fs: add fs.readv() · nodejs/node@30d55a3 · GitHub
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SheikhSajidaddaleax
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fs: add fs.readv()
Fixes: #2298 PR-URL: #32356 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com>
1 parent 6d86651 commit 30d55a3

7 files changed

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‎doc/api/fs.md‎

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‎lib/fs.js‎

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@@ -565,6 +565,39 @@ function readSync(fd, buffer, offset, length, position) {
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return result;
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}
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function readv(fd, buffers, position, callback) {
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function wrapper(err, read) {
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callback(err, read || 0, buffers);
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}
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validateInt32(fd, 'fd', /* min */ 0);
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validateBufferArray(buffers);
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const req = new FSReqCallback();
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req.oncomplete = wrapper;
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callback = maybeCallback(callback || position);
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if (typeof position !== 'number')
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position = null;
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return binding.readBuffers(fd, buffers, position, req);
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}
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function readvSync(fd, buffers, position) {
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validateInt32(fd, 'fd', 0);
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validateBufferArray(buffers);
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const ctx = {};
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if (typeof position !== 'number')
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position = null;
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const result = binding.readBuffers(fd, buffers, position, undefined, ctx);
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handleErrorFromBinding(ctx);
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return result;
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}
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// usage:
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// fs.write(fd, buffer[, offset[, length[, position]]], callback);
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// OR
@@ -1917,6 +1950,8 @@ module.exports = fs = {
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readdirSync,
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read,
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readSync,
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readv,
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readvSync,
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readFile,
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readFileSync,
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readlink,

‎lib/internal/fs/promises.js‎

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@@ -99,6 +99,10 @@ class FileHandle {
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return read(this, buffer, offset, length, position);
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}
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readv(buffers, position) {
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return readv(this, buffers, position);
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}
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readFile(options) {
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return readFile(this, options);
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}
@@ -253,6 +257,18 @@ async function read(handle, buffer, offset, length, position) {
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return { bytesRead, buffer };
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}
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async function readv(handle, buffers, position) {
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validateFileHandle(handle);
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validateBufferArray(buffers);
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if (typeof position !== 'number')
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position = null;
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const bytesRead = (await binding.readBuffers(handle.fd, buffers, position,
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kUsePromises)) || 0;
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return { bytesRead, buffers };
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}
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async function write(handle, buffer, offset, length, position) {
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validateFileHandle(handle);
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‎src/node_file.cc‎

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@@ -1965,6 +1965,52 @@ static void Read(const FunctionCallbackInfo<Value>& args) {
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}
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// Wrapper for readv(2).
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//
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// bytesRead = fs.readv(fd, buffers[, position], callback)
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// 0 fd integer. file descriptor
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// 1 buffers array of buffers to read
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// 2 position if integer, position to read at in the file.
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// if null, read from the current position
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static void ReadBuffers(const FunctionCallbackInfo<Value>& args) {
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Environment* env = Environment::GetCurrent(args);
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const int argc = args.Length();
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CHECK_GE(argc, 3);
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CHECK(args[0]->IsInt32());
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const int fd = args[0].As<Int32>()->Value();
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CHECK(args[1]->IsArray());
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Local<Array> buffers = args[1].As<Array>();
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int64_t pos = GetOffset(args[2]); // -1 if not a valid JS int
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MaybeStackBuffer<uv_buf_t> iovs(buffers->Length());
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// Init uv buffers from ArrayBufferViews
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for (uint32_t i = 0; i < iovs.length(); i++) {
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Local<Value> buffer = buffers->Get(env->context(), i).ToLocalChecked();
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CHECK(Buffer::HasInstance(buffer));
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iovs[i] = uv_buf_init(Buffer::Data(buffer), Buffer::Length(buffer));
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}
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FSReqBase* req_wrap_async = GetReqWrap(env, args[3]);
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if (req_wrap_async != nullptr) { // readBuffers(fd, buffers, pos, req)
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AsyncCall(env, req_wrap_async, args, "read", UTF8, AfterInteger,
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uv_fs_read, fd, *iovs, iovs.length(), pos);
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} else { // readBuffers(fd, buffers, undefined, ctx)
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CHECK_EQ(argc, 5);
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FSReqWrapSync req_wrap_sync;
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FS_SYNC_TRACE_BEGIN(read);
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int bytesRead = SyncCall(env, /* ctx */ args[4], &req_wrap_sync, "read",
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uv_fs_read, fd, *iovs, iovs.length(), pos);
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FS_SYNC_TRACE_END(read, "bytesRead", bytesRead);
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args.GetReturnValue().Set(bytesRead);
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}
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}
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/* fs.chmod(path, mode);
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* Wrapper for chmod(1) / EIO_CHMOD
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*/
@@ -2228,6 +2274,7 @@ void Initialize(Local<Object> target,
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env->SetMethod(target, "open", Open);
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env->SetMethod(target, "openFileHandle", OpenFileHandle);
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env->SetMethod(target, "read", Read);
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env->SetMethod(target, "readBuffers", ReadBuffers);
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env->SetMethod(target, "fdatasync", Fdatasync);
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env->SetMethod(target, "fsync", Fsync);
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env->SetMethod(target, "rename", Rename);

‎test/parallel/test-fs-readv-promises.js‎

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@@ -0,0 +1,67 @@
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'use strict';
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require('../common');
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const assert = require('assert');
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const path = require('path');
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const fs = require('fs').promises;
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const tmpdir = require('../common/tmpdir');
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tmpdir.refresh();
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const expected = 'ümlaut. Лорем 運務ホソモ指及 आपको करने विकास 紙読決多密所 أضف';
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const exptectedBuff = Buffer.from(expected);
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let cnt = 0;
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function getFileName() {
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return path.join(tmpdir.path, `readv_promises_${++cnt}.txt`);
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}
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const allocateEmptyBuffers = (combinedLength) => {
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const bufferArr = [];
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// Allocate two buffers, each half the size of exptectedBuff
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bufferArr[0] = Buffer.alloc(Math.floor(combinedLength / 2)),
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bufferArr[1] = Buffer.alloc(combinedLength - bufferArr[0].length);
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return bufferArr;
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};
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(async () => {
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{
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const filename = getFileName();
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await fs.writeFile(filename, exptectedBuff);
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const handle = await fs.open(filename, 'r');
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// const buffer = Buffer.from(expected);
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const bufferArr = allocateEmptyBuffers(exptectedBuff.length);
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const expectedLength = exptectedBuff.length;
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let { bytesRead, buffers } = await handle.readv([Buffer.from('')],
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null);
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assert.deepStrictEqual(bytesRead, 0);
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assert.deepStrictEqual(buffers, [Buffer.from('')]);
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({ bytesRead, buffers } = await handle.readv(bufferArr, null));
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assert.deepStrictEqual(bytesRead, expectedLength);
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assert.deepStrictEqual(buffers, bufferArr);
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assert(Buffer.concat(bufferArr).equals(await fs.readFile(filename)));
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handle.close();
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}
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{
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const filename = getFileName();
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await fs.writeFile(filename, exptectedBuff);
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const handle = await fs.open(filename, 'r');
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// const buffer = Buffer.from(expected);
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const bufferArr = allocateEmptyBuffers(exptectedBuff.length);
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const expectedLength = exptectedBuff.length;
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let { bytesRead, buffers } = await handle.readv([Buffer.from('')]);
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assert.deepStrictEqual(bytesRead, 0);
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assert.deepStrictEqual(buffers, [Buffer.from('')]);
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({ bytesRead, buffers } = await handle.readv(bufferArr));
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assert.deepStrictEqual(bytesRead, expectedLength);
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assert.deepStrictEqual(buffers, bufferArr);
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assert(Buffer.concat(bufferArr).equals(await fs.readFile(filename)));
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handle.close();
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}
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})();

‎test/parallel/test-fs-readv-sync.js‎

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