| /* pb_decode.h: Functions to decode protocol buffers. Depends on pb_decode.c. |
| * The main function is pb_decode. You also need an input stream, and the |
| * field descriptions created by nanopb_generator.py. |
| */ |
| |
| #ifndef PB_DECODE_H_INCLUDED |
| #define PB_DECODE_H_INCLUDED |
| |
| #include "pb.h" |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| /* Structure for defining custom input streams. You will need to provide |
| * a callback function to read the bytes from your storage, which can be |
| * for example a file or a network socket. |
| * |
| * The callback must conform to these rules: |
| * |
| * 1) Return false on IO errors. This will cause decoding to abort. |
| * 2) You can use state to store your own data (e.g. buffer pointer), |
| * and rely on pb_read to verify that no-body reads past bytes_left. |
| * 3) Your callback may be used with substreams, in which case bytes_left |
| * is different than from the main stream. Don't use bytes_left to compute |
| * any pointers. |
| */ |
| struct pb_istream_s |
| { |
| #ifdef PB_BUFFER_ONLY |
| /* Callback pointer is not used in buffer-only configuration. |
| * Having an int pointer here allows binary compatibility but |
| * gives an error if someone tries to assign callback function. |
| */ |
| int *callback; |
| #else |
| bool (*callback)(pb_istream_t *stream, pb_byte_t *buf, size_t count); |
| #endif |
| |
| /* state is a free field for use of the callback function defined above. |
| * Note that when pb_istream_from_buffer() is used, it reserves this field |
| * for its own use. |
| */ |
| void *state; |
| |
| /* Maximum number of bytes left in this stream. Callback can report |
| * EOF before this limit is reached. Setting a limit is recommended |
| * when decoding directly from file or network streams to avoid |
| * denial-of-service by excessively long messages. |
| */ |
| size_t bytes_left; |
| |
| #ifndef PB_NO_ERRMSG |
| /* Pointer to constant (ROM) string when decoding function returns error */ |
| const char *errmsg; |
| #endif |
| }; |
| |
| #ifndef PB_NO_ERRMSG |
| #define PB_ISTREAM_EMPTY {0,0,0,0} |
| #else |
| #define PB_ISTREAM_EMPTY {0,0,0} |
| #endif |
| |
| /*************************** |
| * Main decoding functions * |
| ***************************/ |
| |
| /* Decode a single protocol buffers message from input stream into a C structure. |
| * Returns true on success, false on any failure. |
| * The actual struct pointed to by dest must match the description in fields. |
| * Callback fields of the destination structure must be initialized by caller. |
| * All other fields will be initialized by this function. |
| * |
| * Example usage: |
| * MyMessage msg = {}; |
| * uint8_t buffer[64]; |
| * pb_istream_t stream; |
| * |
| * // ... read some data into buffer ... |
| * |
| * stream = pb_istream_from_buffer(buffer, count); |
| * pb_decode(&stream, MyMessage_fields, &msg); |
| */ |
| bool pb_decode(pb_istream_t *stream, const pb_msgdesc_t *fields, void *dest_struct); |
| |
| /* Extended version of pb_decode, with several options to control |
| * the decoding process: |
| * |
| * PB_DECODE_NOINIT: Do not initialize the fields to default values. |
| * This is slightly faster if you do not need the default |
| * values and instead initialize the structure to 0 using |
| * e.g. memset(). This can also be used for merging two |
| * messages, i.e. combine already existing data with new |
| * values. |
| * |
| * PB_DECODE_DELIMITED: Input message starts with the message size as varint. |
| * Corresponds to parseDelimitedFrom() in Google's |
| * protobuf API. |
| * |
| * PB_DECODE_NULLTERMINATED: Stop reading when field tag is read as 0. This allows |
| * reading null terminated messages. |
| * NOTE: Until nanopb-0.4.0, pb_decode() also allows |
| * null-termination. This behaviour is not supported in |
| * most other protobuf implementations, so PB_DECODE_DELIMITED |
| * is a better option for compatibility. |
| * |
| * Multiple flags can be combined with bitwise or (| operator) |
| */ |
| #define PB_DECODE_NOINIT 0x01U |
| #define PB_DECODE_DELIMITED 0x02U |
| #define PB_DECODE_NULLTERMINATED 0x04U |
| bool pb_decode_ex(pb_istream_t *stream, const pb_msgdesc_t *fields, void *dest_struct, unsigned int flags); |
| |
| /* Defines for backwards compatibility with code written before nanopb-0.4.0 */ |
| #define pb_decode_noinit(s,f,d) pb_decode_ex(s,f,d, PB_DECODE_NOINIT) |
| #define pb_decode_delimited(s,f,d) pb_decode_ex(s,f,d, PB_DECODE_DELIMITED) |
| #define pb_decode_delimited_noinit(s,f,d) pb_decode_ex(s,f,d, PB_DECODE_DELIMITED | PB_DECODE_NOINIT) |
| #define pb_decode_nullterminated(s,f,d) pb_decode_ex(s,f,d, PB_DECODE_NULLTERMINATED) |
| |
| /* Release any allocated pointer fields. If you use dynamic allocation, you should |
| * call this for any successfully decoded message when you are done with it. If |
| * pb_decode() returns with an error, the message is already released. |
| */ |
| void pb_release(const pb_msgdesc_t *fields, void *dest_struct); |
| |
| /************************************** |
| * Functions for manipulating streams * |
| **************************************/ |
| |
| /* Create an input stream for reading from a memory buffer. |
| * |
| * msglen should be the actual length of the message, not the full size of |
| * allocated buffer. |
| * |
| * Alternatively, you can use a custom stream that reads directly from e.g. |
| * a file or a network socket. |
| */ |
| pb_istream_t pb_istream_from_buffer(const pb_byte_t *buf, size_t msglen); |
| |
| /* Function to read from a pb_istream_t. You can use this if you need to |
| * read some custom header data, or to read data in field callbacks. |
| */ |
| bool pb_read(pb_istream_t *stream, pb_byte_t *buf, size_t count); |
| |
| |
| /************************************************ |
| * Helper functions for writing field callbacks * |
| ************************************************/ |
| |
| /* Decode the tag for the next field in the stream. Gives the wire type and |
| * field tag. At end of the message, returns false and sets eof to true. */ |
| bool pb_decode_tag(pb_istream_t *stream, pb_wire_type_t *wire_type, uint32_t *tag, bool *eof); |
| |
| /* Skip the field payload data, given the wire type. */ |
| bool pb_skip_field(pb_istream_t *stream, pb_wire_type_t wire_type); |
| |
| /* Decode an integer in the varint format. This works for enum, int32, |
| * int64, uint32 and uint64 field types. */ |
| #ifndef PB_WITHOUT_64BIT |
| bool pb_decode_varint(pb_istream_t *stream, uint64_t *dest); |
| #else |
| #define pb_decode_varint pb_decode_varint32 |
| #endif |
| |
| /* Decode an integer in the varint format. This works for enum, int32, |
| * and uint32 field types. */ |
| bool pb_decode_varint32(pb_istream_t *stream, uint32_t *dest); |
| |
| /* Decode a bool value in varint format. */ |
| bool pb_decode_bool(pb_istream_t *stream, bool *dest); |
| |
| /* Decode an integer in the zig-zagged svarint format. This works for sint32 |
| * and sint64. */ |
| #ifndef PB_WITHOUT_64BIT |
| bool pb_decode_svarint(pb_istream_t *stream, int64_t *dest); |
| #else |
| bool pb_decode_svarint(pb_istream_t *stream, int32_t *dest); |
| #endif |
| |
| /* Decode a fixed32, sfixed32 or float value. You need to pass a pointer to |
| * a 4-byte wide C variable. */ |
| bool pb_decode_fixed32(pb_istream_t *stream, void *dest); |
| |
| #ifndef PB_WITHOUT_64BIT |
| /* Decode a fixed64, sfixed64 or double value. You need to pass a pointer to |
| * a 8-byte wide C variable. */ |
| bool pb_decode_fixed64(pb_istream_t *stream, void *dest); |
| #endif |
| |
| #ifdef PB_CONVERT_DOUBLE_FLOAT |
| /* Decode a double value into float variable. */ |
| bool pb_decode_double_as_float(pb_istream_t *stream, float *dest); |
| #endif |
| |
| /* Make a limited-length substream for reading a PB_WT_STRING field. */ |
| bool pb_make_string_substream(pb_istream_t *stream, pb_istream_t *substream); |
| bool pb_close_string_substream(pb_istream_t *stream, pb_istream_t *substream); |
| |
| #ifdef __cplusplus |
| } /* extern "C" */ |
| #endif |
| |
| #endif |