package pdu

import (
    "sync"
)

type BufferPoolManager struct {
    pools map[int]*sync.Pool
    mu    sync.Mutex
}

func NewBufferPoolManager() *BufferPoolManager {
    return &BufferPoolManager{
        pools: make(map[int]*sync.Pool),
    }
}

func (bpm *BufferPoolManager) GetBuffer(size int) *([]uint8) {
    bpm.mu.Lock()
    pool, exists := bpm.pools[size]
    if !exists {
        pool = &sync.Pool{
            New: func() interface{} {
                buf := make([]uint8, size)
                return &buf
            },
        }
        bpm.pools[size] = pool
    }
    bpm.mu.Unlock()
    return pool.Get().(*[]uint8)
}

func (bpm *BufferPoolManager) PutBuffer(buf *([]uint8)) {
    size := len(*buf)
    bpm.mu.Lock()
    pool, exists := bpm.pools[size]
    if !exists {
        bpm.mu.Unlock()
        return
    }
    bpm.mu.Unlock()
    
    // Reset buffer (optional)
    for i := range *buf {
        (*buf)[i] = 0
    }
    pool.Put(buf)
}