JSON serialized storage of properties table.

.vscode/settings.json

@@ -101,6 +101,8 @@
         "ranges": "cpp",
         "stop_token": "cpp",
         "version": "cpp",
-        "shared_mutex": "cpp"
+        "shared_mutex": "cpp",
+        "compare": "cpp",
+        "concepts": "cpp"
     }
 }

src/common/module.mk

@@ -33,6 +33,8 @@ MODULE_OBJS := \
 	src/common/sdl_blitter/QisBlitter.o \
 	src/common/sdl_blitter/BlitterFactory.o \
 	src/common/repository/KeyValueRepositoryPropertyFile.o \
+	src/common/repository/KeyValueRepositoryJsonFile.o \
+	src/common/repository/CompositeKVRJsonAdapter.o
 
 MODULE_DIRS += \
 	src/common

src/common/repository/CompositeKVRJsonAdapter.cxx

@@ -0,0 +1,77 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2021 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#include <sstream>
+
+#include "CompositeKVRJsonAdapter.hxx"
+#include "repository/KeyValueRepositoryJsonFile.hxx"
+
+namespace {
+  class ProxyRepository : public KeyValueRepository {
+      public:
+        ProxyRepository(KeyValueRepositoryAtomic& kvr, const string& key)
+          : myKvr(kvr), myKey(key)
+        {}
+
+        std::map<string, Variant> load() override {
+          if (!myKvr.has(myKey)) return std::map<string, Variant>();
+
+          string serialized;
+          myKvr.get(myKey, serialized);
+
+          stringstream in{serialized};
+
+          return KeyValueRepositoryJsonFile::load(in);
+        }
+
+        bool save(const std::map<string, Variant>& values) override {
+          stringstream out;
+
+          if (!KeyValueRepositoryJsonFile::save(out, values)) return false;
+
+          return myKvr.save(myKey, out.str());
+        }
+
+      private:
+
+        KeyValueRepositoryAtomic& myKvr;
+        const string& myKey;
+    };
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+CompositeKVRJsonAdapter::CompositeKVRJsonAdapter(KeyValueRepositoryAtomic& kvr)
+  : myKvr(kvr)
+{}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+shared_ptr<KeyValueRepository> CompositeKVRJsonAdapter::get(const string& key)
+{
+  return make_shared<ProxyRepository>(myKvr, key);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool CompositeKVRJsonAdapter::has(const string& key)
+{
+  return myKvr.has(key);
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+void CompositeKVRJsonAdapter::remove(const string& key)
+{
+  return myKvr.remove(key);
+}

src/common/repository/CompositeKVRJsonAdapter.hxx

@@ -0,0 +1,41 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2021 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#ifndef COMPOSITE_KVR_JSON_ADAPTER_HXX
+#define COMPOSITE_KVR_JSON_ADAPTER_HXX
+
+#include "repository/CompositeKeyValueRepository.hxx"
+#include "repository/KeyValueRepository.hxx"
+#include "bspf.hxx"
+
+class CompositeKVRJsonAdapter : public CompositeKeyValueRepository {
+  public:
+
+    CompositeKVRJsonAdapter(KeyValueRepositoryAtomic& kvr);
+
+    shared_ptr<KeyValueRepository> get(const string& key) override;
+
+    bool has(const string& key) override;
+
+    void remove(const string& key) override;
+
+  private:
+
+    KeyValueRepositoryAtomic& myKvr;
+};
+
+#endif // COMPOSITE_KVR_JSON_ADAPTER_HXX

src/common/repository/KeyValueRepository.hxx

@@ -23,6 +23,11 @@
 #include "Variant.hxx"
 #include "bspf.hxx"
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Woverloaded-virtual"
+
+class KeyValueRepositoryAtomic;
+
 class KeyValueRepository
 {
   public:
@@ -33,9 +38,22 @@ class KeyValueRepository
 
     virtual bool save(const std::map<string, Variant>& values) = 0;
 
+    virtual KeyValueRepositoryAtomic* atomic() { return nullptr; }
+};
+
+class KeyValueRepositoryAtomic : public KeyValueRepository {
+  public:
+    virtual bool has(const string& key) = 0;
+
+    virtual bool get(const string& key, string& value) = 0;
+
     virtual bool save(const string& key, const Variant& value) = 0;
 
     virtual void remove(const string& key) = 0;
+
+    KeyValueRepositoryAtomic* atomic() override { return this; }
 };
 
+#pragma clang diagnostic pop
+
 #endif // KEY_VALUE_REPOSITORY_HXX

src/common/repository/KeyValueRepositoryConfigfile.hxx

@@ -21,7 +21,7 @@
 #include "FSNode.hxx"
 #include "KeyValueRepository.hxx"
 
-class KeyValueRepositoryConfigfile : public KeyValueRepository
+class KeyValueRepositoryConfigfile : public KeyValueRepositoryAtomic
 {
   public:
 
@@ -31,10 +31,6 @@ class KeyValueRepositoryConfigfile : public KeyValueRepository
 
     bool save(const std::map<string, Variant>& values) override;
 
-    bool save(const string& key, const Variant& value) override { return false; }
-
-    void remove(const string& key) override {}
-
   private:
 
     FilesystemNode myFile;

src/common/repository/KeyValueRepositoryFile.hxx

@@ -0,0 +1,99 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2021 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#ifndef KEY_VALUE_REPOSITORY_FILE_HXX
+#define KEY_VALUE_REPOSITORY_FILE_HXX
+
+#include <sstream>
+
+#include "KeyValueRepository.hxx"
+#include "Logger.hxx"
+#include "FSNode.hxx"
+#include "bspf.hxx"
+
+template<class T>
+class KeyValueRepositoryFile : public KeyValueRepository {
+  public:
+    KeyValueRepositoryFile(const FilesystemNode& node);
+
+    std::map<string, Variant> load() override;
+
+    bool save(const std::map<string, Variant>& values) override;
+
+  protected:
+
+    const FilesystemNode& myNode;
+};
+
+///////////////////////////////////////////////////////////////////////////////
+// IMPLEMEMNTATION
+///////////////////////////////////////////////////////////////////////////////
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+template<class T>
+KeyValueRepositoryFile<T>::KeyValueRepositoryFile(const FilesystemNode& node)
+  : myNode(node)
+{}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+template<class T>
+std::map<string, Variant> KeyValueRepositoryFile<T>::load()
+{
+  if (!myNode.exists()) return std::map<string, Variant>();
+
+  stringstream in;
+
+  try {
+    myNode.read(in);
+    return T::load(in);
+  }
+  catch (const runtime_error& err) {
+    Logger::error(err.what());
+
+    return std::map<string, Variant>();
+  }
+  catch (...) {
+    return std::map<string, Variant>();
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+template<class T>
+bool KeyValueRepositoryFile<T>::save(const std::map<string, Variant>& values)
+{
+  if (values.size() == 0) return true;
+
+  stringstream out;
+
+  try {
+    T::save(out, values);
+    myNode.write(out);
+
+    return true;
+  }
+  catch (const runtime_error& err) {
+    Logger::error(err.what());
+
+    return false;
+  }
+  catch (...)
+  {
+    return false;
+  }
+}
+
+#endif // KEY_VALUE_REPOSITORY_FILE

src/common/repository/KeyValueRepositoryJsonFile.cxx

@@ -0,0 +1,81 @@
+//============================================================================
+//
+//   SSSS    tt          lll  lll
+//  SS  SS   tt           ll   ll
+//  SS     tttttt  eeee   ll   ll   aaaa
+//   SSSS    tt   ee  ee  ll   ll      aa
+//      SS   tt   eeeeee  ll   ll   aaaaa  --  "An Atari 2600 VCS Emulator"
+//  SS  SS   tt   ee      ll   ll  aa  aa
+//   SSSS     ttt  eeeee llll llll  aaaaa
+//
+// Copyright (c) 1995-2021 by Bradford W. Mott, Stephen Anthony
+// and the Stella Team
+//
+// See the file "License.txt" for information on usage and redistribution of
+// this file, and for a DISCLAIMER OF ALL WARRANTIES.
+//============================================================================
+
+#include "repository/KeyValueRepositoryJsonFile.hxx"
+#include "Logger.hxx"
+#include "json_lib.hxx"
+
+using nlohmann::json;
+
+namespace {
+  json jsonIfValid(const string& s) {
+    json parsed = json::parse(s, nullptr, false);
+
+    return parsed.is_discarded() ? json(s) : parsed;
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+KeyValueRepositoryJsonFile::KeyValueRepositoryJsonFile(const FilesystemNode& node)
+  : KeyValueRepositoryFile<KeyValueRepositoryJsonFile>(node)
+{}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+std::map<string, Variant> KeyValueRepositoryJsonFile::load(istream& in)
+{
+  try {
+    std::map<string, Variant> map;
+
+    json deserialized = json::parse(in);
+
+    if (!deserialized.is_object()) {
+      Logger::error("KeyVallueRepositoryJsonFile: not an object");
+
+      return map;
+    }
+
+    for (const auto& [key, value] : deserialized.items())
+      map[key] = value.is_string() ? value.get<string>() : value.dump();
+
+    return map;
+  }
+  catch (const json::exception& err) {
+    Logger::error("KeyValueRepositoryJsonFile: error during deserialization: " + string(err.what()));
+
+    return std::map<string, Variant>();
+  }
+}
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+bool KeyValueRepositoryJsonFile::save(ostream& out, const std::map<string, Variant>& values)
+{
+  try {
+    json serializedJson = json::object();
+
+    for (const auto& [key, value] : values)
+      serializedJson[key] = jsonIfValid(value.toString());
+
+    out << serializedJson.dump(2);
+
+    return true;
+  }
+  catch (const json::exception& err) {
+    Logger::error("KeyValueRepositoryJsonFile: error during serialization: "  + string(err.what()));
+
+    return false;
+  }
+}