C# IEdmModel.GetEntityPropertyMappings方法代码示例

 private static ODataEntityPropertyMappingCache EnsureEpmCacheInternal(IEdmModel model, IEdmEntityType entityType, int maxMappingCount, out bool cacheModified)
 {
     cacheModified = false;
     if (entityType == null)
     {
         return null;
     }
     IEdmEntityType type = entityType.BaseEntityType();
     ODataEntityPropertyMappingCache baseCache = null;
     if (type != null)
     {
         baseCache = EnsureEpmCacheInternal(model, type, maxMappingCount, out cacheModified);
     }
     ODataEntityPropertyMappingCache epmCache = model.GetEpmCache(entityType);
     if (model.HasOwnOrInheritedEpm(entityType))
     {
         ODataEntityPropertyMappingCollection entityPropertyMappings = model.GetEntityPropertyMappings(entityType);
         if (!(((epmCache == null) || cacheModified) || epmCache.IsDirty(entityPropertyMappings)))
         {
             return epmCache;
         }
         cacheModified = true;
         int totalMappingCount = ValidationUtils.ValidateTotalEntityPropertyMappingCount(baseCache, entityPropertyMappings, maxMappingCount);
         epmCache = new ODataEntityPropertyMappingCache(entityPropertyMappings, model, totalMappingCount);
         try
         {
             epmCache.BuildEpmForType(entityType, entityType);
             epmCache.EpmSourceTree.Validate(entityType);
             model.SetAnnotationValue<ODataEntityPropertyMappingCache>(entityType, epmCache);
             return epmCache;
         }
         catch
         {
             model.RemoveEpmCache(entityType);
             throw;
         }
     }
     if (epmCache != null)
     {
         cacheModified = true;
         model.RemoveEpmCache(entityType);
     }
     return epmCache;
 }

        /// <summary>
        /// Ensures that an up-to-date EPM cache exists for the specified <paramref name="entityType"/>. 
        /// If no cache exists, a new one will be created based on the public mappings (if any).
        /// If the public mappings have changed (and the cache is thus dirty), the method re-constructs the cache.
        /// If all public mappings have been removed, the method also removes the EPM cache.
        /// </summary>
        /// <param name="model">IEdmModel instance containing the annotations.</param>
        /// <param name="entityType">IEdmEntityType instance for which to ensure the EPM cache.</param>
        /// <param name="maxMappingCount">The maximum allowed number of entity property mappings 
        /// for a given entity type (on the type itself and all its base types).</param>
        /// <param name="cacheModified">true if the cache was modified; otherwise false.</param>
        /// <returns>An instance of <see cref="ODataEntityPropertyMappingCache"/>, if there are any EPM mappings for the given entity type, otherwise returns null.</returns>
        private static ODataEntityPropertyMappingCache EnsureEpmCacheInternal(
            IEdmModel model, 
            IEdmEntityType entityType, 
            int maxMappingCount, 
            out bool cacheModified)
        {
            cacheModified = false;

            if (entityType == null)
            {
                return null;
            }

            // Make sure the EPM of the base type is initialized.
            IEdmEntityType baseEntityType = entityType.BaseEntityType();
            ODataEntityPropertyMappingCache baseCache = null;
            if (baseEntityType != null)
            {
                baseCache = EnsureEpmCacheInternal(model, baseEntityType, maxMappingCount, out cacheModified);
            }

            ODataEntityPropertyMappingCache epmCache = model.GetEpmCache(entityType);

            if (model.HasOwnOrInheritedEpm(entityType))
            {
                ODataEntityPropertyMappingCollection mappings = model.GetEntityPropertyMappings(entityType);
                bool needToBuildCache = epmCache == null || cacheModified || epmCache.IsDirty(mappings);
                if (needToBuildCache)
                {
                    cacheModified = true;
                    int totalMappingCount = ValidationUtils.ValidateTotalEntityPropertyMappingCount(baseCache, mappings, maxMappingCount);
                    epmCache = new ODataEntityPropertyMappingCache(mappings, model, totalMappingCount);

                    // Build the EPM tree and validate it
                    try
                    {
                        epmCache.BuildEpmForType(entityType, entityType);
                        epmCache.EpmSourceTree.Validate(entityType);
                        epmCache.EpmTargetTree.Validate();

                        // We set the annotation here, so if anything fails during
                        // building of the cache the annotation will not even be set so
                        // not leaving the type in an inconsistent state.
                        model.SetAnnotationValue(entityType, epmCache);
                    }
                    catch
                    {
                        // Remove an existing EPM cache if it is dirty to make sure we don't leave
                        // stale caches in case building of the cache fails.
                        // NOTE: we do this in the catch block to ensure that we always make a single
                        //       SetAnnotation call to either set or clear the existing annotation
                        //       since the SetAnnotation method is thread-safe
                        model.RemoveEpmCache(entityType);

                        throw;
                    }
                }
            }
            else
            {
                if (epmCache != null)
                {
                    // remove an existing EPM cache if the mappings have been removed from the type
                    cacheModified = true;
                    model.RemoveEpmCache(entityType);
                }
            }

            return epmCache;
        }