src: allow per-Environment set of env vars

Abstract the `process.env` backing mechanism in C++ to allow
different kinds of backing stores for `process.env` for different
Environments.

PR-URL: https://github.com/nodejs/node/pull/26544
Fixes: https://github.com/nodejs/node/issues/24947
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Vse Mozhet Byt <vsemozhetbyt@gmail.com>
Reviewed-By: Yongsheng Zhang <zyszys98@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Benjamin Gruenbaum <benjamingr@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/env.h b/src/env.h
index 743c236827..e6c3a1c037 100644
--- a/src/env.h
+++ b/src/env.h
@@ -540,6 +540,23 @@ class AsyncRequest : public MemoryRetainer {
   std::atomic_bool stopped_ {true};
 };
 
+class KVStore {
+ public:
+  virtual v8::Local<v8::String> Get(v8::Isolate* isolate,
+                                    v8::Local<v8::String> key) const = 0;
+  virtual void Set(v8::Isolate* isolate,
+                   v8::Local<v8::String> key,
+                   v8::Local<v8::String> value) = 0;
+  virtual int32_t Query(v8::Isolate* isolate,
+                        v8::Local<v8::String> key) const = 0;
+  virtual void Delete(v8::Isolate* isolate, v8::Local<v8::String> key) = 0;
+  virtual v8::Local<v8::Array> Enumerate(v8::Isolate* isolate) const = 0;
+};
+
+namespace per_process {
+extern std::shared_ptr<KVStore> real_environment;
+}
+
 class AsyncHooks {
  public:
   // Reason for both UidFields and Fields are that one is stored as a double*
@@ -789,6 +806,8 @@ class Environment {
   inline ImmediateInfo* immediate_info();
   inline TickInfo* tick_info();
   inline uint64_t timer_base() const;
+  inline std::shared_ptr<KVStore> envvars();
+  inline void set_envvars(std::shared_ptr<KVStore> envvars);
 
   inline IsolateData* isolate_data() const;
 
@@ -1075,6 +1094,7 @@ class Environment {
   ImmediateInfo immediate_info_;
   TickInfo tick_info_;
   const uint64_t timer_base_;
+  std::shared_ptr<KVStore> envvars_;
   bool printed_error_ = false;
   bool emit_env_nonstring_warning_ = true;
   bool emit_err_name_warning_ = true;