diff options
| -rw-r--r-- | pb_encode.c | 77 |
1 files changed, 55 insertions, 22 deletions
diff --git a/pb_encode.c b/pb_encode.c index b0a736a2..13bda22c 100644 --- a/pb_encode.c +++ b/pb_encode.c @@ -197,41 +197,75 @@ static bool checkreturn encode_array(pb_ostream_t *stream, const pb_field_t *fie 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) +{ + if(PB_LTYPE(field->type) == PB_LTYPE_BYTES) + { + const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData; + return bytes->size == 0; + } + else if (PB_LTYPE(field->type) == PB_LTYPE_STRING) + { + return *(const char*)pData == '\0'; + } + else if (PB_LTYPE(field->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 + { + /* PB_LTYPE_VARINT, UVARINT, SVARINT, FIXED32, FIXED64, + * SUBMESSAGE, EXTENSION: These all have integer or pointer + * value which can be compared with 0. This does the check + * byte-by-byte to avoid the switch-cast logic used in + * pb_enc_varint(). (Casting to char* is safe with regards + * to C strict aliasing rules.) + */ + uint_fast8_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; - const void *pSize; - bool implicit_has = true; + 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 (!field->size_offset && PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL) + } + else if (PB_HTYPE(field->type) == PB_HTYPE_OPTIONAL) { - /* In proto3 there are optional fields but no has_ flag, do not encode this fields - * when value is default or empty. */ - if(PB_LTYPE(field->type) == PB_LTYPE_BYTES) - { - const pb_bytes_array_t *bytes = (const pb_bytes_array_t*)pData; - if(bytes->size == 0) - implicit_has = false; - } - else if ((PB_LTYPE(field->type) == PB_LTYPE_STRING && *(const char*)pData == '\0') || - (field->data_size == sizeof(uint_least8_t) && *(const uint_least8_t*)pData == 0) || - (field->data_size == sizeof(uint_least16_t) && *(const uint_least16_t*)pData == 0) || - (field->data_size == sizeof(uint32_t) && *(const uint_least32_t*)pData == 0) || - (field->data_size == sizeof(uint64_t) && *(const uint_least64_t*)pData == 0)) - { - implicit_has = false; - } - pSize = &implicit_has; + /* Proto3 style field, optional but without explicit has_ field. */ + implicit_has = !pb_check_proto3_default_value(field, pData); } else - pSize = &implicit_has; + { + /* Required field, always present */ + implicit_has = true; + } if (PB_ATYPE(field->type) == PB_ATYPE_POINTER) { @@ -239,7 +273,6 @@ static bool checkreturn encode_basic_field(pb_ostream_t *stream, * 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); } |