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01 Dec 2013

Squid定制开发(三)之添加修改header头

Squid定制开发(三)之添加修改header头

NOTE: 原创文章，转载请注明：转载自 blog.miaohong.org 本文链接地址: http://blog.miaohong.org/2013/12/01/squid_addheader.html

最近有个需求，需要： 源站会输出一个”Cache-Control c-maxage=xxx”的响应头，要求我们的CDN上遇到这样的信息，在CDN缓存仍然遵循”Cache-Control max-age=xxx”前提下，将”Cache-Control c-maxage=xxx”的内容转换为相应”Cache-Control max-age=xxx”, 输出给客户端缓存

懒得写了，贴diff吧

Common subdirectories: squid-suning/src/auth and squid-2.7.STABLE9/src/auth
Only in squid-suning/src/: auth_modules.c
Only in squid-suning/src/: cf.data
Only in squid-suning/src/: cf_gen_defines.h
Only in squid-suning/src/: cf_parser.h
diff squid-suning/src/client_side.c squid-2.7.STABLE9/src/client_side.c
1779,1781d1778
<     //miaohong add 
<     m_httpHeaderPutCc(hdr, http->request->cache_control);
<     
1970,1975d1966
<     //miaohong add
<     //if(httpHeaderHas(hdr,HDR_CACHE_CONTROL))
<     //{
<         //printf("HDR_CACHE_CONTROL exist \n");
<     //}
<     //printf("httpHeaderGetCc : %d---\n",httpHeaderGetCc(hdr)->c_maxage);
2764,2765d2754
<     //miaohong add
<     //printf("cc cmax: %d-----------\n",http->request->cache_control->c_maxage);
3491,3492d3479
< 
< 
3496,3497d3482
<     //miaohong add
<     //printf("-----in clientProcessRequest---\n");
3942,3943d3926
<     //add miaohong
<     //printf("------in clientTryParseRequest----\n");
4155d4137
<     //printf("--------in clientReadRequest-------\n");
Only in squid-suning/src/: .deps
diff squid-suning/src/enums.h squid-2.7.STABLE9/src/enums.h
282,283d281
<     //miaohong add
<     CC_C_MAXAGE,
Common subdirectories: squid-suning/src/fs and squid-2.7.STABLE9/src/fs
Only in squid-suning/src/: globals.c
diff squid-suning/src/HttpHdrCc.c squid-2.7.STABLE9/src/HttpHdrCc.c
51,52d50
<     //miaohong add
<     {"c-maxage", CC_C_MAXAGE},
85,86c83
<     // miaohong modify
<     cc->max_age = cc->s_maxage = cc->c_maxage = cc->max_stale = cc->stale_if_error - 1;
---
>     cc->max_age = cc->s_maxage = cc->max_stale = cc->stale_if_error - 1;
152,160d148
<     //miaohong add
<     case CC_C_MAXAGE:
<         if (!p || !httpHeaderParseInt(p, &cc->c_maxage)) {
<         debug(65, 2) ("httpHdrCcParseInit: invalid c-maxage specs near '%s'\n", item);
<         cc->c_maxage = -1;
<         EBIT_CLR(cc->mask, type);
<         }
<         break;
<         
216,217d203
<     //miaohong modify
<     dup->c_maxage = cc->c_maxage;
222,260d207
< //miaohong add
< 
< void
< m_httpHdrCcPackInto(const HttpHdrCc * cc, Packer * p)
< {
<     http_hdr_cc_type flag;
<     int pcount = 0;
<     assert(cc && p);
<     for (flag = 0; flag < CC_ENUM_END; flag++) {
<     if (EBIT_TEST(cc->mask, flag) && flag != CC_OTHER && flag != CC_C_MAXAGE) {
< 
<         /* print option name */
<         packerPrintf(p, (pcount ? ", %s" : "%s"), strBuf(CcFieldsInfo[flag].name));
< 
<         /* handle options with values */
<         if (flag == CC_MAX_AGE)
<         packerPrintf(p, "=%d", (int) cc->c_maxage);
< 
<         if (flag == CC_S_MAXAGE)
<         packerPrintf(p, "=%d", (int) cc->s_maxage);
<         // miaohong add
<         //if (flag == CC_C_MAXAGE)
<         //packerPrintf(p, "=%d", (int) cc->c_maxage);
<         
<         if (flag == CC_MAX_STALE && cc->max_stale >= 0)
<         packerPrintf(p, "=%d", (int) cc->max_stale);
< 
<         if (flag == CC_STALE_WHILE_REVALIDATE)
<         packerPrintf(p, "=%d", (int) cc->stale_while_revalidate);
< 
<         pcount++;
<     }
<     }
<     if (strLen(cc->other))
<     packerPrintf(p, (pcount ? ", %s" : "%s"), strBuf(cc->other));
< }
< 
< 
< 
279,282c226
<         // miaohong add
<         if (flag == CC_C_MAXAGE)
<         packerPrintf(p, "=%d", (int) cc->c_maxage);
<         
---
> 
304,306d247
<     // miaohong add
<     if (cc->c_maxage < 0)
<     cc->c_maxage = new_cc->c_maxage;
336,350d276
< //miaohong add
< 
< /* negative s_maxage will clean old s-maxage setting */
< void
< httpHdrCcSetCMaxAge(HttpHdrCc * cc, int c_maxage)
< {
<     assert(cc);
<     cc->c_maxage = c_maxage;
<     if (c_maxage >= 0)
<     EBIT_SET(cc->mask, CC_C_MAXAGE);
<     else
<     EBIT_CLR(cc->mask, CC_C_MAXAGE);
< }
< 
< 
diff squid-suning/src/HttpHeader.c squid-2.7.STABLE9/src/HttpHeader.c
570,571d569
<     // add miaohong
<     //printf("[Debug for suning] header info :  %s = %s \n",e->name.buf,e->value.buf);
971,991d968
< //miaohong add
< void
< m_httpHeaderPutCc(HttpHeader * hdr, const HttpHdrCc * cc)
< {
<     MemBuf mb;
<     Packer p;
<     assert(hdr && cc);
<     /* remove old directives if any */
<     httpHeaderDelById(hdr, HDR_CACHE_CONTROL);
<     /* pack into mb */
<     memBufDefInit(&mb);
<     packerToMemInit(&p, &mb);
<     m_httpHdrCcPackInto(cc, &p);
<     /* put */
<     httpHeaderAddEntry(hdr, httpHeaderEntryCreate(HDR_CACHE_CONTROL, NULL, mb.buf));
<     /* cleanup */
<     packerClean(&p);
<     memBufClean(&mb);
< }
< 
< 
Only in squid-suning/src/: Makefile
diff squid-suning/src/protos.h squid-2.7.STABLE9/src/protos.h
377,378d376
< //miaohong add
< extern void httpHdrCcSetCMaxAge(HttpHdrCc * cc, int s_maxage);
Common subdirectories: squid-suning/src/repl and squid-2.7.STABLE9/src/repl
Only in squid-suning/src/: repl_modules.c
Only in squid-suning/src/: squid.conf.default
Only in squid-suning/src/: store_modules.c
Only in squid-suning/src/: string_arrays.c
diff squid-suning/src/structs.h squid-2.7.STABLE9/src/structs.h
1020,1021d1019
<     //miaohong add
<     int c_maxage;

测试环境：

Client  -->   squid  -->  nginx

其中nginx配置如下：

location ~ /true.html {
                   root /tmp;
}
location ~ /(t.html) {
                   set $v "true.html";
                   gzip off;
                   proxy_buffer_size 4k;
                   proxy_buffering on;
                   proxy_buffers 8 128k;
                   proxy_busy_buffers_size  768k;
                   proxy_set_header X-Forwarded-For  $remote_addr;
                   proxy_set_header  Cache-Control  max-age=100;   
                   proxy_set_header  Cache-Control  c-maxage=50;   #源站发出c-maxage头
                   proxy_set_header   Host   xx;
                   proxy_pass http://distribute.vhosts/$v; # refers to squid cluster
}

测试结果： 没命中

[root@ppserver ~]# curl --head http://127.0.0.1/t.html
HTTP/1.1 200 OK
Server: nginx/5.3
Date: Mon, 02 Dec 2013 06:10:32 GMT
Content-Type: text/html
Content-Length: 5
Connection: keep-alive
Last-Modified: Fri, 29 Nov 2013 10:21:40 GMT
ETag: "52986ab4-5"
Accept-Ranges: bytes
Cache-Control: max-age=50  # 将100赋值给max-age
X-Cache: MISS from livesquid
X-Cache-Lookup: MISS from livesquid:18000
Via: 1.1 livesquid:18000 (squid/2.7.STABLE9)

命中：

[root@ppserver ~]# curl --head http://127.0.0.1/t.html
HTTP/1.1 200 OK
Server: nginx/5.3
Date: Mon, 02 Dec 2013 06:15:13 GMT
Content-Type: text/html
Content-Length: 5
Connection: keep-alive
Accept-Ranges: bytes
Last-Modified: Fri, 29 Nov 2013 10:21:40 GMT
ETag: "52986ab4-5"
Cache-Control: max-age=50
X-Cache: HIT from livesquid
X-Cache-Lookup: HIT from livesquid:18000
Via: 1.1 livesquid:18000 (squid/2.7.STABLE9)

另外，打印squid内部信息

[Debug for suning] header info :  X-Forwarded-For = 127.0.0.1
[Debug for suning] header info :  Cache-Control = max-age=100
[Debug for suning] header info :  Cache-Control = c-maxage=50
[Debug for suning] header info :  Host = doghole
[Debug for suning] header info :  Connection = close
[Debug for suning] header info :  User-Agent = curl/7.19.7 (x86_64-redhat-linux-gnu) libcurl/7.19.7 NSS/3.13.6.0 zlib/1.2.3 libidn/1.18 libssh2/1.4.2
[Debug for suning] header info :  Accept = */*
[Debug for suning] header info :  Server = nginx/5.3
[Debug for suning] header info :  Date = Mon, 02 Dec 2013 06:27:14 GMT
[Debug for suning] header info :  Content-Type = text/html
[Debug for suning] header info :  Content-Length = 5
[Debug for suning] header info :  Last-Modified = Fri, 29 Nov 2013 10:21:40 GMT
[Debug for suning] header info :  Connection = keep-alive
[Debug for suning] header info :  ETag = "52986ab4-5"
[Debug for suning] header info :  Accept-Ranges = bytes

可以看到squid内部也识别c-maxage头，另外c-maxage只是添加一个头识别，但不做语义处理，所以不会对缓存策略产生影响，影响的还是max-age


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