woodpecker/vendor/github.com/golangci/golangci-lint/pkg/fsutils/linecache.go
Lukas c28f7cb29f
Add golangci-lint (#502)
Initial part of #435
2021-11-14 21:01:54 +01:00

70 lines
1.6 KiB
Go

package fsutils
import (
"bytes"
"fmt"
"sync"
"github.com/pkg/errors"
)
type fileLinesCache [][]byte
type LineCache struct {
files sync.Map
fileCache *FileCache
}
func NewLineCache(fc *FileCache) *LineCache {
return &LineCache{
fileCache: fc,
}
}
// GetLine returns a index1-th (1-based index) line from the file on filePath
func (lc *LineCache) GetLine(filePath string, index1 int) (string, error) {
if index1 == 0 { // some linters, e.g. gosec can do it: it really means first line
index1 = 1
}
const index1To0Offset = -1
rawLine, err := lc.getRawLine(filePath, index1+index1To0Offset)
if err != nil {
return "", err
}
return string(bytes.Trim(rawLine, "\r")), nil
}
func (lc *LineCache) getRawLine(filePath string, index0 int) ([]byte, error) {
fc, err := lc.getFileCache(filePath)
if err != nil {
return nil, errors.Wrapf(err, "failed to get file %s lines cache", filePath)
}
if index0 < 0 {
return nil, fmt.Errorf("invalid file line index0 < 0: %d", index0)
}
if index0 >= len(fc) {
return nil, fmt.Errorf("invalid file line index0 (%d) >= len(fc) (%d)", index0, len(fc))
}
return fc[index0], nil
}
func (lc *LineCache) getFileCache(filePath string) (fileLinesCache, error) {
loadedFc, ok := lc.files.Load(filePath)
if ok {
return loadedFc.(fileLinesCache), nil
}
fileBytes, err := lc.fileCache.GetFileBytes(filePath)
if err != nil {
return nil, errors.Wrapf(err, "can't get file %s bytes from cache", filePath)
}
fc := bytes.Split(fileBytes, []byte("\n"))
lc.files.Store(filePath, fileLinesCache(fc))
return fc, nil
}