Cache canary results. (#351)

Signed-off-by: Kuat Yessenov <kuat@google.com>

Author: kyessenov

include/proxy-wasm/wasm.h

@@ -337,6 +337,7 @@ class WasmHandleBase : public std::enable_shared_from_this<WasmHandleBase> {
 
 protected:
   std::shared_ptr<WasmBase> wasm_base_;
+  std::unordered_map<std::string, bool> plugin_canary_cache_;
 };
 
 std::string makeVmKey(std::string_view vm_id, std::string_view configuration,

src/wasm.cc

@@ -472,6 +472,10 @@ bool WasmHandleBase::canary(const std::shared_ptr<PluginBase> &plugin,
   if (this->wasm() == nullptr) {
     return false;
   }
+  auto it = plugin_canary_cache_.find(plugin->key());
+  if (it != plugin_canary_cache_.end()) {
+    return it->second;
+  }
   auto configuration_canary_handle = clone_factory(shared_from_this());
   if (!configuration_canary_handle) {
     this->wasm()->fail(FailState::UnableToCloneVm, "Failed to clone Base Wasm");
@@ -490,9 +494,11 @@ bool WasmHandleBase::canary(const std::shared_ptr<PluginBase> &plugin,
   if (!configuration_canary_handle->wasm()->configure(root_context, plugin)) {
     configuration_canary_handle->wasm()->fail(FailState::ConfigureFailed,
                                               "Failed to configure base Wasm plugin");
+    plugin_canary_cache_[plugin->key()] = false;
     return false;
   }
   configuration_canary_handle->kill();
+  plugin_canary_cache_[plugin->key()] = true;
   return true;
 }
 

test/wasm_test.cc

@@ -172,6 +172,7 @@ TEST_P(TestVm, AlwaysApplyCanary) {
   // For each create Wasm, canary should be done.
   EXPECT_EQ(canary_count, 1);
 
+  bool first = true;
   std::unordered_set<std::shared_ptr<WasmHandleBase>> reference_holder;
 
   for (const auto &root_id : root_ids) {
@@ -196,8 +197,15 @@ TEST_P(TestVm, AlwaysApplyCanary) {
             auto wasm_handle_comp =
                 createWasm(vm_key, source, plugin_comp, wasm_handle_factory_comp,
                            wasm_handle_clone_factory_for_canary, false);
-            // For each create Wasm, canary should be done.
-            EXPECT_EQ(canary_count, 1);
+            // Validate that canarying is cached for the first baseline plugin variant.
+            if (first) {
+              first = false;
+              EXPECT_EQ(canary_count, 0);
+            } else {
+              // For each create Wasm, canary should be done.
+              EXPECT_EQ(canary_count, 1);
+              EXPECT_TRUE(TestContext::isGlobalLogged("onConfigure: " + root_id));
+            }
 
             if (plugin_config.empty()) {
               // canary_check.wasm should raise the error at `onConfigure` in canary when the
@@ -212,8 +220,6 @@ TEST_P(TestVm, AlwaysApplyCanary) {
             // destroyed for each iteration.
             reference_holder.insert(wasm_handle_comp);
 
-            EXPECT_TRUE(TestContext::isGlobalLogged("onConfigure: " + root_id));
-
             // Wasm VM is unique for vm_key.
             if (vm_key == vm_key_baseline) {
               EXPECT_EQ(wasm_handle_baseline->wasm(), wasm_handle_comp->wasm());