public void Displayed(ShapeDisplayedContext context)
{
// TODO: Configure duration of sliding expiration
var cacheContext = context.ShapeMetadata.Cache();
// If the shape is not cached, evaluate the ESIs
if (cacheContext == null)
{
string content;
using (var sw = new StringWriter())
{
context.ChildContent.WriteTo(sw, HtmlEncoder.Default);
content = sw.ToString();
}
ProcessESIs(ref content, GetDistributedCache);
context.ChildContent = new HtmlString(content);
}
else if (!_cached.Contains(cacheContext) && context.ChildContent != null)
{
var cacheEntries = GetCacheEntries(cacheContext).ToList();
string cacheKey = GetCacheKey(cacheContext.CacheId, cacheEntries);
using (var sw = new StringWriter())
{
context.ChildContent.WriteTo(sw, HtmlEncoder.Default);
var content = sw.ToString();
_cached.Add(cacheContext);
_cache[cacheKey] = content;
var contexts = String.Join(ContextSeparator.ToString(), cacheContext.Contexts.ToArray());
context.ChildContent = new HtmlString($"[[cache id='{cacheContext.CacheId}' contexts='{contexts}']]");
var bytes = Encoding.UTF8.GetBytes(content);
// Default duration is sliding expiration (permanent as long as it's used)
DistributedCacheEntryOptions options = new DistributedCacheEntryOptions
{
SlidingExpiration = new TimeSpan(0, 1, 0)
};
// If a custom duration is specified, replace the default options
if (cacheContext.Duration.HasValue)
{
options = new DistributedCacheEntryOptions
{
AbsoluteExpirationRelativeToNow = cacheContext.Duration
};
}
_dynamicCache.SetAsync(cacheKey, bytes, options).Wait();
_tagCache.Tag(cacheKey, cacheContext.Tags.ToArray());
}
}
}
private async Task SetCachedValueAsync(string cacheKey, string value, CacheContext context)
{
var failover = _memoryCache.Get <bool>(FailoverKey);
if (failover)
{
return;
}
var bytes = Encoding.UTF8.GetBytes(value);
var options = new DistributedCacheEntryOptions
{
AbsoluteExpiration = context.ExpiresOn,
SlidingExpiration = context.ExpiresSliding,
AbsoluteExpirationRelativeToNow = context.ExpiresAfter
};
// Default duration is sliding expiration (permanent as long as it's used)
if (!options.AbsoluteExpiration.HasValue && !options.SlidingExpiration.HasValue && !options.AbsoluteExpirationRelativeToNow.HasValue)
{
options.SlidingExpiration = new TimeSpan(0, 1, 0);
}
try
{
await _dynamicCache.SetAsync(cacheKey, bytes, options);
}
catch (Exception e)
{
_logger.LogError(e, "Failed to write the '{CacheKey}' to the dynamic cache", cacheKey);
_memoryCache.Set(FailoverKey, true, new MemoryCacheEntryOptions()
{
AbsoluteExpirationRelativeToNow = _dynamicCacheOptions.FailoverRetryLatency
});
return;
}
// Lazy load to prevent cyclic dependency
_tagcache ??= _serviceProvider.GetRequiredService <ITagCache>();
await _tagcache.TagAsync(cacheKey, context.Tags.ToArray());
}
private async Task SetCachedValueAsync(string cacheKey, string value, CacheContext context)
{
var bytes = Encoding.UTF8.GetBytes(value);
var options = new DistributedCacheEntryOptions
{
AbsoluteExpiration = context.ExpiresOn,
SlidingExpiration = context.ExpiresSliding,
AbsoluteExpirationRelativeToNow = context.ExpiresAfter
};
// Default duration is sliding expiration (permanent as long as it's used)
if (!options.AbsoluteExpiration.HasValue && !options.SlidingExpiration.HasValue && !options.AbsoluteExpirationRelativeToNow.HasValue)
{
options.SlidingExpiration = new TimeSpan(0, 1, 0);
}
await _dynamicCache.SetAsync(cacheKey, bytes, options);
// Lazy load to prevent cyclic dependency
_tagcache ??= _serviceProvider.GetRequiredService <ITagCache>();
await _tagcache.TagAsync(cacheKey, context.Tags.ToArray());
}