private static void Remove(CacheDependency dependency)
{
lock (dependencies)
{
dependencies.Remove(dependency.fileOrDirectory);
}
}
/// <summary>
/// 使用指定的文件名或目录获取一个依赖项，如果与指定的文件名或目录对应的依赖项不存在，那么新建一个与其关联的依赖项并返回它。
/// </summary>
/// <param name="fileOrDirectory">指定的文件名或目录。</param>
/// <returns>CacheDependency 对象。</returns>
/// <remarks>
/// 如果传入的文件名或目录不合法，那么该方法返回 null。
/// </remarks>
public static CacheDependency Get(string fileOrDirectory)
{
if (!String.IsNullOrEmpty(fileOrDirectory))
{
// fileOrDirectory GetFileName GetDirectoryName
// \zhaixd\a\b > b \zhaixd\a
// D:\a\b > b D:\a
// D:\a\b\ > String.Empty D:\a\b
// \zhaixd\a\b.txt > b.txt \zhaixd\a
// D:\a\b.txt > b.txt D:\a
// D:\ > String.Empty null
// a > String.Empty String.Empty
string directoryName = Path.GetDirectoryName(fileOrDirectory);
if (!String.IsNullOrEmpty(directoryName))
{
string fileName = Path.GetFileName(fileOrDirectory);
lock (dependencies)
{
CacheDependency cacheDependency;
if (dependencies.ContainsKey(fileOrDirectory))
{
cacheDependency = dependencies[fileOrDirectory];
if (!cacheDependency.hasChanged)
{
return cacheDependency;
}
}
cacheDependency = new CacheDependency(fileOrDirectory, directoryName, fileName);
dependencies.Add(fileOrDirectory, cacheDependency);
cacheDependency.fsw.EnableRaisingEvents = true;
return cacheDependency;
}
}
}
return null;
}
private void SetItemInternal(string key, object value, CacheDependency dependency, TimeSpan timeToLive, DateTime? nextUpdateTime, params string[] tags)
{
if (string.IsNullOrWhiteSpace(key))
{
throw new ArgumentNullOrWhiteSpaceException("key");
}
if (value == null)
{
throw new ArgumentNullException("value");
}
CachedItem item = new CachedItem();
if (tags != null && tags.Length > 0)
{
EnsureTags(tags);
item.Tags = tags;
}
item.Key = key;
item.Value = value;
item.ExpiredTime = timeToLive.Days > 1000 ? DateTime.Now.AddDays(1000) : DateTime.Now + timeToLive;
item.NextUpdateTime = nextUpdateTime;
item.Dependency = dependency;
// 优化实现： 使用读写锁，减少高并发读取阻塞
this.lock4Items.EnterWriteLock();
try
{
// 覆盖时处理旧项
if (this.cachedItems.ContainsKey(key))
{
this.RemoveItemInternal(key);
}
#region LRU 支持
if (this.cachedItems.Count >= this.capacity)
{
this.RemoveItemInternal(this.linkedList.Last.item.Key);
}
#endregion
this.cachedItems.Add(key, item);
#region LRU 支持，新添加的设为第一个
this.linkedList.AddFirst(item);
item.Node = this.linkedList.First;
#endregion
if (tags != null && tags.Length > 0)
{
foreach (string tag in tags)
{
if (!this.cachedItemKeyByTags.ContainsKey(tag))
{
this.cachedItemKeyByTags.Add(tag, new Dictionary<string, KeyValuePair<string, CachedItem>>(StringComparer.InvariantCultureIgnoreCase));
}
Dictionary<string, KeyValuePair<string, CachedItem>> keys = this.cachedItemKeyByTags[tag];
if (!this.cachedItemObjectByTags.ContainsKey(tag))
{
this.cachedItemObjectByTags.Add(tag, new List<KeyValuePair<string, CachedItem>>());
}
List<KeyValuePair<string, CachedItem>> objects = this.cachedItemObjectByTags[tag];
KeyValuePair<string, CachedItem> newKvp = new KeyValuePair<string, CachedItem>(key, item);
int index;
if (keys.ContainsKey(key) && ((index = objects.IndexOf(keys[key])) >= 0)) // 覆盖时
{
objects[index] = newKvp;
}
else
{
objects.Add(newKvp);
}
keys[key] = newKvp;
}
}
}
finally
{
this.lock4Items.ExitWriteLock();
}
}
public void SetItem(string key, object value, CacheDependency dependency, TimeSpan timeToLive, params string[] tags)
{
this.SetItemInternal(key, value, dependency, timeToLive, null, tags);
}
public Region(NamedCache owner, string name, int capacity, int asyncUpdateInterval, string fileOrDirectory)
{
this.owner = owner;
this.name = name;
this.capacity = capacity;
this.asyncUpdateInterval = asyncUpdateInterval;
this.cachedItems = new Dictionary<string, CachedItem>(this.capacity, StringComparer.InvariantCultureIgnoreCase);
this.cachedItemKeyByTags = new Dictionary<string, Dictionary<string, KeyValuePair<string, CachedItem>>>(16, StringComparer.InvariantCultureIgnoreCase);
this.cachedItemObjectByTags = new Dictionary<string, List<KeyValuePair<string, CachedItem>>>(16, StringComparer.InvariantCultureIgnoreCase);
this.Dependency = CacheDependency.Get(fileOrDirectory);
}
public NamedCache(string name, string fileOrDirectory)
{
this.name = name;
this.Dependency = CacheDependency.Get(fileOrDirectory);
}
private object GetAndSetItem(string cacheName, string regionName, string key, Func<object, object> callback, object callBackState, CacheDependency dependency, params string[] tags)
{
if (string.IsNullOrWhiteSpace(cacheName))
{
throw new ArgumentNullOrWhiteSpaceException("cacheName");
}
if (string.IsNullOrWhiteSpace(regionName))
{
throw new ArgumentNullOrWhiteSpaceException("regionName");
}
if (callback == null)
{
throw new ArgumentNullException("callback");
}
return this.GetOrCreateCache(cacheName).GetOrCreateRegion(regionName).GetAndSetItem(key, callback, callBackState, dependency, tags);
}
public object GetAndSetItem(string regionName, string key, Func<object, object> callback, object callBackState, CacheDependency dependency)
{
object result = null;
try
{
result = LocalCacheManager.Instance.GetAndSetItem(CacheName, regionName, key, callback, callBackState, dependency, null);
}
catch (ArgumentException are)
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, are.GetFriendlyToString()), LogCategory.Cache);
}
catch (ConfigurationException confExp)
{
if (confExp is IgnoredConfigurationException) // 这种类型的配置错误不做任何处理，以避免产生大量同类型的配置错误日志
{
}
else
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, confExp.GetFriendlyToString()), LogCategory.Cache);
}
}
catch (Exception err)
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, err.GetFriendlyToString()), LogCategory.Cache);
}
return result;
}
public void SetItem(string cacheName, string regionName, string key, object value, CacheDependency dependency, TimeSpan timeToLive, params string[] tags)
{
if (string.IsNullOrWhiteSpace(cacheName))
{
throw new ArgumentNullOrWhiteSpaceException("cacheName");
}
if (string.IsNullOrWhiteSpace(regionName))
{
throw new ArgumentNullOrWhiteSpaceException("regionName");
}
this.GetOrCreateCache(cacheName).GetOrCreateRegion(regionName).SetItem(key, value, dependency, timeToLive, tags);
}
public void SetItem(string key, object value, CacheDependency dependency, int timeToLiveInSeconds, params string[] tags)
{
this.SetItemInternal(key, value, dependency, TimeSpan.FromSeconds(timeToLiveInSeconds), null, tags);
}
public CachedItemCallbackWrapper(CachedItem item, Func<object, object> callback, object callBackState, CacheDependency dependency, TimeSpan timeToLive, params string[] tags)
{
this.Item = item;
this.Callback = callback;
this.CallBackState = callBackState;
this.Dependency = dependency;
this.TTL = timeToLive;
this.Tags = tags;
}
public Region(NamedCache owner, string name, int capacity, TimeSpan asyncTimeToLive, TimeSpan asyncUpdateInterval, string fileOrDirectory)
{
this.owner = owner;
this.name = name;
if (this.name == "_CFG_AppSettings")
this.isAppsettingRegion = true;
this.capacity = capacity;
this.asyncTimeToLive = asyncTimeToLive;
this.asyncUpdateInterval = asyncUpdateInterval;
this.cachedItems = new Dictionary<string, CachedItem>(this.capacity, StringComparer.InvariantCultureIgnoreCase);
this.cachedItemKeyByTags = new Dictionary<string, Dictionary<string, KeyValuePair<string, CachedItem>>>(16, StringComparer.InvariantCultureIgnoreCase);
this.cachedItemObjectByTags = new Dictionary<string, List<KeyValuePair<string, CachedItem>>>(16, StringComparer.InvariantCultureIgnoreCase);
this.Dependency = CacheDependency.Get(fileOrDirectory);
}
public object GetAndSetItem(string regionName, string key, Func<object, object> callback, object callBackState, CacheDependency dependency, params string[] tags)
{
object result = null;
try
{
result = LocalCacheManager.Instance.GetAndSetItem(CacheName, regionName, key, callback, callBackState, dependency, tags);
}
catch (ArgumentException are)
{
Container.LogService.Warn(are.Message, LogCategory.Cache);
}
catch (Exception err)
{
Container.LogService.Warn(err, LogCategory.Cache);
}
return result;
}
public void SetItemWithNoExpiration(string regionName, string key, object value, CacheDependency dependency, params string[] tags)
{
if (value == null)
{
return;
}
try
{
LocalCacheManager.Instance.SetItemWithNoExpiration(CacheName, regionName, key, value, dependency, tags);
}
catch (ArgumentException are)
{
Container.LogService.Warn(are.Message, LogCategory.Cache);
}
catch (Exception err)
{
Container.LogService.Warn(err, LogCategory.Cache);
}
}
public void SetItem(string regionName, string key, object value, CacheDependency dependency, int timeToLiveInSeconds, params string[] tags)
{
try
{
LocalCacheManager.Instance.SetItem(CacheName, regionName, key, value, dependency, timeToLiveInSeconds, tags);
}
catch (ArgumentException are)
{
Container.LogService.Warn(are.Message, LogCategory.Cache);
}
catch (Exception err)
{
Container.LogService.Warn(err, LogCategory.Cache);
}
}
public CachedItemCallbackWrapper(CachedItem item, Func<object, object> callback, object callBackState, CacheDependency dependency, int timeToLiveInSeconds, params string[] tags)
{
this.Item = item;
this.Callback = callback;
this.CallBackState = callBackState;
this.Dependency = dependency;
this.TTL = TimeSpan.FromSeconds(timeToLiveInSeconds);
this.Tags = tags;
}
public object GetAndSetItem(string key, Func<object, object> callback, object callBackState, CacheDependency dependency, params string[] tags)
{
CachedItem cachedItem = this.GetCachedItem(key);
// 缓存项不存在时立即添加新的缓存项并返回
if (cachedItem == null)
{
object cacheItemLock = null;
lock (cacheItemLocks)
{
if (!cacheItemLocks.ContainsKey(key))
{
cacheItemLock = new object();
cacheItemLocks[key] = cacheItemLock;
}
else
{
cacheItemLock = cacheItemLocks[key];
}
}
object value = null;
lock (cacheItemLock)
{
cachedItem = this.GetCachedItem(key);
if (cachedItem == null)
{
value = callback(callBackState);
if (value != null)
{
// 缓存项在缓存服务器中的生存时间为：异步更新间隔+5分钟，这足够保证缓存项能够及时成功更新
// 同时，可以避免添加当前缓存项的客户端应用终止时（客户端应用中保存的 cacheItemVersions 失效，其它客户端因为仅读取该缓存项而没有存储其版本，永远不会更新该缓存项）
// 缓存项将可能在很长时间（由传入的 timeToLive 值决定）内不再更新的问题
this.SetItemInternal(key, value, dependency, TimeSpan.FromSeconds(this.asyncUpdateInterval + this.asyncUpdateAdditionalLiveTime), DateTime.Now.AddSeconds(this.asyncUpdateInterval), tags);
}
}
else
{
value = cachedItem.Value;
}
}
lock (cacheItemLocks)
{
cacheItemLocks.Remove(key);
}
return value;
}
// 首先不是处于更新过程中且时间上判断应更新缓存项，使用双重检查锁定机制并通过任务并行库异步更新缓存项
if (!cachedItem.IsUpdating && cachedItem.NextUpdateTime < DateTime.Now)
{
lock (cachedItem) // 仅锁定当前缓存项，尽可能的避免阻塞对其它缓存项的访问
{
if (!cachedItem.IsUpdating && cachedItem.NextUpdateTime < DateTime.Now)
{
cachedItem.IsUpdating = true;
System.Threading.Tasks.Task.Factory.StartNew(this.UpdateCacheItem, new CachedItemCallbackWrapper(cachedItem, callback, callBackState, dependency, this.asyncUpdateInterval + this.asyncUpdateAdditionalLiveTime, tags));
}
}
}
// 在异步更新缓存项之前立即返回当前缓存项的值。
return cachedItem.Value;
}
public void SetItem(string cacheName, string regionName, string key, object value, CacheDependency dependency, int timeToLiveInSeconds, params string[] tags)
{
this.SetItem(cacheName, regionName, key, value, dependency, TimeSpan.FromSeconds(timeToLiveInSeconds), tags);
}
public void SetItemWithNoExpiration(string cacheName, string regionName, string key, object value, CacheDependency dependency, params string[] tags)
{
this.SetItem(cacheName, regionName, key, value, dependency, TimeSpan.MaxValue, tags);
}
public bool SetItemWithNoExpiration(string regionName, string key, object value, CacheDependency dependency)
{
if (value == null)
{
return false;
}
try
{
LocalCacheManager.Instance.SetItemWithNoExpiration(CacheName, regionName, key, value, dependency, null);
return true;
}
catch (ArgumentException are)
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, are.GetFriendlyToString()), LogCategory.Cache);
}
catch (ConfigurationException confExp)
{
if (confExp is IgnoredConfigurationException) // 这种类型的配置错误不做任何处理，以避免产生大量同类型的配置错误日志
{
}
else
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, confExp.GetFriendlyToString()), LogCategory.Cache);
}
}
catch (Exception err)
{
Container.LogService.Warn(String.Format("{0}_{1}：{2}", regionName, key, err.GetFriendlyToString()), LogCategory.Cache);
}
return false;
}
