From 4c61d7a0c0edfe5cc2038806519c4283114fe8fd Mon Sep 17 00:00:00 2001
From: Kuat Yessenov <kuat@google.com>
Date: Mon, 20 Apr 2020 15:45:45 -0700
Subject: [PATCH] cherry-pick of
 https://github.com/envoyproxy/envoy-wasm/pull/486

Signed-off-by: Kuat Yessenov <kuat@google.com>
---
 source/extensions/common/wasm/context.cc | 20 +++++++++++++-------
 source/extensions/common/wasm/context.h  | 12 ++++++++----
 2 files changed, 21 insertions(+), 11 deletions(-)

diff --git a/source/extensions/common/wasm/context.cc b/source/extensions/common/wasm/context.cc
index 463d30e8a25c..a79cbfad64f0 100644
--- a/source/extensions/common/wasm/context.cc
+++ b/source/extensions/common/wasm/context.cc
@@ -397,7 +397,7 @@ static absl::flat_hash_map<std::string, PropertyToken> property_tokens = {PROPER
 #undef _PARI
 
 absl::optional<google::api::expr::runtime::CelValue>
-Context::FindValue(absl::string_view name, Protobuf::Arena* arena) const {
+Context::findValue(absl::string_view name, Protobuf::Arena* arena, bool last) const {
   using google::api::expr::runtime::CelValue;
 
   const StreamInfo::StreamInfo* info = getConstRequestStreamInfo();
@@ -411,11 +411,15 @@ Context::FindValue(absl::string_view name, Protobuf::Arena* arena) const {
       const WasmState* state;
       if (info->filterState().hasData<WasmState>(key)) {
         state = &info->filterState().getDataReadOnly<WasmState>(key);
-      } else if (info->upstreamFilterState()->hasData<WasmState>(key)) {
+      } else if (info->upstreamFilterState() &&
+                 info->upstreamFilterState()->hasData<WasmState>(key)) {
         state = &info->upstreamFilterState()->getDataReadOnly<WasmState>(key);
       } else {
         return {};
       }
+      if (last) {
+        return CelValue::CreateBytes(&state->value());
+      }
       return state->exprValue(arena);
     }
     return {};
@@ -542,7 +546,7 @@ WasmResult Context::getProperty(absl::string_view path, std::string* result) {
     if (first) {
       // top-level ident
       first = false;
-      auto top_value = FindValue(part, &arena);
+      auto top_value = findValue(part, &arena, start >= path.size());
       if (!top_value.has_value()) {
         return WasmResult::NotFound;
       }
@@ -1066,12 +1070,14 @@ WasmResult Context::setProperty(absl::string_view path, absl::string_view value)
     state = &stream_info->filterState()->getDataMutable<WasmState>(key);
   } else {
     const auto& it = rootContext()->state_prototypes_.find(path);
-    auto state_ptr = std::make_unique<WasmState>(it == rootContext()->state_prototypes_.end()
-                                                     ? DefaultWasmStatePrototype::get()
-                                                     : *it->second.get());
+    const WasmStatePrototype& prototype = it == rootContext()->state_prototypes_.end()
+                                              ? DefaultWasmStatePrototype::get()
+                                              : *it->second.get();
+    auto state_ptr = std::make_unique<WasmState>(prototype);
     state = state_ptr.get();
     stream_info->filterState()->setData(key, std::move(state_ptr),
-                                        StreamInfo::FilterState::StateType::ReadOnly);
+                                        StreamInfo::FilterState::StateType::Mutable,
+                                        prototype.life_span_);
   }
   if (!state->setValue(value)) {
     return WasmResult::BadArgument;
diff --git a/source/extensions/common/wasm/context.h b/source/extensions/common/wasm/context.h
index dd7fc0351b51..6c30dc1ebbbc 100644
--- a/source/extensions/common/wasm/context.h
+++ b/source/extensions/common/wasm/context.h
@@ -306,13 +306,17 @@ class Context : public Logger::Loggable<Logger::Id::wasm>,
                               bool end_stream); // stream only
 
   // CEL evaluation
-  virtual std::vector<const google::api::expr::runtime::CelFunction*>
+  std::vector<const google::api::expr::runtime::CelFunction*>
   FindFunctionOverloads(absl::string_view) const override {
     return {};
   }
-  virtual absl::optional<google::api::expr::runtime::CelValue>
-  FindValue(absl::string_view name, Protobuf::Arena* arena) const override;
-  virtual bool IsPathUnknown(absl::string_view) const override { return false; }
+  absl::optional<google::api::expr::runtime::CelValue>
+  findValue(absl::string_view name, Protobuf::Arena* arena, bool last) const;
+  absl::optional<google::api::expr::runtime::CelValue>
+  FindValue(absl::string_view name, Protobuf::Arena* arena) const override {
+    return findValue(name, arena, false);
+  }
+  bool IsPathUnknown(absl::string_view) const override { return false; }
   const std::vector<google::api::expr::runtime::CelAttributePattern>&
   unknown_attribute_patterns() const override {
     static const std::vector<google::api::expr::runtime::CelAttributePattern> empty;