repo_zf1/documentation/manual/en/module_specs/Zend_Service_Amazon_S3.xml

<?xml version="1.0" encoding="UTF-8"?>
<!-- Reviewed: no -->
<sect1 id="zend.service.amazon.s3">
    <title>Zend_Service_Amazon_S3</title>

    <sect2 id="zend.service.amazon.s3.introduction">
        <title>Introduction</title>

        <para>
            Amazon S3 provides a simple web services interface that can be used to
            store and retrieve any amount of data, at any time, from anywhere on
            the web. It gives any developer access to the same highly scalable,
            reliable, fast, inexpensive data storage infrastructure that Amazon
            uses to run its own global network of web sites. The service aims to
            maximize benefits of scale and to pass those benefits on to developers.
        </para>
    </sect2>

    <sect2 id="zend.service.amazon.s3.registering">
        <title>Registering with Amazon S3</title>

        <para>
            Before you can get started with <classname>Zend_Service_Amazon_S3</classname>, you must
            first register for an account. Please see the
            <ulink url="http://aws.amazon.com/s3/faqs/">S3 FAQ</ulink>
            page on the Amazon website for more information.
        </para>

        <para>
            After registering, you will receive an application key and a secret key.
            You will need both to access the S3 service.
        </para>
    </sect2>

    <sect2 id="zend.service.amazon.s3.apiDocumentation">
        <title>API Documentation</title>

        <para>
            The <classname>Zend_Service_Amazon_S3</classname> class provides the
            <acronym>PHP</acronym> wrapper to the Amazon S3 REST interface. Please consult the
            <ulink
                url="http://developer.amazonwebservices.com/connect/kbcategory.jspa?categoryID=48">Amazon
                S3 documentation</ulink> for detailed description of the service. You will need to
            be familiar with basic concepts in order to use this service.
        </para>
    </sect2>

    <sect2 id="zend.service.amazon.s3.features">
        <title>Features</title>

        <para>
            <classname>Zend_Service_Amazon_S3</classname> provides the following functionality:

            <itemizedlist>
                <listitem>
                    <para>
                        A single point for configuring your amazon.s3 authentication
                        credentials that can be used across the amazon.s3 namespaces.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        A proxy object that is more convenient to use than an
                        <acronym>HTTP</acronym> client alone, mostly removing the need to manually
                        construct <acronym>HTTP</acronym> POST requests to access the REST service.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        A response wrapper that parses each response body and throws an
                        exception if an error occurred, alleviating the need to repeatedly
                        check the success of many commands.
                    </para>
                </listitem>

                <listitem>
                    <para>
                        Additional convenience methods for some of the more common operations.
                    </para>
                </listitem>
            </itemizedlist>
        </para>
    </sect2>

    <sect2 id="zend.service.amazon.s3.storing-your-first">
        <title>Getting Started</title>

        <para>
            Once you have registered with Amazon S3, you're ready to store your first
            data object on the S3. The objects on S3 are stored in containers, called
            "buckets". Bucket names are unique on S3, and each user can have no more than
            100 buckets simultaneously. Each bucket can contain unlimited amount of objects,
            identified by name.
        </para>

        <para>
            The following example demonstrates creating a bucket, storing and retrieving the data.
        </para>

        <example id="zend.service.amazon.s3.storing-your-first.example">
            <title>Zend_Service_Amazon_S3 Usage Example</title>

             <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$s3->createBucket("my-own-bucket");

$s3->putObject("my-own-bucket/myobject", "somedata");

echo $s3->getObject("my-own-bucket/myobject");
]]></programlisting>
        </example>

        <para>
            Since <classname>Zend_Service_Amazon_S3</classname> service requires authentication,
            you should pass your credentials (AWS key and secret key) to the constructor.
            If you only use one account, you can set default credentials for the service:
        </para>

        <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

Zend_Service_Amazon_S3::setKeys($my_aws_key, $my_aws_secret_key);
$s3 = new Zend_Service_Amazon_S3();
]]></programlisting>
    </sect2>

    <sect2 id="zend.service.amazon.s3.buckets">
        <title>Bucket operations</title>

        <para>
            All objects in S3 system are stored in buckets. Bucket has to be created
            before any storage operation. Bucket name is unique in the system, so
            you can not have bucket named the same as someone else's bucket.
        </para>

        <para>
            Bucket name can contain lowercase letters, digits, periods (.), underscores (_), and
            dashes (-). No other symbols allowed. Bucket name should start with letter or digit, and
            be 3 to 255 characters long. Names looking like an IP address (e.g. "192.168.16.255")
            are not allowed.
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <methodname>createBucket()</methodname> creates a new bucket.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>cleanBucket()</methodname> removes all objects that are contained in
                    a bucket.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>removeBucket()</methodname> removes the bucket from the system. The
                    bucket should be empty to be removed.
                </para>

                <example id="zend.service.amazon.s3.buckets.remove.example">
                    <title>Zend_Service_Amazon_S3 Bucket Removal Example</title>

                    <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$s3->cleanBucket("my-own-bucket");
$s3->removeBucket("my-own-bucket");
]]></programlisting>
                </example>
            </listitem>

            <listitem>
                <para>
                    <methodname>getBuckets()</methodname> returns the list of the names of all
                    buckets belonging to the user.
                </para>

                <example id="zend.service.amazon.s3.buckets.list.example">
                    <title>Zend_Service_Amazon_S3 Bucket Listing Example</title>

                    <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$list = $s3->getBuckets();
foreach($list as $bucket) {
  echo "I have bucket $bucket\n";
}
]]></programlisting>
                </example>
            </listitem>

            <listitem>
                <para>
                    <methodname>isBucketAvailable()</methodname> check if the bucket exists and
                    returns <constant>TRUE</constant> if it does.
                </para>
            </listitem>
        </itemizedlist>
    </sect2>

    <sect2 id="zend.service.amazon.s3.objects">
        <title>Object operations</title>

        <para>
            The object is the basic storage unit in S3. Object stores unstructured data, which can
            be any size up to 4 gigabytes. There's no limit on how many objects can be stored on the
            system.
        </para>

        <para>
            The object are contained in buckets. Object is identified by name, which can be any
            utf-8 string. It is common to use hierarchical names (such as
            <code>Pictures/Myself/CodingInPHP.jpg</code>) to organise object names. Object name is
            prefixed with bucket name when using object functions, so for object "mydata" in bucket
            "my-own-bucket" the name would be <code>my-own-bucket/mydata</code>.
        </para>

        <para>
            Objects can be replaced (by rewriting new data with the same key) or deleted, but not
            modified, appended, etc. Object is always stored whole.
        </para>

        <para>
            By default, all objects are private and can be accessed only by their owner. However, it
            is possible to specify object with public access, in which case it will be available
            through the <acronym>URL</acronym>:
            <code>http://s3.amazonaws.com/[bucket-name]/[object-name]</code>.
        </para>

        <itemizedlist>
            <listitem>
                <para>
                    <methodname>putObject($object, $data, $meta)</methodname> created an object with
                    name <varname>$object</varname> (should contain the bucket name as prefix!)
                    having <varname>$data</varname> as its content.
                </para>

                <para>
                Optional <varname>$meta</varname> parameter is the array of metadata, which
                currently supports the following parameters as keys:
                </para>

                <variablelist>
                    <varlistentry>
                        <term><constant>S3_CONTENT_TYPE_HEADER</constant></term>

                        <listitem>
                            <para>
                                <acronym>MIME</acronym> content type of the data. If not specified,
                                the type will be guessed according to the file extension of the
                                object name.
                            </para>
                        </listitem>
                    </varlistentry>

                    <varlistentry>
                        <term><constant>S3_ACL_HEADER</constant></term>

                        <listitem>
                            <para>
                                The access to the item. Following access constants can be used:

                                <variablelist>
                                    <varlistentry>
                                        <term><constant>S3_ACL_PRIVATE</constant></term>

                                        <listitem>
                                            <para>Only the owner has access to the item.</para>
                                        </listitem>
                                    </varlistentry>

                                    <varlistentry>
                                        <term><constant>S3_ACL_PUBLIC_READ</constant></term>

                                        <listitem>
                                            <para>
                                                Anybody can read the object, but only owner can
                                                write. This is setting may be used to store publicly
                                                accessible content.
                                            </para>
                                        </listitem>
                                    </varlistentry>

                                    <varlistentry>
                                        <term><constant>S3_ACL_PUBLIC_WRITE</constant></term>

                                        <listitem>
                                            <para>
                                                Anybody can read or write the object. This policy is
                                                rarely useful.
                                            </para>
                                        </listitem>
                                    </varlistentry>

                                    <varlistentry>
                                        <term><constant>S3_ACL_AUTH_READ</constant></term>

                                        <listitem>
                                            <para>
                                                Only the owner has write access to the item, and
                                                other authenticated S3 users have read access. This
                                                is useful for sharing data between S3 accounts
                                                without exposing them to the public.
                                            </para>
                                        </listitem>
                                    </varlistentry>
                                </variablelist>

                                By default, all the items are private.
                            </para>

                            <example id="zend.service.amazon.s3.objects.public.example">
                                <title>Zend_Service_Amazon_S3 Public Object Example</title>

                                <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$s3->putObject("my-own-bucket/Pictures/Me.png", file_get_contents("me.png"),
    array(Zend_Service_Amazon_S3::S3_ACL_HEADER =>
          Zend_Service_Amazon_S3::S3_ACL_PUBLIC_READ));
// or:
$s3->putFile("me.png", "my-own-bucket/Pictures/Me.png",
    array(Zend_Service_Amazon_S3::S3_ACL_HEADER =>
          Zend_Service_Amazon_S3::S3_ACL_PUBLIC_READ));
echo "Go to http://s3.amazonaws.com/my-own-bucket/Pictures/Me.png to see me!\n";
]]></programlisting>
                            </example>
                        </listitem>
                    </varlistentry>
                </variablelist>
            </listitem>

            <listitem>
                <para>
                    <methodname>getObject($object)</methodname> retrieves object data from the
                    storage by name.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>removeObject($object)</methodname> removes the object from the
                    storage.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>getInfo($object)</methodname> retrieves the metadata information
                    about the object. The function will return array with metadata information. Some
                    of the useful keys are:

                    <variablelist>
                        <varlistentry>
                            <term><code>type</code></term>

                            <listitem>
                                <para>The <acronym>MIME</acronym> type of the item.</para>
                            </listitem>
                        </varlistentry>
                        <varlistentry>
                            <term><code>size</code></term>

                            <listitem>
                                <para>The size of the object data.</para>
                            </listitem>
                        </varlistentry>

                        <varlistentry>
                            <term><code>mtime</code></term>

                            <listitem>
                                <para>
                                    UNIX-type timestamp of the last modification for the object.
                                </para>
                            </listitem>
                        </varlistentry>

                        <varlistentry>
                            <term><code>etag</code></term>

                            <listitem>
                                <para>
                                    The ETag of the data, which is the MD5 hash of the data,
                                    surrounded by quotes (").
                                </para>
                            </listitem>
                        </varlistentry>
                    </variablelist>

                    The function will return <constant>FALSE</constant> if the key does not
                    correspond to any existing object.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>getObjectsByBucket($bucket)</methodname> returns the list of the
                    object keys, contained in the bucket.
                </para>

                <example id="zend.service.amazon.s3.objects.list.example">
                    <title>Zend_Service_Amazon_S3 Object Listing Example</title>

                    <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$list = $s3->getObjectsByBucket("my-own-bucket");
foreach($list as $name) {
  echo "I have $name key:\n";
  $data = $s3->getObject("my-own-bucket/$name");
  echo "with data: $data\n";
}
]]></programlisting>
                </example>
            </listitem>

            <listitem>
                <para>
                    <methodname>isObjectAvailable($object)</methodname> checks if the object with
                    given name exists.
                </para>
            </listitem>

            <listitem>
                <para>
                    <methodname>putFile($path, $object, $meta)</methodname> puts the content of the
                    file in <varname>$path</varname> into the object named
                    <varname>$object</varname>.
                </para>

                <para>
                    The optional <varname>$meta</varname> argument is the same as for
                    <code>putObject</code>. If the content type is omitted, it will be guessed
                    basing on the source file name.
                </para>
            </listitem>
        </itemizedlist>
    </sect2>

    <sect2 id="zend.service.amazon.s3.streaming">
        <title>Data Streaming</title>

        <para>
            It is possible to get and put objects using not stream data held in memory but files or
            <acronym>PHP</acronym> streams. This is especially useful when file sizes are large in
            order not to overcome memory limits.
        </para>

        <para>
            To receive object using streaming, use method
            <methodname>getObjectStream($object, $filename)</methodname>. This method will return
            <classname>Zend_Http_Response_Stream</classname>, which can be used as described in
            <link linkend="zend.http.client.streaming">HTTP Client Data Streaming</link> section.

            <example id="zend.service.amazon.s3.streaming.example1">
                <title>Zend_Service_Amazon_S3 Data Streaming Example</title>

                <programlisting language="php"><![CDATA[
$response = $amazon->getObjectStream("mybycket/zftest");
// copy file
copy($response->getStreamName(), "my/downloads/file");
// use stream
$fp = fopen("my/downloads/file2", "w");
stream_copy_to_stream($response->getStream(), $fp);
]]></programlisting>
            </example>
        </para>

        <para>
            Second parameter for <methodname>getObjectStream()</methodname> is optional and
            specifies target file to write the data. If not specified, temporary file is used, which
            will be deleted after the response object is destroyed.
        </para>

        <para>
            To send object using streaming, use <methodname>putFileStream()</methodname> which has
            the same signature as <methodname>putFile()</methodname> but will use streaming and not
            read the file into memory.
        </para>

        <para>
            Also, you can pass stream resource to <methodname>putObject()</methodname> method data
            parameter, in which case the data will be read from the stream when sending the request
            to the server.
        </para>
    </sect2>

    <sect2 id="zend.service.amazon.s3.streams">
        <title>Stream wrapper</title>

        <para>
            In addition to the interfaces described above,
            <classname>Zend_Service_Amazon_S3</classname> also supports operating as a stream
            wrapper. For this, you need to register the client object as the stream wrapper:
        </para>

        <example id="zend.service.amazon.s3.streams.example">
            <title>Zend_Service_Amazon_S3 Streams Example</title>

            <programlisting language="php"><![CDATA[
require_once 'Zend/Service/Amazon/S3.php';

$s3 = new Zend_Service_Amazon_S3($my_aws_key, $my_aws_secret_key);

$s3->registerStreamWrapper("s3");

mkdir("s3://my-own-bucket");
file_put_contents("s3://my-own-bucket/testdata", "mydata");

echo file_get_contents("s3://my-own-bucket/testdata");
]]></programlisting>
        </example>

        <para>
            Directory operations (<code>mkdir</code>, <code>rmdir</code>, <code>opendir</code>,
            etc.) will operate on buckets and thus their arguments should be of the form of
            <code>s3://bucketname</code>. File operations operate on objects. Object creation,
            reading, writing, deletion, stat and directory listing is supported.
        </para>
    </sect2>
</sect1>