// Iterate on a set of keys and their values from an omap
// `startAfter`: iterate only on the keys after this specified one
// `filterPrefix`: iterate only on the keys beginning with this prefix
// `maxReturn`: iterate no more than `maxReturn` key/value pairs
// `listFn`: the function called at each iteration
func (ioctx *IOContext) ListOmapValues(oid string, startAfter string, filterPrefix string, maxReturn int64, listFn OmapListFunc) error {
c_oid := C.CString(oid)
c_start_after := C.CString(startAfter)
c_filter_prefix := C.CString(filterPrefix)
c_max_return := C.uint64_t(maxReturn)
defer C.free(unsafe.Pointer(c_oid))
defer C.free(unsafe.Pointer(c_start_after))
defer C.free(unsafe.Pointer(c_filter_prefix))
op := C.rados_create_read_op()
var c_iter C.rados_omap_iter_t
var c_prval C.int
C.rados_read_op_omap_get_vals(
op,
c_start_after,
c_filter_prefix,
c_max_return,
&c_iter,
&c_prval,
)
ret := C.rados_read_op_operate(op, ioctx.ioctx, c_oid, 0)
if int(c_prval) != 0 {
return RadosError(int(c_prval))
} else if int(ret) != 0 {
return GetRadosError(ret)
}
for {
var c_key *C.char
var c_val *C.char
var c_len C.size_t
ret = C.rados_omap_get_next(c_iter, &c_key, &c_val, &c_len)
if int(ret) != 0 {
return GetRadosError(ret)
}
if c_key == nil {
break
}
listFn(C.GoString(c_key), C.GoBytes(unsafe.Pointer(c_val), C.int(c_len)))
}
C.rados_omap_get_end(c_iter)
C.rados_release_read_op(op)
return nil
}
func (ro *ReadOperation) Operate(object *Object, flags ...LibradosOperation) (io.Reader, error) {
oid := C.CString(object.name)
defer freeString(oid)
var f C.int = 0
for _, flag := range flags {
f |= C.int(flag)
}
ret := C.rados_read_op_operate(ro.opContext, ro.ioContext, oid, f)
if err := toRadosError(ret); err != nil {
err.Message = fmt.Sprintf("Unable to perform read operations on object %s.", object.name)
return nil, err
}
if err := toRadosError(ro.retVal); err != nil {
err.Message = fmt.Sprintf("Unable to read from object %s.", object.name)
return nil, err
}
if ro.bytesRead == 0 {
err := toRadosError(-1)
err.Message = fmt.Sprintf("Nothing read from object %s.", object.name)
return nil, err
}
data := bufToReader(ro.buffer, C.int(ro.bytesRead))
return data, nil
}
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
}
