From 8b8af1a9d93353a0776f4a4f891eef8526a1e160 Mon Sep 17 00:00:00 2001
From: Bananymous <oskari.alaranta@bananymous.com>
Date: Sat, 28 Feb 2026 14:20:52 +0200
Subject: [PATCH] Kernel: Rewrite pipes using the new ring buffer

---
 kernel/include/kernel/FS/Pipe.h |  7 +++--
 kernel/kernel/FS/Pipe.cpp       | 47 ++++++++++-----------------------
 2 files changed, 17 insertions(+), 37 deletions(-)

diff --git a/kernel/include/kernel/FS/Pipe.h b/kernel/include/kernel/FS/Pipe.h
index 82f497dd..a4ad4b1b 100644
--- a/kernel/include/kernel/FS/Pipe.h
+++ b/kernel/include/kernel/FS/Pipe.h
@@ -2,6 +2,7 @@
 
 #include <BAN/Array.h>
 #include <kernel/FS/Inode.h>
+#include <kernel/Memory/ByteRingBuffer.h>
 #include <kernel/ThreadBlocker.h>
 
 namespace Kernel
@@ -38,7 +39,7 @@ namespace Kernel
 		virtual BAN::ErrorOr<size_t> write_impl(off_t, BAN::ConstByteSpan) override;
 		virtual BAN::ErrorOr<void> fsync_impl() final override { return {}; }
 
-		virtual bool can_read_impl() const override { return m_buffer_size > 0; }
+		virtual bool can_read_impl() const override { return !m_buffer->empty(); }
 		virtual bool can_write_impl() const override { return true; }
 		virtual bool has_error_impl() const override { return m_reading_count == 0; }
 		virtual bool has_hungup_impl() const override { return m_writing_count == 0; }
@@ -54,9 +55,7 @@ namespace Kernel
 		timespec m_ctime {};
 		ThreadBlocker m_thread_blocker;
 
-		BAN::Array<uint8_t, PAGE_SIZE> m_buffer;
-		BAN::Atomic<size_t> m_buffer_size { 0 };
-		size_t m_buffer_tail { 0 };
+		BAN::UniqPtr<ByteRingBuffer> m_buffer;
 
 		BAN::Atomic<uint32_t> m_writing_count { 1 };
 		BAN::Atomic<uint32_t> m_reading_count { 1 };
diff --git a/kernel/kernel/FS/Pipe.cpp b/kernel/kernel/FS/Pipe.cpp
index c3823b7e..52a142be 100644
--- a/kernel/kernel/FS/Pipe.cpp
+++ b/kernel/kernel/FS/Pipe.cpp
@@ -9,12 +9,16 @@
 namespace Kernel
 {
 
+	static constexpr size_t s_pipe_buffer_size = 0x10000;
+
 	BAN::ErrorOr<BAN::RefPtr<Inode>> Pipe::create(const Credentials& credentials)
 	{
-		Pipe* pipe = new Pipe(credentials);
-		if (pipe == nullptr)
+		auto* pipe_ptr = new Pipe(credentials);
+		if (pipe_ptr == nullptr)
 			return BAN::Error::from_errno(ENOMEM);
-		return BAN::RefPtr<Inode>::adopt(pipe);
+		auto pipe = BAN::RefPtr<Pipe>::adopt(pipe_ptr);
+		pipe->m_buffer = TRY(ByteRingBuffer::create(s_pipe_buffer_size));
+		return BAN::RefPtr<Inode>(pipe);
 	}
 
 	Pipe::Pipe(const Credentials& credentials)
@@ -69,27 +73,16 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::read_impl(off_t, BAN::ByteSpan buffer)
 	{
-		while (m_buffer_size == 0)
+		while (m_buffer->empty())
 		{
 			if (m_writing_count == 0)
 				return 0;
 			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &m_mutex));
 		}
 
-		const size_t to_copy = BAN::Math::min<size_t>(buffer.size(), m_buffer_size);
-
-		if (m_buffer_tail + to_copy <= m_buffer.size())
-			memcpy(buffer.data(), m_buffer.data() + m_buffer_tail, to_copy);
-		else
-		{
-			const size_t before_wrap = m_buffer.size() - m_buffer_tail;
-			const size_t after_wrap = to_copy - before_wrap;
-			memcpy(buffer.data(), m_buffer.data() + m_buffer_tail, before_wrap);
-			memcpy(buffer.data() + before_wrap, m_buffer.data(), after_wrap);
-		}
-
-		m_buffer_tail = (m_buffer_tail + to_copy) % m_buffer.size();
-		m_buffer_size -= to_copy;
+		const size_t to_copy = BAN::Math::min<size_t>(buffer.size(), m_buffer->size());
+		memcpy(buffer.data(), m_buffer->get_data().data(), to_copy);
+		m_buffer->pop(to_copy);
 
 		m_atime = SystemTimer::get().real_time();
 
@@ -102,7 +95,7 @@ namespace Kernel
 
 	BAN::ErrorOr<size_t> Pipe::write_impl(off_t, BAN::ConstByteSpan buffer)
 	{
-		while (m_buffer_size >= m_buffer.size())
+		while (m_buffer->full())
 		{
 			if (m_reading_count == 0)
 			{
@@ -112,20 +105,8 @@ namespace Kernel
 			TRY(Thread::current().block_or_eintr_indefinite(m_thread_blocker, &m_mutex));
 		}
 
-		const size_t to_copy = BAN::Math::min(buffer.size(), m_buffer.size() - m_buffer_size);
-		const size_t buffer_head = (m_buffer_tail + m_buffer_size) % m_buffer.size();
-
-		if (buffer_head + to_copy <= m_buffer.size())
-			memcpy(m_buffer.data() + buffer_head, buffer.data(), to_copy);
-		else
-		{
-			const size_t before_wrap = m_buffer.size() - buffer_head;
-			const size_t after_wrap = to_copy - before_wrap;
-			memcpy(m_buffer.data() + buffer_head, buffer.data(), before_wrap);
-			memcpy(m_buffer.data(), buffer.data() + before_wrap, after_wrap);
-		}
-
-		m_buffer_size += to_copy;
+		const size_t to_copy = BAN::Math::min(buffer.size(), m_buffer->free());
+		m_buffer->push(buffer.slice(0, to_copy));
 
 		timespec current_time = SystemTimer::get().real_time();
 		m_mtime = current_time;