refactor: optimize internal read function

Author: Phillip9587

lib/read.js

@@ -64,61 +64,68 @@ function read (req, res, next, parse, debug, options) {
     return
   }
 
-  var encoding = null
+  var charset = null
   if (options?.skipCharset !== true) {
-    encoding = getCharset(req) || options.defaultCharset
+    charset = getCharset(req) || options.defaultCharset
 
     // validate charset
-    if (!!options?.isValidCharset && !options.isValidCharset(encoding)) {
+    if (!!options?.isValidCharset && !options.isValidCharset(charset)) {
       debug('invalid charset')
-      next(createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
-        charset: encoding,
+      next(createError(415, 'unsupported charset "' + charset.toUpperCase() + '"', {
+        charset,
         type: 'charset.unsupported'
       }))
       return
     }
   }
 
-  var length
-  var opts = options
-  var stream
+  // get the content stream
+  const contentEncoding = (req.headers['content-encoding'] || 'identity').toLowerCase()
+  debug('content-encoding "%s"', contentEncoding)
 
-  // read options
-  var verify = opts.verify
-
-  try {
-    // get the content stream
-    stream = contentstream(req, debug, opts.inflate)
-    length = stream.length
-    stream.length = undefined
-  } catch (err) {
-    return next(err)
+  if (options.inflate === false && contentEncoding !== 'identity') {
+    return next(createError(415, 'content encoding unsupported', {
+      encoding: contentEncoding,
+      type: 'encoding.unsupported'
+    }))
   }
 
-  // set raw-body options
-  opts.length = length
-  opts.encoding = verify
-    ? null
-    : encoding
+  let stream
+  if (contentEncoding === 'identity') {
+    // set raw-body expected length
+    stream = req
+    options.length = req.headers['content-length']
+  } else {
+    try {
+      stream = createDecompressionStream(contentEncoding, debug)
+      req.pipe(stream)
+      options.length = undefined
+    } catch (err) {
+      return next(err)
+    }
+  }
 
   // assert charset is supported
-  if (opts.encoding === null && encoding !== null && !iconv.encodingExists(encoding)) {
-    return next(createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
-      charset: encoding.toLowerCase(),
+  if (options.verify && charset !== null && !iconv.encodingExists(charset)) {
+    return next(createError(415, 'unsupported charset "' + charset.toUpperCase() + '"', {
+      charset: charset.toLowerCase(),
       type: 'charset.unsupported'
     }))
   }
 
+  // set raw-body encoding
+  options.encoding = options.verify ? null : charset
+
   // read body
   debug('read body')
-  getBody(stream, opts, function (error, body) {
+  getBody(stream, options, function (error, body) {
     if (error) {
       var _error
 
       if (error.type === 'encoding.unsupported') {
         // echo back charset
-        _error = createError(415, 'unsupported charset "' + encoding.toUpperCase() + '"', {
-          charset: encoding.toLowerCase(),
+        _error = createError(415, 'unsupported charset "' + charset.toUpperCase() + '"', {
+          charset: charset.toLowerCase(),
           type: 'charset.unsupported'
         })
       } else {
@@ -140,10 +147,10 @@ function read (req, res, next, parse, debug, options) {
     }
 
     // verify
-    if (verify) {
+    if (options.verify) {
       try {
         debug('verify body')
-        verify(req, res, body, encoding)
+        options.verify(req, res, body, charset)
       } catch (err) {
         next(createError(403, err, {
           body: body,
@@ -157,10 +164,10 @@ function read (req, res, next, parse, debug, options) {
     var str = body
     try {
       debug('parse body')
-      str = typeof body !== 'string' && encoding !== null
-        ? iconv.decode(body, encoding)
+      str = typeof body !== 'string' && charset !== null
+        ? iconv.decode(body, charset)
         : body
-      req.body = parse(str, encoding)
+      req.body = parse(str, charset)
     } catch (err) {
       next(createError(400, err, {
         body: str,
@@ -173,39 +180,6 @@ function read (req, res, next, parse, debug, options) {
   })
 }
 
-/**
- * Get the content stream of the request.
- *
- * @param {object} req
- * @param {function} debug
- * @param {boolean} [inflate=true]
- * @return {object}
- * @api private
- */
-
-function contentstream (req, debug, inflate) {
-  var encoding = (req.headers['content-encoding'] || 'identity').toLowerCase()
-  var length = req.headers['content-length']
-
-  debug('content-encoding "%s"', encoding)
-
-  if (inflate === false && encoding !== 'identity') {
-    throw createError(415, 'content encoding unsupported', {
-      encoding: encoding,
-      type: 'encoding.unsupported'
-    })
-  }
-
-  if (encoding === 'identity') {
-    req.length = length
-    return req
-  }
-
-  var stream = createDecompressionStream(encoding, debug)
-  req.pipe(stream)
-  return stream
-}
-
 /**
  * Create a decompression stream for the given encoding.
  * @param {string} encoding