Small Protobuf wire-format reader/writer helpers. More...

#include <cwist/net/grpc/protobuf.h>
#include <cwist/core/mem/alloc.h>
#include <limits.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

Include dependency graph for protobuf.c:

Go to the source code of this file.

Functions
void	cwist_pb_writer_init (cwist_pb_writer *w)
	Initialize a Protobuf writer to an empty buffer.

void	cwist_pb_writer_free (cwist_pb_writer *w)
	Release the buffer owned by a Protobuf writer.

int	cwist_pb_writer_reserve (cwist_pb_writer *w, size_t extra)
	Ensure the writer buffer has room for `extra` more bytes.

int	cwist_pb_write_varint (cwist_pb_writer *w, uint64_t value)
	Append a base-128 varint to the writer buffer.

int	cwist_pb_write_key (cwist_pb_writer *w, uint32_t field_number, cwist_pb_wire_type_t wire_type)
	Write a field key (field number and wire type) as a varint.

int	cwist_pb_write_uint64_field (cwist_pb_writer *w, uint32_t field_number, uint64_t value)
	Write a uint64 field as a varint.

int	cwist_pb_write_int64_field (cwist_pb_writer *w, uint32_t field_number, int64_t value)
	Write an int64 field; negative values are encoded as ten-byte varints.

int	cwist_pb_write_bool_field (cwist_pb_writer *w, uint32_t field_number, int value)
	Write a bool field as a 0/1 varint.

int	cwist_pb_write_raw32 (cwist_pb_writer *w, uint32_t value)
	Append a 32-bit value in little-endian order (no key written).

int	cwist_pb_write_raw64 (cwist_pb_writer *w, uint64_t value)
	Append a 64-bit value in little-endian order (no key written).

int	cwist_pb_write_fixed32_field (cwist_pb_writer *w, uint32_t field_number, uint32_t value)
	Write a fixed32 field (key plus 4 little-endian bytes).

int	cwist_pb_write_fixed64_field (cwist_pb_writer *w, uint32_t field_number, uint64_t value)
	Write a fixed64 field (key plus 8 little-endian bytes).

int	cwist_pb_write_float_field (cwist_pb_writer *w, uint32_t field_number, float value)
	Write a float field by reinterpreting it as fixed32 bits.

int	cwist_pb_write_double_field (cwist_pb_writer *w, uint32_t field_number, double value)
	Write a double field by reinterpreting it as fixed64 bits.

int	cwist_pb_write_bytes_field (cwist_pb_writer w, uint32_t field_number, const void data, size_t len)
	Write a length-delimited bytes field (key, length varint, raw bytes).

int	cwist_pb_write_string_field (cwist_pb_writer w, uint32_t field_number, const char value)
	Write a string field (length-delimited, excluding the NUL terminator).

void	cwist_pb_reader_init (cwist_pb_reader r, const void data, size_t len)
	Initialize a reader over a caller-owned buffer.

int	cwist_pb_read_varint (cwist_pb_reader r, uint64_t out)
	Read a base-128 varint, advancing the reader position.

int	cwist_pb_read_field (cwist_pb_reader r, cwist_pb_field field)
	Read the next field key and payload from the reader.

int	cwist_pb_skip_field (cwist_pb_reader r, const cwist_pb_field field)
	Validate a parsed field descriptor.

uint64_t	cwist_pb_zigzag_encode (int64_t value)
	ZigZag-encode a signed 64-bit value for sint fields.

int64_t	cwist_pb_zigzag_decode (uint64_t value)
	ZigZag-decode an unsigned 64-bit value back to a signed value.

Detailed Description

Small Protobuf wire-format reader/writer helpers.

Definition in file protobuf.c.

Function Documentation

◆ cwist_pb_read_field()

int cwist_pb_read_field	(	cwist_pb_reader *	r,
		cwist_pb_field *	field
	)

Read the next field key and payload from the reader.

Parameters

r	Reader to read from. Must not be NULL.
field	Receives the field number, wire type, and payload descriptor. Must not be NULL.

Return values

1	A field was read and `field` is filled in.
0	The reader is exhausted (end of input); the reader position is unchanged in this case.
-1	Malformed data or invalid argument.

Definition at line 284 of file protobuf.c.

References cwist_pb_field::bytes, cap, CWIST_PB_32BIT, CWIST_PB_64BIT, CWIST_PB_LEN, CWIST_PB_MAX_FIELD_NUMBER, cwist_pb_read_varint(), CWIST_PB_VARINT, cwist_pb_reader::data, cwist_pb_reader::len, cwist_pb_field::len, cwist_pb_field::number, cwist_pb_reader::pos, cwist_pb_field::varint, and cwist_pb_field::wire_type.

◆ cwist_pb_read_varint()

int cwist_pb_read_varint	(	cwist_pb_reader *	r,
		uint64_t *	out
	)

Read a base-128 varint, advancing the reader position.

Parameters

r	Reader to read from. Must not be NULL.
out	Receives the decoded value. Must not be NULL.

Returns: 0 on success, -1 if the reader is exhausted or the varint is malformed (unterminated or longer than 64 bits).

Definition at line 258 of file protobuf.c.

References cap, cwist_pb_reader::data, cwist_pb_reader::len, and cwist_pb_reader::pos.

Referenced by cwist_pb_read_field().

◆ cwist_pb_reader_init()

void cwist_pb_reader_init	(	cwist_pb_reader *	r,
		const void *	data,
		size_t	len
	)

Initialize a reader over a caller-owned buffer.

Parameters

r	Reader to initialize. NULL is accepted and ignored.
data	Buffer to read from; not copied, so it must outlive the reader.
len	Size of `data` in bytes.

Definition at line 244 of file protobuf.c.

References cap, cwist_pb_reader::data, cwist_pb_reader::len, and cwist_pb_reader::pos.

◆ cwist_pb_skip_field()

int cwist_pb_skip_field	(	cwist_pb_reader *	r,
		const cwist_pb_field *	field
	)

Validate a parsed field descriptor.

Note: The reader position is already advanced by cwist_pb_read_field(), so this function only checks that field is non-NULL.

Parameters

r	Reader associated with the field; unused.
field	Field descriptor to validate. Must not be NULL.

Returns: 0 if field is valid, -1 if it is NULL.

Definition at line 333 of file protobuf.c.

References cap.

◆ cwist_pb_write_bool_field()

int cwist_pb_write_bool_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		int	value
	)

Write a bool field as a 0/1 varint.

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Non-zero encodes as 1, zero encodes as 0.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 127 of file protobuf.c.

References cap, and cwist_pb_write_uint64_field().

◆ cwist_pb_write_bytes_field()

int cwist_pb_write_bytes_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		const void *	data,
		size_t	len
	)

Write a length-delimited bytes field (key, length varint, raw bytes).

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
data	Bytes to copy; may be NULL only when `len` is 0. The bytes are copied into the writer buffer, so the caller keeps ownership.
len	Number of bytes to write.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 215 of file protobuf.c.

References cap, CWIST_PB_LEN, cwist_pb_write_key(), cwist_pb_write_varint(), and cwist_pb_writer_reserve().

Referenced by cwist_pb_write_string_field().

◆ cwist_pb_write_double_field()

int cwist_pb_write_double_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		double	value
	)

Write a double field by reinterpreting it as fixed64 bits.

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 202 of file protobuf.c.

References cap, and cwist_pb_write_fixed64_field().

◆ cwist_pb_write_fixed32_field()

int cwist_pb_write_fixed32_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		uint32_t	value
	)

Write a fixed32 field (key plus 4 little-endian bytes).

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 167 of file protobuf.c.

References cap, CWIST_PB_32BIT, cwist_pb_write_key(), and cwist_pb_write_raw32().

Referenced by cwist_pb_write_float_field().

◆ cwist_pb_write_fixed64_field()

int cwist_pb_write_fixed64_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		uint64_t	value
	)

Write a fixed64 field (key plus 8 little-endian bytes).

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 179 of file protobuf.c.

References cap, CWIST_PB_64BIT, cwist_pb_write_key(), and cwist_pb_write_raw64().

Referenced by cwist_pb_write_double_field().

◆ cwist_pb_write_float_field()

int cwist_pb_write_float_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		float	value
	)

Write a float field by reinterpreting it as fixed32 bits.

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 191 of file protobuf.c.

References cap, and cwist_pb_write_fixed32_field().

◆ cwist_pb_write_int64_field()

int cwist_pb_write_int64_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		int64_t	value
	)

Write an int64 field; negative values are encoded as ten-byte varints.

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode (two's-complement, reinterpreted as uint64).

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 116 of file protobuf.c.

References cap, and cwist_pb_write_uint64_field().

◆ cwist_pb_write_key()

int cwist_pb_write_key	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		cwist_pb_wire_type_t	wire_type
	)

Write a field key (field number and wire type) as a varint.

Parameters

w	Writer to append to. Must not be NULL.
field_number	Protobuf field number; must be non-zero.
wire_type	Wire type; must be a valid cwist_pb_wire_type_t value.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 87 of file protobuf.c.

References cap, CWIST_PB_32BIT, CWIST_PB_64BIT, CWIST_PB_LEN, CWIST_PB_MAX_FIELD_NUMBER, CWIST_PB_VARINT, and cwist_pb_write_varint().

Referenced by cwist_pb_write_bytes_field(), cwist_pb_write_fixed32_field(), cwist_pb_write_fixed64_field(), and cwist_pb_write_uint64_field().

◆ cwist_pb_write_raw32()

int cwist_pb_write_raw32	(	cwist_pb_writer *	w,
		uint32_t	value
	)

Append a 32-bit value in little-endian order (no key written).

Parameters

w	Writer to append to. Must not be NULL.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 137 of file protobuf.c.

References cap, and cwist_pb_writer_reserve().

Referenced by cwist_pb_write_fixed32_field().

◆ cwist_pb_write_raw64()

int cwist_pb_write_raw64	(	cwist_pb_writer *	w,
		uint64_t	value
	)

Append a 64-bit value in little-endian order (no key written).

Parameters

w	Writer to append to. Must not be NULL.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 153 of file protobuf.c.

References cap, and cwist_pb_writer_reserve().

Referenced by cwist_pb_write_fixed64_field().

◆ cwist_pb_write_string_field()

int cwist_pb_write_string_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		const char *	value
	)

Write a string field (length-delimited, excluding the NUL terminator).

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	NUL-terminated string to copy; must not be NULL.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 233 of file protobuf.c.

References cap, and cwist_pb_write_bytes_field().

◆ cwist_pb_write_uint64_field()

int cwist_pb_write_uint64_field	(	cwist_pb_writer *	w,
		uint32_t	field_number,
		uint64_t	value
	)

Write a uint64 field as a varint.

Parameters

w	Writer to append to.
field_number	Protobuf field number; must be non-zero.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 104 of file protobuf.c.

References cap, CWIST_PB_VARINT, cwist_pb_write_key(), and cwist_pb_write_varint().

Referenced by cwist_pb_write_bool_field(), and cwist_pb_write_int64_field().

◆ cwist_pb_write_varint()

int cwist_pb_write_varint	(	cwist_pb_writer *	w,
		uint64_t	value
	)

Append a base-128 varint to the writer buffer.

Parameters

w	Writer to append to. Must not be NULL.
value	Value to encode.

Returns: 0 on success, -1 on invalid argument or allocation failure.

Definition at line 69 of file protobuf.c.

References cap, and cwist_pb_writer_reserve().

Referenced by cwist_pb_write_bytes_field(), cwist_pb_write_key(), and cwist_pb_write_uint64_field().

◆ cwist_pb_writer_free()

void cwist_pb_writer_free ( cwist_pb_writer * w )

Release the buffer owned by a Protobuf writer.

Parameters

w	Writer whose data is freed and reset. NULL is accepted and ignored.

Definition at line 28 of file protobuf.c.

References cap, and cwist_free().

◆ cwist_pb_writer_init()

void cwist_pb_writer_init ( cwist_pb_writer * w )

Initialize a Protobuf writer to an empty buffer.

Parameters

w	Writer to reset. NULL is accepted and ignored.

Definition at line 17 of file protobuf.c.

References cap.

◆ cwist_pb_writer_reserve()

int cwist_pb_writer_reserve	(	cwist_pb_writer *	w,
		size_t	extra
	)

Ensure the writer buffer has room for extra more bytes.

Parameters

w	Writer to grow. Must not be NULL.
extra	Number of additional bytes required beyond the current length.

Returns: 0 on success, -1 on invalid argument, overflow, or allocation failure.

Definition at line 42 of file protobuf.c.

References cap, and cwist_realloc().

Referenced by cwist_pb_write_bytes_field(), cwist_pb_write_raw32(), cwist_pb_write_raw64(), and cwist_pb_write_varint().

◆ cwist_pb_zigzag_decode()

int64_t cwist_pb_zigzag_decode ( uint64_t value )

ZigZag-decode an unsigned 64-bit value back to a signed value.

Parameters

value ZigZag-encoded value, as produced by cwist_pb_zigzag_encode().

Returns: The original signed value.

Definition at line 355 of file protobuf.c.

References cap.

◆ cwist_pb_zigzag_encode()

uint64_t cwist_pb_zigzag_encode ( int64_t value )

ZigZag-encode a signed 64-bit value for sint fields.

Parameters

value Signed value to encode.

Returns: The ZigZag-encoded unsigned value: small magnitudes map to small unsigned codes regardless of sign (0, -1, 1, -2, 2 -> 0, 1, 2, 3, 4).

Definition at line 344 of file protobuf.c.

References cap.

Functions

Detailed Description

Function Documentation

◆ cwist_pb_read_field()

◆ cwist_pb_read_varint()

◆ cwist_pb_reader_init()

◆ cwist_pb_skip_field()

◆ cwist_pb_write_bool_field()

◆ cwist_pb_write_bytes_field()

◆ cwist_pb_write_double_field()

◆ cwist_pb_write_fixed32_field()

◆ cwist_pb_write_fixed64_field()

◆ cwist_pb_write_float_field()

◆ cwist_pb_write_int64_field()

◆ cwist_pb_write_key()

◆ cwist_pb_write_raw32()

◆ cwist_pb_write_raw64()

◆ cwist_pb_write_string_field()

◆ cwist_pb_write_uint64_field()

◆ cwist_pb_write_varint()

◆ cwist_pb_writer_free()

◆ cwist_pb_writer_init()

◆ cwist_pb_writer_reserve()

◆ cwist_pb_zigzag_decode()

◆ cwist_pb_zigzag_encode()