我拿着這是由組織部門搜索的Employee類的實例。
儘管該解決方案是不完全動態的，它與資料庫緊密合作。
要實現它，我創建了一個通用的CacheBase類。該類必須從將被調用以獲取數據的外觀派生而來，外觀將調用GetFromCache方法從緩存中獲取數據。如果JSON不允許管理給定cacheKey的緩存以及參數（組鍵和值），facade將直接調用存儲庫。我假設所需的參數將被注入構造函數。
歡迎編輯和代碼審查。
public class EmployeeFacade: CacheBase<IEnumerable<Employee>>
{
private readonly IEmployeeRepository _repository;
public EmployeeFacade(IEmployeeRepository employeeRepository) : base("3600","Employee_Cache",cacheConfigurationJSON)
{
_repository = employeeRepository;
}
public method GetEmployee(string organization, string department)
{
var groupKeyAndValues = new List<Tuple<string, string>>();
groupKeyAndValues.Add(new Tuple<String, string>("Organization", organization));
groupKeyAndValues.Add(new Tuple<String, string>("Department", department));
bool isCacheAllowed;
var employeeInfos = base.GetFromCache(() => _repository.GetEmployee(organization, department), groupKeyAndValues, out isCacheAllowed);
//if cache is not allowed for this combination , return direct from repository.
if (!isCacheAllowed)
return _repository.GetEmployee(organization, department);
}
}
public abstract class CacheBase<T> where T : class
{
private string _cacheTimeoutInSeconds;
private string _cacheConfiguration;
private static readonly object CacheLockObject = new object();
string _cacheKey;
public CacheBase(string cacheTimeoutInSeconds, string cacheKey, string cacheConfigurationJson)
{
_cacheTimeoutInSeconds= cacheTimeoutInSeconds;
_cacheConfiguration = cacheConfigurationJson;
_cacheKey = cacheKey;
}
public T GetFromCache(Func<T> methodToFillCache, IEnumerable<Tuple<string, string>> groupKeyAndValues, out bool isCacheAllowed)
{
var baseCacheKey = _cacheKey;
var detailedCacheKey = GenerateCacheKey(groupKeyAndValues);
isCacheAllowed = IsSaveToCacheAllowed(baseCacheKey, groupKeyAndValues);
if (!isCacheAllowed) return null;
var result = HttpRuntime.Cache[detailedCacheKey] as T;
if (result == null)
{
lock (CacheLockObject)
{
if (result == null)
{
result = methodToFillCache() as T;
SetToCache(result, detailedCacheKey);
}
}
}
return result;
}
private void SetToCache(T data, string detailedCacheKey)
{
HttpRuntime.Cache.Insert(detailedCacheKey, data, null,
DateTime.Now.AddSeconds(Convert.ToInt32(cacheTimeoutInSeconds)), TimeSpan.Zero);
}
private string GenerateCacheKey(IEnumerable<Tuple<string, string>> groupKeyAndValues)
{
string detailedCacheKey = _cacheKey;
if (groupKeyAndValues == null) return detailedCacheKey;
var groupKeys = groupKeyAndValues.Select(x => x.Item1).ToList();
if (groupKeys != null && groupKeys.Count > 0)
{
foreach (var groupKey in groupKeys)
{
if (!String.IsNullOrWhiteSpace(groupKey))
detailedCacheKey += "_" + groupKey;
}
}
return detailedCacheKey;
}
private bool IsSaveToCacheAllowed(string cacheKey, IEnumerable<Tuple<string, string>> groupKeyAndValues)
{
cacheKey = cacheKey.ToUpper();
if (_cacheConfiguration == null) return false;
string valuesAllowed = CacheConstant.All; string valuesDenied = CacheConstant.All;
//CACHE
if (_cacheConfiguration == null) return true;
valuesAllowed = _cacheConfiguration.Allow;
valuesDenied = _cacheConfiguration.Deny;
var matchingCacheConfig = _cacheConfiguration.Keys.FirstOrDefault(x => x.Key.ToUpper() == cacheKey);
if (matchingCacheConfig == null) return IsAllowed(cacheKey, valuesAllowed, valuesDenied); ;
valuesAllowed = matchingCacheConfig.Allow;
valuesDenied = matchingCacheConfig.Deny;
bool isAllowed = IsAllowed(cacheKey, valuesAllowed, valuesDenied);
foreach (var groupKeyAndValue in groupKeyAndValues)
{
var key = groupKeyAndValue.Item1.ToUpper();
var value = groupKeyAndValue.Item2.ToUpper();
matchingCacheConfig = matchingCacheConfig.Keys.FirstOrDefault(x => x.Key.ToUpper() == key);
if (matchingCacheConfig == null) return IsAllowed(key, valuesAllowed, valuesDenied);
valuesAllowed = matchingCacheConfig.Allow;
valuesDenied = matchingCacheConfig.Deny;
isAllowed = IsAllowed(value, matchingCacheConfig.Allow, matchingCacheConfig.Deny);
if (!isAllowed) break;
}
return isAllowed;
}
bool IsAllowed(string value, string allowedValues, string deniedValues)
{
//Prerequisites: among allowed and denied values , one should contain * and other should contain value or empty string
var allowed = allowedValues.ToUpper().Split(',');
var denied = deniedValues.ToUpper().Split(',');
if (denied.Contains(CacheConstant.All))
{
if (allowed.Contains(value) || allowed.Contains(CacheConstant.All))
{
return true;
}
else
{
return false;
}
}
else if (denied.Contains(value))
{
if (allowed.Contains(value))
{
return true;
}
else
{
return false;
}
}
else //denied contains nothing
{
if (allowed.Contains(value) || allowed.Contains(CacheConstant.All) || allowed.Count() == 0)
{
return true;
}
else
{
return false;
}
}
}
}