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Diffstat (limited to 'libs/nanopb/pb_encode.c')
| -rw-r--r-- | libs/nanopb/pb_encode.c | 803 |
1 files changed, 803 insertions, 0 deletions
diff --git a/libs/nanopb/pb_encode.c b/libs/nanopb/pb_encode.c new file mode 100644 index 00000000..05d691df --- /dev/null +++ b/libs/nanopb/pb_encode.c @@ -0,0 +1,803 @@ +/* pb_encode.c -- encode a protobuf using minimal resources + * + * 2011 Petteri Aimonen <jpa@kapsi.fi> + */ + +#include "pb.h" +#include "pb_encode.h" +#include "pb_common.h" + +/* Use the GCC warn_unused_result attribute to check that all return values + * are propagated correctly. On other compilers and gcc before 3.4.0 just + * ignore the annotation. + */ +#if !defined(__GNUC__) || ( __GNUC__ < 3) || (__GNUC__ == 3 && __GNUC_MINOR__ < 4) + #define checkreturn +#else + #define checkreturn __attribute__((warn_unused_result)) +#endif + +/************************************** + * Declarations internal to this file * + **************************************/ +typedef bool (*pb_encoder_t)(pb_ostream_t *stream, const pb_field_t *field, const void *src) checkreturn; + +static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count); +static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, const void *pData, size_t count, pb_encoder_t func); +static bool checkreturn encode_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData); +static bool checkreturn default_extension_encoder(pb_ostream_t *stream, const pb_extension_t *extension); +static bool checkreturn encode_extension_field(pb_ostream_t *stream, const pb_field_t *field, const void *pData); +static void *pb_const_cast(const void *p); +static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src); +static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src); + +/* --- Function pointers to field encoders --- + * Order in the array must match pb_action_t LTYPE numbering. + */ +static const pb_encoder_t PB_ENCODERS[PB_LTYPES_COUNT] = { + &pb_enc_varint, + &pb_enc_uvarint, + &pb_enc_svarint, + &pb_enc_fixed32, + &pb_enc_fixed64, + + &pb_enc_bytes, + &pb_enc_string, + &pb_enc_submessage, + NULL, /* extensions */ + &pb_enc_fixed_length_bytes +}; + +/******************************* + * pb_ostream_t implementation * + *******************************/ + +static bool checkreturn buf_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count) +{ + size_t i; + pb_byte_t *dest = (pb_byte_t*)stream->state; + stream->state = dest + count; + + for (i = 0; i < count; i++) + dest[i] = buf[i]; + + return true; +} + +pb_ostream_t pb_ostream_from_buffer(pb_byte_t *buf, size_t bufsize) +{ + pb_ostream_t stream; +#ifdef PB_BUFFER_ONLY + stream.callback = (void*)1; /* Just a marker value */ +#else + stream.callback = &buf_write; +#endif + stream.state = buf; + stream.max_size = bufsize; + stream.bytes_written = 0; +#ifndef PB_NO_ERRMSG + stream.errmsg = NULL; +#endif + return stream; +} + +bool checkreturn pb_write(pb_ostream_t *stream, const pb_byte_t *buf, size_t count) +{ + if (stream->callback != NULL) + { + if (stream->bytes_written + count > stream->max_size) + PB_RETURN_ERROR(stream, "stream full"); + +#ifdef PB_BUFFER_ONLY + if (!buf_write(stream, buf, count)) + PB_RETURN_ERROR(stream, "io error"); +#else + if (!stream->callback(stream, buf, count)) + PB_RETURN_ERROR(stream, "io error"); +#endif + } + + stream->bytes_written += count; + return true; +} + +/************************* + * Encode a single field * + *************************/ + +/* Encode a static array. Handles the size calculations and possible packing. */ +static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *field, + const void *pData, size_t count, pb_encoder_t func) +{ + size_t i; + const void *p; + size_t size; + + if (count == 0) + return true; + + if (PB_ATYPE(field->type) != PB_ATYPE_POINTER && count > field->array_size) + PB_RETURN_ERROR(stream, "array max size exceeded"); + + /* We always pack arrays if the datatype allows it. */ + if (PB_LTYPE(field->type) <= PB_LTYPE_LAST_PACKABLE) + { + if (!pb_encode_tag(stream, PB_WT_STRING, field->tag)) + return false; + + /* Determine the total size of packed array. */ + if (PB_LTYPE(field->type) == PB_LTYPE_FIXED32) + { + size = 4 * count; + } + else if (PB_LTYPE(field->type) == PB_LTYPE_FIXED64) + { + size = 8 * count; + } + else + { + pb_ostream_t sizestream = PB_OSTREAM_SIZING; + p = pData; + for (i = 0; i < count; i++) + { + if (!func(&sizestream, field, p)) + return false; + p = (const char*)p + field->data_size; + } + size = sizestream.bytes_written; + } + + if (!pb_encode_varint(stream, (uint64_t)size)) + return false; + + if (stream->callback == NULL) + return pb_write(stream, NULL, size); /* Just sizing.. */ + + /* Write the data */ + p = pData; + for (i = 0; i < count; i++) + { + if (!func(stream, field, p)) + return false; + p = (const char*)p + field->data_size; + } + } + else + { + p = pData; + for (i = 0; i < count; i++) + { + if (!pb_encode_tag_for_field(stream, field)) + return false; + + /* Normally the data is stored directly in the array entries, but + * for pointer-type string and bytes fields, the array entries are + * actually pointers themselves also. So we have to dereference once + * more to get to the actual data. */ + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER && + (PB_LTYPE(field->type) == PB_LTYPE_STRING || + PB_LTYPE(field->type) == PB_LTYPE_BYTES)) + { + if (!func(stream, field, *(const void* const*)p)) + return false; + } + else + { + if (!func(stream, field, p)) + return false; + } + p = (const char*)p + field->data_size; + } + } + + return true; +} + +/* In proto3, all fields are optional and are only encoded if their value is "non-zero". + * This function implements the check for the zero value. */ +static bool pb_check_proto3_default_value(const pb_field_t *field, const void *pData) +{ + pb_type_t type = field->type; + const void *pSize = (const char*)pData + field->size_offset; + + if (PB_HTYPE(type) == PB_HTYPE_REQUIRED) + { + /* Required proto2 fields inside proto3 submessage, pretty rare case */ + return false; + } + else if (PB_HTYPE(type) == PB_HTYPE_REPEATED) + { + /* Repeated fields inside proto3 submessage: present if count != 0 */ + return *(const pb_size_t*)pSize == 0; + } + else if (PB_HTYPE(type) == PB_HTYPE_ONEOF) + { + /* Oneof fields */ + return *(const pb_size_t*)pSize == 0; + } + else if (PB_HTYPE(type) == PB_HTYPE_OPTIONAL && field->size_offset) + { + /* Proto2 optional fields inside proto3 submessage */ + return *(const bool*)pSize == false; + } + + /* Rest is proto3 singular fields */ + + if (PB_ATYPE(type) == PB_ATYPE_STATIC) + { + if (PB_LTYPE(type) == PB_LTYPE_BYTES) + { + const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData; + return bytes->size == 0; + } + else if (PB_LTYPE(type) == PB_LTYPE_STRING) + { + return *(const char*)pData == '\0'; + } + else if (PB_LTYPE(type) == PB_LTYPE_FIXED_LENGTH_BYTES) + { + /* Fixed length bytes is only empty if its length is fixed + * as 0. Which would be pretty strange, but we can check + * it anyway. */ + return field->data_size == 0; + } + else if (PB_LTYPE(type) == PB_LTYPE_SUBMESSAGE) + { + /* Check all fields in the submessage to find if any of them + * are non-zero. The comparison cannot be done byte-per-byte + * because the C struct may contain padding bytes that must + * be skipped. + */ + pb_field_iter_t iter; + if (pb_field_iter_begin(&iter, (const pb_field_t*)field->ptr, pb_const_cast(pData))) + { + do + { + if (!pb_check_proto3_default_value(iter.pos, iter.pData)) + { + return false; + } + } while (pb_field_iter_next(&iter)); + } + return true; + } + } + + { + /* Catch-all branch that does byte-per-byte comparison for zero value. + * + * This is for all pointer fields, and for static PB_LTYPE_VARINT, + * UVARINT, SVARINT, FIXED32, FIXED64, EXTENSION fields, and also + * callback fields. These all have integer or pointer value which + * can be compared with 0. + */ + pb_size_t i; + const char *p = (const char*)pData; + for (i = 0; i < field->data_size; i++) + { + if (p[i] != 0) + { + return false; + } + } + + return true; + } +} + +/* Encode a field with static or pointer allocation, i.e. one whose data + * is available to the encoder directly. */ +static bool checkreturn encode_basic_field(pb_ostream_t *stream, + const pb_field_t *field, const void *pData) +{ + pb_encoder_t func; + bool implicit_has; + const void *pSize = &implicit_has; + + func = PB_ENCODERS[PB_LTYPE(field->type)]; + + if (field->size_offset) + { + /* Static optional, repeated or oneof field */ + pSize = (const char*)pData + field->size_offset; + } + else if (PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL) + { + /* Proto3 style field, optional but without explicit has_ field. */ + implicit_has = !pb_check_proto3_default_value(field, pData); + } + else + { + /* Required field, always present */ + implicit_has = true; + } + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { + /* pData is a pointer to the field, which contains pointer to + * the data. If the 2nd pointer is NULL, it is interpreted as if + * the has_field was false. + */ + pData = *(const void* const*)pData; + implicit_has = (pData != NULL); + } + + switch (PB_HTYPE(field->type)) + { + case PB_HTYPE_REQUIRED: + if (!pData) + PB_RETURN_ERROR(stream, "missing required field"); + if (!pb_encode_tag_for_field(stream, field)) + return false; + if (!func(stream, field, pData)) + return false; + break; + + case PB_HTYPE_OPTIONAL: + if (*(const bool*)pSize) + { + if (!pb_encode_tag_for_field(stream, field)) + return false; + + if (!func(stream, field, pData)) + return false; + } + break; + + case PB_HTYPE_REPEATED: + if (!encode_array(stream, field, pData, *(const pb_size_t*)pSize, func)) + return false; + break; + + case PB_HTYPE_ONEOF: + if (*(const pb_size_t*)pSize == field->tag) + { + if (!pb_encode_tag_for_field(stream, field)) + return false; + + if (!func(stream, field, pData)) + return false; + } + break; + + default: + PB_RETURN_ERROR(stream, "invalid field type"); + } + + return true; +} + +/* Encode a field with callback semantics. This means that a user function is + * called to provide and encode the actual data. */ +static bool checkreturn encode_callback_field(pb_ostream_t *stream, + const pb_field_t *field, const void *pData) +{ + const pb_callback_t *callback = (const pb_callback_t*)pData; + +#ifdef PB_OLD_CALLBACK_STYLE + const void *arg = callback->arg; +#else + void * const *arg = &(callback->arg); +#endif + + if (callback->funcs.encode != NULL) + { + if (!callback->funcs.encode(stream, field, arg)) + PB_RETURN_ERROR(stream, "callback error"); + } + return true; +} + +/* Encode a single field of any callback or static type. */ +static bool checkreturn encode_field(pb_ostream_t *stream, + const pb_field_t *field, const void *pData) +{ + switch (PB_ATYPE(field->type)) + { + case PB_ATYPE_STATIC: + case PB_ATYPE_POINTER: + return encode_basic_field(stream, field, pData); + + case PB_ATYPE_CALLBACK: + return encode_callback_field(stream, field, pData); + + default: + PB_RETURN_ERROR(stream, "invalid field type"); + } +} + +/* Default handler for extension fields. Expects to have a pb_field_t + * pointer in the extension->type->arg field. */ +static bool checkreturn default_extension_encoder(pb_ostream_t *stream, + const pb_extension_t *extension) +{ + const pb_field_t *field = (const pb_field_t*)extension->type->arg; + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + { + /* For pointer extensions, the pointer is stored directly + * in the extension structure. This avoids having an extra + * indirection. */ + return encode_field(stream, field, &extension->dest); + } + else + { + return encode_field(stream, field, extension->dest); + } +} + +/* Walk through all the registered extensions and give them a chance + * to encode themselves. */ +static bool checkreturn encode_extension_field(pb_ostream_t *stream, + const pb_field_t *field, const void *pData) +{ + const pb_extension_t *extension = *(const pb_extension_t* const *)pData; + PB_UNUSED(field); + + while (extension) + { + bool status; + if (extension->type->encode) + status = extension->type->encode(stream, extension); + else + status = default_extension_encoder(stream, extension); + + if (!status) + return false; + + extension = extension->next; + } + + return true; +} + +/********************* + * Encode all fields * + *********************/ + +static void *pb_const_cast(const void *p) +{ + /* Note: this casts away const, in order to use the common field iterator + * logic for both encoding and decoding. */ + union { + void *p1; + const void *p2; + } t; + t.p2 = p; + return t.p1; +} + +bool checkreturn pb_encode(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct) +{ + pb_field_iter_t iter; + if (!pb_field_iter_begin(&iter, fields, pb_const_cast(src_struct))) + return true; /* Empty message type */ + + do { + if (PB_LTYPE(iter.pos->type) == PB_LTYPE_EXTENSION) + { + /* Special case for the extension field placeholder */ + if (!encode_extension_field(stream, iter.pos, iter.pData)) + return false; + } + else + { + /* Regular field */ + if (!encode_field(stream, iter.pos, iter.pData)) + return false; + } + } while (pb_field_iter_next(&iter)); + + return true; +} + +bool pb_encode_delimited(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct) +{ + return pb_encode_submessage(stream, fields, src_struct); +} + +bool pb_get_encoded_size(size_t *size, const pb_field_t fields[], const void *src_struct) +{ + pb_ostream_t stream = PB_OSTREAM_SIZING; + + if (!pb_encode(&stream, fields, src_struct)) + return false; + + *size = stream.bytes_written; + return true; +} + +/******************** + * Helper functions * + ********************/ +bool checkreturn pb_encode_varint(pb_ostream_t *stream, uint64_t value) +{ + pb_byte_t buffer[10]; + size_t i = 0; + + if (value <= 0x7F) + { + pb_byte_t v = (pb_byte_t)value; + return pb_write(stream, &v, 1); + } + + while (value) + { + buffer[i] = (pb_byte_t)((value & 0x7F) | 0x80); + value >>= 7; + i++; + } + buffer[i-1] &= 0x7F; /* Unset top bit on last byte */ + + return pb_write(stream, buffer, i); +} + +bool checkreturn pb_encode_svarint(pb_ostream_t *stream, int64_t value) +{ + uint64_t zigzagged; + if (value < 0) + zigzagged = ~((uint64_t)value << 1); + else + zigzagged = (uint64_t)value << 1; + + return pb_encode_varint(stream, zigzagged); +} + +bool checkreturn pb_encode_fixed32(pb_ostream_t *stream, const void *value) +{ + uint32_t val = *(const uint32_t*)value; + pb_byte_t bytes[4]; + bytes[0] = (pb_byte_t)(val & 0xFF); + bytes[1] = (pb_byte_t)((val >> 8) & 0xFF); + bytes[2] = (pb_byte_t)((val >> 16) & 0xFF); + bytes[3] = (pb_byte_t)((val >> 24) & 0xFF); + return pb_write(stream, bytes, 4); +} + +bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value) +{ + uint64_t val = *(const uint64_t*)value; + pb_byte_t bytes[8]; + bytes[0] = (pb_byte_t)(val & 0xFF); + bytes[1] = (pb_byte_t)((val >> 8) & 0xFF); + bytes[2] = (pb_byte_t)((val >> 16) & 0xFF); + bytes[3] = (pb_byte_t)((val >> 24) & 0xFF); + bytes[4] = (pb_byte_t)((val >> 32) & 0xFF); + bytes[5] = (pb_byte_t)((val >> 40) & 0xFF); + bytes[6] = (pb_byte_t)((val >> 48) & 0xFF); + bytes[7] = (pb_byte_t)((val >> 56) & 0xFF); + return pb_write(stream, bytes, 8); +} + +bool checkreturn pb_encode_tag(pb_ostream_t *stream, pb_wire_type_t wiretype, uint32_t field_number) +{ + uint64_t tag = ((uint64_t)field_number << 3) | wiretype; + return pb_encode_varint(stream, tag); +} + +bool checkreturn pb_encode_tag_for_field(pb_ostream_t *stream, const pb_field_t *field) +{ + pb_wire_type_t wiretype; + switch (PB_LTYPE(field->type)) + { + case PB_LTYPE_VARINT: + case PB_LTYPE_UVARINT: + case PB_LTYPE_SVARINT: + wiretype = PB_WT_VARINT; + break; + + case PB_LTYPE_FIXED32: + wiretype = PB_WT_32BIT; + break; + + case PB_LTYPE_FIXED64: + wiretype = PB_WT_64BIT; + break; + + case PB_LTYPE_BYTES: + case PB_LTYPE_STRING: + case PB_LTYPE_SUBMESSAGE: + case PB_LTYPE_FIXED_LENGTH_BYTES: + wiretype = PB_WT_STRING; + break; + + default: + PB_RETURN_ERROR(stream, "invalid field type"); + } + + return pb_encode_tag(stream, wiretype, field->tag); +} + +bool checkreturn pb_encode_string(pb_ostream_t *stream, const pb_byte_t *buffer, size_t size) +{ + if (!pb_encode_varint(stream, (uint64_t)size)) + return false; + + return pb_write(stream, buffer, size); +} + +bool checkreturn pb_encode_submessage(pb_ostream_t *stream, const pb_field_t fields[], const void *src_struct) +{ + /* First calculate the message size using a non-writing substream. */ + pb_ostream_t substream = PB_OSTREAM_SIZING; + size_t size; + bool status; + + if (!pb_encode(&substream, fields, src_struct)) + { +#ifndef PB_NO_ERRMSG + stream->errmsg = substream.errmsg; +#endif + return false; + } + + size = substream.bytes_written; + + if (!pb_encode_varint(stream, (uint64_t)size)) + return false; + + if (stream->callback == NULL) + return pb_write(stream, NULL, size); /* Just sizing */ + + if (stream->bytes_written + size > stream->max_size) + PB_RETURN_ERROR(stream, "stream full"); + + /* Use a substream to verify that a callback doesn't write more than + * what it did the first time. */ + substream.callback = stream->callback; + substream.state = stream->state; + substream.max_size = size; + substream.bytes_written = 0; +#ifndef PB_NO_ERRMSG + substream.errmsg = NULL; +#endif + + status = pb_encode(&substream, fields, src_struct); + + stream->bytes_written += substream.bytes_written; + stream->state = substream.state; +#ifndef PB_NO_ERRMSG + stream->errmsg = substream.errmsg; +#endif + + if (substream.bytes_written != size) + PB_RETURN_ERROR(stream, "submsg size changed"); + + return status; +} + +/* Field encoders */ + +static bool checkreturn pb_enc_varint(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + int64_t value = 0; + + if (field->data_size == sizeof(int_least8_t)) + value = *(const int_least8_t*)src; + else if (field->data_size == sizeof(int_least16_t)) + value = *(const int_least16_t*)src; + else if (field->data_size == sizeof(int32_t)) + value = *(const int32_t*)src; + else if (field->data_size == sizeof(int64_t)) + value = *(const int64_t*)src; + else + PB_RETURN_ERROR(stream, "invalid data_size"); + + return pb_encode_varint(stream, (uint64_t)value); +} + +static bool checkreturn pb_enc_uvarint(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + uint64_t value = 0; + + if (field->data_size == sizeof(uint_least8_t)) + value = *(const uint_least8_t*)src; + else if (field->data_size == sizeof(uint_least16_t)) + value = *(const uint_least16_t*)src; + else if (field->data_size == sizeof(uint32_t)) + value = *(const uint32_t*)src; + else if (field->data_size == sizeof(uint64_t)) + value = *(const uint64_t*)src; + else + PB_RETURN_ERROR(stream, "invalid data_size"); + + return pb_encode_varint(stream, value); +} + +static bool checkreturn pb_enc_svarint(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + int64_t value = 0; + + if (field->data_size == sizeof(int_least8_t)) + value = *(const int_least8_t*)src; + else if (field->data_size == sizeof(int_least16_t)) + value = *(const int_least16_t*)src; + else if (field->data_size == sizeof(int32_t)) + value = *(const int32_t*)src; + else if (field->data_size == sizeof(int64_t)) + value = *(const int64_t*)src; + else + PB_RETURN_ERROR(stream, "invalid data_size"); + + return pb_encode_svarint(stream, value); +} + +static bool checkreturn pb_enc_fixed64(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + PB_UNUSED(field); + return pb_encode_fixed64(stream, src); +} + +static bool checkreturn pb_enc_fixed32(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + PB_UNUSED(field); + return pb_encode_fixed32(stream, src); +} + +static bool checkreturn pb_enc_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + const pb_bytes_array_t *bytes = NULL; + + bytes = (const pb_bytes_array_t*)src; + + if (src == NULL) + { + /* Treat null pointer as an empty bytes field */ + return pb_encode_string(stream, NULL, 0); + } + + if (PB_ATYPE(field->type) == PB_ATYPE_STATIC && + PB_BYTES_ARRAY_T_ALLOCSIZE(bytes->size) > field->data_size) + { + PB_RETURN_ERROR(stream, "bytes size exceeded"); + } + + return pb_encode_string(stream, bytes->bytes, bytes->size); +} + +static bool checkreturn pb_enc_string(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + size_t size = 0; + size_t max_size = field->data_size; + const char *p = (const char*)src; + + if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) + max_size = (size_t)-1; + + if (src == NULL) + { + size = 0; /* Treat null pointer as an empty string */ + } + else + { + /* strnlen() is not always available, so just use a loop */ + while (size < max_size && *p != '\0') + { + size++; + p++; + } + } + + return pb_encode_string(stream, (const pb_byte_t*)src, size); +} + +static bool checkreturn pb_enc_submessage(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + if (field->ptr == NULL) + PB_RETURN_ERROR(stream, "invalid field descriptor"); + + return pb_encode_submessage(stream, (const pb_field_t*)field->ptr, src); +} + +static bool checkreturn pb_enc_fixed_length_bytes(pb_ostream_t *stream, const pb_field_t *field, const void *src) +{ + return pb_encode_string(stream, (const pb_byte_t*)src, field->data_size); +} + |