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Diffstat (limited to 'config/config.go')
-rw-r--r--config/config.go495
1 files changed, 495 insertions, 0 deletions
diff --git a/config/config.go b/config/config.go
new file mode 100644
index 00000000..edee4f3b
--- /dev/null
+++ b/config/config.go
@@ -0,0 +1,495 @@
+package config
+
+import (
+ "bufio"
+ "bytes"
+ "errors"
+ "fmt"
+ "io"
+ "strings"
+ "unicode"
+)
+
+// Config holds all parsed configuration entries from a Git config file.
+//
+// A Config preserves the ordering of entries as they appeared in the source.
+//
+// Lookups are matched case-insensitively for section and key names, and
+// subsections must match exactly.
+type Config struct {
+ entries []ConfigEntry
+}
+
+// ConfigEntry represents a single parsed configuration directive.
+type ConfigEntry struct {
+ // The section name in canonical lowercase form.
+ Section string
+ // The subsection name, retaining the exact form parsed from the input.
+ Subsection string
+ // The key name in canonical lowercase form.
+ Key string
+ // The interpreted value of the configuration entry, including unescaped
+ // characters where appropriate.
+ Value string
+}
+
+// ParseConfig reads and parses Git configuration entries from r.
+func ParseConfig(r io.Reader) (*Config, error) {
+ parser := &configParser{
+ reader: bufio.NewReader(r),
+ lineNum: 1,
+ }
+ return parser.parse()
+}
+
+// Get retrieves the first value for a given section, optional subsection, and key.
+// Returns an empty string if not found.
+func (c *Config) Get(section, subsection, key string) string {
+ section = strings.ToLower(section)
+ key = strings.ToLower(key)
+ for _, entry := range c.entries {
+ if strings.EqualFold(entry.Section, section) &&
+ entry.Subsection == subsection &&
+ strings.EqualFold(entry.Key, key) {
+ return entry.Value
+ }
+ }
+ return ""
+}
+
+// GetAll retrieves all values for a given section, optional subsection, and key.
+func (c *Config) GetAll(section, subsection, key string) []string {
+ section = strings.ToLower(section)
+ key = strings.ToLower(key)
+ var values []string
+ for _, entry := range c.entries {
+ if strings.EqualFold(entry.Section, section) &&
+ entry.Subsection == subsection &&
+ strings.EqualFold(entry.Key, key) {
+ values = append(values, entry.Value)
+ }
+ }
+ return values
+}
+
+// Entries returns a copy of all parsed configuration entries in the order they
+// appeared. Modifying the returned slice does not affect the Config.
+func (c *Config) Entries() []ConfigEntry {
+ result := make([]ConfigEntry, len(c.entries))
+ copy(result, c.entries)
+ return result
+}
+
+type configParser struct {
+ reader *bufio.Reader
+ lineNum int
+ currentSection string
+ currentSubsec string
+ peeked rune
+ hasPeeked bool
+}
+
+func (p *configParser) parse() (*Config, error) {
+ cfg := &Config{}
+
+ if err := p.skipBOM(); err != nil {
+ return nil, err
+ }
+
+ for {
+ ch, err := p.nextChar()
+ if err == io.EOF {
+ break
+ }
+ if err != nil {
+ return nil, err
+ }
+
+ // Skip whitespace and newlines
+ if ch == '\n' || unicode.IsSpace(ch) {
+ continue
+ }
+
+ // Comments
+ if ch == '#' || ch == ';' {
+ if err := p.skipToEOL(); err != nil && err != io.EOF {
+ return nil, err
+ }
+ continue
+ }
+
+ // Section header
+ if ch == '[' {
+ if err := p.parseSection(); err != nil {
+ return nil, fmt.Errorf("furgit: config: line %d: %w", p.lineNum, err)
+ }
+ continue
+ }
+
+ // Key-value pair
+ if unicode.IsLetter(ch) {
+ p.unreadChar(ch)
+ if err := p.parseKeyValue(cfg); err != nil {
+ return nil, fmt.Errorf("furgit: config: line %d: %w", p.lineNum, err)
+ }
+ continue
+ }
+
+ return nil, fmt.Errorf("furgit: config: line %d: unexpected character %q", p.lineNum, ch)
+ }
+
+ return cfg, nil
+}
+
+func (p *configParser) nextChar() (rune, error) {
+ if p.hasPeeked {
+ p.hasPeeked = false
+ return p.peeked, nil
+ }
+
+ ch, _, err := p.reader.ReadRune()
+ if err != nil {
+ return 0, err
+ }
+
+ if ch == '\r' {
+ next, _, err := p.reader.ReadRune()
+ if err == nil && next == '\n' {
+ ch = '\n'
+ } else if err == nil {
+ // Weird but ok
+ _ = p.reader.UnreadRune()
+ }
+ }
+
+ if ch == '\n' {
+ p.lineNum++
+ }
+
+ return ch, nil
+}
+
+func (p *configParser) unreadChar(ch rune) {
+ p.peeked = ch
+ p.hasPeeked = true
+ if ch == '\n' && p.lineNum > 1 {
+ p.lineNum--
+ }
+}
+
+func (p *configParser) skipBOM() error {
+ first, _, err := p.reader.ReadRune()
+ if err == io.EOF {
+ return nil
+ }
+ if err != nil {
+ return err
+ }
+ if first != '\uFEFF' {
+ _ = p.reader.UnreadRune()
+ }
+ return nil
+}
+
+func (p *configParser) skipToEOL() error {
+ for {
+ ch, err := p.nextChar()
+ if err != nil {
+ return err
+ }
+ if ch == '\n' {
+ return nil
+ }
+ }
+}
+
+func (p *configParser) parseSection() error {
+ var name bytes.Buffer
+
+ for {
+ ch, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF in section header")
+ }
+
+ if ch == ']' {
+ section := name.String()
+ if !isValidSection(section) {
+ return fmt.Errorf("invalid section name: %q", section)
+ }
+ p.currentSection = strings.ToLower(section)
+ p.currentSubsec = ""
+ return nil
+ }
+
+ if unicode.IsSpace(ch) {
+ return p.parseExtendedSection(&name)
+ }
+
+ if !isKeyChar(ch) && ch != '.' {
+ return fmt.Errorf("invalid character in section name: %q", ch)
+ }
+
+ name.WriteRune(unicode.ToLower(ch))
+ }
+}
+
+func (p *configParser) parseExtendedSection(sectionName *bytes.Buffer) error {
+ for {
+ ch, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF in section header")
+ }
+ if !unicode.IsSpace(ch) {
+ if ch != '"' {
+ return errors.New("expected quote after section name")
+ }
+ break
+ }
+ }
+
+ var subsec bytes.Buffer
+ for {
+ ch, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF in subsection")
+ }
+
+ if ch == '\n' {
+ return errors.New("newline in subsection")
+ }
+
+ if ch == '"' {
+ break
+ }
+
+ if ch == '\\' {
+ next, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF after backslash in subsection")
+ }
+ if next == '\n' {
+ return errors.New("newline after backslash in subsection")
+ }
+ subsec.WriteRune(next)
+ } else {
+ subsec.WriteRune(ch)
+ }
+ }
+
+ ch, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF after subsection")
+ }
+ if ch != ']' {
+ return fmt.Errorf("expected ']' after subsection, got %q", ch)
+ }
+
+ section := sectionName.String()
+ if !isValidSection(section) {
+ return fmt.Errorf("invalid section name: %q", section)
+ }
+
+ p.currentSection = strings.ToLower(section)
+ p.currentSubsec = subsec.String()
+ return nil
+}
+
+func (p *configParser) parseKeyValue(cfg *Config) error {
+ if p.currentSection == "" {
+ return errors.New("key-value pair before any section header")
+ }
+
+ var key bytes.Buffer
+ for {
+ ch, err := p.nextChar()
+ if err != nil {
+ return errors.New("unexpected EOF reading key")
+ }
+
+ if ch == '=' || ch == '\n' || unicode.IsSpace(ch) {
+ p.unreadChar(ch)
+ break
+ }
+
+ if !isKeyChar(ch) {
+ return fmt.Errorf("invalid character in key: %q", ch)
+ }
+
+ key.WriteRune(unicode.ToLower(ch))
+ }
+
+ keyStr := key.String()
+ if len(keyStr) == 0 {
+ return errors.New("empty key name")
+ }
+ if !unicode.IsLetter(rune(keyStr[0])) {
+ return errors.New("key must start with a letter")
+ }
+
+ for {
+ ch, err := p.nextChar()
+ if err == io.EOF {
+ cfg.entries = append(cfg.entries, ConfigEntry{
+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+ if err != nil {
+ return err
+ }
+
+ if ch == '\n' {
+ cfg.entries = append(cfg.entries, ConfigEntry{
+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+
+ if ch == '#' || ch == ';' {
+ if err := p.skipToEOL(); err != nil && err != io.EOF {
+ return err
+ }
+ cfg.entries = append(cfg.entries, ConfigEntry{
+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: "true",
+ })
+ return nil
+ }
+
+ if ch == '=' {
+ break
+ }
+
+ if !unicode.IsSpace(ch) {
+ return fmt.Errorf("unexpected character after key: %q", ch)
+ }
+ }
+
+ value, err := p.parseValue()
+ if err != nil {
+ return err
+ }
+
+ cfg.entries = append(cfg.entries, ConfigEntry{
+ Section: p.currentSection,
+ Subsection: p.currentSubsec,
+ Key: keyStr,
+ Value: value,
+ })
+
+ return nil
+}
+
+func (p *configParser) parseValue() (string, error) {
+ var value bytes.Buffer
+ var inQuote bool
+ var inComment bool
+ trimLen := 0
+
+ for {
+ ch, err := p.nextChar()
+ if err == io.EOF {
+ if inQuote {
+ return "", errors.New("unexpected EOF in quoted value")
+ }
+ if trimLen > 0 {
+ return value.String()[:trimLen], nil
+ }
+ return value.String(), nil
+ }
+ if err != nil {
+ return "", err
+ }
+
+ if ch == '\n' {
+ if inQuote {
+ return "", errors.New("newline in quoted value")
+ }
+ if trimLen > 0 {
+ return value.String()[:trimLen], nil
+ }
+ return value.String(), nil
+ }
+
+ if inComment {
+ continue
+ }
+
+ if unicode.IsSpace(ch) && !inQuote {
+ if trimLen == 0 && value.Len() > 0 {
+ trimLen = value.Len()
+ }
+ if value.Len() > 0 {
+ value.WriteRune(ch)
+ }
+ continue
+ }
+
+ if !inQuote && (ch == '#' || ch == ';') {
+ inComment = true
+ continue
+ }
+
+ if trimLen > 0 {
+ trimLen = 0
+ }
+
+ if ch == '\\' {
+ next, err := p.nextChar()
+ if err == io.EOF {
+ return "", errors.New("unexpected EOF after backslash")
+ }
+ if err != nil {
+ return "", err
+ }
+
+ switch next {
+ case '\n':
+ continue
+ case 'n':
+ value.WriteRune('\n')
+ case 't':
+ value.WriteRune('\t')
+ case 'b':
+ value.WriteRune('\b')
+ case '\\', '"':
+ value.WriteRune(next)
+ default:
+ return "", fmt.Errorf("invalid escape sequence: \\%c", next)
+ }
+ continue
+ }
+
+ if ch == '"' {
+ inQuote = !inQuote
+ continue
+ }
+
+ value.WriteRune(ch)
+ }
+}
+
+func isValidSection(s string) bool {
+ if len(s) == 0 {
+ return false
+ }
+ for _, ch := range s {
+ if !unicode.IsLetter(ch) && !unicode.IsDigit(ch) && ch != '-' && ch != '.' {
+ return false
+ }
+ }
+ return true
+}
+
+func isKeyChar(ch rune) bool {
+ return unicode.IsLetter(ch) || unicode.IsDigit(ch) || ch == '-'
+}
generated by cgit v1.3.1-10-gc9f91 (git 2.54.0) at 2026-05-25 12:52:15 +0000