public async Task <T> GetEntryFromCache <T>(string endpoint, string identifier, GetLiveEndpointResultDelegate <T> cacheSetCall, DateTimeOffset cacheExpiration, CacheDurationType cacheDurationType = CacheDurationType.Absolute, bool persistInMemory = true, bool persistOnDisk = false) where T : class
{
// Check memory cache first
var responseItem = persistInMemory ? Get(identifier, endpoint) as T : null;
// If not in memory cache, check file system cache
if (responseItem == null)
{
responseItem = persistOnDisk ? await GetFromFsCache(endpoint, identifier, cacheSetCall, cacheExpiration, cacheDurationType) : null;
if (responseItem == null)
{
return(await cacheSetCall.Invoke(identifier, endpoint));
}
if (persistInMemory)
{
var policy = new CacheItemPolicy();
if (cacheDurationType == CacheDurationType.Absolute)
{
policy.AbsoluteExpiration = cacheExpiration;
}
else if (cacheDurationType == CacheDurationType.Sliding)
{
policy.SlidingExpiration = cacheExpiration.Offset;
}
base.Set(GetCacheItemFqn(identifier, endpoint), responseItem, policy);
}
}
return(responseItem);
}
public async Task <T> GetFromFsCache <T>(string endpoint, string identifier, GetLiveEndpointResultDelegate <T> cacheSetCall, DateTimeOffset cacheExpiration, CacheDurationType cacheDurationType = CacheDurationType.Absolute) where T : class
{
string niceEndpointName = GetEndpointNiceName(endpoint);
// Cache it to the file system, if that's enabled or available
if (cacheExpiration.Offset.TotalSeconds > 0 && !string.IsNullOrEmpty(niceEndpointName) && !string.IsNullOrEmpty(this.CacheDirectory))
{
string endpointCacheRoot = $"{niceEndpointName}{CACHE_ENDPOINT_EXTENSION}";
// TODO: For now while we aren't updating fs cache in this function
if (!File.Exists(Path.Combine(this.CacheDirectory, endpointCacheRoot)))
{
return(null);
}
using (var endpointFileStream = new FileStream(Path.Combine(this.CacheDirectory, endpointCacheRoot), FileMode.Open)) {
using (var endpointArchive = new ZipArchive(endpointFileStream, ZipArchiveMode.Update)) {
string entryName = identifier + CACHE_ENTRY_EXTENSION;
var entryFind = endpointArchive.GetEntry(entryName);
// Where we will store the result
T result;
if (entryFind == null || entryFind.LastWriteTime.Subtract(DateTime.Now) > cacheExpiration.Offset)
{
entryFind?.Delete();
result = await cacheSetCall.Invoke(identifier, endpoint);
// TODO: Instead of doing this now, queue it and do them all at once to avoid IO errors
// Add new cache entry into zip
//entryFind = endpointArchive.CreateEntry(entryName, CompressionLevel.Fastest);
//using (var entryStream = entryFind.Open()) {
// ProtoBuf.Serializer.Serialize(entryStream, result);
//}
}
else
{
result = ProtoBuf.Serializer.Deserialize <T>(entryFind.Open());
// If cache duration mode is sliding, then touch the timestamp to update it from this access
if (cacheDurationType == CacheDurationType.Sliding)
{
entryFind.LastWriteTime = DateTimeOffset.Now;
}
}
return(result);
}
}
}
return(null);
}