| // Copyright (c) 2012, Suryandaru Triandana <syndtr@gmail.com> |
| // All rights reserved. |
| // |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package leveldb |
| |
| import ( |
| "github.com/syndtr/goleveldb/leveldb/comparer" |
| ) |
| |
| type iComparer struct { |
| ucmp comparer.Comparer |
| } |
| |
| func (icmp *iComparer) uName() string { |
| return icmp.ucmp.Name() |
| } |
| |
| func (icmp *iComparer) uCompare(a, b []byte) int { |
| return icmp.ucmp.Compare(a, b) |
| } |
| |
| func (icmp *iComparer) uSeparator(dst, a, b []byte) []byte { |
| return icmp.ucmp.Separator(dst, a, b) |
| } |
| |
| func (icmp *iComparer) uSuccessor(dst, b []byte) []byte { |
| return icmp.ucmp.Successor(dst, b) |
| } |
| |
| func (icmp *iComparer) Name() string { |
| return icmp.uName() |
| } |
| |
| func (icmp *iComparer) Compare(a, b []byte) int { |
| x := icmp.uCompare(internalKey(a).ukey(), internalKey(b).ukey()) |
| if x == 0 { |
| if m, n := internalKey(a).num(), internalKey(b).num(); m > n { |
| return -1 |
| } else if m < n { |
| return 1 |
| } |
| } |
| return x |
| } |
| |
| func (icmp *iComparer) Separator(dst, a, b []byte) []byte { |
| ua, ub := internalKey(a).ukey(), internalKey(b).ukey() |
| dst = icmp.uSeparator(dst, ua, ub) |
| if dst != nil && len(dst) < len(ua) && icmp.uCompare(ua, dst) < 0 { |
| // Append earliest possible number. |
| return append(dst, keyMaxNumBytes...) |
| } |
| return nil |
| } |
| |
| func (icmp *iComparer) Successor(dst, b []byte) []byte { |
| ub := internalKey(b).ukey() |
| dst = icmp.uSuccessor(dst, ub) |
| if dst != nil && len(dst) < len(ub) && icmp.uCompare(ub, dst) < 0 { |
| // Append earliest possible number. |
| return append(dst, keyMaxNumBytes...) |
| } |
| return nil |
| } |