Add http cache mode autogate, initialize cache control headers, repea…

…t of #2074

src/workerd/api/http-test.js

@@ -232,10 +232,10 @@ export const cacheMode = {
     // TODO(soon): The no-store and no-cache values will be supported
     // soon, at which time this test will need to be updated.
     await assert.rejects((async () => {
-      await fetch('http://example.org', { cache: 'no-store' });
+      await fetch('http://example.org', { cache: 'no-transform' });
     })(), {
       name: 'TypeError',
-      message: 'Unsupported cache mode: no-store',
+      message: 'Unsupported cache mode: no-transform',
     });
   }
 };

src/workerd/api/http.c++

@@ -15,6 +15,7 @@
 #include <kj/parse/char.h>
 #include <workerd/io/features.h>
 #include <workerd/util/http-util.h>
+#include <workerd/util/autogate.h>
 #include <workerd/util/mimetype.h>
 #include <workerd/util/stream-utils.h>
 #include <workerd/util/thread-scopes.h>
@@ -1198,6 +1199,15 @@ void Request::shallowCopyHeadersTo(kj::HttpHeaders& out) {
 }
 
 kj::Maybe<kj::String> Request::serializeCfBlobJson(jsg::Lock& js) {
+  if(cacheMode != CacheMode::NONE &&
+    util::Autogate::isEnabled(util::AutogateKey::HTTP_REQUEST_CACHE)) {
+    auto clone = cf.deepClone(js);
+    auto obj = KJ_ASSERT_NONNULL(clone.get(js));
+    auto ttl = (CacheMode::NOSTORE == cacheMode) ? -1 : 0;
+    // Works because of the fact there are only two non-none cache modes
+    obj.set(js, "cacheTtl", js.num(ttl));
+    return clone.serialize(js);
+  }
   return cf.serialize(js);
 }
 
@@ -1810,10 +1820,31 @@ jsg::Promise<jsg::Ref<Response>> fetchImplNoOutputLock(
   // If the jsRequest has a CacheMode, we need to handle that here.
   // Currently, the only cache mode we support is undefined, but we will soon support
   // no-cache and no-store. These additional modes will be hidden behind an autogate.
-  if (jsRequest->getCacheMode() != Request::CacheMode::NONE) {
-    return js.rejectedPromise<jsg::Ref<Response>>(
-        js.typeError(kj::str("Unsupported cache mode: ",
-            KJ_ASSERT_NONNULL(jsRequest->getCache(js)))));
+  auto headerIds = ioContext.getHeaderIds();
+  if(util::Autogate::isEnabled(util::AutogateKey::HTTP_REQUEST_CACHE)) {
+    switch(jsRequest->getCacheMode()) {
+      case Request::CacheMode::NOSTORE:
+      case Request::CacheMode::NOCACHE:
+      if(headers.get(headerIds.cacheControl) == kj::none) {
+        headers.set(headerIds.cacheControl, "no-cache");
+      }
+      if(headers.get(headerIds.pragma) == kj::none) {
+        headers.set(headerIds.pragma, "no-cache");
+      }
+      case Request::CacheMode::NONE:
+      if(headers.get(headerIds.cfCacheLevel) == kj::none) {
+        headers.set(headerIds.cfCacheLevel, "byc");
+      }
+      break;
+      default:
+        KJ_UNREACHABLE;
+    }
+  } else {
+    if(jsRequest->getCacheMode() != Request::CacheMode::NONE) {
+      return js.rejectedPromise<jsg::Ref<Response>>(
+          js.typeError(kj::str("Unsupported cache mode: ",
+              KJ_ASSERT_NONNULL(jsRequest->getCache(js)))));
+    }
   }
 
   kj::String url = uriEncodeControlChars(

src/workerd/io/io-thread-context.c++

@@ -7,13 +7,15 @@ ThreadContext::HeaderIdBundle::HeaderIdBundle(kj::HttpHeaderTable::Builder& buil
       contentEncoding(builder.add("Content-Encoding")),
       cfCacheStatus(builder.add("CF-Cache-Status")),
       cacheControl(builder.add("Cache-Control")),
+      pragma(builder.add("Pragma")),
       cfCacheNamespace(builder.add("CF-Cache-Namespace")),
       cfKvMetadata(builder.add("CF-KV-Metadata")),
       cfR2ErrorHeader(builder.add("CF-R2-Error")),
       cfBlobMetadataSize(builder.add("CF-R2-Metadata-Size")),
       cfBlobRequest(builder.add("CF-R2-Request")),
       authorization(builder.add("Authorization")),
-      secWebSocketProtocol(builder.add("Sec-WebSocket-Protocol")) {}
+      secWebSocketProtocol(builder.add("Sec-WebSocket-Protocol")),
+      cfCacheLevel(builder.add("Cf-Cache-Level")) {}
 
 ThreadContext::ThreadContext(
     kj::Timer& timer, kj::EntropySource& entropySource,

src/workerd/io/io-thread-context.h

@@ -17,13 +17,15 @@ class ThreadContext {
     const kj::HttpHeaderId contentEncoding;
     const kj::HttpHeaderId cfCacheStatus;         // used by cache API implementation
     const kj::HttpHeaderId cacheControl;
+    const kj::HttpHeaderId pragma;
     const kj::HttpHeaderId cfCacheNamespace;       // used by Cache binding implementation
     const kj::HttpHeaderId cfKvMetadata;          // used by KV binding implementation
     const kj::HttpHeaderId cfR2ErrorHeader;       // used by R2 binding implementation
     const kj::HttpHeaderId cfBlobMetadataSize;    // used by R2 binding implementation
     const kj::HttpHeaderId cfBlobRequest;         // used by R2 binding implementation
     const kj::HttpHeaderId authorization;         // used by R2 binding implementation
     const kj::HttpHeaderId secWebSocketProtocol;
+    const kj::HttpHeaderId cfCacheLevel;
   };
 
   ThreadContext(

src/workerd/server/server-test.c++

@@ -320,7 +320,9 @@ public:
           }
         }),
         fakeDate(kj::UNIX_EPOCH),
-        mockNetwork(*this, {}, {}) {}
+        mockNetwork(*this, {}, {}) {
+          //workerd::util::Autogate::initAutogate({});
+        }
 
   ~TestServer() noexcept(false) {
     for (auto& subq: subrequests) {

src/workerd/util/autogate.c++

@@ -15,6 +15,8 @@ kj::StringPtr KJ_STRINGIFY(AutogateKey key) {
   switch (key) {
     case AutogateKey::TEST_WORKERD:
       return "test-workerd"_kj;
+    case workerd::util::AutogateKey::HTTP_REQUEST_CACHE:
+      return "http-request-cache"_kj;
     case AutogateKey::NumOfKeys:
       KJ_FAIL_ASSERT("NumOfKeys should not be used in getName");
   }

src/workerd/util/autogate.h

@@ -13,6 +13,7 @@ namespace workerd::util {
 // Workerd-specific list of autogate keys (can also be used in internal repo).
 enum class AutogateKey {
   TEST_WORKERD,
+  HTTP_REQUEST_CACHE,
   NumOfKeys // Reserved for iteration.
 };