From 322e4466d1dedfc210f3f671f9a3411da69c5dad Mon Sep 17 00:00:00 2001
From: WeebDataHoarder <57538841+WeebDataHoarder@users.noreply.github.com>
Date: Fri, 11 Nov 2022 13:46:27 +0100
Subject: [PATCH] libdav1d: optimize allocations with a sync.Pool

---
 decoder/libdav1d/libdav1d.go | 40 ++++++++++++++++++++++++++++++++----
 1 file changed, 36 insertions(+), 4 deletions(-)

diff --git a/decoder/libdav1d/libdav1d.go b/decoder/libdav1d/libdav1d.go
index 1df5234..2d33349 100644
--- a/decoder/libdav1d/libdav1d.go
+++ b/decoder/libdav1d/libdav1d.go
@@ -13,6 +13,8 @@ import (
 	"git.gammaspectra.live/S.O.N.G/Ignite/utilities"
 	"git.gammaspectra.live/S.O.N.G/Ignite/utilities/ivfreader"
 	"io"
+	"runtime"
+	"sync"
 	"sync/atomic"
 	"unsafe"
 )
@@ -29,6 +31,8 @@ type Decoder struct {
 	ctx      *C.Dav1dContext
 	picture  C.Dav1dPicture
 	data     C.Dav1dData
+
+	bufPool sync.Pool
 }
 
 var dav1dVersion = fmt.Sprintf("dav1d %s", C.GoString(C.dav1d_version()))
@@ -208,12 +212,25 @@ func (d *Decoder) pictureToFrame() (frame.Frame, error) {
 
 		}
 
-		buf := make([]byte, len(yData)+len(uData)+len(vData))
+		n := len(yData) + len(uData) + len(vData)
+
+		var buf []byte
+		if b := d.bufPool.Get(); b != nil && len(b.([]byte)) == n {
+			buf = b.([]byte)
+		} else {
+			buf = make([]byte, n)
+		}
+
 		copy(buf, yData)
 		copy(buf[len(yData):], uData)
 		copy(buf[len(yData)+len(uData):], vData)
 
-		return frame.NewUint16FrameFromBytes(properties, int64(d.picture.m.timestamp), buf)
+		if f, err := frame.NewUint16FrameFromBytes(properties, int64(d.picture.m.timestamp), buf); err != nil {
+			return nil, err
+		} else {
+			d.bufPool.Put(buf)
+			return f, nil
+		}
 	} else {
 		yData := unsafe.Slice((*byte)(d.picture.data[planeY]), properties.Height*properties.Width)
 		var uData, vData []byte
@@ -223,12 +240,27 @@ func (d *Decoder) pictureToFrame() (frame.Frame, error) {
 			vData = unsafe.Slice((*byte)(d.picture.data[planeV]), chromaHeight*chromaWidth)
 		}
 
-		buf := make([]byte, len(yData)+len(uData)+len(vData))
+		n := len(yData) + len(uData) + len(vData)
+
+		var buf []byte
+		if b := d.bufPool.Get(); b != nil && len(b.([]byte)) == n {
+			buf = b.([]byte)
+		} else {
+			buf = make([]byte, n)
+		}
+
 		copy(buf, yData)
 		copy(buf[len(yData):], uData)
 		copy(buf[len(yData)+len(uData):], vData)
 
-		return frame.NewUint8FrameFromBytes(properties, int64(d.picture.m.timestamp), buf)
+		if f, err := frame.NewUint8FrameFromBytes(properties, int64(d.picture.m.timestamp), buf); err != nil {
+			return nil, err
+		} else {
+			runtime.SetFinalizer(f, func(frameUint8 *frame.FrameUint8) {
+				d.bufPool.Put(buf)
+			})
+			return f, nil
+		}
 	}
 }