package rados // #cgo LDFLAGS: -lrados // #include // #include // #include // import "C" import ( "unsafe" ) // ReadOp manages a set of discrete object read actions that will be performed // together atomically. type ReadOp struct { operation op C.rados_read_op_t } // CreateReadOp returns a newly constructed read operation. func CreateReadOp() *ReadOp { return &ReadOp{ op: C.rados_create_read_op(), } } // Release the resources associated with this read operation. func (r *ReadOp) Release() { C.rados_release_read_op(r.op) r.op = nil r.free() } // Operate will perform the operation(s). func (r *ReadOp) Operate(ioctx *IOContext, oid string, flags OperationFlags) error { if err := ioctx.validate(); err != nil { return err } cOid := C.CString(oid) defer C.free(unsafe.Pointer(cOid)) ret := C.rados_read_op_operate(r.op, ioctx.ioctx, cOid, C.int(flags)) return r.update(readOp, ret) } func (r *ReadOp) operateCompat(ioctx *IOContext, oid string) error { switch err := r.Operate(ioctx, oid, OperationNoFlag).(type) { case nil: return nil case OperationError: return err.OpError default: return err } } // AssertExists assures the object targeted by the read op exists. // // Implements: // void rados_read_op_assert_exists(rados_read_op_t read_op); func (r *ReadOp) AssertExists() { C.rados_read_op_assert_exists(r.op) } // GetOmapValues is used to iterate over a set, or sub-set, of omap keys // as part of a read operation. An GetOmapStep is returned from this // function. The GetOmapStep may be used to iterate over the key-value // pairs after the Operate call has been performed. func (r *ReadOp) GetOmapValues(startAfter, filterPrefix string, maxReturn uint64) *GetOmapStep { gos := newGetOmapStep(startAfter, filterPrefix, maxReturn) r.steps = append(r.steps, gos) C.rados_read_op_omap_get_vals2( r.op, gos.cStartAfter, gos.cFilterPrefix, C.uint64_t(gos.maxReturn), &gos.iter, &gos.more, &gos.rval, ) return gos }