From 80cb377990a9b6cf8ba65019e71f09a9bf477a7d Mon Sep 17 00:00:00 2001
From: Lucas CHOLLET <lucas.chollet@free.fr>
Date: Fri, 4 Aug 2023 15:48:36 -0400
Subject: [PATCH] LibGfx/JPEGXL: Factorize the code to read symbols from
 distributions

This will soon be used by the LZ77 decoder, so let's avoid some
duplication.
---
 .../LibGfx/ImageFormats/JPEGXLLoader.cpp      | 27 +++++++++++--------
 1 file changed, 16 insertions(+), 11 deletions(-)

diff --git a/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp b/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
index f03f5f1683..e5d9456a33 100644
--- a/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
+++ b/Userland/Libraries/LibGfx/ImageFormats/JPEGXLLoader.cpp
@@ -1208,17 +1208,7 @@ public:
             TODO();
 
         // Read symbol from entropy coded stream using D[clusters[ctx]]
-        u32 token {};
-        TRY(m_distributions.visit(
-            [&](Vector<BrotliCanonicalCode> const& distributions) -> ErrorOr<void> {
-                token = TRY(distributions[m_clusters[context]].read_symbol(stream));
-                return {};
-            },
-            [&](Vector<ANSHistogram> const& distributions) -> ErrorOr<void> {
-                token = TRY(distributions[m_clusters[context]].read_symbol(stream, m_state));
-                return {};
-            }));
-
+        auto const token = TRY(read_symbol(stream, context));
         auto r = TRY(read_uint(stream, m_configs[m_clusters[context]], token));
         return r;
     }
@@ -1276,6 +1266,21 @@ private:
         return config;
     }
 
+    ErrorOr<u32> read_symbol(LittleEndianInputBitStream& stream, u32 context)
+    {
+        u32 token {};
+        TRY(m_distributions.visit(
+            [&](Vector<BrotliCanonicalCode> const& distributions) -> ErrorOr<void> {
+                token = TRY(distributions[m_clusters[context]].read_symbol(stream));
+                return {};
+            },
+            [&](Vector<ANSHistogram> const& distributions) -> ErrorOr<void> {
+                token = TRY(distributions[m_clusters[context]].read_symbol(stream, m_state));
+                return {};
+            }));
+        return token;
+    }
+
     ErrorOr<void> read_pre_clustered_distributions(LittleEndianInputBitStream& stream, u32 num_distrib)
     {
         // C.2.2  Distribution clustering