stream: improve Readable.read() performance

read() performance is improved most by switching from an array to
a linked list for storing buffered data. However, other changes that
also contribute include: making some hot functions inlinable, faster
read() argument checking, and misc code rearrangement to avoid
unnecessary code execution.

PR-URL: #7077
Reviewed-By: Calvin Metcalf <calvin.metcalf@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>

Author: mscdex

benchmark/streams/readable-bigread.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common');
+const v8 = require('v8');
+const Readable = require('stream').Readable;
+
+const bench = common.createBenchmark(main, {
+  n: [100e1]
+});
+
+function main(conf) {
+  const n = +conf.n;
+  const b = new Buffer(32);
+  const s = new Readable();
+  function noop() {}
+  s._read = noop;
+
+  // Force optimization before starting the benchmark
+  s.push(b);
+  v8.setFlagsFromString('--allow_natives_syntax');
+  eval('%OptimizeFunctionOnNextCall(s.read)');
+  s.push(b);
+  while (s.read(128));
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    for (var i = 0; i < 1e4; ++i)
+      s.push(b);
+    while (s.read(128));
+  }
+  bench.end(n);
+}

benchmark/streams/readable-bigunevenread.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common');
+const v8 = require('v8');
+const Readable = require('stream').Readable;
+
+const bench = common.createBenchmark(main, {
+  n: [100e1]
+});
+
+function main(conf) {
+  const n = +conf.n;
+  const b = new Buffer(32);
+  const s = new Readable();
+  function noop() {}
+  s._read = noop;
+
+  // Force optimization before starting the benchmark
+  s.push(b);
+  v8.setFlagsFromString('--allow_natives_syntax');
+  eval('%OptimizeFunctionOnNextCall(s.read)');
+  s.push(b);
+  while (s.read(106));
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    for (var i = 0; i < 1e4; ++i)
+      s.push(b);
+    while (s.read(106));
+  }
+  bench.end(n);
+}

benchmark/streams/readable-boundaryread.js

@@ -0,0 +1,33 @@
+'use strict';
+
+const common = require('../common');
+const v8 = require('v8');
+const Readable = require('stream').Readable;
+
+const bench = common.createBenchmark(main, {
+  n: [200e1]
+});
+
+function main(conf) {
+  const n = +conf.n;
+  const b = new Buffer(32);
+  const s = new Readable();
+  function noop() {}
+  s._read = noop;
+
+  // Force optimization before starting the benchmark
+  s.push(b);
+  v8.setFlagsFromString('--allow_natives_syntax');
+  eval('%OptimizeFunctionOnNextCall(s.push)');
+  eval('%OptimizeFunctionOnNextCall(s.read)');
+  s.push(b);
+  while (s.read(32));
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    for (var i = 0; i < 1e4; ++i)
+      s.push(b);
+    while (s.read(32));
+  }
+  bench.end(n);
+}

benchmark/streams/readable-readall.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common');
+const v8 = require('v8');
+const Readable = require('stream').Readable;
+
+const bench = common.createBenchmark(main, {
+  n: [50e2]
+});
+
+function main(conf) {
+  const n = +conf.n;
+  const b = new Buffer(32);
+  const s = new Readable();
+  function noop() {}
+  s._read = noop;
+
+  // Force optimization before starting the benchmark
+  s.push(b);
+  v8.setFlagsFromString('--allow_natives_syntax');
+  eval('%OptimizeFunctionOnNextCall(s.read)');
+  s.push(b);
+  while (s.read());
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    for (var i = 0; i < 1e4; ++i)
+      s.push(b);
+    while (s.read());
+  }
+  bench.end(n);
+}

benchmark/streams/readable-unevenread.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common');
+const v8 = require('v8');
+const Readable = require('stream').Readable;
+
+const bench = common.createBenchmark(main, {
+  n: [100e1]
+});
+
+function main(conf) {
+  const n = +conf.n;
+  const b = new Buffer(32);
+  const s = new Readable();
+  function noop() {}
+  s._read = noop;
+
+  // Force optimization before starting the benchmark
+  s.push(b);
+  v8.setFlagsFromString('--allow_natives_syntax');
+  eval('%OptimizeFunctionOnNextCall(s.read)');
+  s.push(b);
+  while (s.read(12));
+
+  bench.start();
+  for (var k = 0; k < n; ++k) {
+    for (var i = 0; i < 1e4; ++i)
+      s.push(b);
+    while (s.read(12));
+  }
+  bench.end(n);
+}