queue

Documentation

Index

• type InMemoryQueueStorage
  • func (q *InMemoryQueueStorage) AddRequest(r []byte) error
  • func (q *InMemoryQueueStorage) GetRequest() ([]byte, error)
  • func (q *InMemoryQueueStorage) Init() error
  • func (q *InMemoryQueueStorage) QueueSize() (int, error)
• type Queue
  • func New(threads int, s Storage) (*Queue, error)
  • func (q *Queue) AddRequest(r *colly.Request) error
  • func (q *Queue) AddURL(URL string) error
  • func (q *Queue) IsEmpty() bool
  • func (q *Queue) Run(c *colly.Collector) error
  • func (q *Queue) Size() (int, error)
• type Storage

Types

type InMemoryQueueStorage

type InMemoryQueueStorage struct {
	// MaxSize defines the capacity of the queue.
	// New requests are discarded if the queue size reaches MaxSize
	MaxSize int
	// contains filtered or unexported fields
}

InMemoryQueueStorage is the default implementation of the Storage interface. InMemoryQueueStorage holds the request queue in memory.

func (*InMemoryQueueStorage) AddRequest

func (q *InMemoryQueueStorage) AddRequest(r []byte) error

AddRequest implements Storage.AddRequest() function

func (*InMemoryQueueStorage) GetRequest

func (q *InMemoryQueueStorage) GetRequest() ([]byte, error)

GetRequest implements Storage.GetRequest() function

func (*InMemoryQueueStorage) Init

func (q *InMemoryQueueStorage) Init() error

Init implements Storage.Init() function

func (*InMemoryQueueStorage) QueueSize

func (q *InMemoryQueueStorage) QueueSize() (int, error)

QueueSize implements Storage.QueueSize() function

type Queue

type Queue struct {
	// Threads defines the number of consumer threads
	Threads int
	// contains filtered or unexported fields
}

Queue is a request queue which uses a Collector to consume requests in multiple threads

func New

func New(threads int, s Storage) (*Queue, error)

New creates a new queue with a Storage specified in argument A standard InMemoryQueueStorage is used if Storage argument is nil.

func (*Queue) AddRequest

func (q *Queue) AddRequest(r *colly.Request) error

AddRequest adds a new Request to the queue

func (*Queue) AddURL

func (q *Queue) AddURL(URL string) error

AddURL adds a new URL to the queue

func (*Queue) IsEmpty

func (q *Queue) IsEmpty() bool

IsEmpty returns true if the queue is empty

func (*Queue) Run

func (q *Queue) Run(c *colly.Collector) error

Run starts consumer threads and calls the Collector to perform requests. Run blocks while the queue has active requests The given Storage must not be used directly while Run blocks.

func (*Queue) Size

func (q *Queue) Size() (int, error)

Size returns the size of the queue

type Storage

type Storage interface {
	// Init initializes the storage
	Init() error
	// AddRequest adds a serialized request to the queue
	AddRequest([]byte) error
	// GetRequest pops the next request from the queue
	// or returns error if the queue is empty
	GetRequest() ([]byte, error)
	// QueueSize returns with the size of the queue
	QueueSize() (int, error)
}

Storage is the interface of the queue's storage backend Storage must be concurrently safe for multiple goroutines.