client: cache llhttp wasm buffer view

lib/dispatcher/client-h1.js

@@ -188,6 +188,7 @@ let currentBufferRef = null
  */
 let currentBufferSize = 0
 let currentBufferPtr = null
+let currentBuffer = null
 
 const USE_NATIVE_TIMER = 0
 const USE_FAST_TIMER = 1
@@ -322,7 +323,16 @@ class Parser {
       currentBufferPtr = llhttp.malloc(currentBufferSize)
     }
 
-    new Uint8Array(llhttp.memory.buffer, currentBufferPtr, currentBufferSize).set(chunk)
+    if (
+      currentBuffer === null ||
+      currentBuffer.buffer !== llhttp.memory.buffer ||
+      currentBuffer.byteOffset !== currentBufferPtr ||
+      currentBuffer.byteLength !== currentBufferSize
+    ) {
+      currentBuffer = new Uint8Array(llhttp.memory.buffer, currentBufferPtr, currentBufferSize)
+    }
+
+    currentBuffer.set(chunk)
 
     // Call `execute` on the wasm parser.
     // We pass the `llhttp_parser` pointer address, the pointer address of buffer view data,

test/parser-issues.js

@@ -129,3 +129,69 @@ test('split header value', async (t) => {
 
   await t.completed
 })
+
+test('refreshes wasm input view after reallocating parser buffer', async (t) => {
+  t = tspl(t, { plan: 4 })
+
+  const smallBody = Buffer.from('ok')
+  const largeBody = Buffer.alloc(8192, 'a')
+  const responses = [
+    Buffer.concat([
+      Buffer.from(`HTTP/1.1 200 OK\r\nContent-Length: ${smallBody.length}\r\n\r\n`),
+      smallBody
+    ]),
+    Buffer.concat([
+      Buffer.from(`HTTP/1.1 200 OK\r\nContent-Length: ${largeBody.length}\r\n\r\n`),
+      largeBody
+    ])
+  ]
+
+  const server = net.createServer(socket => {
+    let responsesSent = 0
+
+    socket.on('data', () => {
+      socket.write(responses[responsesSent++])
+    })
+  })
+  after(() => server.close())
+
+  await new Promise(resolve => server.listen(0, resolve))
+
+  const client = new Client(`http://localhost:${server.address().port}`)
+  after(() => client.destroy())
+
+  function request () {
+    return new Promise((resolve, reject) => {
+      client.request({
+        method: 'GET',
+        path: '/'
+      }, (err, { statusCode, body } = {}) => {
+        if (err) {
+          reject(err)
+          return
+        }
+
+        const bufs = []
+
+        body.on('data', buf => {
+          bufs.push(buf)
+        })
+        body.on('end', () => {
+          resolve({
+            statusCode,
+            body: Buffer.concat(bufs)
+          })
+        })
+        body.on('error', reject)
+      })
+    })
+  }
+
+  const smallResponse = await request()
+  t.strictEqual(smallResponse.statusCode, 200)
+  t.strictEqual(smallResponse.body.toString(), smallBody.toString())
+
+  const largeResponse = await request()
+  t.strictEqual(largeResponse.statusCode, 200)
+  t.strictEqual(largeResponse.body.toString(), largeBody.toString())
+})