Documentation

Service extends CatalogService
in package

Application

implements EventSubscriberInterface

Cloud Queues is an open source, scalable, and highly available message and notifications service. Users of this service can create and manage a "producer-consumer" or a "publisher-subscriber" model from one simple API. It is made up of a few basic components: queues, messages, claims, and stats.

In the producer-consumer model, users create queues where producers can post messages. Workers, or consumers, may then claim those messages and delete them once complete. A single claim may contain multiple messages, and administrators are given the ability to query claims for status.

In the publisher-subscriber model, messages are posted to a queue like above, but messages are never claimed. Instead, subscribers, or watchers, simply send GET requests to pull all messages since their last request. In this model, a message will remain in the queue, unclaimed, until the message's time to live (TTL) has expired.

Here is an overview of the Cloud Queues workflow:

You create a queue to which producers post messages.
Producers post messages to the queue.
Workers claim messages from the queue, complete the work in that message, and delete the message.
If a worker plans to be offline before its message completes, the worker can retire the claim TTL, putting the message back into the queue for another worker to claim.
Subscribers monitor the claims of these queues to keep track of activity and help troubleshoot if things go wrong.

For the majority of use cases, Cloud Queues itself will not be responsible for the ordering of messages. If there is only a single producer, however, Cloud Queueing guarantees that messages are handled in a First In, First Out (FIFO) order.

Interfaces, Classes and Traits

EventSubscriberInterface: An EventSubscriber knows itself what events it is interested in.

DEFAULT_NAME = 'cloudQueues'
DEFAULT_TYPE = 'rax:queues'
DEFAULT_URL_TYPE = 'publicURL'
PATCH_CONTENT_TYPE = OpenCloudCommonConstantsMime::JSON_PATCH
SUPPORTED_VERSION = null
$aliases : array<string|int, mixed>: The aliases configure for the properties of the instance.
$client : Client
$endpoint : Endpoint
$namespaces : array<string|int, mixed>
$regionless : bool
$resources : array<string|int, mixed>
$clientId : string: An arbitrary string used to differentiate your worker/subscriber. This is needed, for example, when you return back a list of messages and want to know the ones your worker is processing.
$logger : LoggerInterface: The logger instance
$name : string
$properties : array<string|int, mixed>: Holds all the properties added by overloading.
$region : string
$type : string
$urlType : string
__call() : mixed: Intercept non-existent method calls for dynamic getter/setter functionality.
__construct() : mixed: Creates a service object, based off the specified client.
appendClientIdToRequest() : mixed: Set the Client-ID header to all requests for this service.
checkJsonError() : mixed: Checks the most recent JSON operation for errors.
collection() : mixed
createQueue() : Queue: Create a new Queue.
generateUuid() : mixed
getBaseUrl() : Url: Get the base URL for this service, based on the set URL type.
getClient() : Client
getClientId() : string
getEndpoint() : Endpoint
getExtensions() : array<string|int, mixed>: Returns the /extensions for the service
getInstance() : static
getLogger() : LoggerInterface: Returns the Logger object.
getName() : string
getNamespaces() : array<string|int, mixed>: Returns a list of supported namespaces
getQueue() : Queue: Return an empty Queue.md object.
getRegion() : string
getResources() : array<string|int, mixed>: Get all associated resources for this service.
getSubscribedEvents() : array<string|int, mixed>: Returns an array of event names this subscriber wants to listen to.
getType() : string
getUrl() : Url: Returns the URL for the Service
getUrlType() : string
hasLogger() : bool
hasQueue() : bool: This operation checks to see if the specified queue exists.
limits() : array<string|int, mixed>: Returns the limits for the service
listQueues() : Collection: This operation lists queues for the project, sorting the queues alphabetically by name.
makeResourceIteratorOptions() : mixed
name() : mixed
namespaces() : mixed
populate() : mixed: Populates the current object based on an unknown data type.
region() : mixed
resource() : object: Factory method for instantiating resource objects.
resourceList() : PaginatedIterator: Factory method for instantiating a resource collection.
setClient() : mixed
setClientId() : $this
setEndpoint() : mixed
setLogger() : $this: Sets the logger.
stripNamespace() : mixed
toCamel() : mixed: Convert a string to camelCase format.
toUnderscores() : mixed: Convert string to underscore format.
url() : mixed
getCurrentNamespace() : type: Internal method for accessing child namespace from parent scope.
getJsonHeader() : mixed
getPatchHeaders() : mixed
getProperty() : mixed: Grab value out of the data array.
propertyExists() : bool: Basic check to see whether property exists.
resolveResourceClass() : string: Resolves FQCN for local resource.
setProperty() : mixed: We can set a property under three conditions:
checkAttributePrefix() : bool: Checks the attribute $property and only permits it if the prefix is in the specified $prefixes array
findEndpoint() : Endpoint: Extracts the appropriate endpoint from the service catalog based on the name and type of a service, and sets for further use.
getMetaUrl() : stdClass: Constructs a specified URL from the subresource
isAccessible() : bool: Does the property exist in the object variable list (i.e. does it have public or protected visibility?)

DEFAULT_NAME


    public
    mixed
    DEFAULT_NAME
    = 'cloudQueues'

DEFAULT_TYPE


    public
    mixed
    DEFAULT_TYPE
    = 'rax:queues'

DEFAULT_URL_TYPE


    public
    mixed
    DEFAULT_URL_TYPE
    = 'publicURL'

PATCH_CONTENT_TYPE


    public
    mixed
    PATCH_CONTENT_TYPE
    = OpenCloudCommonConstantsMime::JSON_PATCH

SUPPORTED_VERSION


    public
    mixed
    SUPPORTED_VERSION
    = null

$aliases

The aliases configure for the properties of the instance.


    protected
        array<string|int, mixed>
    $aliases
     = array()

$client


    protected
        Client
    $client

The client which interacts with the API.

$endpoint


    protected
        Endpoint
    $endpoint

The endpoint for this service.

$namespaces


    protected
        array<string|int, mixed>
    $namespaces
     = array()

Namespaces for this service.

$regionless


    protected
        bool
    $regionless
     = false

Indicates whether a service is "regionless" or not. Defaults to FALSE because nearly all services are region-specific.

$resources


    protected
        array<string|int, mixed>
    $resources
     = array()

A collection of resource models that this service has control over.

$clientId

An arbitrary string used to differentiate your worker/subscriber. This is needed, for example, when you return back a list of messages and want to know the ones your worker is processing.


    private
        string
    $clientId

$logger

The logger instance


    private
        LoggerInterface
    $logger

$name


    private
        string
    $name

The name of this service, as set in Catalog.

$properties

Holds all the properties added by overloading.


    private
        array<string|int, mixed>
    $properties
     = array()

$region


    private
        string
    $region

The chosen region(s) for this service.

$type


    private
        string
    $type

The type of this service, as set in Catalog.

$urlType


    private
        string
    $urlType

Either 'publicURL' or 'internalURL'.

__call()

Intercept non-existent method calls for dynamic getter/setter functionality.


    public
                __call( $method,  $args) : mixed

Parameters

$method :
$args :

Return values

mixed —

__construct()

Creates a service object, based off the specified client.


    public
                __construct(Client $client[, string $type = null ][, string $name = null ][, string $region = null ][, string $urlType = null ]) : mixed

The service's URL is defined in the client's serviceCatalog; it uses the $type, $name, $region, and $urlType to find the proper endpoint and set it. If it cannot find a URL in the service catalog that matches the criteria, then an exception is thrown.

Parameters

$client : Client: Client object
$type : string = null: Service type (e.g. 'compute')
$name : string = null: Service name (e.g. 'cloudServersOpenStack')
$region : string = null: Service region (e.g. 'DFW', 'ORD', 'IAD', 'LON', 'SYD' or 'HKG')
$urlType : string = null: Either 'publicURL' or 'internalURL'

Return values

mixed —

appendClientIdToRequest()

Set the Client-ID header to all requests for this service.


    public
                appendClientIdToRequest(Event $event) : mixed

Parameters

$event : Event

Return values

mixed —

checkJsonError()

Checks the most recent JSON operation for errors.


    public
            static    checkJsonError() : mixed

Return values

mixed —

collection()


    public
                collection(mixed $class[, mixed $url = null ][, mixed $parent = null ][, mixed $data = null ]) : mixed

Parameters

$class : mixed
$url : mixed = null
$parent : mixed = null
$data : mixed = null

Return values

mixed —

createQueue()

Create a new Queue.


    public
                createQueue(string $name) : Queue

Parameters

$name : string: Name of the new queue

Return values

Queue —

generateUuid()


    public
            static    generateUuid() : mixed

Return values

mixed —

getBaseUrl()

Get the base URL for this service, based on the set URL type.


    public
                getBaseUrl() : Url

Return values

Url —

getClient()


    public
                getClient() : Client

Return values

Client —

getClientId()


    public
                getClientId() : string

Return values

string —

getEndpoint()


    public
                getEndpoint() : Endpoint

Return values

Endpoint —

getExtensions()

Returns the /extensions for the service


    public
                getExtensions() : array<string|int, mixed>

Return values

array<string|int, mixed> —

of objects

getInstance()


    public
            static    getInstance() : static

Return values

static —

getLogger()

Returns the Logger object.


    public
                getLogger() : LoggerInterface

Return values

LoggerInterface —

getName()


    public
                getName() : string

Return values

string —

getNamespaces()

Returns a list of supported namespaces


    public
                getNamespaces() : array<string|int, mixed>

Return values

array<string|int, mixed> —

getQueue()

Return an empty Queue.md object.


    public
                getQueue([mixed $id = null ]) : Queue

Parameters

$id : mixed = null

Return values

Queue —

getRegion()


    public
                getRegion() : string

Return values

string —

getResources()

Get all associated resources for this service.


    public
                getResources() : array<string|int, mixed>

Return values

array<string|int, mixed> —

getSubscribedEvents()

Returns an array of event names this subscriber wants to listen to.


    public
            static    getSubscribedEvents() : array<string|int, mixed>

The array keys are event names and the value can be:

The method name to call (priority defaults to 0)
An array composed of the method name to call and the priority
An array of arrays composed of the method names to call and respective priorities, or 0 if unset

For instance:

['eventName' => 'methodName']
['eventName' => ['methodName', $priority]]
['eventName' => [['methodName1', $priority], ['methodName2']]]

The code must not depend on runtime state as it will only be called at compile time. All logic depending on runtime state must be put into the individual methods handling the events.

Return values

array<string|int, mixed> —

The event names to listen to

getType()


    public
                getType() : string

Return values

string —

getUrl()

Returns the URL for the Service


    public
                getUrl([string $path = null ][, array<string|int, mixed> $query = array() ]) : Url

Parameters

$path : string = null: URL path segment
$query : array<string|int, mixed> = array(): Array of query pairs

Return values

Url —

getUrlType()


    public
                getUrlType() : string

Return values

string —

hasLogger()


    public
                hasLogger() : bool

Return values

bool —

hasQueue()

This operation checks to see if the specified queue exists.


    public
                hasQueue(string $name) : bool

Parameters

$name : string: The queue name that you want to check

Return values

bool —

limits()

Returns the limits for the service


    public
                limits() : array<string|int, mixed>

Return values

array<string|int, mixed> —

of limits

listQueues()

This operation lists queues for the project, sorting the queues alphabetically by name.


    public
                listQueues([array<string|int, mixed> $params = array() ]) : Collection

Parameters

$params : array<string|int, mixed> = array()

An associative array of optional parameters:

marker (string) Specifies the name of the last queue received in a previous request, or none to get the first page of results. Optional.
limit (integer) Specifies up to 20 (the default, but configurable) queues to return. Optional.
detailed (bool) Determines whether queue metadata is included in the response. Optional.

Return values

Collection —

makeResourceIteratorOptions()


    public
                makeResourceIteratorOptions(mixed $resource) : mixed

Parameters

$resource : mixed

Return values

mixed —

name()


    public
                name() : mixed

Return values

mixed —

namespaces()


    public
                namespaces() : mixed

Return values

mixed —

populate()

Populates the current object based on an unknown data type.


    public
                populate(mixed $info[, mixed $setObjects = true ]) : mixed

Parameters

$info : mixed
$setObjects : mixed = true

Return values

mixed —

region()


    public
                region() : mixed

Return values

mixed —

resource()

Factory method for instantiating resource objects.


    public
                resource(string $resourceName[, mixed $info = null ][, mixed $parent = null ]) : object

Parameters

$resourceName : string
$info : mixed = null: (default: null)
$parent : mixed = null: The parent object

Return values

object —

resourceList()

Factory method for instantiating a resource collection.


    public
                resourceList(string $resourceName[, string|null $url = null ][, string|null $parent = null ]) : PaginatedIterator

Parameters

$resourceName : string
$url : string|null = null
$parent : string|null = null

Return values

PaginatedIterator —

setClient()


    public
                setClient(ClientInterface $client) : mixed

Parameters

$client : ClientInterface

Return values

mixed —

setClientId()


    public
                setClientId([null $clientId = null ]) : $this

Parameters

$clientId : null = null

Return values

$this —

setEndpoint()


    public
                setEndpoint(Endpoint $endpoint) : mixed

Parameters

$endpoint : Endpoint

Return values

mixed —

setLogger()

Sets the logger.


    public
                setLogger([LoggerInterface $logger = null ]) : $this

Parameters

$logger : LoggerInterface = null

Return values

$this —

stripNamespace()


    public
                stripNamespace(mixed $namespace) : mixed

Parameters

$namespace : mixed

Return values

mixed —

toCamel()

Convert a string to camelCase format.


    public
                toCamel( $string[, bool $capitalise = true ]) : mixed

Parameters

$string :
$capitalise : bool = true: Optional flag which allows for word capitalization.

Return values

mixed —

toUnderscores()

Convert string to underscore format.


    public
                toUnderscores( $string) : mixed

Parameters

$string :

Return values

mixed —

url()


    public
                url([mixed $path = null ][, array<string|int, mixed> $query = array() ]) : mixed

Parameters

$path : mixed = null
$query : array<string|int, mixed> = array()

Return values

mixed —

getCurrentNamespace()

Internal method for accessing child namespace from parent scope.


    protected
                getCurrentNamespace() : type

Return values

type —

getJsonHeader()


    protected
            static    getJsonHeader() : mixed

Return values

mixed —

getPatchHeaders()


    protected
            static    getPatchHeaders() : mixed

Return values

mixed —

getProperty()

Grab value out of the data array.


    protected
                getProperty(string $property) : mixed

Parameters

$property : string

Return values

mixed —

propertyExists()

Basic check to see whether property exists.


    protected
                propertyExists(string $property[, bool $allowRetry = true ]) : bool

Parameters

$property : string: The property name being investigated.
$allowRetry : bool = true: If set to TRUE, the check will try to format the name in underscores because there are sometimes discrepancies between camelCaseNames and underscore_names.

Return values

bool —

resolveResourceClass()

Resolves FQCN for local resource.


    protected
                resolveResourceClass( $resourceName) : string

Parameters

$resourceName :

Return values

string —

setProperty()

We can set a property under three conditions:


    protected
                setProperty(mixed $property, mixed $value) : mixed

If it has a concrete setter: setProperty()
If the property exists
If the property name's prefix is in an approved list

Parameters

$property : mixed
$value : mixed

Return values

mixed —

checkAttributePrefix()

Checks the attribute $property and only permits it if the prefix is in the specified $prefixes array


    private
                checkAttributePrefix(string $property) : bool

This is to support extension namespaces in some services.

Parameters

$property : string: the name of the attribute

Return values

bool —

findEndpoint()

Extracts the appropriate endpoint from the service catalog based on the name and type of a service, and sets for further use.


    private
                findEndpoint() : Endpoint

Return values

Endpoint —

getMetaUrl()

Constructs a specified URL from the subresource


    private
                getMetaUrl(string $resource) : stdClass

Given a subresource (e.g., "extensions"), this constructs the proper URL and retrieves the resource.

Parameters

$resource : string: The resource requested; should NOT have slashes at the beginning or end

Return values

stdClass —

object

isAccessible()

Does the property exist in the object variable list (i.e. does it have public or protected visibility?)


    private
                isAccessible( $property) : bool

Parameters

$property :

Return values

bool —