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audio/softsynth/mt32/MidiStreamParser.h

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+/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher
+ * Copyright (C) 2011-2022 Dean Beeler, Jerome Fisher, Sergey V. Mikayev
+ *
+ *  This program 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 2.1 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 Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef MT32EMU_MIDI_STREAM_PARSER_H
+#define MT32EMU_MIDI_STREAM_PARSER_H
+
+#include "globals.h"
+#include "Types.h"
+
+namespace MT32Emu {
+
+class Synth;
+
+// Interface for a user-supplied class to receive parsed well-formed MIDI messages.
+class MT32EMU_EXPORT MidiReceiver {
+public:
+	// Invoked when a complete short MIDI message is parsed in the input MIDI stream.
+	virtual void handleShortMessage(const Bit32u message) = 0;
+
+	// Invoked when a complete well-formed System Exclusive MIDI message is parsed in the input MIDI stream.
+	virtual void handleSysex(const Bit8u stream[], const Bit32u length) = 0;
+
+	// Invoked when a System Realtime MIDI message is parsed in the input MIDI stream.
+	virtual void handleSystemRealtimeMessage(const Bit8u realtime) = 0;
+
+protected:
+	~MidiReceiver() {}
+};
+
+// Interface for a user-supplied class to receive notifications of input MIDI stream parse errors.
+class MT32EMU_EXPORT MidiReporter {
+public:
+	// Invoked when an error occurs during processing the input MIDI stream.
+	virtual void printDebug(const char *debugMessage) = 0;
+
+protected:
+	~MidiReporter() {}
+};
+
+// Provides a context for parsing a stream of MIDI events coming from a single source.
+// There can be multiple MIDI sources feeding MIDI events to a single Synth object.
+// NOTE: Calls from multiple threads which feed a single Synth object with data must be explicitly synchronised,
+// although, no synchronisation is required with the rendering thread.
+class MT32EMU_EXPORT MidiStreamParserImpl {
+public:
+	// The first two arguments provide for implementations of essential interfaces needed.
+	// The third argument specifies streamBuffer initial capacity. The buffer capacity should be large enough to fit the longest SysEx expected.
+	// If a longer SysEx occurs, streamBuffer is reallocated to the maximum size of MAX_STREAM_BUFFER_SIZE (32768 bytes).
+	// Default capacity is SYSEX_BUFFER_SIZE (1000 bytes) which is enough to fit SysEx messages in common use.
+	MidiStreamParserImpl(MidiReceiver &, MidiReporter &, Bit32u initialStreamBufferCapacity = SYSEX_BUFFER_SIZE);
+	virtual ~MidiStreamParserImpl();
+
+	// Parses a block of raw MIDI bytes. All the parsed MIDI messages are sent in sequence to the user-supplied methods for further processing.
+	// SysEx messages are allowed to be fragmented across several calls to this method. Running status is also handled for short messages.
+	// NOTE: the total length of a SysEx message being fragmented shall not exceed MAX_STREAM_BUFFER_SIZE (32768 bytes).
+	void parseStream(const Bit8u *stream, Bit32u length);
+
+	// Convenience method which accepts a Bit32u-encoded short MIDI message and sends it to the user-supplied method for further processing.
+	// The short MIDI message may contain no status byte, the running status is used in this case.
+	void processShortMessage(const Bit32u message);
+
+private:
+	Bit8u runningStatus;
+	Bit8u *streamBuffer;
+	Bit32u streamBufferCapacity;
+	Bit32u streamBufferSize;
+	MidiReceiver &midiReceiver;
+	MidiReporter &midiReporter;
+
+	// Binary compatibility helper.
+	void *reserved;
+
+	bool checkStreamBufferCapacity(const bool preserveContent);
+	bool processStatusByte(Bit8u &status);
+	Bit32u parseShortMessageStatus(const Bit8u stream[]);
+	Bit32u parseShortMessageDataBytes(const Bit8u stream[], Bit32u length);
+	Bit32u parseSysex(const Bit8u stream[], const Bit32u length);
+	Bit32u parseSysexFragment(const Bit8u stream[], const Bit32u length);
+}; // class MidiStreamParserImpl
+
+// An abstract class that provides a context for parsing a stream of MIDI events coming from a single source.
+class MT32EMU_EXPORT MidiStreamParser : public MidiStreamParserImpl, protected MidiReceiver, protected MidiReporter {
+public:
+	// The argument specifies streamBuffer initial capacity. The buffer capacity should be large enough to fit the longest SysEx expected.
+	// If a longer SysEx occurs, streamBuffer is reallocated to the maximum size of MAX_STREAM_BUFFER_SIZE (32768 bytes).
+	// Default capacity is SYSEX_BUFFER_SIZE (1000 bytes) which is enough to fit SysEx messages in common use.
+	explicit MidiStreamParser(Bit32u initialStreamBufferCapacity = SYSEX_BUFFER_SIZE);
+};
+
+class MT32EMU_EXPORT DefaultMidiStreamParser : public MidiStreamParser {
+public:
+	explicit DefaultMidiStreamParser(Synth &synth, Bit32u initialStreamBufferCapacity = SYSEX_BUFFER_SIZE);
+	void setTimestamp(const Bit32u useTimestamp);
+	void resetTimestamp();
+
+protected:
+	void handleShortMessage(const Bit32u message);
+	void handleSysex(const Bit8u *stream, const Bit32u length);
+	void handleSystemRealtimeMessage(const Bit8u realtime);
+	void printDebug(const char *debugMessage);
+
+private:
+	Synth &synth;
+	bool timestampSet;
+	Bit32u timestamp;
+};
+
+} // namespace MT32Emu
+
+#endif // MT32EMU_MIDI_STREAM_PARSER_H