May 2019
Intermediate to advanced
464 pages
9h 22m
Japanese
Content preview from Node.jsデザインパターン 第2版
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.
5.1
ストリームの重要性
109
1.
［クライアント］ファイルからデータを読み込む
2.
［クライアント］読み込んだデータを
Gzip
で圧縮する
3.
［クライアント］圧縮済みデータをサーバに送信する
4.
［サーバ］クライアントからデータを受信する
5.
［サーバ］受信したデータを
Gzip
で展開する
6.
［サーバ］展開済みデータをファイルに書き込む
工場の組み立てラインと似ており、このライン上をデータが通過するときにそれぞれの処理が行わ
れます。図5-3を見ると、バッファを使った場合はファイル全体を一度にラインに流す形になっていま
す。したがってライン上の各処理のステージは、前のステージでファイル全体が処理されるまで待たさ
れることになります。一方、ストリームを使った場合は、データのチャンクごとにラインを流れること
になります。ここで重要なのは、各チャンクは他のチャンクの処理を待つことなく並行処理されること
です。一連
の処理（ファイル読み込み／書き込み、
Gzip
圧縮／展開、ネットワーク送信／受信）は非同
期処理なので、
Node
で簡単に並行実行ができます。唯一の制約として、チャンクの順番が保たれる必
要がありますが、これに関しては
Node
のストリームが内部的に順番を保証してくれるため、開発者は
意識する必要はありません。
図からもわかるとおり、バッファよりもストリームのほうが全体の処理にかかる時間は短くなります。
これは、データを分割処理することで、すべてのデータを一度に処理する場合に発生する待ち時間が
な
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
More than 5,000 organizations count on O’Reilly
O’Reilly covers everything we've got, with content to help us build a world-class technology community, upgrade the capabilities and competencies of our teams, and improve overall team performance as well as their engagement.Julian F.
I wanted to learn C and C++, but it didn't click for me until I picked up an O'Reilly book. When I went on the O’Reilly platform, I was astonished to find all the books there, plus live events and sandboxes so you could play around with the technology.Addison B.
I’ve been on the O’Reilly platform for more than eight years. I use a couple of learning platforms, but I'm on O'Reilly more than anybody else. When you're there, you start learning. I'm never disappointed.Amir M.
I'm always learning. So when I got on to O'Reilly, I was like a kid in a candy store. There are playlists. There are answers. There's on-demand training. It's worth its weight in gold, in terms of what it allows me to do.