bounded_error_queue_impl.go

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package goethe

import (
	"sync"
)

// BoundedErrorQueue provides an error queue with a maximum size
type BoundedErrorQueue struct {
	mux sync.Mutex

	capacity uint32
	queue    []ErrorInformation
}

// NewBoundedErrorQueue creates a new error queue with the given capacity
func NewBoundedErrorQueue(userCapacity uint32) ErrorQueue {
	return &BoundedErrorQueue{
		capacity: userCapacity,
		queue:    make([]ErrorInformation, 0),
	}
}

// Enqueue adds an error to the error queue.  If the queue is
// at capacity should return ErrAtCapacity.  All other errors
// will be ignored
func (errorq *BoundedErrorQueue) Enqueue(info ErrorInformation) error {
	if info == nil {
		return nil
	}

	errorq.mux.Lock()
	defer errorq.mux.Unlock()

	if uint32(len(errorq.queue)) >= errorq.capacity {
		return ErrAtCapacity
	}

	errorq.queue = append(errorq.queue, info)

	return nil
}

// Dequeue removes ErrorInformation from the pools
// error queue.  If there were no errors on the queue
// the second return value is false
func (errorq *BoundedErrorQueue) Dequeue() (ErrorInformation, bool) {
	errorq.mux.Lock()
	defer errorq.mux.Unlock()

	if len(errorq.queue) <= 0 {
		return nil, false
	}

	retVal := errorq.queue[0]
	errorq.queue = errorq.queue[1:]

	return retVal, true
}

// GetSize returns the number of items currently in the queue
func (errorq *BoundedErrorQueue) GetSize() int {
	errorq.mux.Lock()
	defer errorq.mux.Unlock()

	return len(errorq.queue)
}

// IsEmpty Returns true if this queue is currently empty
func (errorq *BoundedErrorQueue) IsEmpty() bool {
	return errorq.GetSize() == 0
}