From 64a552f7a69e20c174f929c5d4e800aa24b480f3 Mon Sep 17 00:00:00 2001 From: Dimitri Sokolyuk Date: Sun, 27 Aug 2017 00:49:24 +0200 Subject: Make go getable --- elegoo/pb/pb_encode.h | 154 ++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 154 insertions(+) create mode 100644 elegoo/pb/pb_encode.h (limited to 'elegoo/pb/pb_encode.h') diff --git a/elegoo/pb/pb_encode.h b/elegoo/pb/pb_encode.h new file mode 100644 index 0000000..d9909fb --- /dev/null +++ b/elegoo/pb/pb_encode.h @@ -0,0 +1,154 @@ +/* pb_encode.h: Functions to encode protocol buffers. Depends on pb_encode.c. + * The main function is pb_encode. You also need an output stream, and the + * field descriptions created by nanopb_generator.py. + */ + +#ifndef PB_ENCODE_H_INCLUDED +#define PB_ENCODE_H_INCLUDED + +#include "pb.h" + +#ifdef __cplusplus +extern "C" { +#endif + +/* Structure for defining custom output streams. You will need to provide + * a callback function to write the bytes to 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 encoding to abort. + * 2) You can use state to store your own data (e.g. buffer pointer). + * 3) pb_write will update bytes_written after your callback runs. + * 4) Substreams will modify max_size and bytes_written. Don't use them + * to calculate any pointers. + */ +struct pb_ostream_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. + * Also, NULL pointer marks a 'sizing stream' that does not + * write anything. + */ + int *callback; +#else + bool (*callback)(pb_ostream_t *stream, const pb_byte_t *buf, size_t count); +#endif + void *state; /* Free field for use by callback implementation. */ + size_t max_size; /* Limit number of output bytes written (or use SIZE_MAX). */ + size_t bytes_written; /* Number of bytes written so far. */ + +#ifndef PB_NO_ERRMSG + const char *errmsg; +#endif +}; + +/*************************** + * Main encoding functions * + ***************************/ + +/* Encode a single protocol buffers message from C structure into a stream. + * Returns true on success, false on any failure. + * The actual struct pointed to by src_struct must match the description in fields. + * All required fields in the struct are assumed to have been filled in. + * + * Example usage: + * MyMessage msg = {}; + * uint8_t buffer[64]; + * pb_ostream_t stream; + * + * msg.field1 = 42; + * stream = pb_ostream_from_buffer(buffer, sizeof(buffer)); + * pb_encode(&stream, MyMessage_fields, &msg); + */ +bool pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct); + +/* Same as pb_encode, but prepends the length of the message as a varint. + * Corresponds to writeDelimitedTo() in Google's protobuf API. + */ +bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct); + +/* Encode the message to get the size of the encoded data, but do not store + * the data. */ +bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct); + +/************************************** + * Functions for manipulating streams * + **************************************/ + +/* Create an output stream for writing into a memory buffer. + * The number of bytes written can be found in stream.bytes_written after + * encoding the message. + * + * Alternatively, you can use a custom stream that writes directly to e.g. + * a file or a network socket. + */ +pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize); + +/* Pseudo-stream for measuring the size of a message without actually storing + * the encoded data. + * + * Example usage: + * MyMessage msg = {}; + * pb_ostream_t stream = PB_OSTREAM_SIZING; + * pb_encode(&stream, MyMessage_fields, &msg); + * printf("Message size is %d\n", stream.bytes_written); + */ +#ifndef PB_NO_ERRMSG +#define PB_OSTREAM_SIZING {0,0,0,0,0} +#else +#define PB_OSTREAM_SIZING {0,0,0,0} +#endif + +/* Function to write into a pb_ostream_t stream. You can use this if you need + * to append or prepend some custom headers to the message. + */ +bool pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count); + + +/************************************************ + * Helper functions for writing field callbacks * + ************************************************/ + +/* Encode field header based on type and field number defined in the field + * structure. Call this from the callback before writing out field contents. */ +bool pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field); + +/* Encode field header by manually specifing wire type. You need to use this + * if you want to write out packed arrays from a callback field. */ +bool pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number); + +/* Encode an integer in the varint format. + * This works for bool, enum, int32, int64, uint32 and uint64 field types. */ +bool pb_encode_varint(pb_ostream_t *stream, uint64_t value); + +/* Encode an integer in the zig-zagged svarint format. + * This works for sint32 and sint64. */ +bool pb_encode_svarint(pb_ostream_t *stream, int64_t value); + +/* Encode a string or bytes type field. For strings, pass strlen(s) as size. */ +bool pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size); + +/* Encode a fixed32, sfixed32 or float value. + * You need to pass a pointer to a 4-byte wide C variable. */ +bool pb_encode_fixed32(pb_ostream_t *stream, const void *value); + +/* Encode a fixed64, sfixed64 or double value. + * You need to pass a pointer to a 8-byte wide C variable. */ +bool pb_encode_fixed64(pb_ostream_t *stream, const void *value); + +/* Encode a submessage field. + * You need to pass the pb_field_t array and pointer to struct, just like + * with pb_encode(). This internally encodes the submessage twice, first to + * calculate message size and then to actually write it out. + */ +bool pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct); + +#ifdef __cplusplus +} /* extern "C" */ +#endif + +#endif -- cgit v1.2.3