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/**
* @file tinybson.h
*
* A simple subset SAX-style BSON parser and generator. See http://bsonspec.org
*
* 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_INT32 = 16,
BSON_INT64 = 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
/**
* Buffer growth increment when writing to a buffer.
*/
#define BSON_BUF_INCREMENT 128
/**
* 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 {
int64_t i;
double d;
bool b;
};
} *bson_node_t;
typedef struct bson_decoder_s *bson_decoder_t;
/**
* Node callback.
*
* The node callback function's return value is returned by bson_decoder_next.
*/
typedef int (* bson_decoder_callback)(bson_decoder_t decoder, void *private, bson_node_t node);
struct bson_decoder_s {
/* file reader state */
int fd;
/* buffer reader state */
uint8_t *buf;
size_t bufsize;
unsigned bufpos;
bool dead;
bson_decoder_callback callback;
void *private;
unsigned nesting;
struct bson_node_s node;
int32_t pending;
};
/**
* Initialise the decoder to read from a file.
*
* @param decoder Decoder state structure to be initialised.
* @param fd File to read BSON data from.
* @param callback Callback to be invoked by bson_decoder_next
* @param private Callback private data, stored in node.
* @return Zero on success.
*/
__EXPORT int bson_decoder_init_file(bson_decoder_t decoder, int fd, bson_decoder_callback callback, void *private);
/**
* Initialise the decoder to read from a buffer in memory.
*
* @param decoder Decoder state structure to be initialised.
* @param buf Buffer to read from.
* @param bufsize Size of the buffer (BSON object may be smaller). May be
* passed as zero if the buffer size should be extracted from the
* BSON header only.
* @param callback Callback to be invoked by bson_decoder_next
* @param private Callback private data, stored in node.
* @return Zero on success.
*/
__EXPORT int bson_decoder_init_buf(bson_decoder_t decoder, void *buf, unsigned bufsize, bson_decoder_callback callback, void *private);
/**
* Process the next node from the stream and invoke the callback.
*
* @param decoder Decoder state, must have been initialised with bson_decoder_init.
* @return -1 if parsing encountered an error, 0 if the BSON stream has ended,
* otherwise the return value from the callback.
*/
__EXPORT int bson_decoder_next(bson_decoder_t decoder);
/**
* Copy node data.
*
* @param decoder Decoder state, must have been initialised with bson_decoder_init.
*/
__EXPORT int bson_decoder_copy_data(bson_decoder_t decoder, void *buf);
/**
* Report copyable data size.
*
* @param decoder Decoder state, must have been initialised with bson_decoder_init.
*/
__EXPORT size_t bson_decoder_data_pending(bson_decoder_t decoder);
/**
* Encoder state structure.
*/
typedef struct bson_encoder_s {
/* file writer state */
int fd;
/* buffer writer state */
uint8_t *buf;
unsigned bufsize;
unsigned bufpos;
bool realloc_ok;
bool dead;
} *bson_encoder_t;
/**
* Initialze the encoder for writing to a file.
*
* @param encoder Encoder state structure to be initialised.
* @param fd File to write to.
* @return Zero on success.
*/
__EXPORT int bson_encoder_init_file(bson_encoder_t encoder, int fd);
/**
* Initialze the encoder for writing to a buffer.
*
* @param encoder Encoder state structure to be initialised.
* @param buf Buffer pointer to use, or NULL if the buffer
* should be allocated by the encoder.
* @param bufsize Maximum buffer size, or zero for no limit. If
* the buffer is supplied, the size of the supplied buffer.
* @return Zero on success.
*/
__EXPORT int bson_encoder_init_buf(bson_encoder_t encoder, void *buf, unsigned bufsize);
/**
* Finalise the encoded stream.
*
* @param encoder The encoder to finalise.
*/
__EXPORT int bson_encoder_fini(bson_encoder_t encoder);
/**
* Fetch the size of the encoded object; only valid for buffer operations.
*/
__EXPORT int bson_encoder_buf_size(bson_encoder_t encoder);
/**
* Get a pointer to the encoded object buffer.
*
* Note that if the buffer was allocated by the encoder, it is the caller's responsibility
* to free this buffer.
*/
__EXPORT void *bson_encoder_buf_data(bson_encoder_t encoder);
/**
* Append a boolean to the encoded stream.
*
* @param encoder Encoder state.
* @param name Node name.
* @param value Value to be encoded.
*/
__EXPORT int bson_encoder_append_bool(bson_encoder_t encoder, const char *name, bool value);
/**
* Append an integer to the encoded stream.
*
* @param encoder Encoder state.
* @param name Node name.
* @param value Value to be encoded.
*/
__EXPORT int bson_encoder_append_int(bson_encoder_t encoder, const char *name, int64_t value);
/**
* Append a double to the encoded stream
*
* @param encoder Encoder state.
* @param name Node name.
* @param value Value to be encoded.
*/
__EXPORT int bson_encoder_append_double(bson_encoder_t encoder, const char *name, double value);
/**
* Append a string to the encoded stream.
*
* @param encoder Encoder state.
* @param name Node name.
* @param string Nul-terminated C string.
*/
__EXPORT int bson_encoder_append_string(bson_encoder_t encoder, const char *name, const char *string);
/**
* Append a binary blob to the encoded stream.
*
* @param encoder Encoder state.
* @param name Node name.
* @param subtype Binary data subtype.
* @param size Data size.
* @param data Buffer containing data to be encoded.
*/
__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
