goldsmith/file.go
2024-03-03 21:39:08 -08:00

156 lines
3.3 KiB
Go

package goldsmith
import (
"bytes"
"fmt"
"io"
"os"
"path/filepath"
"time"
)
type (
FileProp any
FileProps map[string]FileProp
// File represents in-memory or on-disk files in a chain.
File struct {
relPath string
props FileProps
modTime time.Time
size int64
dataPath string
reader *bytes.Reader
index int
}
)
// Rename modifies the file path relative to the source directory.
func (self *File) Rename(path string) error {
if filepath.IsAbs(path) {
return fmt.Errorf("unexpected absolute path: %s", path)
}
self.relPath = path
return nil
}
// Path returns the file path relative to the source directory.
func (self *File) Path() string {
return filepath.ToSlash(self.relPath)
}
// Dir returns the containing directory of the file.
func (self *File) Dir() string {
return filepath.ToSlash(filepath.Dir(self.relPath))
}
// Name returns the base name of the file.
func (self *File) Name() string {
return filepath.Base(self.relPath)
}
// Ext returns the extension of the file.
func (self *File) Ext() string {
return filepath.Ext(self.relPath)
}
// Size returns the file length in bytes.
func (self *File) Size() int64 {
return self.size
}
// ModTime returns the time of the file's last modification.
func (self *File) ModTime() time.Time {
return self.modTime
}
// Read reads file data into the provided buffer.
func (self *File) Read(data []byte) (int, error) {
if err := self.load(); err != nil {
return 0, err
}
return self.reader.Read(data)
}
// Write writes file data into the provided writer.
func (self *File) WriteTo(writer io.Writer) (int64, error) {
if err := self.load(); err != nil {
return 0, err
}
return self.reader.WriteTo(writer)
}
// Seek updates the file pointer to the desired position.
func (self *File) Seek(offset int64, whence int) (int64, error) {
if self.reader == nil && offset == 0 && (whence == io.SeekStart || whence == io.SeekCurrent) {
return 0, nil
}
if err := self.load(); err != nil {
return 0, err
}
return self.reader.Seek(offset, whence)
}
// GoString returns value for string formatting.
func (self *File) GoString() string {
return self.relPath
}
// RemoveProp deletes the metadata property for the provided name.
func (self *File) RemoveProp(name string) {
delete(self.props, name)
}
// SetProp updates the metadata property for the provided name.
func (self *File) SetProp(name string, value FileProp) {
self.props[name] = value
}
// Prop returns the metadata property for the provided name.
func (self *File) Prop(name string) (FileProp, bool) {
value, ok := self.props[name]
return value, ok
}
// PropOrDef returns the metadata property for the provided name or the default.
func (self *File) PropOrDef(name string, valueDef FileProp) FileProp {
if value, ok := self.Prop(name); ok {
return value
}
return valueDef
}
// Props returns all of the metadata properties.
func (self *File) Props() FileProps {
return self.props
}
// CopyProps copies all metadata properties from the provided file.
func (self *File) CopyProps(file *File) {
for key, value := range file.props {
self.props[key] = value
}
}
func (self *File) load() error {
if self.reader != nil {
return nil
}
data, err := os.ReadFile(self.dataPath)
if err != nil {
return err
}
self.reader = bytes.NewReader(data)
return nil
}