Jo Shields a575963da9 Imported Upstream version 3.6.0
Former-commit-id: da6be194a6b1221998fc28233f2503bd61dd9d14
2014-08-13 10:39:27 +01:00

338 lines
13 KiB
C#

namespace System.Web.Mvc {
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Runtime.Caching;
using System.Security.Cryptography;
using System.Text;
using System.Web;
using System.Web.Mvc.Resources;
using System.Web.UI;
[SuppressMessage("Microsoft.Performance", "CA1813:AvoidUnsealedAttributes", Justification = "Unsealed so that subclassed types can set properties in the default constructor.")]
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
public class OutputCacheAttribute : ActionFilterAttribute, IExceptionFilter {
private OutputCacheParameters _cacheSettings = new OutputCacheParameters { VaryByParam = "*" };
private const string _cacheKeyPrefix = "_MvcChildActionCache_";
private static ObjectCache _childActionCache;
private Func<ObjectCache> _childActionCacheThunk = () => ChildActionCache;
private static object _childActionFilterFinishCallbackKey = new object();
private bool _locationWasSet;
private bool _noStoreWasSet;
public OutputCacheAttribute() {
}
internal OutputCacheAttribute(ObjectCache childActionCache) {
_childActionCacheThunk = () => childActionCache;
}
public string CacheProfile {
get {
return _cacheSettings.CacheProfile ?? String.Empty;
}
set {
_cacheSettings.CacheProfile = value;
}
}
internal OutputCacheParameters CacheSettings {
get {
return _cacheSettings;
}
}
public static ObjectCache ChildActionCache {
get {
return _childActionCache ?? MemoryCache.Default;
}
set {
_childActionCache = value;
}
}
private ObjectCache ChildActionCacheInternal {
get {
return _childActionCacheThunk();
}
}
public int Duration {
get {
return _cacheSettings.Duration;
}
set {
_cacheSettings.Duration = value;
}
}
public OutputCacheLocation Location {
get {
return _cacheSettings.Location;
}
set {
_cacheSettings.Location = value;
_locationWasSet = true;
}
}
public bool NoStore {
get {
return _cacheSettings.NoStore;
}
set {
_cacheSettings.NoStore = value;
_noStoreWasSet = true;
}
}
public string SqlDependency {
get {
return _cacheSettings.SqlDependency ?? String.Empty;
}
set {
_cacheSettings.SqlDependency = value;
}
}
public string VaryByContentEncoding {
get {
return _cacheSettings.VaryByContentEncoding ?? String.Empty;
}
set {
_cacheSettings.VaryByContentEncoding = value;
}
}
public string VaryByCustom {
get {
return _cacheSettings.VaryByCustom ?? String.Empty;
}
set {
_cacheSettings.VaryByCustom = value;
}
}
public string VaryByHeader {
get {
return _cacheSettings.VaryByHeader ?? String.Empty;
}
set {
_cacheSettings.VaryByHeader = value;
}
}
[SuppressMessage("Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "Param", Justification = "Matches the @ OutputCache page directive.")]
public string VaryByParam {
get {
return _cacheSettings.VaryByParam ?? String.Empty;
}
set {
_cacheSettings.VaryByParam = value;
}
}
private static void ClearChildActionFilterFinishCallback(ControllerContext controllerContext) {
controllerContext.HttpContext.Items.Remove(_childActionFilterFinishCallbackKey);
}
private static void CompleteChildAction(ControllerContext filterContext, bool wasException) {
Action<bool> callback = GetChildActionFilterFinishCallback(filterContext);
if (callback != null) {
ClearChildActionFilterFinishCallback(filterContext);
callback(wasException);
}
}
private static Action<bool> GetChildActionFilterFinishCallback(ControllerContext controllerContext) {
return controllerContext.HttpContext.Items[_childActionFilterFinishCallbackKey] as Action<bool>;
}
internal string GetChildActionUniqueId(ActionExecutingContext filterContext) {
StringBuilder uniqueIdBuilder = new StringBuilder();
// Start with a prefix, presuming that we share the cache with other users
uniqueIdBuilder.Append(_cacheKeyPrefix);
// Unique ID of the action description
uniqueIdBuilder.Append(filterContext.ActionDescriptor.UniqueId);
// Unique ID from the VaryByCustom settings, if any
uniqueIdBuilder.Append(DescriptorUtil.CreateUniqueId(VaryByCustom));
if (!String.IsNullOrEmpty(VaryByCustom)) {
string varyByCustomResult = filterContext.HttpContext.ApplicationInstance.GetVaryByCustomString(HttpContext.Current, VaryByCustom);
uniqueIdBuilder.Append(varyByCustomResult);
}
// Unique ID from the VaryByParam settings, if any
uniqueIdBuilder.Append(GetUniqueIdFromActionParameters(filterContext, SplitVaryByParam(VaryByParam)));
// The key is typically too long to be useful, so we use a cryptographic hash
// as the actual key (better randomization and key distribution, so small vary
// values will generate dramtically different keys).
using (SHA256 sha = SHA256.Create()) {
return Convert.ToBase64String(sha.ComputeHash(Encoding.UTF8.GetBytes(uniqueIdBuilder.ToString())));
}
}
private static string GetUniqueIdFromActionParameters(ActionExecutingContext filterContext, IEnumerable<string> keys) {
// Generate a unique ID of normalized key names + key values
var keyValues = new Dictionary<string, object>(filterContext.ActionParameters, StringComparer.OrdinalIgnoreCase);
keys = (keys ?? keyValues.Keys).Select(key => key.ToUpperInvariant())
.OrderBy(key => key, StringComparer.Ordinal);
return DescriptorUtil.CreateUniqueId(keys.Concat(keys.Select(key => keyValues.ContainsKey(key) ? keyValues[key] : null)));
}
public static bool IsChildActionCacheActive(ControllerContext controllerContext) {
return GetChildActionFilterFinishCallback(controllerContext) != null;
}
public override void OnActionExecuted(ActionExecutedContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
// Complete the request if the child action threw an exception
if (filterContext.IsChildAction && filterContext.Exception != null) {
CompleteChildAction(filterContext, wasException: true);
}
}
public override void OnActionExecuting(ActionExecutingContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (filterContext.IsChildAction) {
ValidateChildActionConfiguration();
// Already actively being captured? (i.e., cached child action inside of cached child action)
// Realistically, this needs write substitution to do properly (including things like authentication)
if (GetChildActionFilterFinishCallback(filterContext) != null) {
throw new InvalidOperationException(MvcResources.OutputCacheAttribute_CannotNestChildCache);
}
// Already cached?
string uniqueId = GetChildActionUniqueId(filterContext);
string cachedValue = ChildActionCacheInternal.Get(uniqueId) as string;
if (cachedValue != null) {
filterContext.Result = new ContentResult() { Content = cachedValue };
return;
}
// Swap in a new TextWriter so we can capture the output
StringWriter cachingWriter = new StringWriter(CultureInfo.InvariantCulture);
TextWriter originalWriter = filterContext.HttpContext.Response.Output;
filterContext.HttpContext.Response.Output = cachingWriter;
// Set a finish callback to clean up
SetChildActionFilterFinishCallback(filterContext, wasException => {
// Restore original writer
filterContext.HttpContext.Response.Output = originalWriter;
// Grab output and write it
string capturedText = cachingWriter.ToString();
filterContext.HttpContext.Response.Write(capturedText);
// Only cache output if this wasn't an error
if (!wasException) {
ChildActionCacheInternal.Add(uniqueId, capturedText, DateTimeOffset.UtcNow.AddSeconds(Duration));
}
});
}
}
public void OnException(ExceptionContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (filterContext.IsChildAction) {
CompleteChildAction(filterContext, wasException: true);
}
}
public override void OnResultExecuting(ResultExecutingContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (!filterContext.IsChildAction) {
// we need to call ProcessRequest() since there's no other way to set the Page.Response intrinsic
using (OutputCachedPage page = new OutputCachedPage(_cacheSettings)) {
page.ProcessRequest(HttpContext.Current);
}
}
}
public override void OnResultExecuted(ResultExecutedContext filterContext) {
if (filterContext == null) {
throw new ArgumentNullException("filterContext");
}
if (filterContext.IsChildAction) {
CompleteChildAction(filterContext, wasException: filterContext.Exception != null);
}
}
private static void SetChildActionFilterFinishCallback(ControllerContext controllerContext, Action<bool> callback) {
controllerContext.HttpContext.Items[_childActionFilterFinishCallbackKey] = callback;
}
private static IEnumerable<string> SplitVaryByParam(string varyByParam) {
if (String.Equals(varyByParam, "none", StringComparison.OrdinalIgnoreCase)) { // Vary by nothing
return Enumerable.Empty<string>();
}
if (String.Equals(varyByParam, "*", StringComparison.OrdinalIgnoreCase)) { // Vary by everything
return null;
}
return from part in varyByParam.Split(';') // Vary by specific parameters
let trimmed = part.Trim()
where !String.IsNullOrEmpty(trimmed)
select trimmed;
}
private void ValidateChildActionConfiguration() {
if (Duration <= 0) {
throw new InvalidOperationException(MvcResources.OutputCacheAttribute_InvalidDuration);
}
if (String.IsNullOrWhiteSpace(VaryByParam)) {
throw new InvalidOperationException(MvcResources.OutputCacheAttribute_InvalidVaryByParam);
}
if (!String.IsNullOrWhiteSpace(CacheProfile) ||
!String.IsNullOrWhiteSpace(SqlDependency) ||
!String.IsNullOrWhiteSpace(VaryByContentEncoding) ||
!String.IsNullOrWhiteSpace(VaryByHeader) ||
_locationWasSet || _noStoreWasSet) {
throw new InvalidOperationException(MvcResources.OutputCacheAttribute_ChildAction_UnsupportedSetting);
}
}
private sealed class OutputCachedPage : Page {
private OutputCacheParameters _cacheSettings;
public OutputCachedPage(OutputCacheParameters cacheSettings) {
// Tracing requires Page IDs to be unique.
ID = Guid.NewGuid().ToString();
_cacheSettings = cacheSettings;
}
protected override void FrameworkInitialize() {
// when you put the <%@ OutputCache %> directive on a page, the generated code calls InitOutputCache() from here
base.FrameworkInitialize();
InitOutputCache(_cacheSettings);
}
}
}
}