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stream: suggestion stream._writeMany #29034
Description
Currently the stream.writev API has two drawbacks:
- It requires adding properties to the input array (
allBuffers). - It will always creates an array copy.
- The array entries must be allocated objects.
It would be nice if user space could just create the correctly formatted array without having to perform any allocations, copies and transformations.
In order to not break anything I suggest a new signature writev maybe called writeMany?
Which would look something like:
Stream._writeMany = function (chunks, allBuffers, cb) {
}e.g.
const chunks = [];
for (const { chunk } of data) {
chunks.push(chunk);
}
w._writeMany(chunks, true, cb);const chunks = [];
for (const { chunk, encoding } of data) {
chunks.push(chunk, encoding);
}
w._writeMany(chunks, false, cb);Looking at the current Writable implementation, the writev scenario will always create two "unnecessary" array copies in order to pass the chunks. Furthermore all the array entries are allocated objects.
Activity
[-]stream: suggestion writev2[/-][+]stream: suggestion stream._writeMany[/+]mscdex commentedon Aug 7, 2019
allBuffersis an implementation detail and not something that should be requested from the end user and relied upon.ronag commentedon Aug 7, 2019
True, but by exposing it we enable some optimizations that are otherwise not possible.
mscdex commentedon Aug 7, 2019
We would still need to validate that the value for
allBuffersis correct, which would negate any gain.ronag commentedon Aug 7, 2019
I'm not sure I follow?