Blob Storage stores sets of binary data. Blob storage offers the following three
resources: the storage account, containers, and blobs. Within your storage account,
containers provide a way to organize sets of blobs within your storage account.
API Examples
This topic lists some examples of using the
Zend_Service_WindowsAzure_Storage_Blob class. Other features are
available in the download package, as well as a detailed API
documentation of those features.
Creating a storage container
Using the following code, a blob storage container can be created on development
storage.
Example #1 Creating a storage container
span style="color: #ff0000;">'testcontainer''Container name is: ' . $result->Name;
Deleting a storage container
Using the following code, a blob storage container can be removed from development
storage.
Example #2 Deleting a storage container
span style="color: #ff0000;">'testcontainer');
Storing a blob
Using the following code, a blob can be uploaded to a blob storage container on
development storage. Note that the container has already been created before.
Example #3 Storing a blob
span style="color: #808080; font-style: italic;">// upload /home/maarten/example.txt to Azure
$result = $storageClient->putBlob(
'testcontainer', 'example.txt', '/home/maarten/example.txt''Blob name is: ' . $result->Name;
Copying a blob
Using the following code, a blob can be copied from inside the storage account. The
advantage of using this method is that the copy operation occurs in the Azure cloud
and does not involve downloading the blob. Note that the container has already been
created before.
Example #4 Copying a blob
span style="color: #808080; font-style: italic;">// copy example.txt to example2.txt
'testcontainer', 'example.txt', 'testcontainer', 'example2.txt''Copied blob name is: ' . $result->Name;
Downloading a blob
Using the following code, a blob can be downloaded from a blob storage container on
development storage. Note that the container has already been created before and a
blob has been uploaded.
Example #5 Downloading a blob
span style="color: #808080; font-style: italic;">// download file to /home/maarten/example.txt
$storageClient->getBlob(
'testcontainer', 'example.txt', '/home/maarten/example.txt'
);
Making a blob publicly available
By default, blob storage containers on Windows Azure are protected from public
viewing. If any user on the Internet should have access to a blob container, its ACL
can be set to public. Note that this applies to a complete container and not to a
single blob!
Using the following code, blob storage container ACL can be set on development
storage. Note that the container has already been created before.
Example #6 Making a blob publicly available
span style="color: #808080; font-style: italic;">// make container publicly available (enumerate all blobs and read blob data)
$storageClient->setContainerAcl('testcontainer'
Root container
Windows Azure Blob Storage provides support to work with a "root container".
This means that a blob can be stored in the root of your storage account,
i.e. http://myaccount.blob.core.windows.net/somefile.txt.
In order to work with the root container, it should first be created using the
createContainer() method, naming the container
$root. All other operations on the root container should be issued
with the container name set to $root.
Blob storage stream wrapper
The Windows Azure SDK for PHP provides support
for registering a blob storage client as a PHP file stream wrapper.
The blob storage stream wrapper provides support for using regular file operations on
Windows Azure Blob Storage. For example, one can open a file from Windows Azure Blob
Storage with the fopen() function:
Example #7 Example usage of blob storage stream wrapper
span style="color: #ff0000;">'azure://mycontainer/myfile.txt', 'r');
// ...
In order to do this, the Windows Azure SDK for PHP
blob storage client must be registered as a stream wrapper. This can be done by calling
the registerStreamWrapper() method:
Example #8 Registering the blob storage stream wrapper
span style="color: #808080; font-style: italic;">// registers azure:// on this storage client
$storageClient->registerStreamWrapper();
// or:
// regiters blob:// on this storage client
$storageClient->registerStreamWrapper('blob://');
To unregister the stream wrapper, the unregisterStreamWrapper()
method can be used.
Shared Access Signature
Windows Azure Bob Storage provides a feature called "Shared Access Signatures". By
default, there is only one level of authorization possible in Windows Azure Blob
Storage: either a container is private or it is public. Shared Access Signatures provide
a more granular method of authorization: read, write, delete and list permissions can be
assigned on a container or a blob and given to a specific client using an URL-based
model.
An example would be the following signature:
http://phpstorage.blob.core.windows.net/phpazuretestshared1?st=2009-08-17T09%3A06%3A17Z&se=2009-08-17T09%3A56%3A17Z&sr=c&sp=w&sig=hscQ7Su1nqd91OfMTwTkxabhJSaspx%2BD%2Fz8UqZAgn9s%3D
The above signature gives write access to the "phpazuretestshared1"
container of the "phpstorage" account.
Generating a Shared Access Signature
When you are the owner of a Windows Azure Bob Storage account, you can create and
distribute a shared access key for any type of resource in your account. To do this,
the generateSharedAccessUrl() method of the
Zend_Service_WindowsAzure_Storage_Blob storage client can be
used.
The following example code will generate a Shared Access Signature for write access
in a container named "container1", within a timeframe of 3000 seconds.
Example #9 Generating a Shared Access Signature for a container
span style="color: #ff0000;">'container1',
'',
'c',
'w'
The following example code will generate a Shared Access Signature for read access
in a blob named test.txt in a container named "container1"
within a time frame of 3000 seconds.
Example #10 Generating a Shared Access Signature for a blob
span style="color: #ff0000;">'container1',
'test.txt',
'b',
'r'
Working with Shared Access Signatures from others
When you receive a Shared Access Signature from someone else, you can use the
Windows Azure SDK for PHP to work with the
addressed resource. For example, the following signature can be retrieved from the
owner of a storage account:
http://phpstorage.blob.core.windows.net/phpazuretestshared1?st=2009-08-17T09%3A06%3A17Z&se=2009-08-17T09%3A56%3A17Z&sr=c&sp=w&sig=hscQ7Su1nqd91OfMTwTkxabhJSaspx%2BD%2Fz8UqZAgn9s%3D
The above signature gives write access to the "phpazuretestshared1" "container" of
the phpstorage account. Since the shared key for the account is not known, the
Shared Access Signature can be used to work with the authorized resource.
Example #11 Consuming a Shared Access Signature for a container
span style="color: #ff0000;">'blob.core.windows.net', 'phpstorage', '''http://phpstorage.blob.core.windows.net/phpazuretestshared1?st=2009-08-17T09%3A06%3A17Z&se=2009-08-17T09%3A56%3A17Z&sr=c&sp=w&sig=hscQ7Su1nqd91OfMTwTkxabhJSaspx%2BD%2Fz8UqZAgn9s%3D'
));
$storageClient->putBlob(
'phpazuretestshared1', 'NewBlob.txt', 'C:\Files\dataforazure.txt'
);
Note that there was no explicit permission to write to a specific blob. Instead, the
Windows Azure SDK for PHP determined that a
permission was required to either write to that specific blob, or to write to its
container. Since only a signature was available for the latter, the Windows Azure
SDK for PHP chose those credentials to perform
the request on Windows Azure blob storage.