StorageService Introduction
The storage service in the Simple Cloud API implements a basic interface for file storage on
the cloud. The files have no internal structure as far as the service is concerned, and are
identified by a string key that is analogous to a filepath on a filesystem.
StorageService Adapters
The interface Zend_Cloud_StorageService_Adapter defines methods
that each concrete storage service adapter must implement. The following adapters are
shipped with the Simple Cloud API:
Zend_Cloud_StorageService_Adapter_S3
Zend_Cloud_StorageService_Adapter_WindowsAzure
Zend_Cloud_StorageService_Adapter_FileSystem
To create the service object, call the static method
Zend_Cloud_StorageService_Factory::getAdapter(), which accepts
either an array or a Zend_Config object. The key named
storage_adapter should specify the concrete adapter class.
Adapter-specific keys may also be passed in this configuration parameter.
Using the StorageService Factory
'Zend_Cloud_StorageService_Adapter_S3',
Zend_Cloud_StorageService_Adapter_S3::AWS_ACCESS_KEY => $amazonKey,
Zend_Cloud_StorageService_Adapter_S3::AWS_SECRET_KEY => $amazonSecret,
));
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StorageService Adapter Options
Zend_Cloud_StorageService_Adapter_S3 options
Option key
Description
Used in
Required
Default
aws_accesskey
Amazon AWS access key
Constructor
Yes
None
aws_secretkey
Amazon AWS secret key
Constructor
Yes
None
bucket_name
The name of the S3 bucket for this item
Used in the constructor to set the default bucket for the
instantiated service. This option can also be specified in any of
the item access operations.
Yes
None
bucket_as_domain
Indicates that the bucket name is part of the domain name
Used in constructor to set the default behavior for the instantiated
service. This option can also be specified in any of the item access
operations.
No
False
metadata
Array of metadata to associate with the item
storeItem()
No
None
fetch_stream
Indicates whether the response is stream, and not a string
See the Zend_Service_Amazon_S3
documentation for more about handling streamed responses)
fetchItem()
No
False
http_adapter
HTTP adapter to use in all access operations
Constructor
No
Zend_Http_Client_Adapter_Socket
Zend_Cloud_StorageService_Adapter_WindowsAzure options
Option key
Description
Used in
Required
Default
storage_accountname
Windows Azure account name
Constructor
Yes
None
storage_accountkey
Windows Azure account key
Constructor
Yes
None
storage_container
Container to use for this storage object
Constructor
Yes
None
storage_host
Windows Azure access host
Constructor
Yes
blob.core.windows.net
storage_proxy_host
Proxy hostname
Constructor
No
None
storage_proxy_port
Proxy port
Constructor
No
8080
storage_proxy_credentials
Proxy credentials
Constructor
No
None
http_adapter
HTTP adapter to use in all access operations
Constructor
No
Zend_Http_Client_Adapter_Socket
returntype
How to return the results.
For fetchItem():
RETURN_STRING
Return the data as strings.
RETURN_PATH
save data on disk in temp file, return path
name
RETURN_STREAM
Default: Return the data as stream
For listItems():
RETURN_NAMES
return the list of item names (default)
RETURN_LIST
return the list of WindowsAzure objects
fetchItem(),
listItems()
No
RETURN_STREAM for
fetchItem();
RETURN_NAMES for
listItems()
return_path
Return path. This is the URL that can be used to access the item
after it has been uploaded.
fetchItem()
No
System tmp directory
return_openmode
fopen() mode used to open the file for
saving data
fetchItem()
No
'r'
Zend_Cloud_StorageService_Adapter_Filesystem options
Option key
Description
Used in
Required
Default
local_directory
Local directory where the files will be stored
Constructor
No
System tmp directory
Basic concepts
Different cloud storage services use their own unique terminology to refer to document
storage concepts. The SimpleCloud API defines a number of common concepts that are
shared among all major providers.
The storage service identifies files by string keys, which may be URL paths or another
service-specific identifier. The items can be stored and retrieved using this key. Each
item can have metadata associated with it. These metadata carry
service-specific information about the item, such as size, type, permissions, etc. as
defined in the adapter for that provider.
Exceptions
If some error occurs inside the storage service, a
Zend_Cloud_StorageService_Exception is thrown. If the exception
was caused by underlying service driver, you can use the
getClientException() method to retrieve the original exception.
Since different cloud providers implement different sets of services, some adapters do
not implement certain features. In this case, the
Zend_Cloud_OperationNotAvailableException exception is thrown.
Store an item
storeItem() method is used to upload or otherwise add files to
the storage provider.
Storing an item
storeItem('/my/remote/path/picture.jpg', $data);
]]>
An optional third parameter describes service-specific options.
Storing an item with options
storeItem(
'/my/remote/path/picture.jpg',
$data,
array(
Zend_Cloud_StorageService_Adapter_S3::BUCKET_NAME => "myBucket",
Zend_Cloud_StorageService_Adapter_S3::METADATA => array(
Zend_Service_Amazon_S3::S3_ACL_HEADER => Zend_Service_Amazon_S3::S3_ACL_PUBLIC_READ,
)
)
);
]]>
For service adapters that support streaming, data can also be a PHP stream (i.e. opened
file).
Fetch an item
The fetchItem() operation retrieves an item from the storage.
Fetching an item
fetchItem("/my/remote/path/picture.jpg");
file_put_contents($localFilePath, $returnedData);
]]>
Delete an item
The deleteItem() operation removes an item from the storage
service.
Deleting an item
deleteItem("/my/remote/path/picture.jpg");
]]>
Copy an item
The copyItem() operation creates a copy of the item in the
storage.
Not all services support copying natively. If this is the case, the adapter will
simulate the operation, fetching the item and storing it under the target path.
Copying an item
copyItem(
'/my/remote/path/picture.jpg',
'/anothor/remote/dir/picturecopy.jpg'
);
]]>
Move an item
The moveItem() operation moves an item from one key (or
directory) to another.
Not all services support moving natively. If this is the case the adapter will
simulate the operation, fetching the item, storing it under the target path, then
deleting the original file.
Moving an item
moveItem(
'/my/remote/path/picture.jpg',
'/anothor/remote/dir/newpicture.jpg'
);
]]>
Rename an item
The renameItem() operation changes the item name. For some
services, this operation may be equivalent to moving to its original directory with a
new name.
Renaming an item
renameItem('/my/remote/path/picture.jpg', 'newpicture.jpg');
]]>
List items
To list the items stored in the specified path, use the
listItems() method. The method returns a list of names
identifying matching remote items.
List items
listItems('/my/remote/path/');
foreach ($objects as $objname) {
echo "Found: $objname\n";
}
]]>
Fetching metadata
Some services store a set of key-value pairs along with the item as metadata. Use the
fetchMetadata() method to retrieve an item's metadata.
Fetching metadata
fetchMetadata('/my/remote/path/picture.jpg');
foreach ($data as $key => $value) {
echo "Metadata $key: $value\n";
}
]]>
Store metadata
Depending on the service, metadata can be supplied either when storing the item or with
a separate request. In the latter case, use storeMetadata() to
add or update this metadata.
Storing metadata
storeMetadata('/my/remote/path/picture.jpg', array(
'type' => 'JPEG',
'category' => 'Portrait',
));
]]>
Delete metadata
The deleteMetadata() method removes all user-supplied metadata
from an item.
Not all services support removing metadata.
Deleting metadata
deleteMetadata("/my/remote/path/picture.jpg");
]]>
Accessing concrete adapters
Sometimes it is necessary to retrieve the concrete adapter for the service that the
Storage API is working with. This can be achieved by using the
getAdapter() method.
Accessing the underlying adapter breaks portability among services, so it should be
reserved for exceptional circumstances only.
Using a concrete adapter
getClient();
$s3->cleanBucket("oldBucket");
]]>