commit ce309533f4571a82c19861144a1bca2494b89a43
Author: Mathias Buus <mathiasbuus@gmail.com>
Date:   Wed Nov 10 15:15:09 2021 +0100

    first commit

diff --git a/.github/workflows/test-node.yml b/.github/workflows/test-node.yml
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--- /dev/null
+++ b/.github/workflows/test-node.yml
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+name: Build Status
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    branches:
+      - master
+jobs:
+  build:
+    strategy:
+      matrix:
+        node-version: [lts/*]
+        os: [ubuntu-latest, macos-latest, windows-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v2
+      with:
+        node-version: ${{ matrix.node-version }}
+    - run: npm install
+    - run: npm test
diff --git a/.gitignore b/.gitignore
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index 0000000..df9289e
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,4 @@
+node_modules
+sandbox.js
+sandbox
+coverage
diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..702b8e7
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2021 Mathias Buus
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..11c898b
--- /dev/null
+++ b/README.md
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+# protomux
+
+Multiplex multiple message oriented protocols over a stream
+
+```
+npm install protomux
+```
+
+## Usage
+
+``` js
+const Protomux = require('protomux')
+```
+
+## License
+
+MIT
diff --git a/index.js b/index.js
new file mode 100644
index 0000000..b891a3f
--- /dev/null
+++ b/index.js
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+const c = require('compact-encoding')
+const m = require('./messages')
+
+class Protocol {
+  constructor (muxer, offset, protocol) {
+    this.muxer = muxer
+    this.stream = muxer.stream
+    this.start = offset
+    this.end = offset + protocol.messages.length
+    this.name = protocol.name
+    this.version = protocol.version || { major: 0, minor: 0 }
+    this.messages = protocol.messages.length
+    this.remoteOpened = false
+    this.removed = false
+    this.encodings = protocol.messages
+    this.onmessage = noop
+    this.onopen = noop
+    this.onclose = noop
+  }
+
+  get corked () {
+    return this.muxer.corked
+  }
+
+  cork () {
+    this.muxer.cork()
+  }
+
+  uncork () {
+    this.muxer.uncork()
+  }
+
+  send (type, message) {
+    const t = this.start + type
+    const enc = this.encodings[type]
+
+    if (this.muxer.corked > 0) {
+      this.muxer._batch.push({ type: t, encoding: enc, message })
+      return false
+    }
+
+    const state = { start: 0, end: 0, buffer: null }
+
+    c.uint.preencode(state, t)
+    enc.preencode(state, message)
+
+    state.buffer = this.stream.alloc(state.end)
+
+    c.uint.encode(state, t)
+    enc.encode(state, message)
+
+    return this.stream.write(state.buffer)
+  }
+
+  recv (type, state) {
+    this.onmessage(type, this.encodings[type].decode(state))
+  }
+}
+
+module.exports = class Protomux {
+  constructor (stream, protocols, opts = {}) {
+    this.stream = stream
+
+    this.protocols = []
+    this.offset = 2
+
+    this.remoteProtocols = []
+    this.remoteOffset = 2
+
+    this.remoteHandshake = null
+    this.onhandshake = noop
+
+    this.corked = 0
+
+    this._batch = null
+    this._unmatchedProtocols = []
+
+    for (const p of protocols) this.addProtocol(p)
+
+    this.stream.on('data', this._ondata.bind(this))
+
+    if (opts.cork) this.cork()
+    this._sendHandshake()
+  }
+
+  remoteOpened (name) {
+    for (const p of this.remoteProtocols) {
+      if (p.local.name === name) return true
+    }
+    for (const { remote } of this._unmatchedProtocols) {
+      if (remote.name === name) return true
+    }
+    return false
+  }
+
+  addProtocol (p) {
+    const local = new Protocol(this, this.offset, p)
+
+    this.protocols.push(local)
+    this.offset += p.messages.length
+
+    for (let i = 0; i < this._unmatchedProtocols.length; i++) {
+      const { start, remote } = this._unmatchedProtocols[i]
+      if (remote.name !== p.name || remote.version.major !== local.version.major) continue
+      local.remoteOpened = true
+      this._unmatchedProtocols.splice(i, 1)
+      const end = start + Math.min(p.messages, local.messages)
+      this.remoteProtocols.push({ local, remote, start, end })
+      break
+    }
+
+    return local
+  }
+
+  removeProtocol (p) {
+    for (let i = 0; i < this.protocols.length; i++) {
+      const local = this.protocols[i]
+      if (local.name !== p.name || local.version.major !== p.version.major) continue
+      p.removed = true
+      this.protocols.splice(i, 1)
+    }
+
+    for (let i = 0; i < this.remoteProtocols.length; i++) {
+      const { local, remote, start } = this.remoteProtocols[i]
+      if (local.name !== p.name || local.version.major !== p.version.major) continue
+      this.remoteProtocols.splice(i, 1)
+      this._unmatchedProtocols.push({ start, remote })
+    }
+  }
+
+  addRemoteProtocol (p) {
+    const local = this.get(p.name)
+    const start = this.remoteOffset
+
+    this.remoteOffset += p.messages
+
+    if (!local || local.version.major !== p.version.major) {
+      this._unmatchedProtocols.push({ start, remote: p })
+      return
+    }
+
+    if (local.remoteOpened) {
+      this.destroy(new Error('Remote sent duplicate protocols'))
+      return
+    }
+
+    const end = start + Math.min(p.messages, local.messages)
+
+    this.remoteProtocols.push({ local, remote: p, start, end })
+
+    local.remoteOpened = true
+    local.onopen()
+  }
+
+  removeRemoteProtocol (p) {
+    for (let i = 0; i < this.remoteProtocols.length; i++) {
+      const { local } = this.remoteProtocols[i]
+      if (local.name !== p.name || local.version.major !== p.version.major) continue
+      this.remoteProtocols.splice(i, 1)
+      local.remoteOpened = false
+      local.onclose()
+      break
+    }
+
+    for (let i = 0; i < this._unmatchedProtocols.length; i++) {
+      const { remote } = this._unmatchedProtocols[i]
+      if (remote.name !== p.name || remote.version.major !== p.version.major) continue
+      this._unmatchedProtocols.splice(i, 1)
+      break
+    }
+  }
+
+  _ondata (buffer) {
+    const state = { start: 0, end: buffer.byteLength, buffer }
+
+    try {
+      this._recv(state, false)
+    } catch (err) {
+      this.destroy(err)
+    }
+  }
+
+  _recv (state) {
+    const t = c.uint.decode(state)
+
+    if (t < 2) {
+      if (t === 0) {
+        this._recvBatch(state)
+      } else {
+        this._recvHandshake(state)
+      }
+      return
+    }
+
+    for (let i = 0; i < this.remoteProtocols.length; i++) {
+      const p = this.remoteProtocols[i]
+
+      if (p.start <= t && t <= p.end) {
+        p.local.recv(t - p.start, state)
+        break
+      }
+    }
+
+    state.start = state.end
+  }
+
+  _recvBatch (state) {
+    const end = state.end
+
+    while (state.start < state.end) {
+      const len = c.uint.decode(state)
+      state.end = state.start + len
+      this._recv(state, true)
+      state.end = end
+    }
+  }
+
+  _recvHandshake (state) {
+    if (this.remoteHandshake !== null) {
+      this.destroy(new Error('Double handshake'))
+      return
+    }
+
+    this.remoteHandshake = m.handshake.decode(state)
+    for (const p of this.remoteHandshake.protocols) this.addRemoteProtocol(p)
+
+    this.onhandshake(this.remoteHandshake)
+  }
+
+  destroy (err) {
+    this.stream.destroy(err)
+  }
+
+  get (name) {
+    for (const p of this.protocols) {
+      if (p.name === name) return p
+    }
+    return null
+  }
+
+  cork () {
+    if (++this.corked === 1) this._batch = []
+  }
+
+  uncork () {
+    if (--this.corked !== 0) return
+
+    const batch = this._batch
+    this._batch = null
+
+    const state = { start: 0, end: 1, buffer: null }
+    const lens = new Array(batch.length)
+
+    for (let i = 0; i < batch.length; i++) {
+      const b = batch[i]
+      const end = state.end
+
+      c.uint.preencode(state, b.type)
+      b.encoding.preencode(state, b.message)
+      c.uint.preencode(state, lens[i] = (state.end - end))
+    }
+
+    state.buffer = this.stream.alloc(state.end)
+    state.buffer[state.start++] = 0
+
+    for (let i = 0; i < batch.length; i++) {
+      const b = batch[i]
+
+      c.uint.encode(state, lens[i])
+      c.uint.encode(state, b.type)
+      b.encoding.encode(state, b.message)
+    }
+
+    this.stream.write(state.buffer)
+  }
+
+  sendKeepAlive () {
+    this.stream.write(this.stream.alloc(0))
+  }
+
+  _sendHandshake () {
+    const hs = {
+      protocols: this.protocols
+    }
+
+    if (this.corked > 0) {
+      this._batch.push({ type: 0, encoding: m.handshake, message: hs })
+      return
+    }
+
+    const state = { start: 0, end: 0, buffer: null }
+
+    c.uint.preencode(state, 1)
+    m.handshake.preencode(state, hs)
+
+    state.buffer = this.stream.alloc(state.end)
+
+    c.uint.encode(state, 1)
+    m.handshake.encode(state, hs)
+
+    this.stream.write(state.buffer)
+  }
+}
+
+function noop () {}
diff --git a/package.json b/package.json
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+++ b/package.json
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+{
+  "name": "protomux",
+  "version": "0.0.0",
+  "description": "Multiplex multiple message oriented protocols over a stream",
+  "main": "index.js",
+  "dependencies": {},
+  "devDependencies": {
+    "brittle": "^1.6.0",
+    "standard": "^16.0.4"
+  },
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/mafintosh/protomux.git"
+  },
+  "author": "Mathias Buus (@mafintosh)",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/mafintosh/protomux/issues"
+  },
+  "homepage": "https://github.com/mafintosh/protomux"
+}
diff --git a/test.js b/test.js
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+++ b/test.js
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+const Protomux = require('./')
+const SecretStream = require('@hyperswarm/secret-stream')
+const test = require('brittle')
+const c = require('compact-encoding')
+
+test('basic', function (t) {
+  const a = new Protomux(new SecretStream(true), [{
+    name: 'foo',
+    messages: [c.string]
+  }])
+
+  const b = new Protomux(new SecretStream(false), [{
+    name: 'foo',
+    messages: [c.string]
+  }])
+
+  replicate(a, b)
+
+  const ap = a.get('foo')
+  const bp = b.get('foo')
+
+  t.plan(3)
+
+  ap.onopen = function () {
+    t.pass('a opened')
+  }
+
+  ap.onmessage = function (type, message) {
+    t.is(type, 0)
+    t.is(message, 'hello world')
+  }
+
+  bp.send(0, 'hello world')
+})
+
+test('echo message', function (t) {
+  const a = new Protomux(new SecretStream(true), [{
+    name: 'foo',
+    messages: [c.string]
+  }])
+
+  const b = new Protomux(new SecretStream(false), [{
+    name: 'other',
+    messages: [c.bool, c.bool]
+  }, {
+    name: 'foo',
+    messages: [c.string]
+  }])
+
+  replicate(a, b)
+
+  const ap = a.get('foo')
+  const bp = b.get('foo')
+
+  t.plan(3)
+
+  ap.onmessage = function (type, message) {
+    ap.send(type, 'echo: ' + message)
+  }
+
+  bp.send(0, 'hello world')
+
+  bp.onopen = function () {
+    t.pass('b opened')
+  }
+
+  bp.onmessage = function (type, message) {
+    t.is(type, 0)
+    t.is(message, 'echo: hello world')
+  }
+})
+
+test('multi message', function (t) {
+  const a = new Protomux(new SecretStream(true), [{
+    name: 'other',
+    messages: [c.bool, c.bool]
+  }, {
+    name: 'multi',
+    messages: [c.int, c.string, c.string]
+  }])
+
+  const b = new Protomux(new SecretStream(false), [{
+    name: 'multi',
+    messages: [c.int, c.string]
+  }])
+
+  replicate(a, b)
+
+  t.plan(4)
+
+  const ap = a.get('multi')
+  const bp = b.get('multi')
+
+  ap.send(0, 42)
+  ap.send(1, 'a string with 42')
+  ap.send(2, 'should be ignored')
+
+  const expected = [
+    [0, 42],
+    [1, 'a string with 42']
+  ]
+
+  bp.onmessage = function (type, message) {
+    const e = expected.shift()
+    t.is(type, e[0])
+    t.is(message, e[1])
+  }
+})
+
+// test('corks', function (t) {
+//   const a = new Protomux(new SecretStream(true), [{
+//     name: 'other',
+//     messages: [c.bool, c.bool]
+//   }, {
+//     name: 'multi',
+//     messages: [c.int, c.string]
+//   }])
+
+//   const b = new Protomux(new SecretStream(false), [{
+//     name: 'multi',
+//     messages: [c.int, c.string]
+//   }])
+
+//   replicate(a, b)
+
+//   t.plan(4)
+
+//   const ap = a.get('multi')
+//   const bp = b.get('multi')
+
+//   // ap.cork()
+//   // ap.send(0, 1)
+//   // ap.send(0, 2)
+//   // ap.send(0, 3)
+//   // ap.uncork()
+
+//   bp.onmessage = function (type, message) {
+//     console.log(type, message)
+//   }
+// })
+
+function replicate (a, b) {
+  a.stream.rawStream.pipe(b.stream.rawStream).pipe(a.stream.rawStream)
+}