mirror of
https://github.com/octoleo/syncthing.git
synced 2024-09-20 05:39:02 +00:00
74 lines
2.8 KiB
Go
74 lines
2.8 KiB
Go
// Copyright 2014 The b 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 b implements the B+tree flavor of a BTree.
|
|
//
|
|
// Changelog
|
|
//
|
|
// 2016-07-16: Update benchmark results to newer Go version. Add a note on
|
|
// concurrency.
|
|
//
|
|
// 2014-06-26: Lower GC presure by recycling things.
|
|
//
|
|
// 2014-04-18: Added new method Put.
|
|
//
|
|
// Concurrency considerations
|
|
//
|
|
// Tree.{Clear,Delete,Put,Set} mutate the tree. One can use eg. a
|
|
// sync.Mutex.Lock/Unlock (or sync.RWMutex.Lock/Unlock) to wrap those calls if
|
|
// they are to be invoked concurrently.
|
|
//
|
|
// Tree.{First,Get,Last,Len,Seek,SeekFirst,SekLast} read but do not mutate the
|
|
// tree. One can use eg. a sync.RWMutex.RLock/RUnlock to wrap those calls if
|
|
// they are to be invoked concurrently with any of the tree mutating methods.
|
|
//
|
|
// Enumerator.{Next,Prev} mutate the enumerator and read but not mutate the
|
|
// tree. One can use eg. a sync.RWMutex.RLock/RUnlock to wrap those calls if
|
|
// they are to be invoked concurrently with any of the tree mutating methods. A
|
|
// separate mutex for the enumerator, or the whole tree in a simplified
|
|
// variant, is necessary if the enumerator's Next/Prev methods per se are to
|
|
// be invoked concurrently.
|
|
//
|
|
// Generic types
|
|
//
|
|
// Keys and their associated values are interface{} typed, similar to all of
|
|
// the containers in the standard library.
|
|
//
|
|
// Semiautomatic production of a type specific variant of this package is
|
|
// supported via
|
|
//
|
|
// $ make generic
|
|
//
|
|
// This command will write to stdout a version of the btree.go file where every
|
|
// key type occurrence is replaced by the word 'KEY' and every value type
|
|
// occurrence is replaced by the word 'VALUE'. Then you have to replace these
|
|
// tokens with your desired type(s), using any technique you're comfortable
|
|
// with.
|
|
//
|
|
// This is how, for example, 'example/int.go' was created:
|
|
//
|
|
// $ mkdir example
|
|
// $ make generic | sed -e 's/KEY/int/g' -e 's/VALUE/int/g' > example/int.go
|
|
//
|
|
// No other changes to int.go are necessary, it compiles just fine.
|
|
//
|
|
// Running the benchmarks for 1000 keys on a machine with Intel i5-4670 CPU @
|
|
// 3.4GHz, Go 1.7rc1.
|
|
//
|
|
// $ go test -bench 1e3 example/all_test.go example/int.go
|
|
// BenchmarkSetSeq1e3-4 20000 78265 ns/op
|
|
// BenchmarkGetSeq1e3-4 20000 67980 ns/op
|
|
// BenchmarkSetRnd1e3-4 10000 172720 ns/op
|
|
// BenchmarkGetRnd1e3-4 20000 89539 ns/op
|
|
// BenchmarkDelSeq1e3-4 20000 87863 ns/op
|
|
// BenchmarkDelRnd1e3-4 10000 130891 ns/op
|
|
// BenchmarkSeekSeq1e3-4 10000 100118 ns/op
|
|
// BenchmarkSeekRnd1e3-4 10000 121684 ns/op
|
|
// BenchmarkNext1e3-4 200000 6330 ns/op
|
|
// BenchmarkPrev1e3-4 200000 9066 ns/op
|
|
// PASS
|
|
// ok command-line-arguments 42.531s
|
|
// $
|
|
package b
|