First commit

node_modules/restructure/src/LazyArray.js

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+import {Array as ArrayT} from './Array.js';
+import {Number as NumberT} from './Number.js';
+import * as utils from './utils.js';
+
+export class LazyArray extends ArrayT {
+  decode(stream, parent) {
+    const { pos } = stream;
+    const length = utils.resolveLength(this.length, stream, parent);
+
+    if (this.length instanceof NumberT) {
+      parent = {
+        parent,
+        _startOffset: pos,
+        _currentOffset: 0,
+        _length: length
+      };
+    }
+
+    const res = new LazyArrayValue(this.type, length, stream, parent);
+
+    stream.pos += length * this.type.size(null, parent);
+    return res;
+  }
+
+  size(val, ctx) {
+    if (val instanceof LazyArrayValue) {
+      val = val.toArray();
+    }
+
+    return super.size(val, ctx);
+  }
+
+  encode(stream, val, ctx) {
+    if (val instanceof LazyArrayValue) {
+      val = val.toArray();
+    }
+
+    return super.encode(stream, val, ctx);
+  }
+}
+
+class LazyArrayValue {
+  constructor(type, length, stream, ctx) {
+    this.type = type;
+    this.length = length;
+    this.stream = stream;
+    this.ctx = ctx;
+    this.base = this.stream.pos;
+    this.items = [];
+  }
+
+  get(index) {
+    if ((index < 0) || (index >= this.length)) {
+      return undefined;
+    }
+
+    if (this.items[index] == null) {
+      const { pos } = this.stream;
+      this.stream.pos = this.base + (this.type.size(null, this.ctx) * index);
+      this.items[index] = this.type.decode(this.stream, this.ctx);
+      this.stream.pos = pos;
+    }
+
+    return this.items[index];
+  }
+
+  toArray() {
+    const result = [];
+    for (let i = 0, end = this.length; i < end; i++) {
+      result.push(this.get(i));
+    }
+    return result;
+  }
+}