feat(DataView, ConstDataView)

src/index.js

@@ -2,10 +2,11 @@ import { limits } from "./limits"
 import { memcpy } from "./mem"
 import { Type } from "./Type"
 import { ConstString } from './ConstString'
-import { ConstArray } from "./ConstArray" 
+import { ConstArray } from "./ConstArray"
+import { ConstDataView } from './ConstDataView'
 import { Struct } from './Struct'
 
-export { limits, memcpy, Type, ConstString, ConstArray, Struct }
+export { limits, memcpy, Type, ConstString, ConstArray, ConstDataView, Struct }
 
 export function serialize(dv, src, ...types) {
   const [type, ...inner_types] = types
@@ -54,6 +55,19 @@ export function serialize(dv, src, ...types) {
     }
     return
   }
+  if (type == DataView && src instanceof DataView) {
+    if (dv.byteLength < 4 + src.byteLength) {
+      throw new Error('too small buffer')
+    }
+    if (src.byteLength > limits.u32.MAX_VALUE) {
+      throw new Error('data view is too long')
+    }
+
+    dv.setUint32(0, src.byteLength)
+
+    const frame = new DataView(dv.buffer, dv.byteOffset + 4)
+    memcpy(frame, src)
+  }
   if (type instanceof Type) {
     type.serialize(dv, src, ...inner_types)
     return
@@ -84,6 +98,16 @@ export function parse(dv, ...types) {
 
     return array
   }
+  if (type == DataView) {
+    const size = dv.getUint32(0)
+    const res_buffer = new ArrayBuffer(size)
+    const res_dv = new DataView(res_buffer)
+
+    const frame = new DataView(dv.buffer, dv.byteOffset + 4)
+    memcpy(res_dv, frame)
+
+    return res_dv
+  }
   if (type instanceof Type) {
     return type.parse(dv, ...inner_types)
   }
@@ -96,8 +120,10 @@ export function isHeadless(...args) {
   }
   return arg == Array ||
     arg == String ||
+    arg == DataView ||
     Array.isArray(arg) ||
-    typeof arg == 'string'
+    typeof arg == 'string' ||
+    arg instanceof DataView
 }
 
 export function sizeofHead(...args) {
@@ -121,6 +147,9 @@ export function sizeof(...args) {
   if (Array.isArray(arg)) {
     return 4 + sizeofHead(arg[0]) * arg.length
   }
+  if (arg instanceof DataView) {
+    return 4 + arg.byteLength
+  }
   if (arg instanceof Type) {
     return arg.sizeof(...inner_args)
   }