asset onLoad scripts can add and patch assets now

source/base/CMakeLists.txt

@@ -14,6 +14,7 @@ SET (star_base_HEADERS
     StarCellularLiquid.hpp
     StarConfiguration.hpp
     StarDirectoryAssetSource.hpp
+    StarMemoryAssetSource.hpp
     StarMixer.hpp
     StarPackedAssetSource.hpp
     StarVersion.hpp
@@ -27,6 +28,7 @@ SET (star_base_SOURCES
     StarCellularLighting.cpp
     StarConfiguration.cpp
     StarDirectoryAssetSource.cpp
+    StarMemoryAssetSource.cpp
     StarMixer.cpp
     StarPackedAssetSource.cpp
     StarVersionOptionParser.cpp

source/base/StarAssets.cpp

@@ -4,6 +4,7 @@
 #include "StarTime.hpp"
 #include "StarDirectoryAssetSource.hpp"
 #include "StarPackedAssetSource.hpp"
+#include "StarMemoryAssetSource.hpp"
 #include "StarJsonBuilder.hpp"
 #include "StarJsonExtra.hpp"
 #include "StarJsonPatch.hpp"
@@ -108,18 +109,54 @@ Assets::Assets(Settings settings, StringList assetSources) {
   m_assetSources = std::move(assetSources);
 
   auto luaEngine = LuaEngine::create();
-  auto decorateLuaContext = [this](LuaContext& context) {
+  auto decorateLuaContext = [this](LuaContext& context, MemoryAssetSourcePtr mySource) {
     context.setCallbacks("sb", LuaBindings::makeUtilityCallbacks());
     LuaCallbacks callbacks;
     callbacks.registerCallbackWithSignature<StringSet, String>("byExtension", bind(&Assets::scanExtension, this, _1));
     callbacks.registerCallbackWithSignature<Json, String>("json", bind(&Assets::json, this, _1));
+
     callbacks.registerCallback("bytes", [this](String const& path) -> String {
       auto assetBytes = bytes(path);
       return String(assetBytes->ptr(), assetBytes->size());
     });
+
     callbacks.registerCallback("scan", [this](Maybe<String> const& a, Maybe<String> const& b) -> StringList {
       return b ? scan(a.value(), *b) : scan(a.value());
     });
+
+    callbacks.registerCallback("add", [this, &mySource](LuaEngine& engine, String const& path, LuaValue const& data) -> bool {
+      ByteArray bytes;
+      if (auto str = engine.luaMaybeTo<String>(data))
+        bytes = ByteArray(str->utf8Ptr(), str->utf8Size());
+      else {
+        auto json = engine.luaTo<Json>(data).repr();
+        bytes = ByteArray(json.utf8Ptr(), json.utf8Size());
+      }
+      return mySource->set(path, bytes);
+    });
+
+    callbacks.registerCallback("patch", [this, &mySource](String const& path, String const& patchPath) -> bool {
+      if (auto file = m_files.ptr(path)) {
+        if (mySource->contains(patchPath)) {
+          file->patchSources.append(make_pair(patchPath, mySource));
+          return true;
+        } else {
+          if (auto asset = m_files.ptr(patchPath)) {
+            file->patchSources.append(make_pair(patchPath, asset->source));
+            return true;
+          }
+        }
+      }
+      return false;
+    });
+
+    callbacks.registerCallback("erase", [this, &mySource](String const& path) -> bool {
+      bool erased = m_files.erase(path);
+      if (erased)
+        m_filesByExtension[AssetPath::extension(path).toLower()].erase(path);
+      return erased;
+    });
+
     context.setCallbacks("assets", callbacks);
   };
 
@@ -131,6 +168,7 @@ Assets::Assets(Settings settings, StringList assetSources) {
     else
       source = std::make_shared<PackedAssetSource>(sourcePath);
 
+    auto addSource = [&](String const& sourcePath, AssetSourcePtr source) {
       m_assetSourcePaths.add(sourcePath, source);
 
       for (auto const& filename : source->assetPaths()) {
@@ -150,18 +188,26 @@ Assets::Assets(Settings settings, StringList assetSources) {
             }
           }
         }
+
         auto& descriptor = m_files[filename];
         descriptor.sourceName = filename;
         descriptor.source = source;
         m_filesByExtension[AssetPath::extension(filename).toLower()].insert(filename);
       }
+    };
+    addSource(sourcePath, source);
+
     auto metadata = source->metadata();
     if (auto scripts = metadata.ptr("scripts")) {
       if (auto onLoad = scripts->optArray("onLoad")) {
+        JsonObject memoryMetadata{
+          {"name", strf("{}.onLoad", metadata.value("name", File::baseName(sourcePath)))}
+        };
+        auto memoryAssets = make_shared<MemoryAssetSource>(memoryMetadata);
         Logger::info("Running onLoad scripts {}", *onLoad);
         try {
           auto context = luaEngine->createContext();
-          decorateLuaContext(context);
+          decorateLuaContext(context, memoryAssets);
           for (auto& jPath : *onLoad) {
             auto path = jPath.toString();
             auto script = source->read(path);
@@ -171,6 +217,8 @@ Assets::Assets(Settings settings, StringList assetSources) {
         catch (LuaException const& e) {
           Logger::error("Exception while running onLoad scripts from asset source '{}': {}", sourcePath, e.what());
         }
+        if (!memoryAssets->empty())
+          addSource(memoryMetadata.get("name").toString(), memoryAssets);
       }
     }
   }

source/base/StarMemoryAssetSource.cpp

@@ -0,0 +1,86 @@
+#include "StarMemoryAssetSource.hpp"
+#include "StarDataStreamDevices.hpp"
+#include "StarDataStreamExtra.hpp"
+#include "StarSha256.hpp"
+
+namespace Star {
+
+MemoryAssetSource::MemoryAssetSource(JsonObject metadata) : m_metadata(metadata) {}
+
+JsonObject MemoryAssetSource::metadata() const {
+  return m_metadata;
+}
+
+StringList MemoryAssetSource::assetPaths() const {
+  return m_files.keys();
+}
+
+IODevicePtr MemoryAssetSource::open(String const& path) {
+  struct AssetReader : public IODevice {
+    AssetReader(ByteArrayPtr assetData, String name) : assetData(assetData), name(name) { setMode(IOMode::Read); }
+
+    size_t read(char* data, size_t len) override {
+      len = min<StreamOffset>(len, StreamOffset(assetData->size()) - assetPos);
+      assetData->copyTo(data, len);
+      return len;
+    }
+
+    size_t write(char const*, size_t) override {
+      throw IOException("Assets IODevices are read-only");
+    }
+
+    StreamOffset size() override { return assetData->size(); }
+    StreamOffset pos() override { return assetPos; }
+
+    String deviceName() const override { return name; }
+
+    bool atEnd() override {
+      return assetPos >= assetData->size();
+    }
+
+    void seek(StreamOffset p, IOSeek mode) override {
+      if (mode == IOSeek::Absolute)
+        assetPos = p;
+      else if (mode == IOSeek::Relative)
+        assetPos = clamp<StreamOffset>(assetPos + p, 0, assetData->size());
+      else
+        assetPos = clamp<StreamOffset>(assetPos - p, 0, assetData->size());
+    }
+
+    ByteArrayPtr assetData;
+    StreamOffset assetPos;
+    String name;
+  };
+
+  auto p = m_files.ptr(path);
+  if (!p)
+    throw AssetSourceException::format("Requested file '{}' does not exist in memory", path);
+
+  return make_shared<AssetReader>(*p, path);
+}
+
+bool MemoryAssetSource::empty() const {
+  return m_files.empty();
+}
+
+bool MemoryAssetSource::contains(String const& path) const {
+  return m_files.contains(path);
+}
+
+bool MemoryAssetSource::erase(String const& path) {
+  return m_files.erase(path) != 0;
+}
+
+bool MemoryAssetSource::set(String const& path, ByteArray data) {
+  return m_files.emplace(path, make_shared<ByteArray>(std::move(data))).second;
+}
+
+ByteArray MemoryAssetSource::read(String const& path) {
+  auto p = m_files.ptr(path);
+  if (!p)
+    throw AssetSourceException::format("Requested file '{}' does not exist in memory", path);
+  else
+    return *p->get(); // this is a double indirection, and that freaking sucks!!
+}
+
+}

source/base/StarMemoryAssetSource.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include "StarAssetSource.hpp"
+#include "StarIODevice.hpp"
+
+namespace Star {
+
+STAR_CLASS(MemoryAssetSource);
+
+class MemoryAssetSource : public AssetSource {
+public:
+  MemoryAssetSource(JsonObject metadata = JsonObject());
+
+  JsonObject metadata() const override;
+  StringList assetPaths() const override;
+
+  IODevicePtr open(String const& path) override;
+
+  bool empty() const;
+  bool contains(String const& path) const;
+  bool erase(String const& path);
+  bool set(String const& path, ByteArray data);
+  ByteArray read(String const& path) override;
+private:
+  JsonObject m_metadata;
+  StringMap<ByteArrayPtr> m_files;
+};
+
+}