<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <HTML ><HEAD ><TITLE >http_cache_etag</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.79"><LINK REL="HOME" TITLE="PHP 手册" HREF="index.html"><LINK REL="UP" TITLE="HTTP 函数" HREF="ref.http.html"><LINK REL="PREVIOUS" TITLE="HTTP 函数" HREF="ref.http.html"><LINK REL="NEXT" TITLE="http_cache_last_modified" HREF="function.http-cache-last-modified.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=UTF-8"></HEAD ><BODY CLASS="refentry" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >PHP 手册</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="ref.http.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.http-cache-last-modified.html" ACCESSKEY="N" >下一页</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.http-cache-etag" ></A >http_cache_etag</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN74044" ></A ><P > (PECL)</P >http_cache_etag -- Caching by ETag</DIV ><DIV CLASS="refsect1" ><A NAME="AEN74047" ></A ><H2 >说明</H2 >bool <B CLASS="methodname" >http_cache_etag</B > ( [string etag] )<BR ></BR ><P > Attempts to cache the sent entity by its <TT CLASS="literal" >ETag</TT >, either supplied or generated by the hash algorithm specified by the <A HREF="ref.http.html#http.configuration" >INI 设定</A > <A HREF="missing-stuff.html#http.configuration.etag.mode" >http.etag.mode</A >. </P ><P > If the clients <TT CLASS="literal" >If-None-Match</TT > header matches the supplied/calculated ETag, the body is considered cached on the clients side and a <TT CLASS="literal" >304 Not Modified</TT > status code is issued. </P ><P > A log entry is written to the cache log if the <A HREF="ref.http.html#http.configuration" >INI 设定</A > <A HREF="missing-stuff.html#http.configuration.log.cache" >http.log.cache</A > is set and the cache attempt was successful. </P ><DIV CLASS="note" ><BLOCKQUOTE CLASS="note" ><P ><B >注意: </B >This function may be used in conjunction with <A HREF="function.http-send-data.html" ><B CLASS="function" >http_send_data()</B ></A >, <A HREF="function.http-send-file.html" ><B CLASS="function" >http_send_file()</B ></A > 和 <A HREF="function.http-send-stream.html" ><B CLASS="function" >http_send_stream()</B ></A >.</P ></BLOCKQUOTE ></DIV ><P > If this function is used outside the http_send_*() API, it facilitates the <A HREF="function.ob-etaghandler.html" ><B CLASS="function" >ob_etaghandler()</B ></A >. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN74072" ></A ><H2 >参数</H2 ><P > <P ></P ><DIV CLASS="variablelist" ><DL ><DT ><CODE CLASS="parameter" >etag</CODE ></DT ><DD ><P > custom <TT CLASS="literal" >ETag</TT > </P ></DD ></DL ></DIV > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN74082" ></A ><H2 >返回值</H2 ><P > Returns <TT CLASS="constant" ><B >FALSE</B ></TT > or <SPAN CLASS="emphasis" ><I CLASS="emphasis" >exits</I ></SPAN > on success with <TT CLASS="literal" >304 Not Modified</TT > if the entity is cached. See the <A HREF="ref.http.html#http.configuration" >INI 设定</A > <A HREF="missing-stuff.html#http.configuration.force_exit" >http.force_exit</A > for what "exits" means. </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN74090" ></A ><H2 >范例</H2 ><P > <TABLE WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" CLASS="EXAMPLE" ><TR ><TD ><DIV CLASS="example" ><A NAME="AEN74093" ></A ><P ><B >例 1. A <B CLASS="function" >http_cache_etag()</B > example</B ></P ><TABLE BORDER="0" BGCOLOR="#E0E0E0" CELLPADDING="5" ><TR ><TD ><code><font color="#000000"> <font color="#0000BB"><?php<br />http_cache_etag</font><font color="#007700">();<br /></font><font color="#0000BB">http_send_data</font><font color="#007700">(</font><font color="#DD0000">"data"</font><font color="#007700">);<br /></font><font color="#0000BB">?></font> </font> </code></TD ></TR ></TABLE ></DIV ></TD ></TR ></TABLE > </P ></DIV ><DIV CLASS="refsect1" ><A NAME="AEN74097" ></A ><H2 >参见</H2 ><P > <P ></P ><TABLE BORDER="0" ><TBODY ><TR ><TD ><A HREF="function.http-cache-last-modified.html" ><B CLASS="function" >http_cache_last_modified()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.ob-etaghandler.html" ><B CLASS="function" >ob_etaghandler()</B ></A ></TD ></TR ><TR ><TD ><A HREF="function.http-match-etag.html" ><B CLASS="function" >http_match_etag()</B ></A ></TD ></TR ><TR ><TD >the <A HREF="missing-stuff.html#http.HttpResponse" ><B CLASS="classname" >HttpResponse</B ></A > class if you are using PHP-5.1 and above</TD ></TR ></TBODY ></TABLE ><P ></P > </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="ref.http.html" ACCESSKEY="P" >上一页</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >起始页</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.http-cache-last-modified.html" ACCESSKEY="N" >下一页</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >HTTP 函数</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.http.html" ACCESSKEY="U" >上一级</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >http_cache_last_modified</TD ></TR ></TABLE ></DIV ></BODY ></HTML >