frame-stream - npm Package Compare versions

Comparing version 0.2.0 to 0.3.0

gulpfile.js

@@ -9,3 +9,3 @@ 'use strict'
 gulp.task('test', function() {
-  return gulp.src('test/test.js')
+  return gulp.src('test/*.js')
              .pipe(mocha({
@@ -23,2 +23,2 @@ ui: 'tdd',
              .pipe(eslint.failOnError())
-})
+})

lib/index.js

@@ -11,8 +11,14 @@ 'use strict'
 var FrameStream = exports.FrameStream = function(opts) {
-  this.opts = util._extend({ lengthSize: 4, maxSize: 0 }, opts)
+  this.opts = util._extend({
+    lengthSize: 4,
+    maxSize: 0,
+    unbuffered: false
+  }, opts)
 
   this.getLength = this.opts.getLength || createGetLengthMethod(this.opts.lengthSize)
   this.buffer = null
+  this.frameLength = 0
+  this.framePos = 0
 
-  Transform.call(this)
+  Transform.call(this, opts)
 }
@@ -22,37 +28,61 @@
 
-FrameStream.prototype._transform = function transform(chunk, enc, cont) {
-  if (this.buffer) {
-    chunk = Buffer.concat([this.buffer, chunk])
-    this.buffer = null
-  }
+FrameStream.prototype._transform = function(chunk, enc, cont) {
+  while (chunk.length > 0) {
+    var start = 0
 
-  if (chunk.length < this.opts.lengthSize) {
-    this.buffer = chunk
-    return cont()
-  }
+    if (this.framePos === 0) {
+      if (this.buffer) {
+        chunk = Buffer.concat([this.buffer, chunk])
+        this.buffer = null
+      }
 
-  var length = this.getLength(chunk)
+      if (chunk.length < this.opts.lengthSize) {
+        this.buffer = chunk
+        return cont()
+      }
 
-  if (length < 0) {
-    return cont(new Error('Message length is less than zero'))
-  }
+      this.frameLength = this.getLength(chunk)
 
-  // prevent denial-of-service attacks
-  if (this.opts.maxSize > 0 && length > this.opts.maxSize) {
-    return cont(new Error('Message is larger than the allowed maximum of ' + this.opts.maxSize))
-  }
+      if (this.frameLength < 0) {
+        return cont(new Error('Message length is less than zero'))
+      }
 
-  var end = this.opts.lengthSize + length
+      // prevent denial-of-service attacks
+      if (this.opts.maxSize > 0 && this.frameLength > this.opts.maxSize) {
+        return cont(new Error('Message is larger than the allowed maximum of ' + this.opts.maxSize))
+      }
 
-  if (chunk.length < end) {
-    this.buffer = chunk
-    return cont()
-  }
+      start = this.opts.lengthSize
+    }
 
-  this.push(chunk.slice(this.opts.lengthSize, end))
+    var end = start + this.frameLength - this.framePos
 
-  if (chunk.length > end) {
-    transform.call(this, chunk.slice(end), enc, cont)
-  } else {
-    cont()
+    if (this.opts.unbuffered) {
+      end = Math.min(end, chunk.length)
+    } else {
+      if (chunk.length < end) {
+        this.buffer = chunk
+        return cont()
+      }
+    }
+
+    var buf = chunk.slice(start, end)
+
+    buf.framePos = this.framePos
+    buf.frameLength = this.frameLength
+
+    this.framePos += end - start
+    buf.frameEnd = this.framePos === this.frameLength
+
+    if (buf.frameEnd) {
+      this.framePos = 0
+    }
+
+    this.push(buf)
+
+    if (chunk.length > end) {
+      chunk = chunk.slice(end)
+    } else {
+      return cont()
+    }
   }
@@ -118,2 +148,2 @@ }
   }
-}
+}

package.json

 {
   "name": "frame-stream",
-  "version": "0.2.0",
-  "description": "Stream of Length-prefix message framing for Node.js streams.",
+  "version": "0.3.0",
+  "description": "Length-prefixed message framing for Node.js streams.",
   "keywords": ["socket", "tcp", "framing", "streams"],
@@ -6,0 +6,0 @@ "main": "lib/",

README.md

 # frame-stream
 
-Stream of Length-prefix message framing for Node.js streams.
+Length-prefixed message framing for Node.js streams.
 
-[![NPM][npm]](https://npmjs.org/package/frame-stream)
-[![Build Status](travis)](http://travis-ci.org/rkusa/frame-stream)
+[![NPM][npm]](https://npmjs.org/package/frame-stream) [![Build Status][travis]](http://travis-ci.org/rkusa/frame-stream)
 
-Some protocols, e.g. TCP, do not not guarantee to keep message boundaries. One common approach to distinguish such messages is *Length Prefixing*, which prepends each message with its length.
+Some protocols, e.g. TCP, do not not guarantee to keep message boundaries. One common approach to distinguish such messages is *Length Prefixing*, which prepends each message with its length. `frame-stream` accepts a stream with such length-prefixed messages and returns each frame on its own.
 
@@ -35,3 +34,7 @@ ## Usage
 - **getLength** - The function used to read the prepended message size. This function defaults to `readInt8()`, `readInt16BE()` or `readInt32BE()` according to the `lengthSize`.
-- **maxSize** (default: 0)- The maximum allowed message size. This can be used to prevent denial-of-service attacks (`0` = turned off).
+- **maxSize** (default: 0) - The maximum allowed message size. This can be used to prevent denial-of-service attacks (`0` = turned off).
+- **unbuffered** (default: `false`) - Return parts of a message as they arrive, rather than buffering them up until the last part arrives. Useful when you know messages will be large. Each part will be a `Buffer` with the following extra properties:
+  - **framePos** - The index in the message where this part starts. Parts will be returned in order.
+  - **frameLength** - The total message size.
+  - **frameEnd** - A boolean indicating whether this is the last part of the message.
 
@@ -53,3 +56,3 @@ ### frame.prefix(opts)
 
-  var prefixer = new frame.prefix()
+  var prefixer = frame.prefix()
 
@@ -74,3 +77,3 @@ prefixer.pipe(socket)
 
-[npm]: https://badge.fury.io/js/frame-stream.svg
-[travis]: https://secure.travis-ci.org/rkusa/frame-stream.svg
+[npm]: http://img.shields.io/npm/v/frame-stream.svg?style=flat
+[travis]: http://img.shields.io/travis/rkusa/frame-stream.svg?style=flat

No alert changes

Improved metrics

Total package byte prevSize

10303

increased by13.32%

Lines of code

169

increased by18.18%

Number of lines in readme file

77

increased by4.05%

No dependency changes