Class ExecutionContext

packages/blueprint/src/runtime/ExecutionContext.ts:50–270

 * 执行上下文提供对运行时服务的访问
 */
export class ExecutionContext {
    /** Current blueprint asset (当前蓝图资产) */
    readonly blueprint: BlueprintAsset;

    /** Owner entity (所有者实体) */
    readonly entity: Entity;

    /** Current scene (当前场景) */
    readonly scene: IScene;

    /** Frame delta time (帧增量时间) */
    deltaTime: number = 0;

    /** Total time since start (开始以来的总时间) */
    time: number = 0;

    /** Instance variables (实例变量) */
    private _instanceVariables: Map<string, unknown> = new Map();

    /** Local variables (per-execution) (局部变量，每次执行) */
    private _localVariables: Map<string, unknown> = new Map();

    /** Global variables (shared) (全局变量，共享) */
    private static _globalVariables: Map<string, unknown> = new Map();

    /** Node output cache for current execution (当前执行的节点输出缓存) */
    private _outputCache: Map<string, Record<string, unknown>> = new Map();

    /** Connection lookup by target (按目标的连接查找) */
    private _connectionsByTarget: Map<string, BlueprintConnection[]> = new Map();

    /** Connection lookup by source (按源的连接查找) */
    private _connectionsBySource: Map<string, BlueprintConnection[]> = new Map();

    constructor(blueprint: BlueprintAsset, entity: Entity, scene: IScene) {
        this.blueprint = blueprint;
        this.entity = entity;
        this.scene = scene;

        // Initialize instance variables with defaults
        // 使用默认值初始化实例变量
        for (const variable of blueprint.variables) {
            if (variable.scope === 'instance') {
                this._instanceVariables.set(variable.name, variable.defaultValue);
            }
        }

        // Build connection lookup maps
        // 构建连接查找映射
        this._buildConnectionMaps();
    }

    private _buildConnectionMaps(): void {
        for (const conn of this.blueprint.connections) {
            // By target
            const targetKey = `${conn.toNodeId}.${conn.toPin}`;
            if (!this._connectionsByTarget.has(targetKey)) {
                this._connectionsByTarget.set(targetKey, []);