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873 lines
42 KiB
C#
873 lines
42 KiB
C#
//---------------------------------------------------------------------
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// <copyright file="MetadataCache.cs" company="Microsoft">
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// Copyright (c) Microsoft Corporation. All rights reserved.
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// </copyright>
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//
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// @owner Microsoft
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// @backupOwner Microsoft
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//---------------------------------------------------------------------
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namespace System.Data.Metadata.Edm
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{
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using System;
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using System.Collections.Generic;
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using System.Data.Common.Utils;
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using System.Data.Entity;
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using System.Data.Mapping;
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using System.Diagnostics;
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using System.Runtime.Versioning;
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using System.Security.Permissions;
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using System.Threading;
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using System.Xml;
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/// <summary>
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/// Runtime Metadata Cache - this class contains the metadata cache entry for edm and store collections.
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/// </summary>
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internal static class MetadataCache
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{
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#region Fields
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private const string s_dataDirectory = "|datadirectory|";
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private const string s_metadataPathSeparator = "|";
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// This is the period in the periodic cleanup measured in milliseconds
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private const int cleanupPeriod = 5 * 60 * 1000;
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// This dictionary contains the cache entry for the edm item collection. The reason why we need to keep a seperate dictionary
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// for CSpace item collection is that the same model can be used for different providers. We don't want to load the model
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// again and again
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private static readonly Dictionary<string, EdmMetadataEntry> _edmLevelCache = new Dictionary<string, EdmMetadataEntry>(StringComparer.OrdinalIgnoreCase);
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/// <summary>
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/// This dictionary contains the store cache entry - this entry will only keep track of StorageMappingItemCollection, since internally
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/// storage mapping item collection keeps strong references to both edm item collection and store item collection.
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/// </summary>
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private static readonly Dictionary<string, StoreMetadataEntry> _storeLevelCache = new Dictionary<string, StoreMetadataEntry>(StringComparer.OrdinalIgnoreCase);
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/// <summary>
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/// The list maintains the store metadata entries that are still in use, maybe because someone is still holding a strong reference
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/// to it. We need to scan this list everytime the clean up thread wakes up and make sure if the item collection is no longer in use,
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/// call clear on query cache
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/// </summary>
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private static readonly List<StoreMetadataEntry> _metadataEntriesRemovedFromCache = new List<StoreMetadataEntry>();
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private static Memoizer<string, List<MetadataArtifactLoader>> _artifactLoaderCache = new Memoizer<string, List<MetadataArtifactLoader>>(MetadataCache.SplitPaths, null);
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/// <summary>
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/// Read/Write lock for edm cache
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/// </summary>
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private static readonly object _edmLevelLock = new object();
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/// <summary>
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/// Read/Write lock for the store cache
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/// </summary>
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private static readonly object _storeLevelLock = new object();
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// Periodic thread which runs every n mins (look up the cleanupPeriod variable to see the exact time), walks through
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// every item in other store and edm cache and tries to do some cleanup
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private static Timer timer = new Timer(PeriodicCleanupCallback, null, cleanupPeriod, cleanupPeriod);
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#endregion
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#region Methods
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/// <summary>
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/// The purpose of the thread is to do cleanup. It marks the object in various stages before it actually cleans up the object
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/// Here's what this does for each entry in the cache:
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/// 1> First checks if the entry is marked for cleanup.
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/// 2> If the entry is marked for cleanup, that means its in one of the following 3 states
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/// a) If the strong reference to item collection is not null, it means that this item was marked for cleanup in
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/// the last cleanup cycle and we must make the strong reference set to null so that it can be garbage collected.
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/// b) Otherwise, we are waiting for GC to collect the item collection so that we can remove this entry from the cache
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/// If the weak reference to item collection is still alive, we don't do anything
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/// c) If the weak reference to item collection is not alive, we need to remove this entry from the cache
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/// 3> If the entry is not marked for cleanup, then check whether the weak reference to entry token is alive
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/// a) if it is alive, then this entry is in use and we must do nothing
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/// b) Otherwise, we can mark this entry for cleanup
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/// </summary>
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/// <param name="state"></param>
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private static void PeriodicCleanupCallback(object state)
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{
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// Perform clean up on edm cache
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DoCacheClean<EdmMetadataEntry>(_edmLevelCache, _edmLevelLock);
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// Perform clean up on store cache
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DoCacheClean<StoreMetadataEntry>(_storeLevelCache, _storeLevelLock);
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}
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/// <summary>
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/// A helper function for splitting up a string that is a concatenation of strings delimited by the metadata
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/// path separator into a string list. The resulting list is NOT sorted.
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/// </summary>
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/// <param name="paths">The paths to split</param>
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/// <returns>An array of strings</returns>
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[ResourceExposure(ResourceScope.Machine)] //Exposes the file name which is a Machine resource
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[ResourceConsumption(ResourceScope.Machine)] //For MetadataArtifactLoader.Create method call. But the path is not created in this method.
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internal static List<MetadataArtifactLoader> SplitPaths(string paths)
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{
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Debug.Assert(!string.IsNullOrEmpty(paths), "paths cannot be empty or null");
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string[] results;
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// This is the registry of all URIs in the global collection.
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HashSet<string> uriRegistry = new HashSet<string>(StringComparer.OrdinalIgnoreCase);
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List<MetadataArtifactLoader> loaders = new List<MetadataArtifactLoader>();
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// If the argument contains one or more occurrences of the macro '|DataDirectory|', we
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// pull those paths out so that we don't lose them in the string-splitting logic below.
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// Note that the macro '|DataDirectory|' cannot have any whitespace between the pipe
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// symbols and the macro name. Also note that the macro must appear at the beginning of
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// a path (else we will eventually fail with an invalid path exception, because in that
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// case the macro is not expanded). If a real/physical folder named 'DataDirectory' needs
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// to be included in the metadata path, whitespace should be used on either or both sides
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// of the name.
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//
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List<string> dataDirPaths = new List<string>();
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int indexStart = paths.IndexOf(MetadataCache.s_dataDirectory, StringComparison.OrdinalIgnoreCase);
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while (indexStart != -1)
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{
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int prevSeparatorIndex = indexStart == 0 ? -1 : paths.LastIndexOf(
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MetadataCache.s_metadataPathSeparator,
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indexStart - 1, // start looking here
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StringComparison.Ordinal
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);
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int macroPathBeginIndex = prevSeparatorIndex + 1;
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// The '|DataDirectory|' macro is composable, so identify the complete path, like
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// '|DataDirectory|\item1\item2'. If the macro appears anywhere other than at the
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// beginning, splice out the entire path, e.g. 'C:\item1\|DataDirectory|\item2'. In this
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// latter case the macro will not be expanded, and downstream code will throw an exception.
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//
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int indexEnd = paths.IndexOf(MetadataCache.s_metadataPathSeparator,
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indexStart + MetadataCache.s_dataDirectory.Length,
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StringComparison.Ordinal);
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if (indexEnd == -1)
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{
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dataDirPaths.Add(paths.Substring(macroPathBeginIndex));
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paths = paths.Remove(macroPathBeginIndex); // update the concatenated list of paths
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break;
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}
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dataDirPaths.Add(paths.Substring(macroPathBeginIndex, indexEnd - macroPathBeginIndex));
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// Update the concatenated list of paths by removing the one containing the macro.
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//
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paths = paths.Remove(macroPathBeginIndex, indexEnd - macroPathBeginIndex);
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indexStart = paths.IndexOf(MetadataCache.s_dataDirectory, StringComparison.OrdinalIgnoreCase);
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}
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// Split the string on the separator and remove all spaces around each parameter value
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results = paths.Split(new string[] { MetadataCache.s_metadataPathSeparator }, StringSplitOptions.RemoveEmptyEntries);
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// Now that the non-macro paths have been identified, merge the paths containing the macro
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// into the complete list.
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//
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if (dataDirPaths.Count > 0)
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{
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dataDirPaths.AddRange(results);
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results = dataDirPaths.ToArray();
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}
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for (int i = 0; i < results.Length; i++)
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{
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// Trim out all the spaces for this parameter and add it only if it's not blank
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results[i] = results[i].Trim();
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if (results[i].Length > 0)
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{
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loaders.Add(MetadataArtifactLoader.Create(
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results[i],
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MetadataArtifactLoader.ExtensionCheck.All, // validate the extension against all acceptable values
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null,
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uriRegistry
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));
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}
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}
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return loaders;
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}
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/// <summary>
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/// Walks through the given cache and calls cleanup on each entry in the cache
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/// </summary>
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/// <typeparam name="T"></typeparam>
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/// <param name="cache"></param>
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/// <param name="objectToLock"></param>
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private static void DoCacheClean<T>(Dictionary<string, T> cache, object objectToLock) where T: MetadataEntry
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{
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// Sometime, for some reason, timer can be initialized and the cache is still not initialized.
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if (cache != null)
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{
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List<KeyValuePair<string, T>> keysForRemoval = null;
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lock (objectToLock)
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{
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// we should check for type of the lock object first, since otherwise we might be reading the count of the list
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// while some other thread might be modifying it. For e.g. when this function is called for edmcache,
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// we will be acquiring edmlock and trying to get the count for the list, while some other thread
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// might be calling ClearCache and we might be adding entries to the list
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if (objectToLock == _storeLevelLock && _metadataEntriesRemovedFromCache.Count != 0)
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{
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// First check the list of entries and remove things which are no longer in use
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for (int i = _metadataEntriesRemovedFromCache.Count - 1; 0 <= i; i--)
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{
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if (!_metadataEntriesRemovedFromCache[i].IsEntryStillValid())
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{
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// Clear the query cache
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_metadataEntriesRemovedFromCache[i].CleanupQueryCache();
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// Remove the entry at the current index. This is the reason why we
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// go backwards.
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_metadataEntriesRemovedFromCache.RemoveAt(i);
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}
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}
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}
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// We have to use a list to keep track of the keys to remove because we can't remove while enumerating
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foreach (KeyValuePair<string, T> pair in cache)
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{
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if (pair.Value.PeriodicCleanUpThread())
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{
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if (keysForRemoval == null)
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{
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keysForRemoval = new List<KeyValuePair<string, T>>();
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}
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keysForRemoval.Add(pair);
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}
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}
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// Remove all the entries from the cache
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if (keysForRemoval != null)
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{
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for (int i = 0; i < keysForRemoval.Count; i++)
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{
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keysForRemoval[i].Value.Clear();
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cache.Remove(keysForRemoval[i].Key);
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}
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}
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}
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}
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}
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/// <summary>
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/// Retrieves an cache entry holding to edm metadata for a given cache key
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/// </summary>
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/// <param name="cacheKey">string containing all the files from which edm metadata is to be retrieved</param>
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/// <param name="composite">An instance of the composite MetadataArtifactLoader</param>
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/// <param name="entryToken">The metadata entry token for the returned entry</param>
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/// <returns>Returns the entry containing the edm metadata</returns>
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internal static EdmItemCollection GetOrCreateEdmItemCollection(string cacheKey,
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MetadataArtifactLoader loader,
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out object entryToken)
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{
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EdmMetadataEntry entry = GetCacheEntry<EdmMetadataEntry>(_edmLevelCache, cacheKey, _edmLevelLock,
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new EdmMetadataEntryConstructor(), out entryToken);
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// Load the edm item collection or if the collection is already loaded, check for security permission
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LoadItemCollection(new EdmItemCollectionLoader(loader), entry);
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return entry.EdmItemCollection;
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}
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/// <summary>
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/// Retrieves an entry holding store metadata for a given cache key
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/// </summary>
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/// <param name="cacheKey">The connection string whose store metadata is to be retrieved</param>
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/// <param name="composite">An instance of the composite MetadataArtifactLoader</param>
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/// <param name="entryToken">The metadata entry token for the returned entry</param>
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/// <returns>the entry containing the information on how to load store metadata</returns>
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internal static StorageMappingItemCollection GetOrCreateStoreAndMappingItemCollections(
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string cacheKey,
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MetadataArtifactLoader loader,
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EdmItemCollection edmItemCollection,
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out object entryToken)
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{
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StoreMetadataEntry entry = GetCacheEntry<StoreMetadataEntry>(_storeLevelCache, cacheKey, _storeLevelLock,
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new StoreMetadataEntryConstructor(), out entryToken);
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// Load the store item collection or if the collection is already loaded, check for security permission
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LoadItemCollection(new StoreItemCollectionLoader(edmItemCollection, loader), entry);
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return entry.StorageMappingItemCollection;
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}
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internal static List<MetadataArtifactLoader> GetOrCreateMetdataArtifactLoader(string paths)
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{
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return _artifactLoaderCache.Evaluate(paths);
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}
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/// <summary>
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/// Get the entry from the cache given the cache key. If the entry is not present, it creates a new entry and
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/// adds it to the cache
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/// </summary>
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/// <typeparam name="T"></typeparam>
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/// <param name="cache"></param>
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/// <param name="cacheKey"></param>
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/// <param name="entryToken"></param>
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/// <param name="metadataEntry"></param>
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/// <param name="objectToLock"></param>
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/// <returns></returns>
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private static T GetCacheEntry<T>(Dictionary<string, T> cache, string cacheKey, object objectToLock,
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IMetadataEntryConstructor<T> metadataEntry, out object entryToken) where T: MetadataEntry
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{
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T entry;
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// In the critical section, we need to do the minimal thing to ensure correctness
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// Within the lock, we will see if an entry is present. If it is not, we will create a new entry and
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// add it to the cache. In either case, we need to ensure the token to make sure so that any other
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// thread that comes looking for the same entry does nothing in this critical section
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// Also the cleanup thread doesn't do anything since the token is alive
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lock (objectToLock)
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{
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if (cache.TryGetValue(cacheKey, out entry))
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{
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entryToken = entry.EnsureToken();
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}
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else
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{
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entry = metadataEntry.GetMetadataEntry();
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entryToken = entry.EnsureToken();
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cache.Add(cacheKey, entry);
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}
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}
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return entry;
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}
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/// <summary>
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/// Loads the item collection for the entry
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/// </summary>
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/// <param name="itemCollectionLoader">struct which loads an item collection</param>
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/// <param name="entry">entry whose item collection needs to be loaded</param>
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private static void LoadItemCollection<T>(IItemCollectionLoader<T> itemCollectionLoader, T entry) where T : MetadataEntry
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{
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// At this point, you have made sure that there is an entry with an alive token in the cache so that
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// other threads can find it if they come querying for it, and cleanup thread won't clean the entry
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// If two or more threads come one after the other, we don't won't both of them to load the metadata.
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// So if one of them is loading the metadata, the other should wait and then use the same metadata.
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// For that reason, we have this lock on the entry itself to make sure that this happens. Its okay to
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// update the item collection outside the lock, since assignment are guarantees to be atomic and no two
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// thread are updating this at the same time
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bool isItemCollectionAlreadyLoaded = true;
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if (!entry.IsLoaded)
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{
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lock (entry)
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{
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if (!entry.IsLoaded)
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{
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itemCollectionLoader.LoadItemCollection(entry);
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isItemCollectionAlreadyLoaded = false;
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}
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}
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}
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Debug.Assert(entry.IsLoaded, "The entry must be loaded at this point");
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// Making sure that the thread which loaded the item collection is not checking for file permisssions
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// again
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if (isItemCollectionAlreadyLoaded)
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{
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entry.CheckFilePermission();
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}
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}
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/// <summary>
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/// Remove all the entries from the cache
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/// </summary>
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internal static void Clear()
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{
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lock (_edmLevelLock)
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{
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_edmLevelCache.Clear();
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}
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lock (_storeLevelLock)
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{
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// Call clear on each of the metadata entries. This is to make sure we clear all the performance
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// counters associated with the query cache
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foreach (StoreMetadataEntry entry in _storeLevelCache.Values)
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{
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// Check if the weak reference to item collection is still alive
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if (entry.IsEntryStillValid())
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{
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_metadataEntriesRemovedFromCache.Add(entry);
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}
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else
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{
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entry.Clear();
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}
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}
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_storeLevelCache.Clear();
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}
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Memoizer<string, List<MetadataArtifactLoader>> artifactLoaderCacheTemp =
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new Memoizer<string, List<MetadataArtifactLoader>>(MetadataCache.SplitPaths, null);
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Interlocked.CompareExchange(ref _artifactLoaderCache, artifactLoaderCacheTemp, _artifactLoaderCache);
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}
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#endregion
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#region InlineClasses
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/// <summary>
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/// The base class having common implementation for all metadata entry classes
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/// </summary>
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private abstract class MetadataEntry
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{
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private WeakReference _entryTokenReference;
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private ItemCollection _itemCollection;
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private WeakReference _weakReferenceItemCollection;
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private bool _markEntryForCleanup;
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private FileIOPermission _filePermissions;
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/// <summary>
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/// The constructor for constructing this MetadataEntry
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/// </summary>
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internal MetadataEntry()
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{
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// Create this once per life time of the object. Creating extra weak references causing unnecessary GC pressure
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_entryTokenReference = new WeakReference(null);
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_weakReferenceItemCollection = new WeakReference(null);
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}
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/// <summary>
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/// returns the item collection inside this metadata entry
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/// </summary>
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protected ItemCollection ItemCollection { get { return _itemCollection; } }
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/// <summary>
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/// Update the entry with the given item collection
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/// </summary>
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/// <param name="itemCollection"></param>
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protected void UpdateMetadataEntry(ItemCollection itemCollection, FileIOPermission filePermissions)
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{
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Debug.Assert(_entryTokenReference.IsAlive, "You must call Ensure token before you call this method");
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Debug.Assert(_markEntryForCleanup == false, "The entry must not be marked for cleanup");
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Debug.Assert(_itemCollection == null, "Item collection must be null");
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Debug.Assert(_filePermissions == null, "filePermissions must be null");
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// Update strong and weak reference for item collection
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_weakReferenceItemCollection.Target = itemCollection;
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_filePermissions = filePermissions;
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// do this last, because it signals that we are loaded
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_itemCollection = itemCollection;
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}
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internal bool IsLoaded { get { return _itemCollection != null; } }
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/// <summary>
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/// This method is called periodically by the cleanup thread to make the unused entries
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/// go through various stages, before it is ready for cleanup. If it is ready, this method
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/// returns true and then the entry is completely removed from the cache
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/// </summary>
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/// <returns></returns>
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internal bool PeriodicCleanUpThread()
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{
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// Here's what this does for each entry in the cache:
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// 1> First checks if the entry is marked for cleanup.
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// 2> If the entry is marked for cleanup, that means its in one of the following 3 states
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// a) If the strong reference to item collection is not null, it means that this item was marked for cleanup in
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// the last cleanup cycle and we must make the strong reference set to null so that it can be garbage collected. (GEN 2)
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// b) Otherwise, we are waiting for GC to collect the item collection so that we can remove this entry from the cache
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// If the weak reference to item collection is still alive, we don't do anything
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// c) If the weak reference to item collection is not alive, we need to remove this entry from the cache (GEN 3)
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// 3> If the entry is not marked for cleanup, then check whether the weak reference to entry token is alive
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// a) if it is alive, then this entry is in use and we must do nothing
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// b) Otherwise, we can mark this entry for cleanup (GEN 1)
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|
if (_markEntryForCleanup)
|
|
{
|
|
Debug.Assert(_entryTokenReference.IsAlive == false, "Entry Token must never be alive if the entry is marked for cleanup");
|
|
|
|
if (_itemCollection != null)
|
|
{
|
|
// GEN 2
|
|
_itemCollection = null;
|
|
}
|
|
else if (!_weakReferenceItemCollection.IsAlive)
|
|
{
|
|
// GEN 3
|
|
_filePermissions = null;
|
|
// this entry must be removed from the cache
|
|
return true;
|
|
}
|
|
}
|
|
else if (!_entryTokenReference.IsAlive)
|
|
{
|
|
// GEN 1
|
|
|
|
// If someone creates a entity connection, and calls GetMetadataWorkspace. This creates an cache entry,
|
|
// but the item collection is not initialized yet (since store item collection are initialized only
|
|
// when one calls connection.Open()). Suppose now the connection is no longer used - in other words,
|
|
// open was never called and it goes out of scope. After some time when the connection gets GC'ed,
|
|
// entry token won't be alive any longer, but item collection inside it will be null, since it was never initialized.
|
|
// So we can't assert that item collection must be always initialized here
|
|
_markEntryForCleanup = true;
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Make sure that the entry has a alive token and returns that token - it can be new token or an existing
|
|
/// one, depending on the state of the entry
|
|
/// </summary>
|
|
/// <returns></returns>
|
|
internal object EnsureToken()
|
|
{
|
|
object entryToken = _entryTokenReference.Target;
|
|
ItemCollection itemCollection = (ItemCollection)_weakReferenceItemCollection.Target;
|
|
|
|
// When ensure token is called, the entry can be in different stages
|
|
// 1> Its a newly created entry - no token, no item collection, etc. Just create a new token and
|
|
// return back
|
|
// 2> An entry already in use - the weak reference to token must be alive. We just need to grab the token
|
|
// and return it
|
|
// 3> No one is using this entry and hence the token is no longer alive. If we have strong reference to item
|
|
// collection, then create a new token and return it
|
|
// 4> No one has used this token for one cleanup cycle and hence strong reference is null. But the weak reference
|
|
// is still alive. We need to make the initialize the strong reference again, create a new token and return it
|
|
// 5> This entry has not been used for long enough that even the weak reference is no longer alive. This entry is
|
|
// now exactly like a new entry, except that it is still marked for cleanup. Create a new token, set mark for
|
|
// cleanup to false and return the token
|
|
if (_entryTokenReference.IsAlive)
|
|
{
|
|
Debug.Assert(_markEntryForCleanup == false, "An entry with alive token cannot be marked for cleanup");
|
|
// ItemCollection strong pointer can be null or not null. If the entry has been created, and loadItemCollection
|
|
// hasn't been called yet, the token will be alive, but item collection will be null. If someone called
|
|
// load item collection, then item collection will not be non-null
|
|
return entryToken;
|
|
}
|
|
// If the entry token is not alive, then it can be either a new created entry with everything set
|
|
// to null or it must be one of the entries which is no longer in use
|
|
else if (_itemCollection != null)
|
|
{
|
|
Debug.Assert(_weakReferenceItemCollection.IsAlive, "Since the strong reference is still there, weak reference must also be alive");
|
|
// This means that no one is using the item collection, and its waiting to be cleanuped
|
|
}
|
|
else
|
|
{
|
|
if (_weakReferenceItemCollection.IsAlive)
|
|
{
|
|
Debug.Assert(_markEntryForCleanup, "Since the strong reference is null, this entry must be marked for cleanup");
|
|
// Initialize the strong reference to item collection
|
|
_itemCollection = itemCollection;
|
|
}
|
|
else
|
|
{
|
|
// no more references to the collection
|
|
// are available, so get rid of the permissions
|
|
// object. We will get a new one when we get a new collection
|
|
_filePermissions = null;
|
|
}
|
|
}
|
|
// Even if the _weakReferenceItemCollection is no longer alive, we will reuse this entry. Assign a new entry token and set mark for cleanup to false
|
|
// so that this entry is not cleared by the cleanup thread
|
|
|
|
entryToken = new object();
|
|
_entryTokenReference.Target = entryToken;
|
|
_markEntryForCleanup = false;
|
|
return entryToken;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Check if the thread has appropriate permissions to use the already loaded metadata
|
|
/// </summary>
|
|
internal void CheckFilePermission()
|
|
{
|
|
Debug.Assert(_itemCollection != null, "Item collection must be present since we want to reuse the metadata");
|
|
Debug.Assert(_entryTokenReference.IsAlive, "This entry must be in use");
|
|
Debug.Assert(_markEntryForCleanup == false, "The entry must not marked for cleanup");
|
|
Debug.Assert(_weakReferenceItemCollection.IsAlive, "Weak reference to item collection must be alive");
|
|
|
|
// we will have an empty ItemCollection (no files were used to load it)
|
|
if (_filePermissions != null)
|
|
{
|
|
_filePermissions.Demand();
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Dispose the composite loader that encapsulates all artifacts
|
|
/// </summary>
|
|
internal virtual void Clear()
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// This returns true if the entry is still in use - the entry can be use if the entry token is
|
|
/// still alive.If the entry token is still not alive, it means that no one is using this entry
|
|
/// and its okay to remove it. Today there is no
|
|
/// </summary>
|
|
/// <returns></returns>
|
|
internal bool IsEntryStillValid()
|
|
{
|
|
return _entryTokenReference.IsAlive;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// A metadata entry holding EdmItemCollection object for the cache
|
|
/// </summary>
|
|
private class EdmMetadataEntry : MetadataEntry
|
|
{
|
|
/// <summary>
|
|
/// Gets the EdmItemCollection for this entry
|
|
/// </summary>
|
|
internal EdmItemCollection EdmItemCollection
|
|
{
|
|
get
|
|
{
|
|
return (EdmItemCollection)this.ItemCollection;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Just loads the edm item collection
|
|
/// </summary>
|
|
/// <returns></returns>
|
|
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2103:ReviewImperativeSecurity")]
|
|
internal void LoadEdmItemCollection(MetadataArtifactLoader loader)
|
|
{
|
|
Debug.Assert(loader != null, "loader is null");
|
|
|
|
List<XmlReader> readers = loader.CreateReaders(DataSpace.CSpace);
|
|
try
|
|
{
|
|
EdmItemCollection itemCollection = new EdmItemCollection(
|
|
readers,
|
|
loader.GetPaths(DataSpace.CSpace)
|
|
);
|
|
|
|
List<string> permissionPaths = new List<string>();
|
|
loader.CollectFilePermissionPaths(permissionPaths, DataSpace.CSpace);
|
|
FileIOPermission filePermissions = null;
|
|
if (permissionPaths.Count > 0)
|
|
{
|
|
filePermissions = new FileIOPermission(FileIOPermissionAccess.Read, permissionPaths.ToArray());
|
|
}
|
|
|
|
UpdateMetadataEntry(itemCollection, filePermissions);
|
|
}
|
|
finally
|
|
{
|
|
Helper.DisposeXmlReaders(readers);
|
|
}
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// A metadata entry holding a StoreItemCollection and a StorageMappingItemCollection objects for the cache
|
|
/// </summary>
|
|
private class StoreMetadataEntry : MetadataEntry
|
|
{
|
|
private System.Data.Common.QueryCache.QueryCacheManager _queryCacheManager;
|
|
|
|
/// <summary>
|
|
/// The constructor for constructing this entry with an StoreItemCollection and a StorageMappingItemCollection
|
|
/// </summary>
|
|
/// <param name="compositeLoader">An instance of the composite MetadataArtifactLoader</param>
|
|
internal StoreMetadataEntry()
|
|
{
|
|
}
|
|
|
|
/// <summary>
|
|
/// Gets the StorageMappingItemCollection for this entry
|
|
/// </summary>
|
|
internal StorageMappingItemCollection StorageMappingItemCollection
|
|
{
|
|
get
|
|
{
|
|
return (StorageMappingItemCollection)this.ItemCollection;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Load store specific metadata into the StoreItemCollection for this entry
|
|
/// </summary>
|
|
/// <param name="factory">The store-specific provider factory</param>
|
|
/// <param name="edmItemCollection">edmItemCollection</param>
|
|
[System.Diagnostics.CodeAnalysis.SuppressMessage("Microsoft.Security", "CA2103:ReviewImperativeSecurity")]
|
|
internal void LoadStoreCollection(EdmItemCollection edmItemCollection, MetadataArtifactLoader loader)
|
|
{
|
|
StoreItemCollection storeItemCollection = null;
|
|
IEnumerable<XmlReader> sSpaceXmlReaders = loader.CreateReaders(DataSpace.SSpace);
|
|
try
|
|
{
|
|
// Load the store side, however, only do so if we don't already have one
|
|
storeItemCollection = new StoreItemCollection(
|
|
sSpaceXmlReaders,
|
|
loader.GetPaths(DataSpace.SSpace));
|
|
|
|
}
|
|
finally
|
|
{
|
|
Helper.DisposeXmlReaders(sSpaceXmlReaders);
|
|
}
|
|
|
|
// If this entry is getting re-used, make sure that the previous query cache manager gets
|
|
// cleared up
|
|
if (_queryCacheManager != null)
|
|
{
|
|
_queryCacheManager.Clear();
|
|
}
|
|
|
|
// Update the query cache manager reference
|
|
_queryCacheManager = storeItemCollection.QueryCacheManager;
|
|
|
|
// With the store metadata in place, we can then load the mappings, however, only use it
|
|
// if we don't already have one
|
|
//
|
|
StorageMappingItemCollection storageMappingItemCollection = null;
|
|
IEnumerable<XmlReader> csSpaceXmlReaders = loader.CreateReaders(DataSpace.CSSpace);
|
|
try
|
|
{
|
|
storageMappingItemCollection = new StorageMappingItemCollection(
|
|
edmItemCollection,
|
|
storeItemCollection,
|
|
csSpaceXmlReaders,
|
|
loader.GetPaths(DataSpace.CSSpace));
|
|
}
|
|
finally
|
|
{
|
|
Helper.DisposeXmlReaders(csSpaceXmlReaders);
|
|
}
|
|
|
|
List<string> permissionPaths = new List<string>();
|
|
loader.CollectFilePermissionPaths(permissionPaths, DataSpace.SSpace);
|
|
loader.CollectFilePermissionPaths(permissionPaths, DataSpace.CSSpace);
|
|
FileIOPermission filePermissions = null;
|
|
if (permissionPaths.Count > 0)
|
|
{
|
|
filePermissions = new FileIOPermission(FileIOPermissionAccess.Read, permissionPaths.ToArray());
|
|
}
|
|
this.UpdateMetadataEntry(storageMappingItemCollection, filePermissions);
|
|
|
|
}
|
|
|
|
/// <summary>
|
|
/// Calls clear on query cache manager to make sure all the performance counters associated with the query
|
|
/// cache are gone
|
|
/// </summary>
|
|
internal override void Clear()
|
|
{
|
|
// there can be entries in cache for which the store item collection was never created. For e.g.
|
|
// if you create a new entity connection, but never call open on it
|
|
CleanupQueryCache();
|
|
base.Clear();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Cleans and Dispose query cache manager
|
|
/// </summary>
|
|
internal void CleanupQueryCache()
|
|
{
|
|
if (null != _queryCacheManager)
|
|
{
|
|
_queryCacheManager.Dispose();
|
|
_queryCacheManager = null;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
/// <summary>
|
|
/// Interface to construct the metadata entry so that code can be reused
|
|
/// </summary>
|
|
/// <typeparam name="T"></typeparam>
|
|
interface IMetadataEntryConstructor<T>
|
|
{
|
|
T GetMetadataEntry();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Struct for creating EdmMetadataEntry
|
|
/// </summary>
|
|
private struct EdmMetadataEntryConstructor : IMetadataEntryConstructor<EdmMetadataEntry>
|
|
{
|
|
public EdmMetadataEntry GetMetadataEntry()
|
|
{
|
|
return new EdmMetadataEntry();
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Struct for creating StoreMetadataEntry
|
|
/// </summary>
|
|
private struct StoreMetadataEntryConstructor : IMetadataEntryConstructor<StoreMetadataEntry>
|
|
{
|
|
public StoreMetadataEntry GetMetadataEntry()
|
|
{
|
|
return new StoreMetadataEntry();
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Interface which constructs a new Item collection
|
|
/// </summary>
|
|
/// <typeparam name="T"></typeparam>
|
|
interface IItemCollectionLoader<T> where T : MetadataEntry
|
|
{
|
|
void LoadItemCollection(T entry);
|
|
}
|
|
|
|
private struct EdmItemCollectionLoader : IItemCollectionLoader<EdmMetadataEntry>
|
|
{
|
|
|
|
private MetadataArtifactLoader _loader;
|
|
|
|
public EdmItemCollectionLoader(MetadataArtifactLoader loader)
|
|
{
|
|
Debug.Assert(loader != null, "loader must never be null");
|
|
_loader = loader;
|
|
}
|
|
|
|
/// <summary>
|
|
/// Creates a new item collection and updates the entry with the item collection
|
|
/// </summary>
|
|
/// <param name="entry"></param>
|
|
/// <returns></returns>
|
|
public void LoadItemCollection(EdmMetadataEntry entry)
|
|
{
|
|
entry.LoadEdmItemCollection(_loader);
|
|
}
|
|
}
|
|
|
|
private struct StoreItemCollectionLoader : IItemCollectionLoader<StoreMetadataEntry>
|
|
{
|
|
private EdmItemCollection _edmItemCollection;
|
|
private MetadataArtifactLoader _loader;
|
|
|
|
/// <summary>
|
|
/// Constructs a struct from which you can load edm item collection
|
|
/// </summary>
|
|
/// <param name="factory"></param>
|
|
/// <param name="edmItemCollection"></param>
|
|
internal StoreItemCollectionLoader(EdmItemCollection edmItemCollection, MetadataArtifactLoader loader)
|
|
{
|
|
Debug.Assert(edmItemCollection != null, "EdmItemCollection must never be null");
|
|
Debug.Assert(loader != null, "loader must never be null");
|
|
//StoreItemCollection requires atleast one SSDL path.
|
|
if ((loader.GetPaths(DataSpace.SSpace) == null) || (loader.GetPaths(DataSpace.SSpace).Count == 0))
|
|
{
|
|
throw EntityUtil.Metadata(Strings.AtleastOneSSDLNeeded);
|
|
}
|
|
|
|
_edmItemCollection = edmItemCollection;
|
|
_loader = loader;
|
|
}
|
|
|
|
public void LoadItemCollection(StoreMetadataEntry entry)
|
|
{
|
|
entry.LoadStoreCollection(_edmItemCollection, _loader);
|
|
}
|
|
}
|
|
|
|
#endregion
|
|
}
|
|
}
|