From f4afee4278f681ad788f781e24df73ab22baa1f4 Mon Sep 17 00:00:00 2001
From: Tim Schumacher <timschumi@gmx.de>
Date: Tue, 3 Jan 2023 18:59:27 +0100
Subject: [PATCH] LibCompress: Switch `DeflateCompressor` to a fallible
 constructor

---
 Userland/Libraries/LibCompress/Deflate.cpp | 17 ++++++++++++-----
 Userland/Libraries/LibCompress/Deflate.h   |  4 +++-
 Userland/Libraries/LibCompress/Gzip.cpp    |  6 +++---
 Userland/Libraries/LibCompress/Zlib.cpp    |  2 +-
 4 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/Userland/Libraries/LibCompress/Deflate.cpp b/Userland/Libraries/LibCompress/Deflate.cpp
index cc0f786913..5beeb55ea6 100644
--- a/Userland/Libraries/LibCompress/Deflate.cpp
+++ b/Userland/Libraries/LibCompress/Deflate.cpp
@@ -438,10 +438,17 @@ ErrorOr<void> DeflateDecompressor::decode_codes(CanonicalCode& literal_code, Opt
     return {};
 }
 
-DeflateCompressor::DeflateCompressor(Core::Stream::Handle<Core::Stream::Stream> stream, CompressionLevel compression_level)
+ErrorOr<NonnullOwnPtr<DeflateCompressor>> DeflateCompressor::construct(Core::Stream::Handle<Core::Stream::Stream> stream, CompressionLevel compression_level)
+{
+    auto bit_stream = TRY(Core::Stream::LittleEndianOutputBitStream::construct(move(stream)));
+    auto deflate_compressor = TRY(adopt_nonnull_own_or_enomem(new (nothrow) DeflateCompressor(move(bit_stream), compression_level)));
+    return deflate_compressor;
+}
+
+DeflateCompressor::DeflateCompressor(NonnullOwnPtr<Core::Stream::LittleEndianOutputBitStream> stream, CompressionLevel compression_level)
     : m_compression_level(compression_level)
     , m_compression_constants(compression_constants[static_cast<int>(m_compression_level)])
-    , m_output_stream(Core::Stream::LittleEndianOutputBitStream::construct(move(stream)).release_value_but_fixme_should_propagate_errors())
+    , m_output_stream(move(stream))
 {
     m_symbol_frequencies.fill(0);
     m_distance_frequencies.fill(0);
@@ -1002,10 +1009,10 @@ ErrorOr<void> DeflateCompressor::final_flush()
 ErrorOr<ByteBuffer> DeflateCompressor::compress_all(ReadonlyBytes bytes, CompressionLevel compression_level)
 {
     auto output_stream = TRY(try_make<Core::Stream::AllocatingMemoryStream>());
-    DeflateCompressor deflate_stream { Core::Stream::Handle<Core::Stream::Stream>(*output_stream), compression_level };
+    auto deflate_stream = TRY(DeflateCompressor::construct(Core::Stream::Handle<Core::Stream::Stream>(*output_stream), compression_level));
 
-    TRY(deflate_stream.write_entire_buffer(bytes));
-    TRY(deflate_stream.final_flush());
+    TRY(deflate_stream->write_entire_buffer(bytes));
+    TRY(deflate_stream->final_flush());
 
     auto buffer = TRY(ByteBuffer::create_uninitialized(output_stream->used_buffer_size()));
     TRY(output_stream->read_entire_buffer(buffer));
diff --git a/Userland/Libraries/LibCompress/Deflate.h b/Userland/Libraries/LibCompress/Deflate.h
index 8cdfaee287..22b60730df 100644
--- a/Userland/Libraries/LibCompress/Deflate.h
+++ b/Userland/Libraries/LibCompress/Deflate.h
@@ -139,7 +139,7 @@ public:
         BEST // WARNING: this one can take an unreasonable amount of time!
     };
 
-    DeflateCompressor(Core::Stream::Handle<Core::Stream::Stream>, CompressionLevel = CompressionLevel::GOOD);
+    static ErrorOr<NonnullOwnPtr<DeflateCompressor>> construct(Core::Stream::Handle<Core::Stream::Stream>, CompressionLevel = CompressionLevel::GOOD);
     ~DeflateCompressor();
 
     virtual ErrorOr<Bytes> read(Bytes) override;
@@ -152,6 +152,8 @@ public:
     static ErrorOr<ByteBuffer> compress_all(ReadonlyBytes bytes, CompressionLevel = CompressionLevel::GOOD);
 
 private:
+    DeflateCompressor(NonnullOwnPtr<Core::Stream::LittleEndianOutputBitStream>, CompressionLevel = CompressionLevel::GOOD);
+
     Bytes pending_block() { return { m_rolling_window + block_size, block_size }; }
 
     // LZ77 Compression
diff --git a/Userland/Libraries/LibCompress/Gzip.cpp b/Userland/Libraries/LibCompress/Gzip.cpp
index 5675b30eb4..0a6f7dd978 100644
--- a/Userland/Libraries/LibCompress/Gzip.cpp
+++ b/Userland/Libraries/LibCompress/Gzip.cpp
@@ -194,9 +194,9 @@ ErrorOr<size_t> GzipCompressor::write(ReadonlyBytes bytes)
     header.extra_flags = 3;      // DEFLATE sets 2 for maximum compression and 4 for minimum compression
     header.operating_system = 3; // unix
     TRY(m_output_stream->write_entire_buffer({ &header, sizeof(header) }));
-    DeflateCompressor compressed_stream { Core::Stream::Handle(*m_output_stream) };
-    TRY(compressed_stream.write_entire_buffer(bytes));
-    TRY(compressed_stream.final_flush());
+    auto compressed_stream = TRY(DeflateCompressor::construct(Core::Stream::Handle(*m_output_stream)));
+    TRY(compressed_stream->write_entire_buffer(bytes));
+    TRY(compressed_stream->final_flush());
     Crypto::Checksum::CRC32 crc32;
     crc32.update(bytes);
     LittleEndian<u32> digest = crc32.digest();
diff --git a/Userland/Libraries/LibCompress/Zlib.cpp b/Userland/Libraries/LibCompress/Zlib.cpp
index 83924b8d5d..c731191e9b 100644
--- a/Userland/Libraries/LibCompress/Zlib.cpp
+++ b/Userland/Libraries/LibCompress/Zlib.cpp
@@ -83,7 +83,7 @@ ErrorOr<NonnullOwnPtr<ZlibCompressor>> ZlibCompressor::construct(Core::Stream::H
 ZlibCompressor::ZlibCompressor(Core::Stream::Handle<Core::Stream::Stream> stream, ZlibCompressionLevel compression_level)
     : m_output_stream(move(stream))
     // FIXME: Find a way to compress with Deflate's "Best" compression level.
-    , m_compressor(make<DeflateCompressor>(Core::Stream::Handle(*m_output_stream), static_cast<DeflateCompressor::CompressionLevel>(compression_level)))
+    , m_compressor(DeflateCompressor::construct(Core::Stream::Handle(*m_output_stream), static_cast<DeflateCompressor::CompressionLevel>(compression_level)).release_value_but_fixme_should_propagate_errors())
 {
 }