prometheus/config/load.go
2013-02-14 19:03:17 +01:00

80 lines
2.1 KiB
Go

// Copyright 2013 Prometheus Team
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package config
import (
"errors"
"fmt"
"io"
"os"
"strings"
)
// NOTE: This parser is non-reentrant due to its dependence on global state.
// GoLex sadly needs these global variables for storing temporary token/parsing information.
var yylval *yySymType // For storing extra token information, like the contents of a string.
var yyline int // Line number within the current file or buffer.
var yypos int // Character position within the current line.
var parsedConfig *Config // Temporary variable for storing the parsed configuration.
type ConfigLexer struct {
errors []string
}
func (lexer *ConfigLexer) Lex(lval *yySymType) int {
yylval = lval
token_type := yylex()
return token_type
}
func (lexer *ConfigLexer) Error(errorStr string) {
err := fmt.Sprintf("Error reading config at line %v, char %v: %v", yyline, yypos, errorStr)
lexer.errors = append(lexer.errors, err)
}
func LoadFromReader(configReader io.Reader) (*Config, error) {
parsedConfig = New()
yyin = configReader
yypos = 1
yyline = 1
yydata = ""
yytext = ""
lexer := &ConfigLexer{}
yyParse(lexer)
if len(lexer.errors) > 0 {
err := errors.New(strings.Join(lexer.errors, "\n"))
return &Config{}, err
}
return parsedConfig, nil
}
func LoadFromString(configString string) (*Config, error) {
configReader := strings.NewReader(configString)
return LoadFromReader(configReader)
}
func LoadFromFile(fileName string) (*Config, error) {
configReader, err := os.Open(fileName)
if err != nil {
return &Config{}, err
}
defer configReader.Close()
return LoadFromReader(configReader)
}