| /* 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 uint8_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 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); |
| |
| /* --- 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_ostream_t implementation * |
| *******************************/ |
| |
| static bool checkreturn buf_write(pb_ostream_t *stream, const uint8_t *buf, size_t count) |
| { |
| uint8_t *dest = (uint8_t*)stream->state; |
| stream->state = dest + count; |
| |
| while (count--) |
| *dest++ = *buf++; |
| |
| return true; |
| } |
| |
| pb_ostream_t pb_ostream_from_buffer(uint8_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 uint8_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; |
| } |
| |
| /* 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; |
| |
| func = PB_ENCODERS[PB_LTYPE(field->type)]; |
| |
| if (field->size_offset) |
| pSize = (const char*)pData + field->size_offset; |
| else |
| pSize = &implicit_has; |
| |
| 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 *remove_const(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, remove_const(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) |
| { |
| uint8_t buffer[10]; |
| size_t i = 0; |
| |
| if (value == 0) |
| return pb_write(stream, (uint8_t*)&value, 1); |
| |
| while (value) |
| { |
| buffer[i] = (uint8_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) |
| { |
| #ifdef __BIG_ENDIAN__ |
| const uint8_t *bytes = value; |
| uint8_t lebytes[4]; |
| lebytes[0] = bytes[3]; |
| lebytes[1] = bytes[2]; |
| lebytes[2] = bytes[1]; |
| lebytes[3] = bytes[0]; |
| return pb_write(stream, lebytes, 4); |
| #else |
| return pb_write(stream, (const uint8_t*)value, 4); |
| #endif |
| } |
| |
| bool checkreturn pb_encode_fixed64(pb_ostream_t *stream, const void *value) |
| { |
| #ifdef __BIG_ENDIAN__ |
| const uint8_t *bytes = value; |
| uint8_t lebytes[8]; |
| lebytes[0] = bytes[7]; |
| lebytes[1] = bytes[6]; |
| lebytes[2] = bytes[5]; |
| lebytes[3] = bytes[4]; |
| lebytes[4] = bytes[3]; |
| lebytes[5] = bytes[2]; |
| lebytes[6] = bytes[1]; |
| lebytes[7] = bytes[0]; |
| return pb_write(stream, lebytes, 8); |
| #else |
| return pb_write(stream, (const uint8_t*)value, 8); |
| #endif |
| } |
| |
| 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: |
| 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 uint8_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; |
| |
| /* Cases 1 and 2 are for compilers that have smaller types for bool |
| * or enums, and for int_size option. */ |
| switch (field->data_size) |
| { |
| case 1: value = *(const int8_t*)src; break; |
| case 2: value = *(const int16_t*)src; break; |
| case 4: value = *(const int32_t*)src; break; |
| case 8: value = *(const int64_t*)src; break; |
| default: 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; |
| |
| switch (field->data_size) |
| { |
| case 1: value = *(const uint8_t*)src; break; |
| case 2: value = *(const uint16_t*)src; break; |
| case 4: value = *(const uint32_t*)src; break; |
| case 8: value = *(const uint64_t*)src; break; |
| default: 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; |
| |
| switch (field->data_size) |
| { |
| case 1: value = *(const int8_t*)src; break; |
| case 2: value = *(const int16_t*)src; break; |
| case 4: value = *(const int32_t*)src; break; |
| case 8: value = *(const int64_t*)src; break; |
| default: 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 = (const pb_bytes_array_t*)src; |
| |
| if (src == NULL) |
| { |
| /* Threat 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; /* Threat 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 uint8_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); |
| } |
| |
