battlemap - utils.go

     1  package battlemap
     2  
     3  import (
     4  	"io"
     5  	"net/http"
     6  	"strconv"
     7  	"unsafe"
     8  )
     9  
    10  type fileType uint8
    11  
    12  const (
    13  	fileTypeUnknown fileType = iota
    14  	fileTypeImage
    15  	fileTypeAudio
    16  	fileTypeCharacter
    17  	fileTypeMap
    18  )
    19  
    20  type getFileType struct {
    21  	Buffer [512]byte
    22  	Type   fileType
    23  }
    24  
    25  func (g *getFileType) ReadFrom(r io.Reader) (int64, error) {
    26  	n, err := io.ReadFull(r, g.Buffer[:])
    27  	if err != nil {
    28  		return int64(n), err
    29  	}
    30  	switch http.DetectContentType(g.Buffer[:n]) {
    31  	case "image/gif", "image/png", "image/jpeg", "image/webp", "video/apng":
    32  		g.Type = fileTypeImage
    33  	case "application/ogg", "audio/mpeg":
    34  		g.Type = fileTypeAudio
    35  	case "application/x-gzip":
    36  		g.Type = fileTypeCharacter
    37  	case "text/plain; charset=utf-8":
    38  		g.Type = fileTypeMap
    39  	default:
    40  		g.Type = fileTypeUnknown
    41  	}
    42  	return int64(n), nil
    43  }
    44  
    45  func isRoot(path string) bool {
    46  	return path == "/" || path == ""
    47  }
    48  
    49  func uniqueName(name string, checker func(string) bool) string {
    50  	if checker(name) {
    51  		return name
    52  	}
    53  	n := make([]byte, len(name)+32)
    54  	m := n[len(name)+1 : len(name)+1]
    55  	copy(n, name)
    56  	n[len(name)] = '.'
    57  	for i := uint64(0); ; i++ {
    58  		p := n[:len(name)+1+len(strconv.AppendUint(m, i, 10))]
    59  		newName := *(*string)(unsafe.Pointer(&p))
    60  		if checker(newName) {
    61  			return newName
    62  		}
    63  	}
    64  }
    65