Java, Python, Ruby, PHP, C等语言性能对比

代码功能：循环拼接字符串，并替换子字符串

**硬件环境：**Intel Core2 Duo T7500@2.20Ghz CPU; 2 GB RAM; OS Debian GNU/Linux 2.6.32 i686

代码执行时长

代码性能对比图

最慢: Java gcj (native executable)
较慢: Java (openJDK); Java (Sun); Lua
稍慢: tcl; Javascript (spidermonkey)
较快: Python; Ruby; PHP; C++; Javascript V8; C; Perl5
最快的是Perl，最慢的gcj，你能接受吗？

内存使用情况

内存对比图：

测试源码：

C (source); Result: C gcc (Debian 4.4.4-1) 4.4.4

~~~.c

include

include

include

include

include

include

include

!/usr/local/bin/js

var str = “abcdefgh”+”efghefgh”;

var imax = 1024 / str.length * 1024 * 4;

var time = new Date();

print(“exec.tm.sec\tstr.length”);

var gstr = “”;

var i=0;

var lngth;

while (i++ < imax+1000) {

gstr += str;

gstr = gstr.replace(/efgh/g, “__“);

lngth=str.length*i;

if ((lngth % (1024*256)) == 0) {

var curdate=new Date();

print(parseInt(((curdate.getTime()-time.getTime())/1000))+”sec\t\t”+lngth/1024+”kb”);

}

}

~~~

Java (source) Results: Java (OpenJDK) “1.6.0 18”,

Java (Sun) “1.6.0 16”,

Java (gcj) (Debian 4.4.3-1) 4.4.3

~~~.java

public class java_test {

public static final void main(String[] args) throws Exception {
String str = "abcdefgh"+"efghefgh";
int imax = 1024 / str.length() * 1024 * 4;

long time = System.currentTimeMillis();
System.out.println("exec.tm.sec\tstr.length\tallocated memory:free memory:memory used");
Runtime runtime = Runtime.getRuntime();
System.out.println("0\t\t0\t\t"+runtime.totalMemory()/1024 +":"+ runtime.freeMemory()/1024+":"+(runtime.totalMemory()-runtime.freeMemory())/1024);

String gstr = "";
int i=0;
int lngth;

while (i++ < imax+1000) {
gstr += str;
gstr = gstr.replaceAll("efgh", "____");
lngth=str.length()*i;
if ((lngth % (1024*256)) == 0) {
System.out.println(((System.currentTimeMillis()-time)/1000)+"sec\t\t"+lngth/1024+"kb\t\t"+runtime.totalMemory()/1024+":"+runtime.freeMemory()/1024+":"+(runtime.totalMemory()-runtime.freeMemory())/1024);
}
}
}

}

~~~

Perl5 (source); Result: This is perl, v5.10.1

~~~.perl

!/usr/bin/perl

$|=1; #disable output buffering, this is necessary for proper output through pipe

my str=′abcdefgh′.′efghefgh′;myimax=1024/length($str)*1024*4; # 4mb

my $starttime=time();

print “exec.tm.sec\tstr.length\n”;

my gstr=”;myi=0;

while(i++<imax+1000){ #adding 1000 iterations to delay exit. This will allow to capture memory usage on last step

$gstr.=$str;
$gstr=~s/efgh/____/g;
my $lngth=length($str)*$i;   ##     my $lngth=length($gstr);        # Perhaps that would be a slower way
print time()-$starttime,"sec\t\t",$lngth/1024,"kb\n" unless $lngth % (1024*256); #print out every 256kb

}

~~~

PHP (source); Result: PHP 5.3.1-5 with Suhosin-Patch (cgi-fcgi)

~~~.php

!/usr/bin/python3 -u

import re

import time

import sys

str=’abcdefgh’+’efghefgh’

imax=1024/len(str)*1024*4 # 4mb

starttime=time.time();

print “exec.tm.sec\tstr.length”

sys.stdout.flush()

gstr=”

i=0

while (i < imax+1000):

i=i+1

gstr+=str

gstr=re.sub(‘efgh’,’__‘,gstr)

lngth=len(str)*i

if(lngth % (1024*256) == 0):

print int(time.time()-starttime),”sec\t\t”,(lngth/1024),”kb”

sys.stdout.flush()

~~~

Ruby (source); Result: ruby 1.8.7

~~~.ruby

!/usr/bin/ruby

$stdout.sync=true;

str=’abcdefgh’+’efghefgh’;

imax=1024/str.length*1024*4; # 4mb

starttime=Time.new;

print(“exec.tm.sec\tstr.length\n”);

gstr=”;

i=0;

while i < imax+1000

i=i+1;

gstr+=str;

gstr=gstr.gsub(/efgh/, “__“)

lngth=str.length*i;
if(lngth % (1024*256)==0)
print(((Time.new-starttime).ceil).to_s+"sec\t\t",(lngth/1024).to_s,"kb\n");
end

end

puts gstr;

~~~

Lua (source); Result: Lua 5.1.4

~~~.lua

!/usr/bin/lua

io.stdout:setvbuf “no”; – io.flush();

str=’abcdefgh’..’efghefgh’;

imax=1024/string.len(str)*1024*4; – 4mb

starttime=os.time();

print “exec.tm.sec\tstr.length”;

gstr=”;

i=0;

while i < imax+1000 do

i=i+1;

gstr=gstr..str;

gstr=string.gsub(gstr,”efgh”,”__“);

lngth=string.len(str)*i;

if(math.mod(lngth,1024*256)==0) then

print(os.time()-starttime..”sec\t\t”..(lngth/1024)..”kb”);

end

end

~~~

tcl (source); Result: tcl 8.4.19

~~~.tcl

!/usr/bin/tclsh

set str “abcdefgh”

append str “efghefgh”

set imax [expr {1024/[string length $str]*1024*4}]

set starttime [clock clicks -milliseconds]

puts “exec.tm.sec\tstr.length”;

set gstr “”

set i 0

while {i<[expr {imax+1000}]} {

incr i

append gstr str;regsub−allefghgstr __ gstr

set lngth [expr {[string length str]∗i}]

if {[expr {lngthputs“[exprint([expr[clockclicks−milliseconds]−starttime] / 1000)]sec\t\t[expr {$lngth/1024}]kb”

}

}

exit

~~~

结论

各语言随着版本升级，也在不断优化，想要用好每个语言的特性，需要摸透她的脾气，这个需要不断的加深了解。

选语言就像选恋人，情人眼里出西施，你中意的，就是最好的，所以对以上结果别太较真。

转自：http://www.yinqisen.cn/blog-685.html