5 files changed, 56 insertions, 49 deletions

diff --git a/Kernel/DoubleBuffer.cpp b/Kernel/DoubleBuffer.cpp
new file mode 100644
index 0000000000..3937ed2740
--- /dev/null
+++ b/Kernel/DoubleBuffer.cpp
@@ -0,0 +1,27 @@
+#include "DoubleBuffer.h"
+
+void DoubleBuffer::flip()
+{
+    ASSERT(m_read_buffer_index == m_read_buffer->size());
+    swap(m_read_buffer, m_write_buffer);
+    m_write_buffer->clear();
+    m_read_buffer_index = 0;
+}
+
+ssize_t DoubleBuffer::write(const byte* data, size_t size)
+{
+    m_write_buffer->append(data, size);
+    return size;
+}
+
+ssize_t DoubleBuffer::read(byte* data, size_t size)
+{
+    if (m_read_buffer_index >= m_read_buffer->size() && !m_write_buffer->isEmpty())
+        flip();
+    if (m_read_buffer_index >= m_read_buffer->size())
+        return 0;
+    ssize_t nread = min(m_read_buffer->size() - m_read_buffer_index, size);
+    memcpy(data, m_read_buffer->data() + m_read_buffer_index, nread);
+    m_read_buffer_index += nread;
+    return nread;
+}
diff --git a/Kernel/DoubleBuffer.h b/Kernel/DoubleBuffer.h
new file mode 100644
index 0000000000..46e0e56da3
--- /dev/null
+++ b/Kernel/DoubleBuffer.h
@@ -0,0 +1,27 @@
+#pragma once
+
+#include <AK/Types.h>
+#include <AK/Vector.h>
+
+class DoubleBuffer {
+public:
+    DoubleBuffer()
+        : m_write_buffer(&m_buffer1)
+        , m_read_buffer(&m_buffer2)
+    {
+    }
+
+    ssize_t write(const byte*, size_t);
+    ssize_t read(byte*, size_t);
+
+    bool is_empty() const { return m_read_buffer_index >= m_read_buffer->size() && m_write_buffer->isEmpty(); }
+
+private:
+    void flip();
+
+    Vector<byte>* m_write_buffer { nullptr };
+    Vector<byte>* m_read_buffer { nullptr };
+    Vector<byte> m_buffer1;
+    Vector<byte> m_buffer2;
+    size_t m_read_buffer_index { 0 };
+};
diff --git a/Kernel/Makefile b/Kernel/Makefile
index 6195ec00cb..68628d2700 100644
--- a/Kernel/Makefile
+++ b/Kernel/Makefile
@@ -21,6 +21,7 @@ KERNEL_OBJS = \
        VirtualConsole.o \
        FIFO.o \
        Scheduler.o \
+       DoubleBuffer.o \
        ELFImage.o \
        ELFLoader.o
 
diff --git a/Kernel/TTY.cpp b/Kernel/TTY.cpp
index 775250bc2a..11f78a1a50 100644
--- a/Kernel/TTY.cpp
+++ b/Kernel/TTY.cpp
@@ -6,32 +6,6 @@
 
 //#define TTY_DEBUG
 
-void DoubleBuffer::flip()
-{
-    ASSERT(m_read_buffer_index == m_read_buffer->size());
-    swap(m_read_buffer, m_write_buffer);
-    m_write_buffer->clear();
-    m_read_buffer_index = 0;
-}
-
-ssize_t DoubleBuffer::write(const byte* data, size_t size)
-{
-    m_write_buffer->append(data, size);
-    return size;
-}
-
-ssize_t DoubleBuffer::read(byte* data, size_t size)
-{
-    if (m_read_buffer_index >= m_read_buffer->size() && !m_write_buffer->isEmpty())
-        flip();
-    if (m_read_buffer_index >= m_read_buffer->size())
-        return 0;
-    ssize_t nread = min(m_read_buffer->size() - m_read_buffer_index, size);
-    memcpy(data, m_read_buffer->data() + m_read_buffer_index, nread);
-    m_read_buffer_index += nread;
-    return nread;
-}
-
 TTY::TTY(unsigned major, unsigned minor)
     : CharacterDevice(major, minor)
 {
diff --git a/Kernel/TTY.h b/Kernel/TTY.h
index a5e6385489..eb1f18d74f 100644
--- a/Kernel/TTY.h
+++ b/Kernel/TTY.h
@@ -1,33 +1,11 @@
 #pragma once
 
+#include "DoubleBuffer.h"
 #include <VirtualFileSystem/CharacterDevice.h>
 #include <VirtualFileSystem/UnixTypes.h>
 
 class Process;
 
-class DoubleBuffer {
-public:
-    DoubleBuffer()
-        : m_write_buffer(&m_buffer1)
-        , m_read_buffer(&m_buffer2)
-    {
-    }
-
-    ssize_t write(const byte*, size_t);
-    ssize_t read(byte*, size_t);
-
-    bool is_empty() const { return m_read_buffer_index >= m_read_buffer->size() && m_write_buffer->isEmpty(); }
-
-private:
-    void flip();
-
-    Vector<byte>* m_write_buffer { nullptr };
-    Vector<byte>* m_read_buffer { nullptr };
-    Vector<byte> m_buffer1;
-    Vector<byte> m_buffer2;
-    size_t m_read_buffer_index { 0 };
-};
-
 class TTY : public CharacterDevice {
 public:
     virtual ~TTY() override;