From 349f3444e64ed0ddf22bfef3c04ceab46bf8499d Mon Sep 17 00:00:00 2001
From: Pavel Feldman <pavel.feldman@gmail.com>
Date: Thu, 7 Oct 2021 18:25:02 -0800
Subject: [PATCH] browser(webkit): dedupe screencast frames (#9386)

---
 browser_patches/webkit/BUILD_NUMBER           |  4 ++--
 browser_patches/webkit/patches/bootstrap.diff | 24 +++++++++++++++----
 2 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/browser_patches/webkit/BUILD_NUMBER b/browser_patches/webkit/BUILD_NUMBER
index aea3e97eff..c27bae9c85 100644
--- a/browser_patches/webkit/BUILD_NUMBER
+++ b/browser_patches/webkit/BUILD_NUMBER
@@ -1,2 +1,2 @@
-1558
-Changed: yurys@chromium.org Tue 05 Oct 2021 03:13:20 PM PDT
+1559
+Changed: pavel.feldman@gmail.com Thu 07 Oct 2021 06:57:27 PM PDT
diff --git a/browser_patches/webkit/patches/bootstrap.diff b/browser_patches/webkit/patches/bootstrap.diff
index 0300ae071c..07c5e4c180 100644
--- a/browser_patches/webkit/patches/bootstrap.diff
+++ b/browser_patches/webkit/patches/bootstrap.diff
@@ -13438,10 +13438,10 @@ index 0000000000000000000000000000000000000000..4ec8b96bbbddf8a7b042f53a8068754a
 +cairo_status_t cairo_image_surface_write_to_jpeg_mem(cairo_surface_t *sfc, unsigned char **data, size_t *len, int quality);
 diff --git a/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp
 new file mode 100644
-index 0000000000000000000000000000000000000000..20122bd89c3ba0ec4ff878ac895bddd497cc9789
+index 0000000000000000000000000000000000000000..9a1547d6ad27f58d8276b657c6c7190ebc6b75dc
 --- /dev/null
 +++ b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.cpp
-@@ -0,0 +1,269 @@
+@@ -0,0 +1,284 @@
 +/*
 + * Copyright (C) 2020 Microsoft Corporation.
 + *
@@ -13476,6 +13476,7 @@ index 0000000000000000000000000000000000000000..20122bd89c3ba0ec4ff878ac895bddd4
 +#include "WebPageInspectorController.h"
 +#include "WebPageProxy.h"
 +#include "WebsiteDataStore.h"
++#include <pal/crypto/CryptoDigest.h>
 +#include <JavaScriptCore/InspectorFrontendRouter.h>
 +#include <WebCore/NotImplemented.h>
 +#include <wtf/RunLoop.h>
@@ -13534,6 +13535,20 @@ index 0000000000000000000000000000000000000000..20122bd89c3ba0ec4ff878ac895bddd4
 +    if (m_encoder)
 +        m_encoder->encodeFrame(surface, m_page.drawingArea()->size());
 +    if (m_screencast) {
++
++        {
++            // Do not send the same frame over and over.
++            unsigned char *data = cairo_image_surface_get_data(surface);
++            int stride = cairo_image_surface_get_stride(surface);
++            int height = cairo_image_surface_get_height(surface);
++            auto cryptoDigest = PAL::CryptoDigest::create(PAL::CryptoDigest::Algorithm::SHA_1);
++            cryptoDigest->addBytes(data, stride * height);
++            auto digest = cryptoDigest->computeHash();
++            if (m_lastFrameDigest == digest)
++                return;
++            m_lastFrameDigest = digest;
++        }
++
 +        if (m_screencastFramesInFlight > kMaxFramesInFlight)
 +            return;
 +        // Scale image to fit width / height
@@ -13713,10 +13728,10 @@ index 0000000000000000000000000000000000000000..20122bd89c3ba0ec4ff878ac895bddd4
 +} // namespace WebKit
 diff --git a/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h
 new file mode 100644
-index 0000000000000000000000000000000000000000..8f2795dbf1323dd8d5f986f18e6fe16431dd7f70
+index 0000000000000000000000000000000000000000..a45b32a1c839cf019fcece2f950e595d89d93fa7
 --- /dev/null
 +++ b/Source/WebKit/UIProcess/Inspector/Agents/InspectorScreencastAgent.h
-@@ -0,0 +1,96 @@
+@@ -0,0 +1,97 @@
 +/*
 + * Copyright (C) 2020 Microsoft Corporation.
 + *
@@ -13800,6 +13815,7 @@ index 0000000000000000000000000000000000000000..8f2795dbf1323dd8d5f986f18e6fe164
 +    std::unique_ptr<Inspector::ScreencastFrontendDispatcher> m_frontendDispatcher;
 +    Ref<Inspector::ScreencastBackendDispatcher> m_backendDispatcher;
 +    WebPageProxy& m_page;
++    Vector<uint8_t> m_lastFrameDigest;
 +    RefPtr<ScreencastEncoder> m_encoder;
 +    bool m_screencast = false;
 +    bool m_framesAreGoing = false;