1 files changed, 114 insertions, 0 deletions
diff --git a/source/q_fifo.h b/source/q_fifo.h
new file mode 100644
index 0000000..9d70bce
--- /dev/null
+++ b/source/q_fifo.h
@@ -0,0 +1,114 @@
+/*
+Copyright (C) 2003-2008 Andrey Nazarov
+
+This program 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 2
+of the License, or (at your option) any later version.
+
+This program 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 this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+
+*/
+
+//
+// q_fifo.h
+//
+
+typedef struct {
+    byte *data;
+    size_t size;
+    size_t ax, ay, bs;
+} fifo_t;
+
+static inline void *FIFO_Reserve( fifo_t *fifo, size_t *reserved ) {
+    size_t tail;
+
+    if( fifo->bs ) {
+        *reserved = fifo->ax - fifo->bs;
+        return fifo->data + fifo->bs;
+    }
+
+    tail = fifo->size - fifo->ay;
+    if( fifo->ax < tail ) {
+        *reserved = tail;
+        return fifo->data + fifo->ay;
+    }
+
+    *reserved = fifo->ax;
+    return fifo->data;
+}
+
+static inline void FIFO_Commit( fifo_t *fifo, size_t len ) {
+    size_t tail;
+
+    if( fifo->bs ) {
+        fifo->bs += len;
+        return;
+    }
+
+    tail = fifo->size - fifo->ay;
+    if( fifo->ax < tail ) {
+        fifo->ay += len;
+        return;
+    }
+
+    fifo->bs = len;
+}
+
+static inline void *FIFO_Peek( fifo_t *fifo, size_t *len ) {
+    *len = fifo->ay - fifo->ax;
+    return fifo->data + fifo->ax;
+}
+
+static inline void FIFO_Decommit( fifo_t *fifo, size_t len ) {
+    if( fifo->ax + len < fifo->ay ) {
+        fifo->ax += len;
+        return;
+    }
+
+    fifo->ay = fifo->bs;
+    fifo->ax = fifo->bs = 0;
+}
+
+static inline size_t FIFO_Usage( fifo_t *fifo ) {
+    return fifo->ay - fifo->ax + fifo->bs;
+}
+
+static inline int FIFO_Percent( fifo_t *fifo ) {
+    if( !fifo->size ) {
+        return 0;
+    }
+    return ( int )( FIFO_Usage( fifo ) * 100 / fifo->size );
+}
+
+static inline void FIFO_Clear( fifo_t *fifo ) {
+    fifo->ax = fifo->ay = fifo->bs = 0;
+}
+
+size_t FIFO_Read( fifo_t *fifo, void *buffer, size_t len );
+size_t FIFO_Write( fifo_t *fifo, const void *buffer, size_t len );
+
+static inline qboolean FIFO_TryRead( fifo_t *fifo, void *buffer, size_t len ) {
+    if( FIFO_Read( fifo, NULL, len ) < len ) {
+        return qfalse;
+    }
+    FIFO_Read( fifo, buffer, len );
+    return qtrue;
+}
+
+static inline qboolean FIFO_TryWrite( fifo_t *fifo, void *buffer, size_t len ) {
+    if( FIFO_Write( fifo, NULL, len ) < len ) {
+        return qfalse;
+    }
+    FIFO_Write( fifo, buffer, len );
+    return qtrue;
+}
+