btree_mem.go

Documentation: github.com/google/btree

     1  // Copyright 2014 Google Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // +build ignore
    16  
    17  // This binary compares memory usage between btree and gollrb.
    18  package main
    19  
    20  import (
    21  	"flag"
    22  	"fmt"
    23  	"math/rand"
    24  	"runtime"
    25  	"time"
    26  
    27  	"github.com/google/btree"
    28  	"github.com/petar/GoLLRB/llrb"
    29  )
    30  
    31  var (
    32  	size   = flag.Int("size", 1000000, "size of the tree to build")
    33  	degree = flag.Int("degree", 8, "degree of btree")
    34  	gollrb = flag.Bool("llrb", false, "use llrb instead of btree")
    35  )
    36  
    37  func main() {
    38  	flag.Parse()
    39  	vals := rand.Perm(*size)
    40  	var t, v interface{}
    41  	v = vals
    42  	var stats runtime.MemStats
    43  	for i := 0; i < 10; i++ {
    44  		runtime.GC()
    45  	}
    46  	fmt.Println("-------- BEFORE ----------")
    47  	runtime.ReadMemStats(&stats)
    48  	fmt.Printf("%+v\n", stats)
    49  	start := time.Now()
    50  	if *gollrb {
    51  		tr := llrb.New()
    52  		for _, v := range vals {
    53  			tr.ReplaceOrInsert(llrb.Int(v))
    54  		}
    55  		t = tr // keep it around
    56  	} else {
    57  		tr := btree.New(*degree)
    58  		for _, v := range vals {
    59  			tr.ReplaceOrInsert(btree.Int(v))
    60  		}
    61  		t = tr // keep it around
    62  	}
    63  	fmt.Printf("%v inserts in %v\n", *size, time.Since(start))
    64  	fmt.Println("-------- AFTER ----------")
    65  	runtime.ReadMemStats(&stats)
    66  	fmt.Printf("%+v\n", stats)
    67  	for i := 0; i < 10; i++ {
    68  		runtime.GC()
    69  	}
    70  	fmt.Println("-------- AFTER GC ----------")
    71  	runtime.ReadMemStats(&stats)
    72  	fmt.Printf("%+v\n", stats)
    73  	if t == v {
    74  		fmt.Println("to make sure vals and tree aren't GC'd")
    75  	}
    76  }
    77
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