forgejo/modules/util/io.go
zeripath 78e6b21c1a
Improve checkIfPRContentChanged ()
The code for checking if a commit has caused a change in a PR is
extremely inefficient and affects the head repository instead of using a
temporary repository.

This PR therefore makes several significant improvements:

* A temporary repo like that used in merging.
* The diff code is then significant improved to use a three-way diff
instead of comparing diffs (possibly binary) line-by-line - in memory...

Ref 

Signed-off-by: Andrew Thornton <art27@cantab.net>
2023-01-28 15:54:40 +00:00

42 lines
903 B
Go

// Copyright 2021 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT
package util
import (
"errors"
"io"
)
// ReadAtMost reads at most len(buf) bytes from r into buf.
// It returns the number of bytes copied. n is only less than len(buf) if r provides fewer bytes.
// If EOF occurs while reading, err will be nil.
func ReadAtMost(r io.Reader, buf []byte) (n int, err error) {
n, err = io.ReadFull(r, buf)
if err == io.EOF || err == io.ErrUnexpectedEOF {
err = nil
}
return n, err
}
// ErrNotEmpty is an error reported when there is a non-empty reader
var ErrNotEmpty = errors.New("not-empty")
// IsEmptyReader reads a reader and ensures it is empty
func IsEmptyReader(r io.Reader) (err error) {
var buf [1]byte
for {
n, err := r.Read(buf[:])
if err != nil {
if err == io.EOF {
return nil
}
return err
}
if n > 0 {
return ErrNotEmpty
}
}
}