diff options
Diffstat (limited to 'shared/protocol.c')
| -rw-r--r-- | shared/protocol.c | 32 |
1 files changed, 27 insertions, 5 deletions
diff --git a/shared/protocol.c b/shared/protocol.c index 474398a..1d66f17 100644 --- a/shared/protocol.c +++ b/shared/protocol.c @@ -1,3 +1,5 @@ +#include <stddef.h> + #include "protocol.h" #ifdef __cplusplus @@ -16,13 +18,33 @@ size_t cd_cmd_sizeof(uint8_t data[CD_SERIAL_READ_BUFFER_SIZE], uint8_t data_leng return length; } -#define CD_DYN_MEMBER_SIZEOF(struct_t, length_byte, trailing_type) \ - sizeof(struct_t) + \ - (data->bytes > length_byte ? (sizeof(trailing_type) * data->data[length_byte]) : 0) +/** + * @brief macro to calculate size of message based on struct with member to + * indicate length of dynamic (last) field + * + * @param data cd_s_bin pointer to currently received data + * @param struct_t message struct + * @param length_field struct field with dynamic length + * + * @return size_t with calculated size + * + * equivalent c code: + * + * size_t size = sizeof(struct_t); + * size_t dyn_member_offset = offsetof(struct_t, length_field); + * size_t dyn_member_size = sizeof(((struct_t*)0)->length_field); + * if (data->bytes >= (dyn_member_offset + dyn_member_size)) + * size += cd_bin_ntohd(&data->data[dyn_member_offset], dyn_member_size); + * return size; + */ +#define CD_DYN_MEMBER_SIZEOF(data, struct_t, length_field) \ + sizeof(struct_t) + ( \ + (data->bytes >= (offsetof(struct_t, length_field) + sizeof(((struct_t*)0)->length_field))) ? \ + (cd_bin_ntohd(&data->data[offsetof(struct_t, length_field)], sizeof(((struct_t*)0)->length_field))) :\ + 0); size_t cd_cmd_response_sizeof(cd_s_bin* data) { - (void) data; // unused variable TODO: implement this - return 0; + return CD_DYN_MEMBER_SIZEOF(data, cd_s_cmd_response, response_size); } #ifdef __cplusplus |