decoder/*: move to decoder/plugins/

src/decoder/DecoderBuffer.hxx

@@ -0,0 +1,111 @@
+/*
+ * Copyright (C) 2003-2014 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_DECODER_BUFFER_HXX
+#define MPD_DECODER_BUFFER_HXX
+
+#include "Compiler.h"
+
+#include <stddef.h>
+
+/**
+ * This objects handles buffered reads in decoder plugins easily.  You
+ * create a buffer object, and use its high-level methods to fill and
+ * read it.  It will automatically handle shifting the buffer.
+ */
+struct DecoderBuffer;
+
+struct Decoder;
+struct InputStream;
+
+template<typename T> struct ConstBuffer;
+
+/**
+ * Creates a new buffer.
+ *
+ * @param decoder the decoder object, used for decoder_read(), may be nullptr
+ * @param is the input stream object where we should read from
+ * @param size the maximum size of the buffer
+ * @return the new decoder_buffer object
+ */
+DecoderBuffer *
+decoder_buffer_new(Decoder *decoder, InputStream &is,
+		   size_t size);
+
+/**
+ * Frees resources used by the decoder_buffer object.
+ */
+void
+decoder_buffer_free(DecoderBuffer *buffer);
+
+gcc_pure
+bool
+decoder_buffer_is_empty(const DecoderBuffer *buffer);
+
+gcc_pure
+bool
+decoder_buffer_is_full(const DecoderBuffer *buffer);
+
+void
+decoder_buffer_clear(DecoderBuffer *buffer);
+
+/**
+ * Read data from the input_stream and append it to the buffer.
+ *
+ * @return true if data was appended; false if there is no data
+ * available (yet), end of file, I/O error or a decoder command was
+ * received
+ */
+bool
+decoder_buffer_fill(DecoderBuffer *buffer);
+
+/**
+ * Reads data from the buffer.  This data is not yet consumed, you
+ * have to call decoder_buffer_consume() to do that.  The returned
+ * buffer becomes invalid after a decoder_buffer_fill() or a
+ * decoder_buffer_consume() call.
+ *
+ * @param buffer the decoder_buffer object
+ */
+gcc_pure
+ConstBuffer<void>
+decoder_buffer_read(const DecoderBuffer *buffer);
+
+/**
+ * Consume (delete, invalidate) a part of the buffer.  The "nbytes"
+ * parameter must not be larger than the length returned by
+ * decoder_buffer_read().
+ *
+ * @param buffer the decoder_buffer object
+ * @param nbytes the number of bytes to consume
+ */
+void
+decoder_buffer_consume(DecoderBuffer *buffer, size_t nbytes);
+
+/**
+ * Skips the specified number of bytes, discarding its data.
+ *
+ * @param buffer the decoder_buffer object
+ * @param nbytes the number of bytes to skip
+ * @return true on success, false on error
+ */
+bool
+decoder_buffer_skip(DecoderBuffer *buffer, size_t nbytes);
+
+#endif