Goodbye to the Mongo BSON codec; too big. Hello to a really small SAX-style decoder and matching encoder.

apps/systemlib/bson/tinybson.h

@@ -0,0 +1,169 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2012 PX4 Development Team. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. 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.
+ * 3. Neither the name PX4 nor the names of its contributors may be
+ *    used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * 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
+ * COPYRIGHT OWNER 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 tinybson.h
+ *
+ * A simple subset SAX-style BSON parser and generator.
+ *
+ * Some types and defines taken from the standalone BSON parser/generator 
+ * in the Mongo C connector.
+ */
+
+#ifndef _TINYBSON_H
+#define _TINYBSON_H
+
+#include <sys/types.h>
+#include <stdint.h>
+#include <stdbool.h>
+
+/** subset of the BSON node types we might care about */
+typedef enum {
+	BSON_EOO = 0,
+	BSON_DOUBLE = 1,
+	BSON_STRING = 2,
+	BSON_OBJECT = 3,
+	BSON_ARRAY = 4,
+	BSON_BINDATA = 5,
+	BSON_UNDEFINED = 6,
+	BSON_BOOL = 8,
+	BSON_DATE = 9,
+	BSON_NULL = 10,
+	BSON_INT = 16,
+	BSON_TIMESTAMP = 17,
+	BSON_LONG = 18
+} bson_type_t;
+
+typedef enum bson_binary_subtype {
+	BSON_BIN_BINARY = 0,
+	BSON_BIN_USER = 128
+} bson_binary_subtype_t;
+
+/**
+ * Maximum node name length.
+ */
+#define BSON_MAXNAME		32
+
+/**
+ * Node structure passed to the callback.
+ */
+typedef struct bson_node_s
+{
+	char			name[BSON_MAXNAME];
+	bson_type_t		type;
+	bson_binary_subtype_t	subtype;
+	union {
+		int32_t		i;
+		double		d;
+		bool		b;
+	};
+} *bson_node_t;
+
+typedef struct bson_decoder_s *bson_decoder_t;
+
+/**
+ * Node callback.
+ */
+typedef int	(* bson_decoder_callback)(bson_decoder_t decoder, void *private, bson_node_t node);
+
+struct bson_decoder_s
+{
+	int			fd;
+	bson_decoder_callback	callback;
+	void			*private;
+	unsigned		nesting;
+	struct bson_node_s	node;
+	int32_t			pending;
+};
+
+/**
+ * Initialise the decoder.
+ */
+__EXPORT int bson_decoder_init(bson_decoder_t decoder, int fd, bson_decoder_callback callback, void *private);
+
+/**
+ * Process the next node from the stream and invoke the callback.
+ */
+__EXPORT int bson_decoder_next(bson_decoder_t decoder);
+
+/**
+ * Copy node data.
+ */
+__EXPORT int bson_decoder_copy_data(bson_decoder_t decoder, void *buf);
+
+/**
+ * Report copyable data size.
+ */
+__EXPORT size_t bson_decoder_data_pending(bson_decoder_t decoder);
+
+/**
+ * Encoder state structure.
+ */
+typedef struct bson_encoder_s
+{
+	int		fd;
+
+} *bson_encoder_t;
+
+/**
+ * Initialze the encoder.
+ */
+__EXPORT int bson_encoder_init(bson_encoder_t encoder, int fd);
+
+/**
+ * Finalise the encoded stream.
+ */
+__EXPORT int bson_encoder_fini(bson_encoder_t encoder);
+
+/**
+ * Append an integer to the encoded stream.
+ */
+__EXPORT int bson_encoder_append_int(bson_encoder_t encoder, const char *name, int32_t value);
+
+/**
+ * Append a double to the encoded stream
+ */
+__EXPORT int bson_encoder_append_double(bson_encoder_t encoder, const char *name, double value);
+
+/** 
+ * Append a string to the encoded stream.
+ */
+__EXPORT int bson_encoder_append_string(bson_encoder_t encoder, const char *name, const char *string);
+
+/**
+ * Append a binary blob to the encoded stream.
+ */
+__EXPORT int bson_encoder_append_binary(bson_encoder_t encoder, const char *name, bson_binary_subtype_t subtype, size_t size, const void *data);
+
+
+#endif