Userland: Use Buffered<T> in gunzip.

Author: https://github.com/asynts
Commit: 612c1bc84d
Pull-request: https://github.com/SerenityOS/serenity/pull/3405

Libraries/LibCore/FileStream.h

@@ -26,6 +26,7 @@
 
 #pragma once
 
+#include <AK/Buffered.h>
 #include <AK/Stream.h>
 #include <LibCore/File.h>
 
@@ -50,6 +51,18 @@ public:
         return InputFileStream { file_result.value() };
     }
 
+    static Result<Buffered<InputFileStream>, String> open_buffered(StringView filename, IODevice::OpenMode mode = IODevice::OpenMode::ReadOnly, mode_t permissions = 0644)
+    {
+        ASSERT((mode & 0xf) == IODevice::OpenMode::ReadOnly || (mode & 0xf) == IODevice::OpenMode::ReadWrite);
+
+        auto file_result = File::open(filename, mode, permissions);
+
+        if (file_result.is_error())
+            return file_result.error();
+
+        return Buffered<InputFileStream> { file_result.value() };
+    }
+
     size_t read(Bytes bytes) override
     {
         size_t nread = 0;
@@ -145,11 +158,28 @@ public:
         return OutputFileStream { file_result.value() };
     }
 
+    static Result<Buffered<OutputFileStream>, String> open_buffered(StringView filename, IODevice::OpenMode mode = IODevice::OpenMode::WriteOnly, mode_t permissions = 0644)
+    {
+        ASSERT((mode & 0xf) == IODevice::OpenMode::WriteOnly || (mode & 0xf) == IODevice::OpenMode::ReadWrite);
+
+        auto file_result = File::open(filename, mode, permissions);
+
+        if (file_result.is_error())
+            return file_result.error();
+
+        return Buffered<OutputFileStream> { file_result.value() };
+    }
+
     static OutputFileStream stdout()
     {
         return OutputFileStream { Core::File::stdout() };
     }
 
+    static Buffered<OutputFileStream> stdout_buffered()
+    {
+        return Buffered<OutputFileStream> { Core::File::stdout() };
+    }
+
     size_t write(ReadonlyBytes bytes) override
     {
         if (!m_file->write(bytes.data(), bytes.size())) {

Userland/gunzip.cpp

@@ -28,7 +28,7 @@
 #include <LibCore/ArgsParser.h>
 #include <LibCore/FileStream.h>
 
-static void decompress_file(Core::InputFileStream input_stream, Core::OutputFileStream output_stream)
+static void decompress_file(Buffered<Core::InputFileStream>& input_stream, Buffered<Core::OutputFileStream>& output_stream)
 {
     auto gzip_stream = Compress::GzipDecompressor { input_stream };
 
@@ -38,9 +38,6 @@ static void decompress_file(Core::InputFileStream input_stream, Core::OutputFile
         const auto nread = gzip_stream.read({ buffer, sizeof(buffer) });
         output_stream.write_or_error({ buffer, nread });
     }
-
-    input_stream.close();
-    output_stream.close();
 }
 
 int main(int argc, char** argv)
@@ -64,12 +61,13 @@ int main(int argc, char** argv)
         const auto input_filename = filename;
         const auto output_filename = filename.substring_view(0, filename.length() - 3);
 
-        auto input_stream_result = Core::InputFileStream::open(input_filename);
+        auto input_stream_result = Core::InputFileStream::open_buffered(input_filename);
 
         if (write_to_stdout) {
-            decompress_file(input_stream_result.value(), Core::OutputFileStream::stdout());
+            auto stdout = Core::OutputFileStream::stdout_buffered();
+            decompress_file(input_stream_result.value(), stdout);
         } else {
-            auto output_stream_result = Core::OutputFileStream::open(output_filename);
+            auto output_stream_result = Core::OutputFileStream::open_buffered(output_filename);
             decompress_file(input_stream_result.value(), output_stream_result.value());
         }