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<h1>Package httpcache</h1>
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<dd><code>import "github.com/gregjones/httpcache"</code></dd>
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<dd><a href="index.html#pkg-index" class="indexLink">Index</a></dd>
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<p>
Package httpcache provides a http.RoundTripper implementation that works as a
mostly RFC-compliant cache for http responses.
</p>
<p>
It is only suitable for use as a &#39;private&#39; cache (i.e. for a web-browser or an API-client
and not for a shared proxy).
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<dd><a href="index.html#pkg-constants">Constants</a></dd>
<dd><a href="index.html#pkg-variables">Variables</a></dd>
<dd><a href="index.html#CachedResponse">func CachedResponse(c Cache, req *http.Request) (resp *http.Response, err error)</a></dd>
<dd><a href="index.html#Date">func Date(respHeaders http.Header) (date time.Time, err error)</a></dd>
<dd><a href="index.html#Cache">type Cache</a></dd>
<dd><a href="index.html#MemoryCache">type MemoryCache</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#NewMemoryCache">func NewMemoryCache() *MemoryCache</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#MemoryCache.Delete">func (c *MemoryCache) Delete(key string)</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#MemoryCache.Get">func (c *MemoryCache) Get(key string) (resp []byte, ok bool)</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#MemoryCache.Set">func (c *MemoryCache) Set(key string, resp []byte)</a></dd>
<dd><a href="index.html#Transport">type Transport</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#NewMemoryCacheTransport">func NewMemoryCacheTransport() *Transport</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#NewTransport">func NewTransport(c Cache) *Transport</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#Transport.CancelRequest">func (t *Transport) CancelRequest(req *http.Request)</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#Transport.Client">func (t *Transport) Client() *http.Client</a></dd>
<dd>&nbsp; &nbsp; <a href="index.html#Transport.RoundTrip">func (t *Transport) RoundTrip(req *http.Request) (resp *http.Response, err error)</a></dd>
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<h4>Package files</h4>
<p>
<span style="font-size:90%">
<a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go">httpcache.go</a>
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In the call graph viewer below, each node
is a function belonging to this package
and its children are the functions it
calls&mdash;perhaps dynamically.
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package: functions that may be called from
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There may be non-exported or anonymous
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<h2 id="pkg-constants">Constants</h2>
<pre>const (
<span class="comment">// XFromCache is the header added to responses that are returned from the cache</span>
<span id="XFromCache">XFromCache</span> = &#34;X-From-Cache&#34;
)</pre>
<h2 id="pkg-variables">Variables</h2>
<pre>var <span id="ErrNoDateHeader">ErrNoDateHeader</span> = <a href="../../../errors/index.html">errors</a>.<a href="../../../errors/index.html#New">New</a>(&#34;no Date header&#34;)</pre>
<p>
ErrNoDateHeader indicates that the HTTP headers contained no Date header.
</p>
<h2 id="CachedResponse">func <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=1212:1292#L39">CachedResponse</a></h2>
<pre>func CachedResponse(c <a href="index.html#Cache">Cache</a>, req *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Request">Request</a>) (resp *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Response">Response</a>, err <a href="../../../builtin/index.html#error">error</a>)</pre>
<p>
CachedResponse returns the cached http.Response for req if present, and nil
otherwise.
</p>
<h2 id="Date">func <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=9487:9549#L322">Date</a></h2>
<pre>func Date(respHeaders <a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Header">Header</a>) (date <a href="../../../time/index.html">time</a>.<a href="../../../time/index.html#Time">Time</a>, err <a href="../../../builtin/index.html#error">error</a>)</pre>
<p>
Date parses and returns the value of the Date header.
</p>
<h2 id="Cache">type <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=635:1004#L22">Cache</a></h2>
<pre>type Cache interface {
<span class="comment">// Get returns the []byte representation of a cached response and a bool</span>
<span class="comment">// set to true if the value isn&#39;t empty</span>
Get(key <a href="../../../builtin/index.html#string">string</a>) (responseBytes []<a href="../../../builtin/index.html#byte">byte</a>, ok <a href="../../../builtin/index.html#bool">bool</a>)
<span class="comment">// Set stores the []byte representation of a response against a key</span>
Set(key <a href="../../../builtin/index.html#string">string</a>, responseBytes []<a href="../../../builtin/index.html#byte">byte</a>)
<span class="comment">// Delete removes the value associated with the key</span>
Delete(key <a href="../../../builtin/index.html#string">string</a>)
}</pre>
<p>
A Cache interface is used by the Transport to store and retrieve responses.
</p>
<h2 id="MemoryCache">type <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=1530:1602#L50">MemoryCache</a></h2>
<pre>type MemoryCache struct {
<span class="comment">// contains filtered or unexported fields</span>
}</pre>
<p>
MemoryCache is an implemtation of Cache that stores responses in an in-memory map.
</p>
<h3 id="NewMemoryCache">func <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=2200:2234#L78">NewMemoryCache</a></h3>
<pre>func NewMemoryCache() *<a href="index.html#MemoryCache">MemoryCache</a></pre>
<p>
NewMemoryCache returns a new Cache that will store items in an in-memory map
</p>
<h3 id="MemoryCache.Delete">func (*MemoryCache) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=2024:2064#L71">Delete</a></h3>
<pre>func (c *<a href="index.html#MemoryCache">MemoryCache</a>) Delete(key <a href="../../../builtin/index.html#string">string</a>)</pre>
<p>
Delete removes key from the cache
</p>
<h3 id="MemoryCache.Get">func (*MemoryCache) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=1695:1755#L56">Get</a></h3>
<pre>func (c *<a href="index.html#MemoryCache">MemoryCache</a>) Get(key <a href="../../../builtin/index.html#string">string</a>) (resp []<a href="../../../builtin/index.html#byte">byte</a>, ok <a href="../../../builtin/index.html#bool">bool</a>)</pre>
<p>
Get returns the []byte representation of the response and true if present, false if not
</p>
<h3 id="MemoryCache.Set">func (*MemoryCache) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=1882:1932#L64">Set</a></h3>
<pre>func (c *<a href="index.html#MemoryCache">MemoryCache</a>) Set(key <a href="../../../builtin/index.html#string">string</a>, resp []<a href="../../../builtin/index.html#byte">byte</a>)</pre>
<p>
Set saves response resp to the cache with key
</p>
<h2 id="Transport">type <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=2988:3397#L113">Transport</a></h2>
<pre>type Transport struct {
<span class="comment">// The RoundTripper interface actually used to make requests</span>
<span class="comment">// If nil, http.DefaultTransport is used</span>
Transport <a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#RoundTripper">RoundTripper</a>
Cache <a href="index.html#Cache">Cache</a>
<span class="comment">// If true, responses returned from the cache will be given an extra header, X-From-Cache</span>
MarkCachedResponses <a href="../../../builtin/index.html#bool">bool</a>
<span class="comment">// contains filtered or unexported fields</span>
}</pre>
<p>
Transport is an implementation of http.RoundTripper that will return values from a cache
where possible (avoiding a network request) and will additionally add validators (etag/if-modified-since)
to repeated requests allowing servers to return 304 / Not Modified
</p>
<h3 id="NewMemoryCacheTransport">func <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=17096:17137#L580">NewMemoryCacheTransport</a></h3>
<pre>func NewMemoryCacheTransport() *<a href="index.html#Transport">Transport</a></pre>
<p>
NewMemoryCacheTransport returns a new Transport using the in-memory cache implementation
</p>
<h3 id="NewTransport">func <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=3517:3554#L128">NewTransport</a></h3>
<pre>func NewTransport(c <a href="index.html#Cache">Cache</a>) *<a href="index.html#Transport">Transport</a></pre>
<p>
NewTransport returns a new Transport with the
provided Cache implementation and MarkCachedResponses set to true
</p>
<h3 id="Transport.CancelRequest">func (*Transport) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=8800:8852#L295">CancelRequest</a></h3>
<pre>func (t *<a href="index.html#Transport">Transport</a>) CancelRequest(req *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Request">Request</a>)</pre>
<p>
CancelRequest calls CancelRequest on the underlaying transport if implemented or
throw a warning otherwise.
</p>
<h3 id="Transport.Client">func (*Transport) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=3673:3714#L133">Client</a></h3>
<pre>func (t *<a href="index.html#Transport">Transport</a>) Client() *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Client">Client</a></pre>
<p>
Client returns an *http.Client that caches responses.
</p>
<h3 id="Transport.RoundTrip">func (*Transport) <a href="http://localhost:6060/src/github.com/gregjones/httpcache/httpcache.go?s=4923:5004#L171">RoundTrip</a></h3>
<pre>func (t *<a href="index.html#Transport">Transport</a>) RoundTrip(req *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Request">Request</a>) (resp *<a href="../../../net/http/index.html">http</a>.<a href="../../../net/http/index.html#Response">Response</a>, err <a href="../../../builtin/index.html#error">error</a>)</pre>
<p>
RoundTrip takes a Request and returns a Response
</p>
<p>
If there is a fresh Response already in cache, then it will be returned without connecting to
the server.
</p>
<p>
If there is a stale Response, then any validators it contains will be set on the new request
to give the server a chance to respond with NotModified. If this happens, then the cached Response
will be returned.
</p>
<h2 id="pkg-subdirectories">Subdirectories</h2>
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<table>
<tr>
<th class="pkg-name">Name</th>
<th class="pkg-synopsis">Synopsis</th>
</tr>
<tr>
<td colspan="2"><a href="../index.html">..</a></td>
</tr>
<tr>
<td class="pkg-name" style="padding-left: 0px;">
<a href="diskcache/index.html">diskcache</a>
</td>
<td class="pkg-synopsis">
Package diskcache provides an implementation of httpcache.Cache that uses the diskv package to supplement an in-memory map with persistent storage
</td>
</tr>
<tr>
<td class="pkg-name" style="padding-left: 0px;">
<a href="leveldbcache/index.html">leveldbcache</a>
</td>
<td class="pkg-synopsis">
Package leveldbcache provides an implementation of httpcache.Cache that uses github.com/syndtr/goleveldb/leveldb
</td>
</tr>
<tr>
<td class="pkg-name" style="padding-left: 0px;">
<a href="memcache/index.html">memcache</a>
</td>
<td class="pkg-synopsis">
Package memcache provides an implementation of httpcache.Cache that uses App Engine&#39;s memcache package to store cached responses.
</td>
</tr>
<tr>
<td class="pkg-name" style="padding-left: 0px;">
<a href="redis/index.html">redis</a>
</td>
<td class="pkg-synopsis">
Package redis provides a redis interface for http caching.
</td>
</tr>
</table>
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