// BaseKey<delimiter>H<delimiter>HeaderName=HeaderValue<delimiter>Q<delimiter>QueryName=QueryValue1<subdelimiter>QueryValue2
public string CreateStorageVaryByKey(ResponseCachingContext context)
{
if (context == null)
{
throw new ArgumentNullException(nameof(context));
}
var varyByRules = context.CachedVaryByRules;
if (varyByRules == null)
{
throw new InvalidOperationException($"{nameof(CachedVaryByRules)} must not be null on the {nameof(ResponseCachingContext)}");
}
if (StringValues.IsNullOrEmpty(varyByRules.Headers) && StringValues.IsNullOrEmpty(varyByRules.QueryKeys))
{
return(varyByRules.VaryByKeyPrefix);
}
var request = context.HttpContext.Request;
var builder = _builderPool.Get();
try
{
// Prepend with the Guid of the CachedVaryByRules
builder.Append(varyByRules.VaryByKeyPrefix);
// Vary by headers
if (varyByRules?.Headers.Count > 0)
{
// Append a group separator for the header segment of the cache key
builder.Append(KeyDelimiter)
.Append('H');
for (var i = 0; i < varyByRules.Headers.Count; i++)
{
var header = varyByRules.Headers[i];
var headerValues = context.HttpContext.Request.Headers[header];
builder.Append(KeyDelimiter)
.Append(header)
.Append("=");
var headerValuesArray = headerValues.ToArray();
Array.Sort(headerValuesArray, StringComparer.Ordinal);
for (var j = 0; j < headerValuesArray.Length; j++)
{
builder.Append(headerValuesArray[j]);
}
}
}
// Vary by query keys
if (varyByRules?.QueryKeys.Count > 0)
{
// Append a group separator for the query key segment of the cache key
builder.Append(KeyDelimiter)
.Append('Q');
if (varyByRules.QueryKeys.Count == 1 && string.Equals(varyByRules.QueryKeys[0], "*", StringComparison.Ordinal))
{
// Vary by all available query keys
var queryArray = context.HttpContext.Request.Query.ToArray();
// Query keys are aggregated case-insensitively whereas the query values are compared ordinally.
Array.Sort(queryArray, QueryKeyComparer.OrdinalIgnoreCase);
for (var i = 0; i < queryArray.Length; i++)
{
builder.Append(KeyDelimiter)
.AppendUpperInvariant(queryArray[i].Key)
.Append("=");
var queryValueArray = queryArray[i].Value.ToArray();
Array.Sort(queryValueArray, StringComparer.Ordinal);
for (var j = 0; j < queryValueArray.Length; j++)
{
if (j > 0)
{
builder.Append(KeySubDelimiter);
}
builder.Append(queryValueArray[j]);
}
}
}
else
{
for (var i = 0; i < varyByRules.QueryKeys.Count; i++)
{
var queryKey = varyByRules.QueryKeys[i];
var queryKeyValues = context.HttpContext.Request.Query[queryKey];
builder.Append(KeyDelimiter)
.Append(queryKey)
.Append("=");
var queryValueArray = queryKeyValues.ToArray();
Array.Sort(queryValueArray, StringComparer.Ordinal);
for (var j = 0; j < queryValueArray.Length; j++)
{
if (j > 0)
{
builder.Append(KeySubDelimiter);
}
builder.Append(queryValueArray[j]);
}
}
}
}
return(builder.ToString());
}
finally
{
_builderPool.Return(builder);
}
}
public IEnumerable <string> CreateLookupVaryByKeys(ResponseCachingContext context)
{
return(new string[] { CreateStorageVaryByKey(context) });
}