Fixes #53658. io.Copy() uses sendfile(2) to avoid allocating extra buffers when src is a file and dst is a TCPConn. However if src returns no bytes current logic treats it as failure and falls back to copying via user space. The following is a benchmark that illustrates the bug.
Benchmark: https://go.dev/play/p/zgZwpjUatSq
Before:
BenchmarkCopy-16 541006 2137 ns/op 4077 B/op 0 allocs/op
After:
BenchmarkCopy-16 490383 2365 ns/op 174 B/op 8 allocs/op
Change-Id: I703376d53b20e080c6204a73c96867cce16b24cf
GitHub-Last-Rev:
|
||
|---|---|---|
| .github | ||
| api | ||
| doc | ||
| lib/time | ||
| misc | ||
| src | ||
| test | ||
| .gitattributes | ||
| .gitignore | ||
| CONTRIBUTING.md | ||
| LICENSE | ||
| PATENTS | ||
| README.md | ||
| SECURITY.md | ||
| codereview.cfg | ||
README.md
The Go Programming Language
Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.
Gopher image by Renee French, licensed under Creative Commons 4.0 Attributions license.
Our canonical Git repository is located at https://go.googlesource.com/go. There is a mirror of the repository at https://github.com/golang/go.
Unless otherwise noted, the Go source files are distributed under the BSD-style license found in the LICENSE file.
Download and Install
Binary Distributions
Official binary distributions are available at https://go.dev/dl/.
After downloading a binary release, visit https://go.dev/doc/install for installation instructions.
Install From Source
If a binary distribution is not available for your combination of operating system and architecture, visit https://go.dev/doc/install/source for source installation instructions.
Contributing
Go is the work of thousands of contributors. We appreciate your help!
To contribute, please read the contribution guidelines at https://go.dev/doc/contribute.
Note that the Go project uses the issue tracker for bug reports and proposals only. See https://go.dev/wiki/Questions for a list of places to ask questions about the Go language.