init: UserBaseFront (frontend)

src/utils/nodeIdUtil.ts

@@ -0,0 +1,50 @@
+/**
+ * NodeId 解码工具
+ */
+const ROOT_BITS = 4,
+    TYPE_BITS = 4,
+    SUBJ_BITS = 20,
+    STAGE_BITS = 4,
+    GRADE_BITS = 4,
+    NODE_BITS = 28;
+
+const ROOT_MASK = mask(ROOT_BITS),
+    TYPE_MASK = mask(TYPE_BITS),
+    SUBJ_MASK = mask(SUBJ_BITS),
+    STAGE_MASK = mask(STAGE_BITS),
+    GRADE_MASK = mask(GRADE_BITS),
+    NODE_MASK = mask(NODE_BITS);
+
+function mask(bits: number) {
+    return (1n << BigInt(bits)) - 1n;
+}
+
+function intToSubject(n: number) {
+    if (n === 0) return null;
+    return n <= 6 ? `SUB0${n}` : `SUB${n}`;
+}
+
+/**
+ * 解码入口：long → 普通对象
+ * @param {string|number} compositeId  后端传来的 long 字符串或数字
+ * @returns {Object}
+ */
+export function decodeNodeId(compositeId: number | string) {
+    const id = BigInt(compositeId);
+
+    const root = Number((id >> BigInt(TYPE_BITS + SUBJ_BITS + STAGE_BITS + GRADE_BITS + NODE_BITS)) & ROOT_MASK);
+    const type = Number((id >> BigInt(SUBJ_BITS + STAGE_BITS + GRADE_BITS + NODE_BITS)) & TYPE_MASK);
+    const subNum = Number((id >> BigInt(STAGE_BITS + GRADE_BITS + NODE_BITS)) & SUBJ_MASK);
+    const stage = Number((id >> BigInt(GRADE_BITS + NODE_BITS)) & STAGE_MASK);
+    const grade = Number((id >> BigInt(NODE_BITS)) & GRADE_MASK);
+    const nodeId = Number(id & NODE_MASK);
+
+    return {
+        rootType: root === 0 ? null : root,
+        nodeType: type === 0 ? null : type,
+        subject: intToSubject(subNum),
+        stage: stage === 0 ? null : stage,
+        grade: grade === 0 ? null : grade,
+        nodeId: nodeId === 0 ? null : nodeId,
+    };
+}