Kernel: Move FIFO into FileSystem/ and Socket+LocalSocket into Net/.

Kernel/FileSystem/FIFO.cpp

@@ -0,0 +1,79 @@
+#include <Kernel/FileSystem/FIFO.h>
+#include <AK/StdLibExtras.h>
+
+//#define FIFO_DEBUG
+
+Retained<FIFO> FIFO::create()
+{
+    return adopt(*new FIFO);
+}
+
+FIFO::FIFO()
+{
+}
+
+void FIFO::open(Direction direction)
+{
+    if (direction == Reader) {
+        ++m_readers;
+#ifdef FIFO_DEBUG
+        kprintf("open reader (%u)\n", m_readers);
+#endif
+    } else if (direction == Writer) {
+        ++m_writers;
+#ifdef FIFO_DEBUG
+        kprintf("open writer (%u)\n", m_writers);
+#endif
+    }
+}
+
+void FIFO::close(Direction direction)
+{
+    if (direction == Reader) {
+#ifdef FIFO_DEBUG
+        kprintf("close reader (%u - 1)\n", m_readers);
+#endif
+        ASSERT(m_readers);
+        --m_readers;
+    } else if (direction == Writer) {
+#ifdef FIFO_DEBUG
+        kprintf("close writer (%u - 1)\n", m_writers);
+#endif
+        ASSERT(m_writers);
+        --m_writers;
+    }
+}
+
+bool FIFO::can_read() const
+{
+    return !m_buffer.is_empty() || !m_writers;
+}
+
+bool FIFO::can_write() const
+{
+    return m_buffer.bytes_in_write_buffer() < 4096;
+}
+
+ssize_t FIFO::read(byte* buffer, ssize_t size)
+{
+    if (!m_writers && m_buffer.is_empty())
+        return 0;
+#ifdef FIFO_DEBUG
+    dbgprintf("fifo: read(%u)\n",size);
+#endif
+    ssize_t nread = m_buffer.read(buffer, size);
+#ifdef FIFO_DEBUG
+    dbgprintf("   -> read (%c) %u\n", buffer[0], nread);
+#endif
+    return nread;
+}
+
+ssize_t FIFO::write(const byte* buffer, ssize_t size)
+{
+    if (!m_readers)
+        return 0;
+#ifdef FIFO_DEBUG
+    dbgprintf("fifo: write(%p, %u)\n", buffer, size);
+#endif
+    return m_buffer.write(buffer, size);
+}