From f5a478f65d7262dbe194641d384f24fbbc03ed85 Mon Sep 17 00:00:00 2001
From: Roman Shaposhnik <roman@shaposhnik.org>
Date: Thu, 21 Sep 2006 07:31:53 +0000
Subject:    * Moving FifoBuffer out of libavformat/avformat.h and     
 libavformat/utils.c into libavutil

Originally committed as revision 6310 to svn://svn.ffmpeg.org/ffmpeg/trunk
---
 libavutil/fifo.c | 135 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 135 insertions(+)
 create mode 100644 libavutil/fifo.c

(limited to 'libavutil/fifo.c')

diff --git a/libavutil/fifo.c b/libavutil/fifo.c
new file mode 100644
index 0000000000..77461829d2
--- /dev/null
+++ b/libavutil/fifo.c
@@ -0,0 +1,135 @@
+/*
+ * A very simple circular buffer FIFO implementation
+ * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
+ * Copyright (c) 2006 Roman Shaposhnik
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#include "common.h"
+#include "fifo.h"
+
+int av_fifo_init(AVFifoBuffer *f, int size)
+{
+    f->buffer = av_malloc(size);
+    if (!f->buffer)
+        return -1;
+    f->end = f->buffer + size;
+    f->wptr = f->rptr = f->buffer;
+    return 0;
+}
+
+void av_fifo_free(AVFifoBuffer *f)
+{
+    av_free(f->buffer);
+}
+
+int av_fifo_size(AVFifoBuffer *f)
+{
+    int size = f->wptr - f->rptr;
+    if (size < 0)
+        size += f->end - f->buffer;
+    return size;
+}
+
+/**
+ * Get data from the fifo (returns -1 if not enough data).
+ */
+int av_fifo_read(AVFifoBuffer *f, uint8_t *buf, int buf_size)
+{
+    int len;
+    int size = f->wptr - f->rptr;
+    if (size < 0)
+        size += f->end - f->buffer;
+
+    if (size < buf_size)
+        return -1;
+    while (buf_size > 0) {
+        len = FFMIN(f->end - f->rptr, buf_size);
+        memcpy(buf, f->rptr, len);
+        buf += len;
+        f->rptr += len;
+        if (f->rptr >= f->end)
+            f->rptr = f->buffer;
+        buf_size -= len;
+    }
+    return 0;
+}
+
+/**
+ * Resizes a FIFO.
+ */
+void av_fifo_realloc(AVFifoBuffer *f, unsigned int new_size) {
+    unsigned int old_size= f->end - f->buffer;
+
+    if(old_size < new_size){
+        uint8_t *old= f->buffer;
+
+        f->buffer= av_realloc(f->buffer, new_size);
+
+        f->rptr += f->buffer - old;
+        f->wptr += f->buffer - old;
+
+        if(f->wptr < f->rptr){
+            memmove(f->rptr + new_size - old_size, f->rptr, f->buffer + old_size - f->rptr);
+            f->rptr += new_size - old_size;
+        }
+        f->end= f->buffer + new_size;
+    }
+}
+
+void av_fifo_write(AVFifoBuffer *f, const uint8_t *buf, int size)
+{
+    int len;
+
+    while (size > 0) {
+        len = FFMIN(f->end - f->wptr, size);
+        memcpy(f->wptr, buf, len);
+        f->wptr += len;
+        if (f->wptr >= f->end)
+            f->wptr = f->buffer;
+        buf += len;
+        size -= len;
+    }
+}
+
+
+/* get data from the fifo (return -1 if not enough data) */
+int av_fifo_generic_read(AVFifoBuffer *f, int buf_size, void (*func)(void*, void*, int), void* dest)
+{
+    int len;
+    int size = f->wptr - f->rptr;
+    if (size < 0)
+        size += f->end - f->buffer;
+
+    if (size < buf_size)
+        return -1;
+    while (buf_size > 0) {
+        len = FFMIN(f->end - f->rptr, buf_size);
+        func(dest, f->rptr, len);
+        f->rptr += len;
+        if (f->rptr >= f->end)
+            f->rptr = f->buffer;
+        buf_size -= len;
+    }
+    return 0;
+}
+
+/* discard data from the fifo */
+void av_fifo_drain(AVFifoBuffer *f, int size)
+{
+    f->rptr += size;
+    if (f->rptr >= f->end)
+        f->rptr -= f->end - f->buffer;
+}
-- 
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