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author | Taylor Gerring <taylor.gerring@gmail.com> | 2015-02-16 21:28:33 +0800 |
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committer | Taylor Gerring <taylor.gerring@gmail.com> | 2015-02-16 21:28:33 +0800 |
commit | 702218008ee2b6d708d6b2821cdef80736bb3224 (patch) | |
tree | d55ff7ce88187082378e7d8e4c2f3aad14d23b4e /Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer | |
parent | 202362d9258335c695eb75f55f4be74a50a1af33 (diff) | |
download | go-tangerine-702218008ee2b6d708d6b2821cdef80736bb3224.tar.gz go-tangerine-702218008ee2b6d708d6b2821cdef80736bb3224.tar.zst go-tangerine-702218008ee2b6d708d6b2821cdef80736bb3224.zip |
Add versioned dependencies from godep
Diffstat (limited to 'Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer')
-rw-r--r-- | Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/bytes_comparer.go | 51 | ||||
-rw-r--r-- | Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/comparer.go | 57 |
2 files changed, 108 insertions, 0 deletions
diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/bytes_comparer.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/bytes_comparer.go new file mode 100644 index 000000000..14dddf88d --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/bytes_comparer.go @@ -0,0 +1,51 @@ +// 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 comparer + +import "bytes" + +type bytesComparer struct{} + +func (bytesComparer) Compare(a, b []byte) int { + return bytes.Compare(a, b) +} + +func (bytesComparer) Name() string { + return "leveldb.BytewiseComparator" +} + +func (bytesComparer) Separator(dst, a, b []byte) []byte { + i, n := 0, len(a) + if n > len(b) { + n = len(b) + } + for ; i < n && a[i] == b[i]; i++ { + } + if i >= n { + // Do not shorten if one string is a prefix of the other + } else if c := a[i]; c < 0xff && c+1 < b[i] { + dst = append(dst, a[:i+1]...) + dst[i]++ + return dst + } + return nil +} + +func (bytesComparer) Successor(dst, b []byte) []byte { + for i, c := range b { + if c != 0xff { + dst = append(dst, b[:i+1]...) + dst[i]++ + return dst + } + } + return nil +} + +// DefaultComparer are default implementation of the Comparer interface. +// It uses the natural ordering, consistent with bytes.Compare. +var DefaultComparer = bytesComparer{} diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/comparer.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/comparer.go new file mode 100644 index 000000000..14a28f16f --- /dev/null +++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/comparer/comparer.go @@ -0,0 +1,57 @@ +// 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 comparer provides interface and implementation for ordering +// sets of data. +package comparer + +// BasicComparer is the interface that wraps the basic Compare method. +type BasicComparer interface { + // Compare returns -1, 0, or +1 depending on whether a is 'less than', + // 'equal to' or 'greater than' b. The two arguments can only be 'equal' + // if their contents are exactly equal. Furthermore, the empty slice + // must be 'less than' any non-empty slice. + Compare(a, b []byte) int +} + +// Comparer defines a total ordering over the space of []byte keys: a 'less +// than' relationship. +type Comparer interface { + BasicComparer + + // Name returns name of the comparer. + // + // The Level-DB on-disk format stores the comparer name, and opening a + // database with a different comparer from the one it was created with + // will result in an error. + // + // An implementation to a new name whenever the comparer implementation + // changes in a way that will cause the relative ordering of any two keys + // to change. + // + // Names starting with "leveldb." are reserved and should not be used + // by any users of this package. + Name() string + + // Bellow are advanced functions used used to reduce the space requirements + // for internal data structures such as index blocks. + + // Separator appends a sequence of bytes x to dst such that a <= x && x < b, + // where 'less than' is consistent with Compare. An implementation should + // return nil if x equal to a. + // + // Either contents of a or b should not by any means modified. Doing so + // may cause corruption on the internal state. + Separator(dst, a, b []byte) []byte + + // Successor appends a sequence of bytes x to dst such that x >= b, where + // 'less than' is consistent with Compare. An implementation should return + // nil if x equal to b. + // + // Contents of b should not by any means modified. Doing so may cause + // corruption on the internal state. + Successor(dst, b []byte) []byte +} |