diff options
Diffstat (limited to 'vendor/github.com/syndtr/goleveldb/leveldb/comparer.go')
-rw-r--r-- | vendor/github.com/syndtr/goleveldb/leveldb/comparer.go | 67 |
1 files changed, 67 insertions, 0 deletions
diff --git a/vendor/github.com/syndtr/goleveldb/leveldb/comparer.go b/vendor/github.com/syndtr/goleveldb/leveldb/comparer.go new file mode 100644 index 000000000..448402b82 --- /dev/null +++ b/vendor/github.com/syndtr/goleveldb/leveldb/comparer.go @@ -0,0 +1,67 @@ +// 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 +} |