growing_fifo: new utility library for growing fifo_buffer

1 files changed, 73 insertions, 0 deletions

diff --git a/src/growing_fifo.h b/src/growing_fifo.h
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+++ b/src/growing_fifo.h
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+/*
+ * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the
+ * distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE
+ * FOUNDATION OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/** \file
+ *
+ * Helper functions for our FIFO buffer library (fifo_buffer.h) that
+ * allows growing the buffer on demand.
+ *
+ * This library is not thread safe.
+ */
+
+#ifndef MPD_GROWING_FIFO_H
+#define MPD_GROWING_FIFO_H
+
+#include <stddef.h>
+
+struct fifo_buffer;
+
+/**
+ * Allocate a new #fifo_buffer with the default size.
+ */
+struct fifo_buffer *
+growing_fifo_new(void);
+
+/**
+ * Prepares writing to the buffer, see fifo_buffer_write() for
+ * details.  The difference is that this function will automatically
+ * grow the buffer if it is too small.
+ *
+ * The caller is responsible for limiting the capacity of the buffer.
+ *
+ * @param length the number of bytes that will be written
+ * @return a pointer to the end of the buffer (will not be NULL)
+ */
+void *
+growing_fifo_write(struct fifo_buffer **buffer_p, size_t length);
+
+/**
+ * A helper function that combines growing_fifo_write(), memcpy(),
+ * fifo_buffer_append().
+ */
+void
+growing_fifo_append(struct fifo_buffer **buffer_p,
+		    const void *data, size_t length);
+
+#endif