Properly implement buffer pool

It wasn't reusing buffers, idiot idiot idiot...

pdu/bufpool.go

@@ -2,12 +2,20 @@ package pdu
 
 import (
 	"bytes"
+	"log"
 	"sync"
 )
 
 type BufferPoolManager struct {
 	pools map[int]*sync.Pool
 	mu    sync.RWMutex
+	debug bool
+}
+
+func (bpm *BufferPoolManager) logf(format string, args ...interface{}) {
+	if bpm.debug {
+		log.Printf(format, args...)
+	}
 }
 
 func NewBufferPoolManager() *BufferPoolManager {
@@ -26,9 +34,13 @@ func (bpm *BufferPoolManager) Get(size int) *bytes.Buffer {
 		// Double-check if another goroutine added the pool while we were waiting
 		pool, exists = bpm.pools[size]
 		if !exists {
+			bpm.logf("Creating new pool for size %d\n", size)
 			pool = &sync.Pool{
 				New: func() interface{} {
-					return bytes.NewBuffer(make([]byte, size))
+					bpm.logf("Creating new buffer of size %d\n", size)
+					buf := bytes.NewBuffer(make([]byte, size))
+					buf.Reset()
+					return buf
 				},
 			}
 			bpm.pools[size] = pool
@@ -36,19 +48,23 @@ func (bpm *BufferPoolManager) Get(size int) *bytes.Buffer {
 		bpm.mu.Unlock()
 	}
 
-	return pool.Get().(*bytes.Buffer);
+	buf := pool.Get().(*bytes.Buffer)
+	bpm.logf("Returning buffer of size %d: %p\n", buf.Cap(), buf)
+	return buf
 }
 
 func (bpm *BufferPoolManager) Put(buf *bytes.Buffer) {
-	size := buf.Len()
+	size := buf.Cap()
 	bpm.mu.RLock()
 	pool, exists := bpm.pools[size]
 	bpm.mu.RUnlock()
 
 	if !exists {
+		bpm.logf("Cannot return %p, No pool for size %d\n", buf, size)
 		return
 	}
 
 	buf.Reset()
 	pool.Put(buf)
+	bpm.logf("Returned buffer of size %d: %p\n", size, buf)
 }