func (ro *ReadOperation) Read(offset, length uint64) {
ro.buffer = bufferAddress(int(length))
C.rados_read_op_read(ro.opContext, C.uint64_t(offset), C.size_t(length), ro.buffer, &ro.bytesRead, &ro.retVal)
}
func (ioctx *IOContext) ReadTaggedFull(oid string, tagName string, data []byte, offset int) (n int, tag []byte, err error) {
if len(data) == 0 {
return 0, nil, nil
}
c_oid := C.CString(oid)
c_tagName := C.CString(tagName)
defer C.free(unsafe.Pointer(c_oid))
defer C.free(unsafe.Pointer(c_tagName))
var size C.size_t
var rval_read C.int
var rval_attr C.int
var it C.rados_xattrs_iter_t
op := C.rados_create_read_op()
defer func() { C.rados_release_read_op(op) }()
C.rados_read_op_read(
op,
(C.uint64_t)(offset),
(C.size_t)(len(data)),
(*C.char)(unsafe.Pointer(&data[0])),
&size,
&rval_read)
C.rados_read_op_getxattrs(
op,
&it,
&rval_attr)
ret := C.rados_read_op_operate(op, ioctx.ioctx, c_oid, 0)
if ret < 0 {
return 0, nil, GetRadosError(ret)
}
if rval_read < 0 {
return 0, nil, GetRadosError(rval_read)
}
if rval_attr < 0 {
return 0, nil, GetRadosError(ret)
}
defer func() { C.rados_getxattrs_end(it) }()
for {
var c_name, c_val *C.char
var c_len C.size_t
defer C.free(unsafe.Pointer(c_name))
defer C.free(unsafe.Pointer(c_val))
ret := C.rados_getxattrs_next(it, &c_name, &c_val, &c_len)
if ret < 0 {
return int(size), nil, GetRadosError(ret)
}
// rados api returns a null name,val & 0-length upon
// end of iteration
if c_name == nil {
return int(size), nil, GetRadosError(ret)
}
if tagName == C.GoString(c_name) {
tag = C.GoBytes(unsafe.Pointer(c_val), (C.int)(c_len))
break
}
}
return int(size), tag, nil
}
