Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fs: improve promises.readFile performance #37127

Closed
wants to merge 3 commits into from
Closed

fs: improve promises.readFile performance #37127

Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
69c87cc
fs: only use Buffer.concat in promises.readFile when necessary
addaleax Jan 29, 2021
5ce769e
fs: read full size if known in promises.readFile
addaleax Jan 29, 2021
759440f
fixup! fs: read full size if known in promises.readFile
addaleax Jan 29, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
13 changes: 7 additions & 6 deletions lib/internal/fs/promises.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -315,23 +315,24 @@ async function readFileHandle(filehandle, options) {
throw new ERR_FS_FILE_TOO_LARGE(size);

const chunks = [];
const chunkSize = size === 0 ?
kReadFileMaxChunkSize :
MathMin(size, kReadFileMaxChunkSize);
let isFirstChunk = true;
const firstChunkSize = size === 0 ? kReadFileMaxChunkSize : size;
const chunkSize = MathMin(firstChunkSize, kReadFileMaxChunkSize);
let endOfFile = false;
do {
if (signal?.aborted) {
throw lazyDOMException('The operation was aborted', 'AbortError');
}
const buf = Buffer.alloc(chunkSize);
const buf = Buffer.alloc(isFirstChunk ? firstChunkSize : chunkSize);
const { bytesRead, buffer } =
await read(filehandle, buf, 0, chunkSize, -1);
await read(filehandle, buf, 0, buf.length, -1);
endOfFile = bytesRead === 0;
if (bytesRead > 0)
ArrayPrototypePush(chunks, buffer.slice(0, bytesRead));
isFirstChunk = false;
} while (!endOfFile);

const result = Buffer.concat(chunks);
const result = chunks.length === 1 ? chunks[0] : Buffer.concat(chunks);

return options.encoding ? result.toString(options.encoding) : result;
}
Expand Down