func (w *WriteCloser) Write(p []byte) (int, error) {
plen := len(p)
src := (*C.char)(unsafe.Pointer(&p[0]))
srcLimit := (*C.char)(unsafe.Pointer(&p[plen]))
uErr := C.UErrorCode(C.U_ZERO_ERROR)
oMaxLen, err := ucnvMaxLen(plen, w.from, w.to)
if err != nil {
return 0, err
}
// reallocate write buffer
if oMaxLen > cap(w.obuf) {
w.obuf = make([]byte, oMaxLen*2)
}
dst := (*C.char)(unsafe.Pointer(&w.obuf[0]))
dstLimit := (*C.char)(unsafe.Pointer(&w.obuf[oMaxLen]))
dstStart := uintptr(unsafe.Pointer(dst))
// fill write buffer by C.ucnv_convertEx
_, err = C.ucnv_convertEx(w.to, w.from, &dst, dstLimit, &src, srcLimit, nil, nil, nil, nil, C.UBool(1), C.UBool(1), &uErr)
if err != nil {
return 0, err
}
if err = uErrorToGoError(uErr); err != nil {
return 0, err
}
w.olen = int(uintptr(unsafe.Pointer(dst)) - dstStart)
n, err := w.w.Write(w.obuf[:w.olen])
if err != nil {
return n, err
}
return n, nil
}
func (r *ReadCloser) Read(p []byte) (int, error) {
plen := len(p)
if plen == 0 {
return 0, nil
}
n := 0
olen := r.oend - r.ostart
// flush write buffer if exist
if olen > 0 {
if olen > plen {
copy(p, r.obuf[r.ostart:plen])
r.ostart += plen
return plen, nil
}
copy(p, r.obuf[r.ostart:r.oend])
r.ostart = 0
r.oend = 0
if olen == plen {
return plen, nil
}
n = olen
}
// reallocate read buffer or set Len
if plen != len(r.ibuf) {
if plen > cap(r.ibuf) {
r.ibuf = make([]byte, plen, plen*2)
} else {
r.ibuf = r.ibuf[:plen]
}
}
// fill read buffer
ilen, err := r.r.Read(r.ibuf)
r.ilen = ilen
if err != nil {
return n, err
}
if ilen == 0 {
return n, io.EOF
}
src := (*C.char)(unsafe.Pointer(&r.ibuf[0]))
srcLimit := (*C.char)(unsafe.Pointer(&r.ibuf[ilen]))
uErr := C.UErrorCode(C.U_ZERO_ERROR)
oMaxLen, err := ucnvMaxLen(ilen, r.from, r.to)
if err != nil {
return n, err
}
// reallocate write buffer
if oMaxLen > cap(r.obuf) {
r.obuf = make([]byte, oMaxLen*2)
}
dst := (*C.char)(unsafe.Pointer(&r.obuf[0]))
dstLimit := (*C.char)(unsafe.Pointer(&r.obuf[oMaxLen]))
dstStart := uintptr(unsafe.Pointer(dst))
// fill write buffer by C.ucnv_convertEx
_, err = C.ucnv_convertEx(r.to, r.from, &dst, dstLimit, &src, srcLimit, nil, nil, nil, nil, C.UBool(1), C.UBool(1), &uErr)
if err != nil {
return n, err
}
if err = uErrorToGoError(uErr); err != nil {
return n, err
}
r.ilen = 0
olen = int(uintptr(unsafe.Pointer(dst)) - dstStart)
// flush write buffer
if olen > plen-n {
copy(p[n:], r.obuf[:plen-n])
r.ostart = plen - n
r.oend = olen
return plen, nil
}
copy(p[n:], r.obuf[:olen])
return olen + n, nil
}