PHP Curl Queue Class

A queue based curl wrapping class. Processes curl GET and POST requests from a queue in batches. Output is handled by callback functions which can be set globally for all requests or individually for each request.

Example usage can be found in example.php.

Features

• Efficient queue based processing of HTTP requests.
• Easy to use interface.
• Customizeable window size defines number of requests that are processed in parallel at any one time.
• Ability to define per request or global output callback functions.
• Ability to customize the curl options for each request.
• Ability to choose either GET or POST for each request.

Configurable Options

Config values can be set using the config($values) where $values is an array in the form of $values = array($key => $value).

• window sets how many requests will be processed at the same time
• timeout sets the maximum timeout in seconds
• options is an array of additional default CURLOPT $key => $value pairs pass to each Curl request
• callback specifies the default function to call when a request finishes, must be of type function($output,$info)

Adding a Request

CurlQueue offers 3 ways to add new requests to the waiting queue. In all cases, the only required parameter is $url. If you have not defined a default callback function via the config() function then a callback must be included with each request.

• get($url,$headers,$options,$callback)
• post($url,$post_data,$headers,$options,$callback)
• request($url,$method,$post_data,$headers,$options,$callback)

Parameters

Depending on the type of request being created, there are 4-6 parameters available to further customize the request.

• $url is a string that contains the URL that should be queried.
• $method is a string that specifies what type of request this should be - 'GET' or 'POST'.
• $post_data contains the CURLOPT_POSTFIELDS formatted data to be sent to the remote host.
• $headers is an array of CURLOPT_HTTPHEADER formatted header fields to be sent to the remote host.
• $options is an array of additional CURLOPT $key => $value pairs to further customize each request.
• $callback is the function to be called, when data has been returned, in the PHP callable format. See below for more details.

Callback Functions

CurlQueue returns data from each request through a user defined callback function. A default callback function can be set via the config() function or a callback can be included with each request. Callbacks included with a request overrite the default callback, if one exists.

Functions must be formatted according to the PHP callable type specifications (http://php.net/manual/en/language.types.callable.php). Typically, callback functions will be formatted in one of the following ways.

• Static Function: $callback = "myfunctionname"
• Static Class Method: $callback = array("myclass","method_name_in_myclass")
• Static Class Method: $callback = "myclass::method_name_in_myclass"
• Object Method: $callback = array($myclass,"method_name_in_myclass")

The provided callback must have two parameters - $output and $info, in that order. $output contains the raw output from the curl request and $info contains an array of information about the request from Curl.

Please note that a callback is optional when only a single request has been added. The $output will be returned via the execute() function in this case.

Running Requests

Once all requests have been created and are ready to be executed, you should call the execute() method. This method will return one of the following.

• TRUE returned when all requests have been processed succedfully.
• FALSE returned when all requests have NOT been processed, possibly because of bad config values.
• $output is the raw output from a single request. This will only be returned when a single request has been added.

Legal

Copyright 2011 Matthew Colf mattcolf@mattcolf.com

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.