mirror of
https://github.com/tailscale/tailscale.git
synced 2024-12-12 03:04:40 +00:00
71029cea2d
This updates all source files to use a new standard header for copyright and license declaration. Notably, copyright no longer includes a date, and we now use the standard SPDX-License-Identifier header. This commit was done almost entirely mechanically with perl, and then some minimal manual fixes. Updates #6865 Signed-off-by: Will Norris <will@tailscale.com>
58 lines
1.0 KiB
Go
58 lines
1.0 KiB
Go
// Copyright (c) Tailscale Inc & AUTHORS
|
|
// SPDX-License-Identifier: BSD-3-Clause
|
|
|
|
// Package jsondb provides a trivial "database": a Go object saved to
|
|
// disk as JSON.
|
|
package jsondb
|
|
|
|
import (
|
|
"encoding/json"
|
|
"errors"
|
|
"io/fs"
|
|
"os"
|
|
|
|
"tailscale.com/atomicfile"
|
|
)
|
|
|
|
// DB is a database backed by a JSON file.
|
|
type DB[T any] struct {
|
|
// Data is the contents of the database.
|
|
Data *T
|
|
|
|
path string
|
|
}
|
|
|
|
// Open opens the database at path, creating it with a zero value if
|
|
// necessary.
|
|
func Open[T any](path string) (*DB[T], error) {
|
|
bs, err := os.ReadFile(path)
|
|
if errors.Is(err, fs.ErrNotExist) {
|
|
return &DB[T]{
|
|
Data: new(T),
|
|
path: path,
|
|
}, nil
|
|
} else if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
var val T
|
|
if err := json.Unmarshal(bs, &val); err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return &DB[T]{
|
|
Data: &val,
|
|
path: path,
|
|
}, nil
|
|
}
|
|
|
|
// Save writes db.Data back to disk.
|
|
func (db *DB[T]) Save() error {
|
|
bs, err := json.Marshal(db.Data)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
return atomicfile.WriteFile(db.path, bs, 0600)
|
|
}
|