpaces; ++i) {
 327       prefixBuilder.append(' ');
 328     }
 329     final String indentPrefix = prefixBuilder.toString();
 330
 331     StringWriter stringWriter = new StringWriter();
 332     YamlConfig yamlConfig = new YamlConfig();
 333     yamlConfig.writeConfig.setIndentSize(2);
 334     yamlConfig.writeConfig.setWriteRootTags(false);
 335
 336     YamlWriter writer = new YamlWriter(stringWriter, yamlConfig);
 337     try {
 338       writer.write(collection);
 339       writer.close();
 340     } catch (YamlException e) {
 341       throw new AppEngineConfigException("Unable to generate YAML.", e);
 342     }
 343
 344     for (String line : stringWriter.toString().split("\n")) {
 345       builder.append(indentPrefix);
 346       builder.append(line);
 347       builder.append("\n");
 348     }
 349   }
 350
 351   /**
 352    * Surrounds the provided string with single quotes, escaping any single
 353    * quotes in the string by replacing them with ''.
 354    */
 355   private String yamlQuote(String str) {
 356     return "'" + str.replace("'", "''") + "'";
 357   }
 358
 359   private void translateApiVersion(StringBuilder builder) {
 360     if (apiVersion == null) {
 361       builder.append("api_version: '" + NO_API_VERSION + "'\n");
 362     } else {
 363       builder.append("api_version: '" + apiVersion + "'\n");
 364     }
 365   }
 366
 367   private void translateWebXml(StringBuilder builder) {
 368     builder.append("handlers:\n");
 369
 370     AbstractHandlerGenerator staticGenerator = null;
 371     if (staticFiles.isEmpty()) {
 372       staticGenerator = new EmptyHandlerGenerator();
 373     } else {
 374       staticGenerator = new StaticHandlerGenerator(appEngineWebXml.getPublicRoot());
 375     }
 376
 377     DynamicHandlerGenerator dynamicGenerator =
 378         new DynamicHandlerGenerator(webXml.getFallThroughToRuntime());
 379     if (staticGenerator.size() + dynamicGenerator.size() > MAX_HANDLERS) {
 380       dynamicGenerator = new DynamicHandlerGenerator(true);
 381     }
 382
 383     staticGenerator.translate(builder);
 384     dynamicGenerator.translate(builder);
 385   }
 386
 387   class StaticHandlerGenerator extends AbstractHandlerGenerator {
 388     private final String root;
 389
 390     public StaticHandlerGenerator(String root) {
 391       this.root = root;
 392     }
 393
 394     @Override
 395     protected Map<String, Object> getWelcomeProperties() {
 396       List<String> staticWelcomeFiles = new ArrayList<String>();
 397       for (String welcomeFile : webXml.getWelcomeFiles()) {
 398         for (String staticFile : staticFiles) {
 399           if (staticFile.endsWith("/" + welcomeFile)) {
 400             staticWelcomeFiles.add(welcomeFile);
 401             break;
 402           }
 403         }
 404       }
 405       return Collections.<String,Object>singletonMap(WELCOME_FILES, staticWelcomeFiles);
 406     }
 407
 408     @Override
 409     protected void addPatterns(GlobIntersector intersector) {
 410       List<AppEngineWebXml.StaticFileInclude> includes = appEngineWebXml.getStaticFileIncludes();
 411       if (includes.isEmpty()) {
 412         intersector.addGlob(GlobFactory.createGlob("/*", STATIC_PROPERTY, true));
 413       } else {
 414         for (AppEngineWebXml.StaticFileInclude include : includes) {
 415           String pattern = include.getPattern().replaceAll("\\*\\*", "*");
 416           if (!pattern.startsWith("/")) {
 417             pattern = "/" + pattern;
 418           }
 419           Map<String, Object> props = new HashMap<String, Object>();
 420           props.put(STATIC_PROPERTY, true);
 421           if (include.getExpiration() != null) {
 422             props.put(EXPIRATION_PROPERTY, include.getExpiration());
 423           }
 424           if (include.getHttpHeaders() != null) {
 425             props.put(HTTP_HEADERS_PROPERTY, include.getHttpHeaders());
 426           }
 427
 428           intersector.addGlob(GlobFactory.createGlob(pattern, props));
 429         }
 430       }
 431     }
 432
 433     @Override
 434     public void translateGlob(StringBuilder builder, Glob glob) {
 435       String regex = glob.getRegularExpression().pattern();
 436       if (!root.isEmpty()) {
 437         if (regex.startsWith(root)){
 438           regex = regex.substring(root.length(), regex.length());
 439         }
 440       }
 441       @SuppressWarnings("unchecked")
 442       List<String> welcomeFiles =
 443           (List<String>) glob.getProperty(WELCOME_FILES, RESOLVER);
 444       if (welcomeFiles != null) {
 445         for (String welcomeFile : welcomeFiles) {
 446           builder.append("- url: (" + regex + ")\n");
 447           builder.append("  static_files: __static__" + root + "\\1" + welcomeFile + "\n");
 448           builder.append("  upload: __NOT_USED__\n");
 449           builder.append("  require_matching_file: True\n");
 450           translateHandlerOptions(builder, glob);
 451           translateAdditionalStaticOptions(builder, glob);
 452         }
 453       } else {
 454         Boolean isStatic = (Boolean) glob.getProperty(STATIC_PROPERTY, RESOLVER);
 455         if (isStatic != null && isStatic.booleanValue()) {
 456           builder.append("- url: (" + regex + ")\n");
 457           builder.append("  static_files: __static__" + root + "\\1\n");
 458           builder.append("  upload: __NOT_USED__\n");
 459           builder.append("  require_matching_file: True\n");
 460           translateHandlerOptions(builder, glob);
 461           translateAdditionalStaticOptions(builder, glob);
 462         }
 463       }
 464     }
 465
 466     private void translateAdditionalStaticOptions(StringBuilder builder, Glob glob)
 467         throws AppEngineConfigException {
 468       String expiration = (String) glob.getProperty(EXPIRATION_PROPERTY, RESOLVER);
 469       if (expiration != null) {
 470         builder.append("  expiration: " + expiration + "\n");
 471       }
 472
 473       @SuppressWarnings("unchecked")
 474       Map<String, String> httpHeaders =
 475           (Map<String, String>) glob.getProperty(HTTP_HEADERS_PROPERTY, RESOLVER);
 476       if (httpHeaders != null && !httpHeaders.isEmpty()) {
 477         builder.append("  http_headers:\n");
 478         appendObjectAsYaml(builder, httpHeaders, 4);
 479       }
 480     }
 481   }
 482
 483   /**
 484    * According to the example In section 12.2.2 of Servlet Spec 3.0 , /baz/* should also match /baz,
 485    * so add an additional glob for that.
 486    */
 487   private static void extendMeaningOfTrailingStar(
 488       GlobIntersector intersector, String pattern, String property, Object value) {
 489     if (pattern.endsWith("/*") && pattern.length() > 2) {
 490       intersector.addGlob(
 491           GlobFactory.createGlob(pattern.substring(0, pattern.length() - 2), property, value));
 492     }
 493   }
 494
 495   class DynamicHandlerGenerator extends AbstractHandlerGenerator {
 496     private final List<String> patterns;
 497     private boolean fallthrough;
 498     private boolean hasJsps;
 499
 500     DynamicHandlerGenerator(boolean alwaysFallthrough) {
 501       fallthrough = alwaysFallthrough;
 502       patterns = new ArrayList<String>();
 503       for (String servletPattern : webXml.getServletPatterns()) {
 504         if (servletPattern.equals("/") || servletPattern.equals("/*")) {
 505           fallthrough = true;
 506         } else if (servletPattern.equals(API_ENDPOINT_REGEX)) {
 507           hasApiEndpoint = true;
 508         } else if (servletPattern.endsWith(".jsp")) {
 509           hasJsps = true;
 510         } else {
 511           patterns.add(servletPattern);
 512         }
 513       }
 514     }
 515
 516     @Override
 517     protected Map<String, Object> getWelcomeProperties() {
 518       if (fallthrough) {
 519         return null;
 520       } else {
 521         return Collections.<String,Object>singletonMap(DYNAMIC_PROPERTY, true);
 522       }
 523     }
 524
 525     @Override
 526     protected void addPatterns(GlobIntersector intersector) {
 527       if (fallthrough) {
 528         intersector.addGlob(GlobFactory.createGlob(
 529             "/*",
 530             DYNAMIC_PROPERTY, true));
 531       } else {
 532         for (String servletPattern : patterns) {
 533           intersector.addGlob(GlobFactory.createGlob(
 534               servletPattern,
 535               DYNAMIC_PROPERTY, true));
 536           extendMeaningOfTrailingStar(intersector, servletPattern, DYNAMIC_PROPERTY, true);
 537         }
 538         if (hasJsps) {
 539           intersector.addGlob(GlobFactory.createGlob(
 540               "*.jsp",
 541               DYNAMIC_PROPERTY, true));
 542         } else if (appEngineWebXml.getUseVm()) {
 543           intersector.addGlob(GlobFactory.createGlob(
 544               "*.jsp",
 545               DYNAMIC_PROPERTY, true));
 546         }
 547         intersector.addGlob(GlobFactory.createGlob(
 548             "/_ah/*",
 549             DYNAMIC_PROPERTY, true));
 550       }
 551     }
 552
 553     @Override
 554     public void translateGlob(StringBuilder builder, Glob glob) {
 555       String regex = glob.getRegularExpression().pattern();
 556
 557       Boolean isDynamic = (Boolean) glob.getProperty(DYNAMIC_PROPERTY, RESOLVER);
 558       if (isDynamic != null && isDynamic.booleanValue()) {
 559         builder.append("- url: " + regex + "\n");
 560         builder.append("  script: unused\n");
 561         translateHandlerOptions(builder, glob);
 562       }
 563     }
 564   }
 565
 566   /**
 567    * An {@code AbstractHandlerGenerator} that returns no globs.
 568    */
 569   class EmptyHandlerGenerator extends AbstractHandlerGenerator {
 570     @Override
 571     protected void addPatterns(GlobIntersector intersector) {
 572     }
 573
 574     @Override
 575     protected void translateGlob(StringBuilder builder, Glob glob) {
 576     }
 577
 578     @Override
 579     protected Map<String, Object> getWelcomeProperties() {
 580       return Collections.emptyMap();
 581     }
 582   }
 583
 584   abstract class AbstractHandlerGenerator {
 585     private List<Glob> globs = null;
 586     protected boolean hasApiEndpoint;
 587
 588     public int size() {
 589       return getGlobPatterns().size();
 590     }
 591
 592     public void translate(StringBuilder builder) {
 593       for (Glob glob : getGlobPatterns()) {
 594         translateGlob(builder, glob);
 595       }
 596     }
 597
 598     abstract protected void addPatterns(GlobIntersector intersector);
 599     abstract protected void translateGlob(StringBuilder builder, Glob glob);
 600
 601     /**
 602      * @returns a map of welcome properties to apply to the welcome
 603      * file entries, or {@code null} if no welcome file entries are
 604      * necessary.
 605      */
 606     abstract protected Map<String, Object> getWelcomeProperties();
 607
 608     protected List<Glob> getGlobPatterns() {
 609       if (globs == null) {
 610         GlobIntersector intersector = new GlobIntersector();
 611         addPatterns(intersector);
 612         addSecurityConstraints(intersector);
 613         addWelcomeFiles(intersector);
 614
 615         globs = intersector.getIntersection();
 616         removeNearDuplicates(globs);
 617         if (hasApiEndpoint) {
 618           globs.add(GlobFactory.createGlob(API_ENDPOINT_REGEX, DYNAMIC_PROPERTY, true));
 619         }
 620       }
 621       return globs;
 622     }
 623
 624     protected void addWelcomeFiles(GlobIntersector intersector) {
 625       Map<String, Object> welcomeProperties = getWelcomeProperties();
 626       if (welcomeProperties != null) {
 627         intersector.addGlob(GlobFactory.createGlob("/", welcomeProperties));
 628         intersector.addGlob(GlobFactory.createGlob("/*/", welcomeProperties));
 629       }
 630     }
 631
 632     protected void addSecurityConstraints(GlobIntersector intersector) {
 633       for (SecurityConstraint constraint : webXml.getSecurityConstraints()) {
 634         for (String pattern : constraint.getUrlPatterns()) {
 635           intersector.addGlob(GlobFactory.createGlob(
 636               pattern,
 637               TRANSPORT_GUARANTEE_PROPERTY,
 638               constraint.getTransportGuarantee()));
 639           extendMeaningOfTrailingStar(intersector, pattern, TRANSPORT_GUARANTEE_PROPERTY,
 640               constraint.getTransportGuarantee());
 641           intersector.addGlob(GlobFactory.createGlob(
 642               pattern,
 643               REQUIRED_ROLE_PROPERTY,
 644               constraint.getRequiredRole()));
 645           extendMeaningOfTrailingStar(
 646               intersector, pattern, REQUIRED_ROLE_PROPERTY, constraint.getRequiredRole());
 647         }
 648       }
 649     }
 650
 651     protected void translateHandlerOptions(StringBuilder builder, Glob glob) {
 652       SecurityConstraint.RequiredRole requiredRole =
 653           (SecurityConstraint.RequiredRole) glob.getProperty(REQUIRED_ROLE_PROPERTY, RESOLVER);
 654       if (requiredRole == null) {
 655         requiredRole = SecurityConstraint.RequiredRole.NONE;
 656       }
 657       switch (requiredRole) {
 658         case NONE:
 659           builder.append("  login: optional\n");
 660           break;
 661         case ANY_USER:
 662           builder.append("  login: required\n");
 663           break;
 664         case ADMIN:
 665           builder.append("  login: admin\n");
 666           break;
 667       }
 668
 669       SecurityConstraint.TransportGuarantee transportGuarantee =
 670           (SecurityConstraint.TransportGuarantee) glob.getProperty(TRANSPORT_GUARANTEE_PROPERTY,
 671                                                                    RESOLVER);
 672       if (transportGuarantee == null) {
 673         transportGuarantee = SecurityConstraint.TransportGuarantee.NONE;
 674       }
 675       switch (transportGuarantee) {
 676         case NONE:
 677           if (appEngineWebXml.getSslEnabled()) {
 678             builder.append("  secure: optional\n");
 679           } else {
 680             builder.append("  secure: never\n");
 681           }
 682           break;
 683         case INTEGRAL:
 684         case CONFIDENTIAL:
 685           if (!appEngineWebXml.getSslEnabled()) {
 686             throw new AppEngineConfigException(
 687                 "SSL must be enabled in appengine-web.xml to use transport-guarantee");
 688           }
 689           builder.append("  secure: always\n");
 690           break;
 691       }
 692
 693       String pattern = glob.getRegularExpression().pattern();
 694       String id = webXml.getHandlerIdForPattern(pattern);
 695       if (id != null) {
 696         if (appEngineWebXml.isApiEndpoint(id)) {
 697           builder.append("  api_endpoint: True\n");
 698         }
 699       }
 700     }
 701
 702     private void removeNearDuplicates(List<Glob> globs) {
 703       for (int i = 0; i < globs.size(); i++) {
 704         Glob topGlob = globs.get(i);
 705         for (int j = i + 1; j < globs.size(); j++) {
 706           Glob bottomGlob = globs.get(j);
 707           if (bottomGlob.matchesAll(topGlob)) {
 708             if (propertiesMatch(topGlob, bottomGlob)) {
 709               globs.remove(i);
 710               i--;
 711             }
 712             break;
 713           }
 714         }
 715       }
 716     }
 717
 718     private boolean propertiesMatch(Glob glob1, Glob glob2) {
 719       for (String property : PROPERTIES) {
 720         Object value1 = glob1.getProperty(property, RESOLVER);
 721         Object value2 = glob2.getProperty(property, RESOLVER);
 722         if (value1 != value2 && (value1 == null || !value1.equals(value2))) {
 723           return false;
 724         }
 725       }
 726       return true;
 727     }
 728   }
 729 }