snapshot of https://github.com/casbin/casbin.git (master, 2026-09-15; blobs > 131072B omitted)

config/config.go

@@ -0,0 +1,270 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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 (
+	"bufio"
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+var (
+	// DEFAULT_SECTION specifies the name of a section if no name provided.
+	DEFAULT_SECTION = "default"
+	// DEFAULT_COMMENT defines what character(s) indicate a comment `#`.
+	DEFAULT_COMMENT = []byte{'#'}
+	// DEFAULT_COMMENT_SEM defines what alternate character(s) indicate a comment `;`.
+	DEFAULT_COMMENT_SEM = []byte{';'}
+	// DEFAULT_MULTI_LINE_SEPARATOR defines what character indicates a multi-line content.
+	DEFAULT_MULTI_LINE_SEPARATOR = []byte{'\\'}
+)
+
+// ConfigInterface defines the behavior of a Config implementation.
+type ConfigInterface interface {
+	String(key string) string
+	Strings(key string) []string
+	Bool(key string) (bool, error)
+	Int(key string) (int, error)
+	Int64(key string) (int64, error)
+	Float64(key string) (float64, error)
+	Set(key string, value string) error
+}
+
+// Config represents an implementation of the ConfigInterface.
+type Config struct {
+	// Section:key=value
+	data map[string]map[string]string
+}
+
+// NewConfig create an empty configuration representation from file.
+func NewConfig(confName string) (ConfigInterface, error) {
+	c := &Config{
+		data: make(map[string]map[string]string),
+	}
+	err := c.parse(confName)
+	return c, err
+}
+
+// NewConfigFromText create an empty configuration representation from text.
+func NewConfigFromText(text string) (ConfigInterface, error) {
+	c := &Config{
+		data: make(map[string]map[string]string),
+	}
+	err := c.parseBuffer(bufio.NewReader(strings.NewReader(text)))
+	return c, err
+}
+
+// AddConfig adds a new section->key:value to the configuration.
+func (c *Config) AddConfig(section string, option string, value string) bool {
+	if section == "" {
+		section = DEFAULT_SECTION
+	}
+
+	if _, ok := c.data[section]; !ok {
+		c.data[section] = make(map[string]string)
+	}
+
+	_, ok := c.data[section][option]
+	c.data[section][option] = value
+
+	return !ok
+}
+
+func (c *Config) parse(fname string) (err error) {
+	f, err := os.Open(fname)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	buf := bufio.NewReader(f)
+	return c.parseBuffer(buf)
+}
+
+func (c *Config) parseBuffer(buf *bufio.Reader) error {
+	var section string
+	var lineNum int
+	var buffer bytes.Buffer
+	var canWrite bool
+	for {
+		if canWrite {
+			if err := c.write(section, lineNum, &buffer); err != nil {
+				return err
+			} else {
+				canWrite = false
+			}
+		}
+		lineNum++
+		line, _, err := buf.ReadLine()
+		if err == io.EOF {
+			// force write when buffer is not flushed yet
+			if buffer.Len() > 0 {
+				if err = c.write(section, lineNum, &buffer); err != nil {
+					return err
+				}
+			}
+			break
+		} else if err != nil {
+			return err
+		}
+
+		line = bytes.TrimSpace(line)
+		switch {
+		case bytes.Equal(line, []byte{}), bytes.HasPrefix(line, DEFAULT_COMMENT_SEM),
+			bytes.HasPrefix(line, DEFAULT_COMMENT):
+			canWrite = true
+			continue
+		case bytes.HasPrefix(line, []byte{'['}) && bytes.HasSuffix(line, []byte{']'}):
+			// force write when buffer is not flushed yet
+			if buffer.Len() > 0 {
+				if err := c.write(section, lineNum, &buffer); err != nil {
+					return err
+				}
+				canWrite = false
+			}
+			section = string(line[1 : len(line)-1])
+		default:
+			var p []byte
+			if bytes.HasSuffix(line, DEFAULT_MULTI_LINE_SEPARATOR) {
+				p = bytes.TrimSpace(line[:len(line)-1])
+				p = append(p, " "...)
+			} else {
+				p = line
+				canWrite = true
+			}
+
+			end := len(p)
+			for i, value := range p {
+				if value == DEFAULT_COMMENT[0] || value == DEFAULT_COMMENT_SEM[0] {
+					end = i
+					break
+				}
+			}
+			if _, err := buffer.Write(p[:end]); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func (c *Config) write(section string, lineNum int, b *bytes.Buffer) error {
+	if b.Len() <= 0 {
+		return nil
+	}
+
+	optionVal := bytes.SplitN(b.Bytes(), []byte{'='}, 2)
+	if len(optionVal) != 2 {
+		return fmt.Errorf("parse the content error : line %d , %s = ? ", lineNum, optionVal[0])
+	}
+	option := bytes.TrimSpace(optionVal[0])
+	value := bytes.TrimSpace(optionVal[1])
+	c.AddConfig(section, string(option), string(value))
+
+	// flush buffer after adding
+	b.Reset()
+
+	return nil
+}
+
+// Bool lookups up the value using the provided key and converts the value to a bool.
+func (c *Config) Bool(key string) (bool, error) {
+	return strconv.ParseBool(c.get(key))
+}
+
+// Int lookups up the value using the provided key and converts the value to a int.
+func (c *Config) Int(key string) (int, error) {
+	return strconv.Atoi(c.get(key))
+}
+
+// Int64 lookups up the value using the provided key and converts the value to a int64.
+func (c *Config) Int64(key string) (int64, error) {
+	return strconv.ParseInt(c.get(key), 10, 64)
+}
+
+// Float64 lookups up the value using the provided key and converts the value to a float64.
+func (c *Config) Float64(key string) (float64, error) {
+	return strconv.ParseFloat(c.get(key), 64)
+}
+
+// String lookups up the value using the provided key and converts the value to a string.
+func (c *Config) String(key string) string {
+	return c.get(key)
+}
+
+// Strings lookups up the value using the provided key and converts the value to an array of string
+// by splitting the string by comma.
+func (c *Config) Strings(key string) []string {
+	v := c.get(key)
+	if v == "" {
+		return nil
+	}
+	return strings.Split(v, ",")
+}
+
+// Set sets the value for the specific key in the Config.
+func (c *Config) Set(key string, value string) error {
+	if len(key) == 0 {
+		return errors.New("key is empty")
+	}
+
+	var (
+		section string
+		option  string
+	)
+
+	keys := strings.Split(strings.ToLower(key), "::")
+	if len(keys) >= 2 {
+		section = keys[0]
+		option = keys[1]
+	} else {
+		option = keys[0]
+	}
+
+	c.AddConfig(section, option, value)
+	return nil
+}
+
+// section.key or key.
+func (c *Config) get(key string) string {
+	var (
+		section string
+		option  string
+	)
+
+	keys := strings.Split(strings.ToLower(key), "::")
+	if len(keys) >= 2 {
+		section = keys[0]
+		option = keys[1]
+	} else {
+		section = DEFAULT_SECTION
+		option = keys[0]
+	}
+
+	if value, ok := c.data[section][option]; ok {
+		return value
+	}
+
+	return ""
+}