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// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package nosql
import (
"v.io/syncbase/v23/syncbase/util"
)
// RowRange represents all rows with keys in [start, limit). If limit is "", all
// rows with keys >= start are included.
type RowRange interface {
Start() string
Limit() string
}
// PrefixRange represents all rows with keys that have some prefix.
type PrefixRange interface {
RowRange
Prefix() string
}
// rowRange implements the RowRange interface.
type rowRange struct {
start string
limit string
}
var _ RowRange = (*rowRange)(nil)
func (r *rowRange) Start() string {
return r.start
}
func (r *rowRange) Limit() string {
return r.limit
}
func SingleRow(row string) RowRange {
return &rowRange{start: row, limit: row + "\x00"}
}
func Range(start, limit string) RowRange {
return &rowRange{start: start, limit: limit}
}
// prefixRange implements the PrefixRange interface (and thus also the RowRange
// interface). We do not represent a prefix as a rowRange because we want to be
// able to distinguish prefixes from ranges (e.g. syncgroups work with prefixes,
// not ranges).
type prefixRange struct {
prefix string
}
var _ PrefixRange = (*prefixRange)(nil)
func (r *prefixRange) Start() string {
return util.PrefixRangeStart(r.prefix)
}
func (r *prefixRange) Limit() string {
return util.PrefixRangeLimit(r.prefix)
}
func (r *prefixRange) Prefix() string {
return r.prefix
}
func Prefix(prefix string) PrefixRange {
return &prefixRange{prefix: prefix}
}