[#276] Merge repo with frostfs-api-go

Signed-off-by: Pavel Pogodaev <p.pogodaev@yadro.com>

api/util/pool/buffer.go

@@ -0,0 +1,54 @@
+package pool
+
+import (
+	"sync"
+)
+
+// Buffer contains a byte slice.
+type Buffer struct {
+	Data []byte
+}
+
+// BufferPool manages a pool of Buffers.
+type BufferPool struct {
+	poolSliceSize uint32 // Size for the buffer slices in the pool.
+	buffersPool   *sync.Pool
+}
+
+// NewBufferPool creates a BufferPool with a specified size.
+func NewBufferPool(poolSliceSize uint32) BufferPool {
+	pool := sync.Pool{
+		New: func() any {
+			return new(Buffer)
+		},
+	}
+	return BufferPool{poolSliceSize: poolSliceSize, buffersPool: &pool}
+}
+
+// Get retrieves a Buffer from the pool or creates a new one if necessary.
+// It ensures the buffer's capacity is at least the specified size.
+func (pool BufferPool) Get(size uint32) *Buffer {
+	result := pool.buffersPool.Get().(*Buffer)
+
+	if cap(result.Data) < int(size) {
+		result.Data = make([]byte, size)
+	} else {
+		result.Data = result.Data[:size]
+	}
+	return result
+}
+
+// Put returns a Buffer to the pool if its capacity does not exceed poolSliceSize.
+func (pool BufferPool) Put(buf *Buffer) {
+	if cap(buf.Data) > int(pool.poolSliceSize) {
+		return
+	}
+
+	buf.Data = buf.Data[:0]
+	pool.buffersPool.Put(buf)
+}
+
+// PoolSliceSize returns the size for buffer slices in the pool.
+func (pool BufferPool) PoolSliceSize() uint32 {
+	return uint32(pool.poolSliceSize)
+}