/
file.go
95 lines (83 loc) · 2.31 KB
/
file.go
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package cluster
import (
"fmt"
"io"
"os"
)
// FileCollector collects data from a YAML file.
type FileCollector struct {
// path is a path to a YAML file.
path string
// fileReadFunc is a function to read a file.
fileReadFunc FileReadFunc
}
// defaultFileReadFunc is a default read file function.
func defaultFileReadFunc(path string) (io.ReadCloser, error) {
return os.Open(path)
}
// NewFileCollector creates a new file collector for a path.
func NewFileCollector(path string) FileCollector {
return FileCollector{
path: path,
fileReadFunc: defaultFileReadFunc,
}
}
// NewIntegrityFileCollector creates a new file collector for a path with
// additional integrity checks.
func NewIntegrityFileCollector(fileReadFunc FileReadFunc, path string) FileCollector {
return FileCollector{
path: path,
fileReadFunc: fileReadFunc,
}
}
// Collect collects a configuration from a file located at a specified path.
func (collector FileCollector) Collect() ([]Data, error) {
const fmtErr = "unable to read file %q: %w"
reader, err := collector.fileReadFunc(collector.path)
if err != nil {
return nil, fmt.Errorf(fmtErr, collector.path, err)
}
defer reader.Close()
data, err := io.ReadAll(reader)
if err != nil {
return nil, fmt.Errorf(fmtErr, collector.path, err)
}
return []Data{
{
Source: collector.path,
Value: data,
},
}, nil
}
// FileDataPublisher publishes a data into a file as is.
type FileDataPublisher struct {
// path is a path to the file.
path string
}
// NewFileDataPublisher creates a new FileDataPublisher object to publish
// a data into a file for the given path.
func NewFileDataPublisher(path string) FileDataPublisher {
return FileDataPublisher{
path: path,
}
}
// Publish publishes the data to a file for the given path.
func (publisher FileDataPublisher) Publish(revision int64, data []byte) error {
if revision != 0 {
return fmt.Errorf("failed to publish data into file: target revision %d is not supported",
revision)
}
if publisher.path == "" {
return fmt.Errorf("file path is empty")
}
if data == nil {
return fmt.Errorf("failed to publish data into %q: data does not exist",
publisher.path)
}
err := os.WriteFile(publisher.path, data, 0644)
if err != nil {
return fmt.Errorf("failed to publish data into %q: %w",
publisher.path, err)
}
return nil
}