fastcgi+lighttpd+c语言 实现搜索输入提示

1.lighttpd 服务器

lighttpd是一个比较轻量的服务器，在运行fastcgi上效率较高。lighttpd只负责投递请求到fastcgi。

centos输入yum install lighttpd安装　　

2.fastcgi

fastcgi解决了cgi程序处理请求每次都要初始化和结束造成的性能问题。fastcgi并且是独立于webserver的，fastcgi的crash并不影响webserver，然后他们之间通过soket通信。与fastcgi不同的另一种解决cgi程序反复创建，销毁的方法是让webserver开放api，然后编写cgi的时候，把cgi嵌入到webserver中，这样有个不好的地方就是cgi的crash会影响到webserver。

支持fastcgi的服务器有很多比如，nginx IIS什么的。他们都是把http请求转换为stdin和一些环境变量传递给fastcgi程序，然后返回stdout。编写fastcgi程序最终要的一个api就是int FCGI_Accept(void);当一个请求被送达的时候返回。一个基本的fastcgi结构如下。

echo.c

#include "fcgi_stdio.h"
#include <stdlib.h>

void main(void)
{
//初始化一些全局变量，这里只在fastcgi启动时候运行一次
while(FCGI_Accept() >= 0)  {
//fastcgi的处理逻辑

//根据http协议返回处理结果
printf("Content-type: text/html\r\n");
printf("\r\n");
printf("hello world");
}
}

3.编译echo.c

编译时候首先要安装fastcti

wget http://www.fastcgi.com/dist/fcgi.tar.gz
tar -zxvf fcgi.tar.gz

cd fcgi-2.4.1-SNAP-0311112127/

./configure --prefix=/etc/fcgi

make && make install

出现fcgio.cpp:50: error: 'EOF' was not declared in this scope的话 在/include/fcgio.h文件中加上 #include <cstdio>

到此就安装完了。然后我们来编译echo.c

gcc echo.c -o echo.cgi -I/etc/fcgi/include -L/etc/fcgi/lib/ -lfcgi

注意-I -L -l都不能少。

4.lighttpd+fastcgi配置

lighttpd支持fastcgi需要安装fastcgi模块

yum install lighttpd-fastcgi

创建配置文件 vim /etc/fcgi/fcgi.conf

server.document-root = "/var/www/cgi-bin/"
server.port = 8080
server.username = "www-data"
server.groupname = "www-data"
server.modules = ("mod_access", "mod_accesslog", "mod_fastcgi")
server.errorlog = "/var/www/cgi-bin/error.log"
accesslog.filename = "/var/www/cgi-bin/access.log"
static-file.exclude-extensions = (".cgi" )
fastcgi.debug = 1
fastcgi.server = (
"echo.cgi" => ((
"host" => "127.0.0.1",
"port" => "9000",
"bin-path" => "/var/www/cgi-bin/echo.cgi",
))
)

lighttpd -D -f fcgi.conf 时候会出现error while loading shared libraries: libfcgi.so.0: cannot open shared object file: No such file or directory
反正就是找不到动态链接库，比较无脑的方式就是把fastcgi安装目录下的include和lib都拷贝到/usr/include 和 /usr/lib中。注意，不是/usr/local

设置过之后可能还是找不到，参考网上另一种方法是。

首先vim /etc/ld.so.conf 添加libfcgi.so.0的路径，然后运行/sbin/ldconfig，重新编译trie.cgi，ldd trie.cgi一下，看到libfcgi.so.0找到就OKAY了。

在浏览器输入http://127.0.0.1:8080/echo.cgi 就可以看到hello world了

5.实例 输入提示

输入提示的具体实现方法已经在这篇博客里说过 /article/6284304.html

这次把他通过fastcgi的api改写成fastcgi程序。
trie.c

#include "stdio.h"
#include "stdlib.h"
#include "string.h"
#include "malloc.h"
#include "fcgi_stdio.h"

char* strcatch(char *str, char ch) {
char *p = str;
while (*p!='\0') {
p++;
}
*p = ch;
*(p+1) = '\0';
return str;
}

#define MAX_NODE 100000
#define ALPHA_COUNT 128

typedef struct t_trie{
int ch[MAX_NODE][ALPHA_COUNT];
int val[MAX_NODE];
int size;
}trie;

trie* create() {
trie *root = (trie *)malloc(sizeof(trie));
root->size = 1;
memset(root->ch[0], 0, sizeof(root->ch[0]));
return root;
}

void insert(trie *root, char *str, int n) {
int i, cur = 0, pre = cur;
for (i=0; i<n; i++) {
int c = str[i]-'\0';
if (!root->ch[cur][c]) {
memset(root->ch[root->size], 0, sizeof(root->ch[root->size]));
root->val[root->size] = 0;
root->ch[cur][c] = root->size++;
}
cur = root->ch[cur][c];
}
root->val[cur] = 1;
}

int search(trie *root, char *str) {
int i, cur = 0, n = strlen(str);
for (i=0; i<n; i++) {
int c = str[i]-'\0';
cur = root->ch[cur][c];
}
if (root->val[cur]) {
return 1;
}
return 0;
}

void suggest_helper(trie *root, char* str, int cur, int i, int *count) {
if (*count > 9) {
return;
}
if (root->val[cur]) {
*count = *count+1;
char c = i+'\0';
printf("<li onclick=\"fill('%s%c')\">%s%c</li>", str, c, str, c);
}
int j=0;
for (j=0; j<ALPHA_COUNT; j++) {
if (root->ch[cur][j]) {
char c = i+'\0';
char temp[128];
strcpy(temp, str);
strcatch(temp, c);
suggest_helper(root, temp, root->ch[cur][j], j, count);
}
}
}

void suggest(trie *root, char *str) {
int i, cur = 0, n = strlen(str), count=0;
for (i=0; i<n; i++) {
int c = str[i] - '\0';
if (root->ch[cur][c]) {
cur = root->ch[cur][c];
} else {
printf("no suggestion found\n");
return;
}
}
for (i=0; i<ALPHA_COUNT; i++) {
if (root->ch[cur][i]) {
suggest_helper(root, str, root->ch[cur][i], i, &count);
}
}
}

int http_get(char *key, char *query, char *result) {
char *p = result;
query = strstr(query, key);
int write = 0;
while (*query) {
if (*query=='=') {
query++;
write = 1;
continue;
}
if (write) {
if (*query=='&') {
*p = '\0';
return 1;
}
*p = *query;
p++;query++;
} else {
query++;
}
}
*p = '\0';
return 1;
}

int main() {
trie *root = create();
char ch;
FILE *fp;
char line[255];
size_t len = 0;
ssize_t read;
char keyword[64];
if ((fp = fopen("phpfunc.txt", "r")) == NULL) {
printf("open error\n");
exit(1);
}
while (fgets(line, 255, fp) != NULL) {
char *end = strchr(line,'\n');
*end = '\0';
insert(root, line, strlen(line));
}
while (FCGI_Accept() >= 0) {
printf("Content-Type:text/html; charset=utf-8\n\n");
char *query = getenv("QUERY_STRING");
http_get("q", query, keyword);
suggest(root, keyword);
}
return 0;
}

然后编译gcc trie.c -o trie.cgi -I/etc/fcgi/include -L/etc/fcgi/lib/ -lfcgi

修改fcgi.conf

fastcgi.server = (
"trie.cgi" => ((
"host" => "127.0.0.1",
"port" => "9000",
"bin-path" => "/var/www/cgi-bin/trie.cgi",
))
)

在浏览器输入http://127.0.0.1:8080/trie.cgi?q=var

可以看到输出var_dump:var_export:variant_abs:variant_add:variant_and:variant_cast:variant_cat:variant_cmp:variant_date_from_timestamp:variant_date_to_timestamp:

下面是编写前端JS请求

index.html

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Ajax Auto Suggest</title>
<script type="text/javascript" src="http://ajax.aspnetcdn.com/ajax/jquery/jquery-1.8.0.js"></script>
<script type="text/javascript">
function lookup(inputString) {
$.get("http://192.168.2.165:8880/trie.cgi", {q: ""+inputString+""}, function(data){
if(data.length >0) {
$('#suggestions').show();
$('#autoSuggestionsList').html(data);
}
});
}

function fill(thisValue) {
$('#inputString').val(thisValue);
setTimeout("$('#suggestions').hide();", 200);
}
</script>
<style type="text/css">
body {
font-family: Helvetica;
font-size: 11px;
}
h3 {
margin: 0px;
padding: 0px;
}
.suggestionsBox {
position: relative;
left: 30px;
margin: 10px 0px 0px 0px;
width: 200px;
-moz-border-radius: 7px;
-webkit-border-radius: 7px;
border: 2px solid #000;
}
.suggestionList {
margin: 0px;
padding: 0px;
}
.suggestionList li {
margin: 0px 0px 3px 0px;
padding: 3px;
cursor: pointer;
}
.suggestionList li:hover {
background-color: #659CD8;
}
</style>
</head>
<body>
<div>
<form>
<div>
Type php functions:
<br />
<input type="text" size="30" value="" id="inputString" onkeyup="lookup(this.value);" onblur="fill();" />
</div>
<div class="suggestionsBox" id="suggestions" style="display: none;">
<img src="upArrow.png" style="position: relative; top: -12px; left: 30px;" alt="upArrow" />
<div class="suggestionList" id="autoSuggestionsList">
</div>
</div>
</form>
</div>
</body>
</html>

因为服务器需要解析html文件所以在fcgi.conf中添加

mimetype.assign = (
".html" => "text/html",
)

启动lighttpd sudo /usr/local/webserver/lighttpd/sbin/lighttpd -D -f /usr/local/webserver/lighttpd/conf/fcgi.conf

在浏览器输入http://127.0.0.1:8080/index.html 就可以访问了。

fastcgi，swoole都一定程度弥补了php这种对于开发者类似CGI模式（如果不写PHP扩展，实际就是CGI模式~）对于开发者在开发网站时候的诸多不足。下一篇会介绍thrift并且用thrift编写一个主键生成服务器。