feat(Struct)

src/ConstArray.js

@@ -0,0 +1,47 @@
+import { limits, parse, serialize, sizeofHead, Type } from "."
+
+export function ConstArray(size) {
+  const obj = { _size: size }
+  Object.setPrototypeOf(obj, ConstArray.prototype)
+  obj.new(ConstArray, arguments)
+  return obj
+}
+ConstArray.prototype.serialize = function(dv, src, ...inner_types) {
+  const item_size = sizeofHead(src[0])
+  let size = this._size
+
+  if (dv.byteLength < size * item_size) {
+    throw new Error('too small buffer')
+  }
+  if (size > limits.u32.MAX_VALUE) {
+    throw new Error('array is too long')
+  }
+
+  dv.setUint32(0, size)
+
+  for (let i = 0; i < size; i++) {
+    const item_frame = new DataView(dv.buffer, dv.byteOffset + item_size * i)
+    serialize(item_frame, src[i], ...inner_types)
+  }
+  return
+}
+ConstArray.prototype.parse = function(dv, ...inner_types) { 
+  const size = this._size
+  const item_size = sizeofHead(...inner_types)
+  const array = Array(size)
+
+  for (let i = 0; i < size; i++) {
+    const item_frame = new DataView(dv.buffer, dv.byteOffset + item_size * i)
+    array[i] = parse(item_frame, ...inner_types)
+  }
+
+  return array
+}
+ConstArray.prototype.isHeadless = function() {
+  return false
+}
+ConstArray.prototype.sizeof = function(...inner_types) {
+  return sizeofHead(...inner_types) * this._size
+}
+Object.setPrototypeOf(ConstArray.prototype, Type.prototype)
+Object.freeze(ConstArray.prototype)