fs: fill out more of the FileHandle pull/writer impl

Author: jasnell

benchmark/fs/bench-filehandle-pipetosync.js

@@ -0,0 +1,104 @@
+// Flags: --experimental-stream-iter
+// Benchmark: pipeToSync with sync compression transforms.
+// Measures fully synchronous file-to-file pipeline (no threadpool, no promises).
+'use strict';
+
+const common = require('../common.js');
+const fs = require('fs');
+const { openSync, closeSync, writeSync, readFileSync, unlinkSync } = fs;
+
+const tmpdir = require('../../test/common/tmpdir');
+tmpdir.refresh();
+const srcFile = tmpdir.resolve(`.removeme-sync-bench-src-${process.pid}`);
+const dstFile = tmpdir.resolve(`.removeme-sync-bench-dst-${process.pid}`);
+
+const bench = common.createBenchmark(main, {
+  compression: ['gzip', 'deflate', 'brotli', 'zstd'],
+  filesize: [1024 * 1024, 16 * 1024 * 1024, 64 * 1024 * 1024],
+  n: [5],
+});
+
+function main({ compression, filesize, n }) {
+  // Create the fixture file with repeating lowercase ASCII
+  const chunk = Buffer.alloc(Math.min(filesize, 64 * 1024), 'abcdefghij');
+  const fd = openSync(srcFile, 'w');
+  let remaining = filesize;
+  while (remaining > 0) {
+    const toWrite = Math.min(remaining, chunk.length);
+    writeSync(fd, chunk, 0, toWrite);
+    remaining -= toWrite;
+  }
+  closeSync(fd);
+
+  const {
+    pipeToSync,
+    compressGzipSync,
+    compressDeflateSync,
+    compressBrotliSync,
+    compressZstdSync,
+  } = require('stream/iter');
+  const { open } = fs.promises;
+
+  const compressFactory = {
+    gzip: compressGzipSync,
+    deflate: compressDeflateSync,
+    brotli: compressBrotliSync,
+    zstd: compressZstdSync,
+  }[compression];
+
+  // Stateless uppercase transform (sync)
+  const upper = (chunks) => {
+    if (chunks === null) return null;
+    const out = new Array(chunks.length);
+    for (let j = 0; j < chunks.length; j++) {
+      const src = chunks[j];
+      const buf = Buffer.allocUnsafe(src.length);
+      for (let i = 0; i < src.length; i++) {
+        const b = src[i];
+        buf[i] = (b >= 0x61 && b <= 0x7a) ? b - 0x20 : b;
+      }
+      out[j] = buf;
+    }
+    return out;
+  };
+
+  // Use a synchronous wrapper since pipeToSync is fully sync.
+  // We need FileHandle for pullSync/writer, so open async then run sync.
+  (async () => {
+    const srcFh = await open(srcFile, 'r');
+    const dstFh = await open(dstFile, 'w');
+
+    // Warm up
+    runSync(srcFh, dstFh, upper, compressFactory, pipeToSync);
+
+    // Reset file positions for the benchmark
+    await srcFh.close();
+    await dstFh.close();
+
+    bench.start();
+    let totalBytes = 0;
+    for (let i = 0; i < n; i++) {
+      const src = await open(srcFile, 'r');
+      const dst = await open(dstFile, 'w');
+      totalBytes += runSync(src, dst, upper, compressFactory, pipeToSync);
+      await src.close();
+      await dst.close();
+    }
+    bench.end(totalBytes / (1024 * 1024));
+
+    cleanup();
+  })();
+}
+
+function runSync(srcFh, dstFh, upper, compressFactory, pipeToSync) {
+  const w = dstFh.writer();
+  pipeToSync(srcFh.pullSync(upper, compressFactory()), w);
+
+  // Read back compressed size
+  return readFileSync(dstFile).length;
+}
+
+function cleanup() {
+  try { unlinkSync(srcFile); } catch { /* Ignore */ }
+  try { unlinkSync(dstFile); } catch { /* Ignore */ }
+}

benchmark/fs/bench-filehandle-pull-vs-webstream.js

@@ -1,6 +1,6 @@
 // Flags: --experimental-stream-iter
 // Compare FileHandle.createReadStream() vs readableWebStream() vs pull()
-// reading a large file through two transforms: uppercase then gzip compress.
+// reading a large file through two transforms: uppercase then compress.
 'use strict';
 
 const common = require('../common.js');
@@ -14,11 +14,20 @@ const filename = tmpdir.resolve(`.removeme-benchmark-garbage-${process.pid}`);
 
 const bench = common.createBenchmark(main, {
   api: ['classic', 'webstream', 'pull'],
+  compression: ['gzip', 'deflate', 'brotli', 'zstd'],
   filesize: [1024 * 1024, 16 * 1024 * 1024, 64 * 1024 * 1024],
   n: [5],
+}, {
+  // Classic and webstream only support gzip (native zlib / CompressionStream).
+  // Brotli, deflate, zstd are pull-only via stream/iter transforms.
+  combinationFilter({ api, compression }) {
+    if (api === 'classic' && compression !== 'gzip') return false;
+    if (api === 'webstream' && compression !== 'gzip') return false;
+    return true;
+  },
 });
 
-function main({ api, filesize, n }) {
+function main({ api, compression, filesize, n }) {
   // Create the fixture file with repeating lowercase ASCII
   const chunk = Buffer.alloc(Math.min(filesize, 64 * 1024), 'abcdefghij');
   const fd = fs.openSync(filename, 'w');
@@ -35,19 +44,28 @@ function main({ api, filesize, n }) {
   } else if (api === 'webstream') {
     benchWebStream(n, filesize).then(() => cleanup());
   } else {
-    benchPull(n, filesize).then(() => cleanup());
+    benchPull(n, filesize, compression).then(() => cleanup());
   }
 }
 
 function cleanup() {
   try { fs.unlinkSync(filename); } catch { /* ignore */ }
 }
 
+// Stateless uppercase transform (shared by all paths)
+function uppercaseChunk(chunk) {
+  const buf = Buffer.allocUnsafe(chunk.length);
+  for (let i = 0; i < chunk.length; i++) {
+    const b = chunk[i];
+    buf[i] = (b >= 0x61 && b <= 0x7a) ? b - 0x20 : b;
+  }
+  return buf;
+}
+
 // ---------------------------------------------------------------------------
 // Classic streams path: createReadStream -> Transform (upper) -> createGzip
 // ---------------------------------------------------------------------------
 async function benchClassic(n, filesize) {
-  // Warm up
   await runClassic();
 
   bench.start();
@@ -62,22 +80,14 @@ function runClassic() {
   return new Promise((resolve, reject) => {
     const rs = fs.createReadStream(filename);
 
-    // Transform 1: uppercase
     const upper = new Transform({
       transform(chunk, encoding, callback) {
-        const buf = Buffer.allocUnsafe(chunk.length);
-        for (let i = 0; i < chunk.length; i++) {
-          const b = chunk[i];
-          buf[i] = (b >= 0x61 && b <= 0x7a) ? b - 0x20 : b;
-        }
-        callback(null, buf);
+        callback(null, uppercaseChunk(chunk));
       },
     });
 
-    // Transform 2: gzip
     const gz = zlib.createGzip();
 
-    // Sink: count compressed bytes
     let totalBytes = 0;
     const sink = new Writable({
       write(chunk, encoding, callback) {
@@ -97,7 +107,6 @@ function runClassic() {
 // WebStream path: readableWebStream -> TransformStream (upper) -> CompressionStream
 // ---------------------------------------------------------------------------
 async function benchWebStream(n, filesize) {
-  // Warm up
   await runWebStream();
 
   bench.start();
@@ -113,22 +122,18 @@ async function runWebStream() {
   try {
     const rs = fh.readableWebStream();
 
-    // Transform 1: uppercase
     const upper = new TransformStream({
       transform(chunk, controller) {
         const buf = new Uint8Array(chunk.length);
         for (let i = 0; i < chunk.length; i++) {
           const b = chunk[i];
-          // a-z (0x61-0x7a) -> A-Z (0x41-0x5a)
           buf[i] = (b >= 0x61 && b <= 0x7a) ? b - 0x20 : b;
         }
         controller.enqueue(buf);
       },
     });
 
-    // Transform 2: gzip via CompressionStream
     const compress = new CompressionStream('gzip');
-
     const output = rs.pipeThrough(upper).pipeThrough(compress);
     const reader = output.getReader();
 
@@ -145,45 +150,44 @@ async function runWebStream() {
 }
 
 // ---------------------------------------------------------------------------
-// New streams path: pull() with uppercase transform + gzip transform
+// Pull/iter path: pull() with uppercase transform + selected compression
 // ---------------------------------------------------------------------------
-async function benchPull(n, filesize) {
-  const { pull, compressGzip } = require('stream/iter');
+async function benchPull(n, filesize, compression) {
+  const iter = require('stream/iter');
+
+  const compressFactory = {
+    gzip: iter.compressGzip,
+    deflate: iter.compressDeflate,
+    brotli: iter.compressBrotli,
+    zstd: iter.compressZstd,
+  }[compression];
 
   // Warm up
-  await runPull(pull, compressGzip);
+  await runPull(compressFactory);
 
   bench.start();
   let totalBytes = 0;
   for (let i = 0; i < n; i++) {
-    totalBytes += await runPull(pull, compressGzip);
+    totalBytes += await runPull(compressFactory);
   }
   bench.end(totalBytes / (1024 * 1024));
 }
 
-async function runPull(pull, compressGzip) {
+async function runPull(compressFactory) {
   const fh = await fs.promises.open(filename, 'r');
   try {
     // Stateless transform: uppercase each chunk in the batch
     const upper = (chunks) => {
       if (chunks === null) return null;
       const out = new Array(chunks.length);
       for (let j = 0; j < chunks.length; j++) {
-        const src = chunks[j];
-        const buf = new Uint8Array(src.length);
-        for (let i = 0; i < src.length; i++) {
-          const b = src[i];
-          buf[i] = (b >= 0x61 && b <= 0x7a) ? b - 0x20 : b;
-        }
-        out[j] = buf;
+        out[j] = uppercaseChunk(chunks[j]);
       }
       return out;
     };
 
-    const readable = fh.pull(upper, compressGzip());
+    const readable = fh.pull(upper, compressFactory());
 
-    // Count bytes symmetrically with the classic path (no final
-    // concatenation into a single buffer).
     let totalBytes = 0;
     for await (const chunks of readable) {
       for (let i = 0; i < chunks.length; i++) {