package buffer

import (
	"github.com/Ehco1996/ehco/internal/constant"
)

// 全局pool
var BufferPool *BytePool

func init() {
	BufferPool = NewBytePool(constant.BUFFER_POOL_SIZE, constant.BUFFER_SIZE)
}

// BytePool implements a leaky pool of []byte in the form of a bounded channel
type BytePool struct {
	c    chan []byte
	size int
}

// NewBytePool creates a new BytePool bounded to the given maxSize, with new
// byte arrays sized based on width.
func NewBytePool(maxSize int, size int) (bp *BytePool) {
	return &BytePool{
		c:    make(chan []byte, maxSize),
		size: size,
	}
}

// Get gets a []byte from the BytePool, or creates a new one if none are available in the pool.
func (bp *BytePool) Get() (b []byte) {
	select {
	case b = <-bp.c:
	// reuse existing buffer
	default:
		// create new buffer
		b = make([]byte, bp.size)
	}
	return
}

// Put returns the given Buffer to the BytePool.
func (bp *BytePool) Put(b []byte) {
	select {
	case bp.c <- b:
		// buffer went back into pool
	default:
		// buffer didn't go back into pool, just discard
	}
}