diff --git a/lib/zlib.js b/lib/zlib.js
index b6817749bae35d..19328d381adb60 100644
--- a/lib/zlib.js
+++ b/lib/zlib.js
@@ -1,31 +1,16 @@
 'use strict';
 
 const Buffer = require('buffer').Buffer;
+const internalUtil = require('internal/util');
 const Transform = require('_stream_transform');
 const binding = process.binding('zlib');
-const util = require('util');
 const assert = require('assert').ok;
 const kMaxLength = require('buffer').kMaxLength;
 const kRangeErrorMessage = 'Cannot create final Buffer. It would be larger ' +
-                           'than 0x' + kMaxLength.toString(16) + ' bytes';
+                           `than 0x${kMaxLength.toString(16)} bytes`;
 
 const constants = process.binding('constants').zlib;
-
-// These should be considered deprecated
-// expose all the zlib constants
-const bkeys = Object.keys(constants);
-for (var bk = 0; bk < bkeys.length; bk++) {
-  var bkey = bkeys[bk];
-  Object.defineProperty(exports, bkey, {
-    enumerable: true, value: constants[bkey], writable: false
-  });
-}
-
-Object.defineProperty(exports, 'constants', {
-  configurable: false,
-  enumerable: true,
-  value: constants
-});
+const createClassWrapper = internalUtil.createClassWrapper;
 
 // translation table for return codes.
 const codes = {
@@ -46,132 +31,29 @@ for (var ck = 0; ck < ckeys.length; ck++) {
   codes[codes[ckey]] = ckey;
 }
 
-Object.defineProperty(exports, 'codes', {
-  enumerable: true, value: Object.freeze(codes), writable: false
-});
-
-exports.Deflate = Deflate;
-exports.Inflate = Inflate;
-exports.Gzip = Gzip;
-exports.Gunzip = Gunzip;
-exports.DeflateRaw = DeflateRaw;
-exports.InflateRaw = InflateRaw;
-exports.Unzip = Unzip;
-
-exports.createDeflate = function(o) {
-  return new Deflate(o);
-};
-
-exports.createInflate = function(o) {
-  return new Inflate(o);
-};
-
-exports.createDeflateRaw = function(o) {
-  return new DeflateRaw(o);
-};
-
-exports.createInflateRaw = function(o) {
-  return new InflateRaw(o);
-};
-
-exports.createGzip = function(o) {
-  return new Gzip(o);
-};
-
-exports.createGunzip = function(o) {
-  return new Gunzip(o);
-};
-
-exports.createUnzip = function(o) {
-  return new Unzip(o);
-};
-
-
-// Convenience methods.
-// compress/decompress a string or buffer in one step.
-exports.deflate = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new Deflate(opts), buffer, callback);
-};
-
-exports.deflateSync = function(buffer, opts) {
-  return zlibBufferSync(new Deflate(opts), buffer);
-};
-
-exports.gzip = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new Gzip(opts), buffer, callback);
-};
-
-exports.gzipSync = function(buffer, opts) {
-  return zlibBufferSync(new Gzip(opts), buffer);
-};
-
-exports.deflateRaw = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new DeflateRaw(opts), buffer, callback);
-};
-
-exports.deflateRawSync = function(buffer, opts) {
-  return zlibBufferSync(new DeflateRaw(opts), buffer);
-};
-
-exports.unzip = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new Unzip(opts), buffer, callback);
-};
-
-exports.unzipSync = function(buffer, opts) {
-  return zlibBufferSync(new Unzip(opts), buffer);
-};
-
-exports.inflate = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new Inflate(opts), buffer, callback);
-};
-
-exports.inflateSync = function(buffer, opts) {
-  return zlibBufferSync(new Inflate(opts), buffer);
-};
-
-exports.gunzip = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new Gunzip(opts), buffer, callback);
-};
-
-exports.gunzipSync = function(buffer, opts) {
-  return zlibBufferSync(new Gunzip(opts), buffer);
-};
+function isValidFlushFlag(flag) {
+  return flag >= constants.Z_NO_FLUSH &&
+         flag <= constants.Z_BLOCK;
+
+  // Covers: constants.Z_NO_FLUSH (0),
+  //         constants.Z_PARTIAL_FLUSH (1),
+  //         constants.Z_SYNC_FLUSH (2),
+  //         constants.Z_FULL_FLUSH (3),
+  //         constants.Z_FINISH (4), and
+  //         constants.Z_BLOCK (5)
+}
 
-exports.inflateRaw = function(buffer, opts, callback) {
-  if (typeof opts === 'function') {
-    callback = opts;
-    opts = {};
-  }
-  return zlibBuffer(new InflateRaw(opts), buffer, callback);
-};
+function isInvalidStrategy(strategy) {
+  return typeof strategy !== 'number' ||
+         strategy < constants.Z_DEFAULT_STRATEGY ||
+         strategy > constants.Z_FIXED;
 
-exports.inflateRawSync = function(buffer, opts) {
-  return zlibBufferSync(new InflateRaw(opts), buffer);
-};
+  // Covers: constants.Z_FILTERED, (1)
+  //         constants.Z_HUFFMAN_ONLY (2),
+  //         constants.Z_RLE (3),
+  //         constants.Z_FIXED (4), and
+  //         constants.Z_DEFAULT_STRATEGY (0)
+}
 
 function zlibBuffer(engine, buffer, callback) {
   var buffers = [];
@@ -225,230 +107,326 @@ function zlibBufferSync(engine, buffer) {
   return engine._processChunk(buffer, flushFlag);
 }
 
-// generic zlib
-// minimal 2-byte header
-function Deflate(opts) {
-  if (!(this instanceof Deflate)) return new Deflate(opts);
-  Zlib.call(this, opts, constants.DEFLATE);
+function zlibOnError(message, errno) {
+  // there is no way to cleanly recover.
+  // continuing only obscures problems.
+  _close(this);
+  this._hadError = true;
+
+  var error = new Error(message);
+  error.errno = errno;
+  error.code = codes[errno];
+  this.emit('error', error);
 }
 
-function Inflate(opts) {
-  if (!(this instanceof Inflate)) return new Inflate(opts);
-  Zlib.call(this, opts, constants.INFLATE);
+function flushCallback(level, strategy, callback) {
+  assert(this._handle, 'zlib binding closed');
+  this._handle.params(level, strategy);
+  if (!this._hadError) {
+    this._level = level;
+    this._strategy = strategy;
+    if (callback) callback();
+  }
 }
 
+// the Zlib class they all inherit from
+// This thing manages the queue of requests, and returns
+// true or false if there is anything in the queue when
+// you call the .write() method.
+class Zlib extends Transform {
+  constructor(opts, mode) {
+    opts = opts || {};
+    super(opts);
 
-// gzip - bigger header, same deflate compression
-function Gzip(opts) {
-  if (!(this instanceof Gzip)) return new Gzip(opts);
-  Zlib.call(this, opts, constants.GZIP);
-}
+    this._opts = opts;
+    this._chunkSize = opts.chunkSize || constants.Z_DEFAULT_CHUNK;
 
-function Gunzip(opts) {
-  if (!(this instanceof Gunzip)) return new Gunzip(opts);
-  Zlib.call(this, opts, constants.GUNZIP);
-}
+    if (opts.flush && !isValidFlushFlag(opts.flush)) {
+      throw new Error('Invalid flush flag: ' + opts.flush);
+    }
+    if (opts.finishFlush && !isValidFlushFlag(opts.finishFlush)) {
+      throw new Error('Invalid flush flag: ' + opts.finishFlush);
+    }
 
+    this._flushFlag = opts.flush || constants.Z_NO_FLUSH;
+    this._finishFlushFlag = opts.finishFlush !== undefined ?
+      opts.finishFlush : constants.Z_FINISH;
 
-// raw - no header
-function DeflateRaw(opts) {
-  if (!(this instanceof DeflateRaw)) return new DeflateRaw(opts);
-  Zlib.call(this, opts, constants.DEFLATERAW);
-}
+    if (opts.chunkSize) {
+      if (opts.chunkSize < constants.Z_MIN_CHUNK) {
+        throw new Error('Invalid chunk size: ' + opts.chunkSize);
+      }
+    }
 
-function InflateRaw(opts) {
-  if (!(this instanceof InflateRaw)) return new InflateRaw(opts);
-  Zlib.call(this, opts, constants.INFLATERAW);
-}
+    if (opts.windowBits) {
+      if (opts.windowBits < constants.Z_MIN_WINDOWBITS ||
+          opts.windowBits > constants.Z_MAX_WINDOWBITS) {
+        throw new Error('Invalid windowBits: ' + opts.windowBits);
+      }
+    }
 
+    if (opts.level) {
+      if (opts.level < constants.Z_MIN_LEVEL ||
+          opts.level > constants.Z_MAX_LEVEL) {
+        throw new Error('Invalid compression level: ' + opts.level);
+      }
+    }
 
-// auto-detect header.
-function Unzip(opts) {
-  if (!(this instanceof Unzip)) return new Unzip(opts);
-  Zlib.call(this, opts, constants.UNZIP);
-}
+    if (opts.memLevel) {
+      if (opts.memLevel < constants.Z_MIN_MEMLEVEL ||
+          opts.memLevel > constants.Z_MAX_MEMLEVEL) {
+        throw new Error('Invalid memLevel: ' + opts.memLevel);
+      }
+    }
 
-function isValidFlushFlag(flag) {
-  return flag === constants.Z_NO_FLUSH ||
-         flag === constants.Z_PARTIAL_FLUSH ||
-         flag === constants.Z_SYNC_FLUSH ||
-         flag === constants.Z_FULL_FLUSH ||
-         flag === constants.Z_FINISH ||
-         flag === constants.Z_BLOCK;
-}
+    if (opts.strategy && isInvalidStrategy(opts.strategy))
+      throw new Error('Invalid strategy: ' + opts.strategy);
 
-const strategies = [constants.Z_FILTERED,
-                    constants.Z_HUFFMAN_ONLY,
-                    constants.Z_RLE,
-                    constants.Z_FIXED,
-                    constants.Z_DEFAULT_STRATEGY];
+    if (opts.dictionary) {
+      if (!(opts.dictionary instanceof Buffer)) {
+        throw new Error('Invalid dictionary: it should be a Buffer instance');
+      }
+    }
 
-// the Zlib class they all inherit from
-// This thing manages the queue of requests, and returns
-// true or false if there is anything in the queue when
-// you call the .write() method.
+    this._handle = new binding.Zlib(mode);
+    this._handle.onerror = zlibOnError.bind(this);
+    this._hadError = false;
 
-function Zlib(opts, mode) {
-  this._opts = opts = opts || {};
-  this._chunkSize = opts.chunkSize || constants.Z_DEFAULT_CHUNK;
+    var level = constants.Z_DEFAULT_COMPRESSION;
+    if (typeof opts.level === 'number') level = opts.level;
 
-  Transform.call(this, opts);
+    var strategy = constants.Z_DEFAULT_STRATEGY;
+    if (typeof opts.strategy === 'number') strategy = opts.strategy;
 
-  if (opts.flush && !isValidFlushFlag(opts.flush)) {
-    throw new Error('Invalid flush flag: ' + opts.flush);
-  }
-  if (opts.finishFlush && !isValidFlushFlag(opts.finishFlush)) {
-    throw new Error('Invalid flush flag: ' + opts.finishFlush);
-  }
+    this._handle.init(opts.windowBits || constants.Z_DEFAULT_WINDOWBITS,
+                      level,
+                      opts.memLevel || constants.Z_DEFAULT_MEMLEVEL,
+                      strategy,
+                      opts.dictionary);
 
-  this._flushFlag = opts.flush || constants.Z_NO_FLUSH;
-  this._finishFlushFlag = typeof opts.finishFlush !== 'undefined' ?
-    opts.finishFlush : constants.Z_FINISH;
+    this._buffer = Buffer.allocUnsafe(this._chunkSize);
+    this._offset = 0;
+    this._level = level;
+    this._strategy = strategy;
 
-  if (opts.chunkSize) {
-    if (opts.chunkSize < constants.Z_MIN_CHUNK) {
-      throw new Error('Invalid chunk size: ' + opts.chunkSize);
-    }
+    this.once('end', this.close);
   }
 
-  if (opts.windowBits) {
-    if (opts.windowBits < constants.Z_MIN_WINDOWBITS ||
-        opts.windowBits > constants.Z_MAX_WINDOWBITS) {
-      throw new Error('Invalid windowBits: ' + opts.windowBits);
-    }
+  get _closed() {
+    return !this._handle;
   }
 
-  if (opts.level) {
-    if (opts.level < constants.Z_MIN_LEVEL ||
-        opts.level > constants.Z_MAX_LEVEL) {
-      throw new Error('Invalid compression level: ' + opts.level);
+  params(level, strategy, callback) {
+    if (level < constants.Z_MIN_LEVEL ||
+        level > constants.Z_MAX_LEVEL) {
+      throw new RangeError('Invalid compression level: ' + level);
     }
-  }
+    if (isInvalidStrategy(strategy))
+      throw new TypeError('Invalid strategy: ' + strategy);
 
-  if (opts.memLevel) {
-    if (opts.memLevel < constants.Z_MIN_MEMLEVEL ||
-        opts.memLevel > constants.Z_MAX_MEMLEVEL) {
-      throw new Error('Invalid memLevel: ' + opts.memLevel);
+    if (this._level !== level || this._strategy !== strategy) {
+      this.flush(constants.Z_SYNC_FLUSH,
+                 flushCallback.bind(this, level, strategy, callback));
+    } else {
+      process.nextTick(callback);
     }
   }
 
-  if (opts.strategy && !(strategies.includes(opts.strategy)))
-    throw new Error('Invalid strategy: ' + opts.strategy);
+  reset() {
+    assert(this._handle, 'zlib binding closed');
+    return this._handle.reset();
+  }
 
-  if (opts.dictionary) {
-    if (!(opts.dictionary instanceof Buffer)) {
-      throw new Error('Invalid dictionary: it should be a Buffer instance');
-    }
+  // This is the _flush function called by the transform class,
+  // internally, when the last chunk has been written.
+  _flush(callback) {
+    this._transform(Buffer.alloc(0), '', callback);
   }
 
-  this._handle = new binding.Zlib(mode);
+  flush(kind, callback) {
+    var ws = this._writableState;
 
-  var self = this;
-  this._hadError = false;
-  this._handle.onerror = function(message, errno) {
-    // there is no way to cleanly recover.
-    // continuing only obscures problems.
-    _close(self);
-    self._hadError = true;
+    if (typeof kind === 'function' || (kind === undefined && !callback)) {
+      callback = kind;
+      kind = constants.Z_FULL_FLUSH;
+    }
 
-    var error = new Error(message);
-    error.errno = errno;
-    error.code = exports.codes[errno];
-    self.emit('error', error);
-  };
+    if (ws.ended) {
+      if (callback)
+        process.nextTick(callback);
+    } else if (ws.ending) {
+      if (callback)
+        this.once('end', callback);
+    } else if (ws.needDrain) {
+      if (callback) {
+        const drainHandler = () => this.flush(kind, callback);
+        this.once('drain', drainHandler);
+      }
+    } else {
+      this._flushFlag = kind;
+      this.write(Buffer.alloc(0), '', callback);
+    }
+  }
 
-  var level = constants.Z_DEFAULT_COMPRESSION;
-  if (typeof opts.level === 'number') level = opts.level;
+  close(callback) {
+    _close(this, callback);
+    process.nextTick(emitCloseNT, this);
+  }
 
-  var strategy = constants.Z_DEFAULT_STRATEGY;
-  if (typeof opts.strategy === 'number') strategy = opts.strategy;
+  _transform(chunk, encoding, cb) {
+    var flushFlag;
+    var ws = this._writableState;
+    var ending = ws.ending || ws.ended;
+    var last = ending && (!chunk || ws.length === chunk.length);
+
+    if (chunk !== null && !(chunk instanceof Buffer))
+      return cb(new Error('invalid input'));
+
+    if (!this._handle)
+      return cb(new Error('zlib binding closed'));
+
+    // If it's the last chunk, or a final flush, we use the Z_FINISH flush flag
+    // (or whatever flag was provided using opts.finishFlush).
+    // If it's explicitly flushing at some other time, then we use
+    // Z_FULL_FLUSH. Otherwise, use Z_NO_FLUSH for maximum compression
+    // goodness.
+    if (last)
+      flushFlag = this._finishFlushFlag;
+    else {
+      flushFlag = this._flushFlag;
+      // once we've flushed the last of the queue, stop flushing and
+      // go back to the normal behavior.
+      if (chunk.length >= ws.length) {
+        this._flushFlag = this._opts.flush || constants.Z_NO_FLUSH;
+      }
+    }
 
-  this._handle.init(opts.windowBits || constants.Z_DEFAULT_WINDOWBITS,
-                    level,
-                    opts.memLevel || constants.Z_DEFAULT_MEMLEVEL,
-                    strategy,
-                    opts.dictionary);
+    this._processChunk(chunk, flushFlag, cb);
+  }
 
-  this._buffer = Buffer.allocUnsafe(this._chunkSize);
-  this._offset = 0;
-  this._level = level;
-  this._strategy = strategy;
+  _processChunk(chunk, flushFlag, cb) {
+    var availInBefore = chunk && chunk.length;
+    var availOutBefore = this._chunkSize - this._offset;
+    var inOff = 0;
 
-  this.once('end', this.close);
+    var self = this;
 
-  Object.defineProperty(this, '_closed', {
-    get: () => !this._handle,
-    configurable: true,
-    enumerable: true
-  });
-}
+    var async = typeof cb === 'function';
+
+    if (!async) {
+      var buffers = [];
+      var nread = 0;
+
+      var error;
+      this.on('error', function(er) {
+        error = er;
+      });
+
+      assert(this._handle, 'zlib binding closed');
+      do {
+        var res = this._handle.writeSync(flushFlag,
+                                         chunk, // in
+                                         inOff, // in_off
+                                         availInBefore, // in_len
+                                         this._buffer, // out
+                                         this._offset, //out_off
+                                         availOutBefore); // out_len
+      } while (!this._hadError && callback(res[0], res[1]));
+
+      if (this._hadError) {
+        throw error;
+      }
 
-util.inherits(Zlib, Transform);
+      if (nread >= kMaxLength) {
+        _close(this);
+        throw new RangeError(kRangeErrorMessage);
+      }
 
-Zlib.prototype.params = function(level, strategy, callback) {
-  if (level < constants.Z_MIN_LEVEL ||
-      level > constants.Z_MAX_LEVEL) {
-    throw new RangeError('Invalid compression level: ' + level);
-  }
-  if (!(strategies.includes(strategy)))
-    throw new TypeError('Invalid strategy: ' + strategy);
+      var buf = Buffer.concat(buffers, nread);
+      _close(this);
 
-  if (this._level !== level || this._strategy !== strategy) {
-    var self = this;
-    this.flush(constants.Z_SYNC_FLUSH, function flushCallback() {
-      assert(self._handle, 'zlib binding closed');
-      self._handle.params(level, strategy);
-      if (!self._hadError) {
-        self._level = level;
-        self._strategy = strategy;
-        if (callback) callback();
+      return buf;
+    }
+
+    assert(this._handle, 'zlib binding closed');
+    var req = this._handle.write(flushFlag,
+                                 chunk, // in
+                                 inOff, // in_off
+                                 availInBefore, // in_len
+                                 this._buffer, // out
+                                 this._offset, //out_off
+                                 availOutBefore); // out_len
+
+    req.buffer = chunk;
+    req.callback = callback;
+
+    function callback(availInAfter, availOutAfter) {
+      // When the callback is used in an async write, the callback's
+      // context is the `req` object that was created. The req object
+      // is === this._handle, and that's why it's important to null
+      // out the values after they are done being used. `this._handle`
+      // can stay in memory longer than the callback and buffer are needed.
+      if (this) {
+        this.buffer = null;
+        this.callback = null;
       }
-    });
-  } else {
-    process.nextTick(callback);
-  }
-};
 
-Zlib.prototype.reset = function() {
-  assert(this._handle, 'zlib binding closed');
-  return this._handle.reset();
-};
+      if (self._hadError)
+        return;
+
+      var have = availOutBefore - availOutAfter;
+      assert(have >= 0, 'have should not go down');
+
+      if (have > 0) {
+        var out = self._buffer.slice(self._offset, self._offset + have);
+        self._offset += have;
+        // serve some output to the consumer.
+        if (async) {
+          self.push(out);
+        } else {
+          buffers.push(out);
+          nread += out.length;
+        }
+      }
 
-// This is the _flush function called by the transform class,
-// internally, when the last chunk has been written.
-Zlib.prototype._flush = function(callback) {
-  this._transform(Buffer.alloc(0), '', callback);
-};
+      // exhausted the output buffer, or used all the input create a new one.
+      if (availOutAfter === 0 || self._offset >= self._chunkSize) {
+        availOutBefore = self._chunkSize;
+        self._offset = 0;
+        self._buffer = Buffer.allocUnsafe(self._chunkSize);
+      }
 
-Zlib.prototype.flush = function(kind, callback) {
-  var ws = this._writableState;
+      if (availOutAfter === 0) {
+        // Not actually done.  Need to reprocess.
+        // Also, update the availInBefore to the availInAfter value,
+        // so that if we have to hit it a third (fourth, etc.) time,
+        // it'll have the correct byte counts.
+        inOff += (availInBefore - availInAfter);
+        availInBefore = availInAfter;
+
+        if (!async)
+          return true;
+
+        var newReq = self._handle.write(flushFlag,
+                                        chunk,
+                                        inOff,
+                                        availInBefore,
+                                        self._buffer,
+                                        self._offset,
+                                        self._chunkSize);
+        newReq.callback = callback; // this same function
+        newReq.buffer = chunk;
+        return;
+      }
 
-  if (typeof kind === 'function' || (kind === undefined && !callback)) {
-    callback = kind;
-    kind = constants.Z_FULL_FLUSH;
-  }
+      if (!async)
+        return false;
 
-  if (ws.ended) {
-    if (callback)
-      process.nextTick(callback);
-  } else if (ws.ending) {
-    if (callback)
-      this.once('end', callback);
-  } else if (ws.needDrain) {
-    if (callback) {
-      const drainHandler = () => this.flush(kind, callback);
-      this.once('drain', drainHandler);
+      // finished with the chunk.
+      cb();
     }
-  } else {
-    this._flushFlag = kind;
-    this.write(Buffer.alloc(0), '', callback);
   }
-};
-
-Zlib.prototype.close = function(callback) {
-  _close(this, callback);
-  process.nextTick(emitCloseNT, this);
-};
+}
 
 function _close(engine, callback) {
   if (callback)
@@ -466,164 +444,127 @@ function emitCloseNT(self) {
   self.emit('close');
 }
 
-Zlib.prototype._transform = function(chunk, encoding, cb) {
-  var flushFlag;
-  var ws = this._writableState;
-  var ending = ws.ending || ws.ended;
-  var last = ending && (!chunk || ws.length === chunk.length);
-
-  if (chunk !== null && !(chunk instanceof Buffer))
-    return cb(new Error('invalid input'));
-
-  if (!this._handle)
-    return cb(new Error('zlib binding closed'));
-
-  // If it's the last chunk, or a final flush, we use the Z_FINISH flush flag
-  // (or whatever flag was provided using opts.finishFlush).
-  // If it's explicitly flushing at some other time, then we use
-  // Z_FULL_FLUSH. Otherwise, use Z_NO_FLUSH for maximum compression
-  // goodness.
-  if (last)
-    flushFlag = this._finishFlushFlag;
-  else {
-    flushFlag = this._flushFlag;
-    // once we've flushed the last of the queue, stop flushing and
-    // go back to the normal behavior.
-    if (chunk.length >= ws.length) {
-      this._flushFlag = this._opts.flush || constants.Z_NO_FLUSH;
-    }
+// generic zlib
+// minimal 2-byte header
+class Deflate extends Zlib {
+  constructor(opts) {
+    super(opts, constants.DEFLATE);
   }
+}
 
-  this._processChunk(chunk, flushFlag, cb);
-};
-
-Zlib.prototype._processChunk = function(chunk, flushFlag, cb) {
-  var availInBefore = chunk && chunk.length;
-  var availOutBefore = this._chunkSize - this._offset;
-  var inOff = 0;
-
-  var self = this;
-
-  var async = typeof cb === 'function';
-
-  if (!async) {
-    var buffers = [];
-    var nread = 0;
-
-    var error;
-    this.on('error', function(er) {
-      error = er;
-    });
+class Inflate extends Zlib {
+  constructor(opts) {
+    super(opts, constants.INFLATE);
+  }
+}
 
-    assert(this._handle, 'zlib binding closed');
-    do {
-      var res = this._handle.writeSync(flushFlag,
-                                       chunk, // in
-                                       inOff, // in_off
-                                       availInBefore, // in_len
-                                       this._buffer, // out
-                                       this._offset, //out_off
-                                       availOutBefore); // out_len
-    } while (!this._hadError && callback(res[0], res[1]));
-
-    if (this._hadError) {
-      throw error;
-    }
+class Gzip extends Zlib {
+  constructor(opts) {
+    super(opts, constants.GZIP);
+  }
+}
 
-    if (nread >= kMaxLength) {
-      _close(this);
-      throw new RangeError(kRangeErrorMessage);
-    }
+class Gunzip extends Zlib {
+  constructor(opts) {
+    super(opts, constants.GUNZIP);
+  }
+}
 
-    var buf = Buffer.concat(buffers, nread);
-    _close(this);
+class DeflateRaw extends Zlib {
+  constructor(opts) {
+    super(opts, constants.DEFLATERAW);
+  }
+}
 
-    return buf;
+class InflateRaw extends Zlib {
+  constructor(opts) {
+    super(opts, constants.INFLATERAW);
   }
+}
 
-  assert(this._handle, 'zlib binding closed');
-  var req = this._handle.write(flushFlag,
-                               chunk, // in
-                               inOff, // in_off
-                               availInBefore, // in_len
-                               this._buffer, // out
-                               this._offset, //out_off
-                               availOutBefore); // out_len
-
-  req.buffer = chunk;
-  req.callback = callback;
-
-  function callback(availInAfter, availOutAfter) {
-    // When the callback is used in an async write, the callback's
-    // context is the `req` object that was created. The req object
-    // is === this._handle, and that's why it's important to null
-    // out the values after they are done being used. `this._handle`
-    // can stay in memory longer than the callback and buffer are needed.
-    if (this) {
-      this.buffer = null;
-      this.callback = null;
-    }
+class Unzip extends Zlib {
+  constructor(opts) {
+    super(opts, constants.UNZIP);
+  }
+}
 
-    if (self._hadError)
-      return;
-
-    var have = availOutBefore - availOutAfter;
-    assert(have >= 0, 'have should not go down');
-
-    if (have > 0) {
-      var out = self._buffer.slice(self._offset, self._offset + have);
-      self._offset += have;
-      // serve some output to the consumer.
-      if (async) {
-        self.push(out);
-      } else {
-        buffers.push(out);
-        nread += out.length;
+function createConvenienceMethod(type, sync) {
+  if (sync) {
+    return function(buffer, opts) {
+      return zlibBufferSync(new type(opts), buffer);
+    };
+  } else {
+    return function(buffer, opts, callback) {
+      if (typeof opts === 'function') {
+        callback = opts;
+        opts = {};
       }
-    }
-
-    // exhausted the output buffer, or used all the input create a new one.
-    if (availOutAfter === 0 || self._offset >= self._chunkSize) {
-      availOutBefore = self._chunkSize;
-      self._offset = 0;
-      self._buffer = Buffer.allocUnsafe(self._chunkSize);
-    }
-
-    if (availOutAfter === 0) {
-      // Not actually done.  Need to reprocess.
-      // Also, update the availInBefore to the availInAfter value,
-      // so that if we have to hit it a third (fourth, etc.) time,
-      // it'll have the correct byte counts.
-      inOff += (availInBefore - availInAfter);
-      availInBefore = availInAfter;
+      return zlibBuffer(new type(opts), buffer, callback);
+    };
+  }
+}
 
-      if (!async)
-        return true;
-
-      var newReq = self._handle.write(flushFlag,
-                                      chunk,
-                                      inOff,
-                                      availInBefore,
-                                      self._buffer,
-                                      self._offset,
-                                      self._chunkSize);
-      newReq.callback = callback; // this same function
-      newReq.buffer = chunk;
-      return;
-    }
+function createProperty(type) {
+  return {
+    configurable: true,
+    enumerable: true,
+    value: type
+  };
+}
 
-    if (!async)
-      return false;
+module.exports = {
+  Deflate: createClassWrapper(Deflate),
+  Inflate: createClassWrapper(Inflate),
+  Gzip: createClassWrapper(Gzip),
+  Gunzip: createClassWrapper(Gunzip),
+  DeflateRaw: createClassWrapper(DeflateRaw),
+  InflateRaw: createClassWrapper(InflateRaw),
+  Unzip: createClassWrapper(Unzip),
+
+  // Convenience methods.
+  // compress/decompress a string or buffer in one step.
+  deflate: createConvenienceMethod(Deflate, false),
+  deflateSync: createConvenienceMethod(Deflate, true),
+  gzip: createConvenienceMethod(Gzip, false),
+  gzipSync: createConvenienceMethod(Gzip, true),
+  deflateRaw: createConvenienceMethod(DeflateRaw, false),
+  deflateRawSync: createConvenienceMethod(DeflateRaw, true),
+  unzip: createConvenienceMethod(Unzip, false),
+  unzipSync: createConvenienceMethod(Unzip, true),
+  inflate: createConvenienceMethod(Inflate, false),
+  inflateSync: createConvenienceMethod(Inflate, true),
+  gunzip: createConvenienceMethod(Gunzip, false),
+  gunzipSync: createConvenienceMethod(Gunzip, true),
+  inflateRaw: createConvenienceMethod(InflateRaw, false),
+  inflateRawSync: createConvenienceMethod(InflateRaw, true)
+};
 
-    // finished with the chunk.
-    cb();
+Object.defineProperties(module.exports, {
+  createDeflate: createProperty(module.exports.Deflate),
+  createInflate: createProperty(module.exports.Inflate),
+  createDeflateRaw: createProperty(module.exports.DeflateRaw),
+  createInflateRaw: createProperty(module.exports.InflateRaw),
+  createGzip: createProperty(module.exports.Gzip),
+  createGunzip: createProperty(module.exports.Gunzip),
+  createUnzip: createProperty(module.exports.Unzip),
+  constants: {
+    configurable: false,
+    enumerable: true,
+    value: constants
+  },
+  codes: {
+    enumerable: true,
+    writable: false,
+    value: Object.freeze(codes)
   }
-};
+});
 
-util.inherits(Deflate, Zlib);
-util.inherits(Inflate, Zlib);
-util.inherits(Gzip, Zlib);
-util.inherits(Gunzip, Zlib);
-util.inherits(DeflateRaw, Zlib);
-util.inherits(InflateRaw, Zlib);
-util.inherits(Unzip, Zlib);
+// These should be considered deprecated
+// expose all the zlib constants
+const bkeys = Object.keys(constants);
+for (var bk = 0; bk < bkeys.length; bk++) {
+  var bkey = bkeys[bk];
+  Object.defineProperty(module.exports, bkey, {
+    enumerable: true, value: constants[bkey], writable: false
+  });
+}