From b1e3176f9f46b6126a93437764eef6914d7f23e5 Mon Sep 17 00:00:00 2001
From: Idan Horowitz <idan.horowitz@gmail.com>
Date: Sat, 13 Mar 2021 23:40:10 +0200
Subject: [PATCH] LibCompress: Replace goto with simple recursion in
 DeflateCompressor

This is just a bit easier on the eyes :^)
---
 Userland/Libraries/LibCompress/Deflate.cpp | 7 ++-----
 Userland/Libraries/LibCompress/Deflate.h   | 2 +-
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/Userland/Libraries/LibCompress/Deflate.cpp b/Userland/Libraries/LibCompress/Deflate.cpp
index b2bb4d0475..cf6115956c 100644
--- a/Userland/Libraries/LibCompress/Deflate.cpp
+++ b/Userland/Libraries/LibCompress/Deflate.cpp
@@ -578,15 +578,13 @@ ALWAYS_INLINE u8 DeflateCompressor::distance_to_base(u16 distance)
 }
 
 template<size_t Size>
-void DeflateCompressor::generate_huffman_lengths(Array<u8, Size>& lengths, const Array<u16, Size>& frequencies, size_t max_bit_length)
+void DeflateCompressor::generate_huffman_lengths(Array<u8, Size>& lengths, const Array<u16, Size>& frequencies, size_t max_bit_length, u16 frequency_cap)
 {
     VERIFY((1u << max_bit_length) >= Size);
     u16 heap_keys[Size]; // Used for O(n) heap construction
     u16 heap_values[Size];
 
     u16 huffman_links[Size * 2 + 1] = { 0 };
-    u16 frequency_cap = UINT16_MAX;
-try_again:
     size_t non_zero_freqs = 0;
     for (size_t i = 0; i < Size; i++) {
         auto frequency = frequencies[i];
@@ -644,8 +642,7 @@ try_again:
 
         if (bit_length > max_bit_length) {
             VERIFY(frequency_cap != 1);
-            frequency_cap /= 2;
-            goto try_again; // FIXME: gotos are ugly, but i cant think of a good way to flatten this
+            return generate_huffman_lengths(lengths, frequencies, max_bit_length, frequency_cap / 2);
         }
 
         lengths[i] = bit_length;
diff --git a/Userland/Libraries/LibCompress/Deflate.h b/Userland/Libraries/LibCompress/Deflate.h
index 05d0f3cfe0..b933f60fcb 100644
--- a/Userland/Libraries/LibCompress/Deflate.h
+++ b/Userland/Libraries/LibCompress/Deflate.h
@@ -188,7 +188,7 @@ private:
     };
     static u8 distance_to_base(u16 distance);
     template<size_t Size>
-    static void generate_huffman_lengths(Array<u8, Size>& lengths, const Array<u16, Size>& frequencies, size_t max_bit_length);
+    static void generate_huffman_lengths(Array<u8, Size>& lengths, const Array<u16, Size>& frequencies, size_t max_bit_length, u16 frequency_cap = UINT16_MAX);
     size_t huffman_block_length(const Array<u8, max_huffman_literals>& literal_bit_lengths, const Array<u8, max_huffman_distances>& distance_bit_lengths);
     void write_huffman(const CanonicalCode& literal_code, const CanonicalCode& distance_code);
     static size_t encode_huffman_lengths(const Array<u8, max_huffman_literals + max_huffman_distances>& lengths, size_t lengths_count, Array<code_length_symbol, max_huffman_literals + max_huffman_distances>& encoded_lengths);