wasm: friendlier resolver API (#191)

Signed-off-by: Kuat Yessenov <kuat@google.com>
envoyproxy · Sep 16, 2019 · 16d41f2 · 16d41f2
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commit 16d41f2
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Showing 2 changed files with 26 additions and 11 deletions.
diff --git a/api/wasm/cpp/proxy_wasm_api.h b/api/wasm/cpp/proxy_wasm_api.h
@@ -527,13 +527,26 @@ inline Optional<WasmDataPtr> getSelectorExpression(std::initializer_list<StringV
   return std::make_unique<WasmData>(value_ptr, value_size);
 }
 
+inline bool getStringValue(std::initializer_list<StringView> parts, std::string* out) {
+  auto buf = getSelectorExpression(parts);
+  if (!buf.has_value()) {
+    return false;
+  }
+  out->assign(buf.value()->data(), buf.value()->size());
+  return true;
+}
+
 inline WasmResult getRequestProtocol(std::string *result) {
-  auto value = getSelectorExpression({"request_protocol"});
-  if (value.has_value()) {
-    result->assign(value.value()->data(), value.value()->size());
-    return WasmResult::Ok;
+  return getStringValue({"request_protocol"}, result) ? WasmResult::Ok : WasmResult::NotFound;
+}
+
+template <typename T> inline bool getValue(std::initializer_list<StringView> parts, T* out) {
+  auto buf = getSelectorExpression(parts);
+  if (!buf.has_value() || buf.value()->size() != sizeof(T)) {
+    return false;
   }
-  return WasmResult::NotFound;
+  *out = *reinterpret_cast<const T *>(buf.value()->data());
+  return true;
 }
 
 // Metadata
@@ -579,6 +592,11 @@ inline WasmResult getMetadataStringValue(MetadataType type, StringView key,
   return result;
 }
 
+// Requires that the value is a serialized google.protobuf.Value.
+inline WasmResult setFilterState(StringView key, StringView value) {
+  return static_cast<WasmResult>(proxy_setState(key.data(), key.size(), value.data(), value.size()));
+}
+
 inline WasmResult setFilterStateValue(StringView key, const google::protobuf::Value& value) {
   std::string output;
   if (!value.SerializeToString(&output)) {

diff --git a/source/extensions/common/wasm/null/sample_plugin/plugin.cc b/source/extensions/common/wasm/null/sample_plugin/plugin.cc
@@ -58,12 +58,9 @@ void PluginContext::onLog() {
                 {"metadata", "filter_metadata", "envoy.filters.http.wasm", "wasm_request_get_key"})
                 .value()
                 ->toString());
-    auto responseCode = getSelectorExpression({"response", "code"}).value();
-    if (responseCode->size() == sizeof(int64_t)) {
-      char buf[sizeof(int64_t)];
-      responseCode->view().copy(buf, sizeof(int64_t), 0);
-      int64_t code = absl::bit_cast<int64_t>(buf);
-      logWarn("response.code: " + absl::StrCat(code));
+    int64_t responseCode;
+    if (getValue({"response", "code"}, &responseCode)) {
+      logWarn("response.code: " + absl::StrCat(responseCode));
     }
     logWarn("state: " + getSelectorExpression({"filter_state", "wasm_state"}).value()->toString());
   } else {