go-strfs/regularfile.go

106 lines
2.5 KiB
Go

package strfs
import (
"io/fs"
"time"
)
// RegularFile lets you turn a string into a fs.File.
//
// Example usage:
//
// var content strfs.Content = strfs.CreateContent("<!DOCTYPE html>"+"\n"+"<html><body>Hello world!</body></html>")
//
// var regularfile strfs.RegularFile = strfs.RegularFile{
// FileContent: content,
// FileName: "helloworld.html",
// FileModTime: time.Date(2022, 12, 12, 10, 30, 14, 2, time.UTC),
// }
type RegularFile struct {
FileContent Content
FileName string
FileModTime time.Time
}
// A trick to make sure strfs.RegularFile fits the fs.File interface.
// This is a compile-time check.
var _ fs.File = &RegularFile{}
// Close will stop the Read method from working.
//
// Close can safely be called more than once.
//
// Close helps strfs.RegularFile fit the fs.File interface.
// Close makes strfs.RegularFile fit the io.Closer interface.
func (receiver *RegularFile) Close() error {
if nil == receiver {
return errNilReceiver
}
return receiver.FileContent.Close()
}
// Read reads up to len(p) bytes into 'p'.
// Read returns the number of bytes actually read, and any errors it encountered.
//
// Read helps strfs.RegularFile fit the fs.File interface.
// Read makes strfs.Content fit the io.Reader interface.
//
// Example usage:
//
// var content strfs.Content = strfs.CreateContent("ABCDEFGHIJKLMNOPQRSTUVWXYZ")
//
// var regularfile strfs.RegularFile = strfs.RegularFile{
// FileContent: content,
// FileName: "alphabet.txt",
// FileModTime: time.Now(),
// }
//
// var b1 [5]byte
// var p1 []byte = b1[:]
//
// n, err := regularfile.Read(p1)
//
// // n == 5
// // b1 == [5]byte{'A', 'B', 'C', 'D', 'E'}
//
// // ...
//
// var b2 [4]byte
// var p2 []byte = b2[:]
//
// n, err := regularfile.Read(p2)
//
// // n == 4
// // b2 == [5]byte{'F', 'G', 'H', 'I'}
func (receiver *RegularFile) Read(p []byte) (int, error) {
if nil == receiver {
return 0, errNilReceiver
}
return receiver.FileContent.Read(p)
}
// Stat returns a fs.FileInfo for a *strfs.RegularFile.
//
// Stat helps strfs.RegularFile fit the fs.File interface.
func (receiver *RegularFile) Stat() (fs.FileInfo, error) {
if nil == receiver {
return nil, errNilReceiver
}
if EmptyContent() == receiver.FileContent {
return nil, errEmptyContent
}
const modeRegularFile = 0
return internalFileInfo{
sys: receiver.FileContent.String(),
name: receiver.FileName,
size: receiver.FileContent.Size(),
mode: modeRegularFile,
modtime: receiver.FileModTime,
}, nil
}