dispatch/vendor/github.com/magiconair/properties/load.go

125 lines
3.5 KiB
Go

// Copyright 2013-2014 Frank Schroeder. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package properties
import (
"fmt"
"io/ioutil"
"os"
)
// Encoding specifies encoding of the input data.
type Encoding uint
const (
// UTF8 interprets the input data as UTF-8.
UTF8 Encoding = 1 << iota
// ISO_8859_1 interprets the input data as ISO-8859-1.
ISO_8859_1
)
// Load reads a buffer into a Properties struct.
func Load(buf []byte, enc Encoding) (*Properties, error) {
return loadBuf(buf, enc)
}
// LoadFile reads a file into a Properties struct.
func LoadFile(filename string, enc Encoding) (*Properties, error) {
return loadFiles([]string{filename}, enc, false)
}
// LoadFiles reads multiple files in the given order into
// a Properties struct. If 'ignoreMissing' is true then
// non-existent files will not be reported as error.
func LoadFiles(filenames []string, enc Encoding, ignoreMissing bool) (*Properties, error) {
return loadFiles(filenames, enc, ignoreMissing)
}
// MustLoadFile reads a file into a Properties struct and
// panics on error.
func MustLoadFile(filename string, enc Encoding) *Properties {
return mustLoadFiles([]string{filename}, enc, false)
}
// MustLoadFiles reads multiple files in the given order into
// a Properties struct and panics on error. If 'ignoreMissing'
// is true then non-existent files will not be reported as error.
func MustLoadFiles(filenames []string, enc Encoding, ignoreMissing bool) *Properties {
return mustLoadFiles(filenames, enc, ignoreMissing)
}
// ----------------------------------------------------------------------------
func loadBuf(buf []byte, enc Encoding) (*Properties, error) {
p, err := parse(convert(buf, enc))
if err != nil {
return nil, err
}
return p, p.check()
}
func loadFiles(filenames []string, enc Encoding, ignoreMissing bool) (*Properties, error) {
buff := make([]byte, 0, 4096)
for _, filename := range filenames {
f, err := expandFilename(filename)
if err != nil {
return nil, err
}
buf, err := ioutil.ReadFile(f)
if err != nil {
if ignoreMissing && os.IsNotExist(err) {
// TODO(frank): should we log that we are skipping the file?
continue
}
return nil, err
}
// concatenate the buffers and add a new line in case
// the previous file didn't end with a new line
buff = append(append(buff, buf...), '\n')
}
return loadBuf(buff, enc)
}
func mustLoadFiles(filenames []string, enc Encoding, ignoreMissing bool) *Properties {
p, err := loadFiles(filenames, enc, ignoreMissing)
if err != nil {
ErrorHandler(err)
}
return p
}
// expandFilename expands ${ENV_VAR} expressions in a filename.
// If the environment variable does not exist then it will be replaced
// with an empty string. Malformed expressions like "${ENV_VAR" will
// be reported as error.
func expandFilename(filename string) (string, error) {
return expand(filename, make(map[string]bool), "${", "}", make(map[string]string))
}
// Interprets a byte buffer either as an ISO-8859-1 or UTF-8 encoded string.
// For ISO-8859-1 we can convert each byte straight into a rune since the
// first 256 unicode code points cover ISO-8859-1.
func convert(buf []byte, enc Encoding) string {
switch enc {
case UTF8:
return string(buf)
case ISO_8859_1:
runes := make([]rune, len(buf))
for i, b := range buf {
runes[i] = rune(b)
}
return string(runes)
default:
ErrorHandler(fmt.Errorf("unsupported encoding %v", enc))
}
panic("ErrorHandler should exit")
}