IPC FIFO emulation.

FIFO.cpp

@@ -0,0 +1,72 @@
+/*
+    Copyright 2016-2017 StapleButter
+
+    This file is part of melonDS.
+
+    melonDS is free software: you can redistribute it and/or modify it under
+    the terms of the GNU General Public License as published by the Free
+    Software Foundation, either version 3 of the License, or (at your option)
+    any later version.
+
+    melonDS is distributed in the hope that it will be useful, but WITHOUT ANY
+    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+    FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License along
+    with melonDS. If not, see http://www.gnu.org/licenses/.
+*/
+
+#include "FIFO.h"
+
+
+FIFO::FIFO(u32 num)
+{
+    NumEntries = num;
+    Entries = new u32[num];
+    Clear();
+}
+
+FIFO::~FIFO()
+{
+    delete[] Entries;
+}
+
+void FIFO::Clear()
+{
+    NumOccupied = 0;
+    ReadPos = 0;
+    WritePos = 0;
+    Entries[ReadPos] = 0;
+}
+
+void FIFO::Write(u32 val)
+{
+    if (IsFull()) return;
+
+    Entries[WritePos] = val;
+
+    WritePos++;
+    if (WritePos >= NumEntries)
+        WritePos = 0;
+
+    NumOccupied++;
+}
+
+u32 FIFO::Read()
+{
+    u32 ret = Entries[ReadPos];
+    if (IsEmpty())
+        return ret;
+
+    ReadPos++;
+    if (ReadPos >= NumEntries)
+        ReadPos = 0;
+
+    NumOccupied--;
+    return ret;
+}
+
+u32 FIFO::Peek()
+{
+    return Entries[ReadPos];
+}