kaspar/RIOT
1
0
Fork 0
mirror of https://github.com/RIOT-OS/RIOT.git synced 2025-12-31 17:31:18 +01:00
Code Releases Activity

Merge pull request #21428 from benpicco/sys/bcd_buf_from_str

Browse Source 
sys/bcd: add `bcd_buf_to_u32()` and `bcd_buf_from_str()`
This commit is contained in:
Marian Buschsieweke 2025-04-26 14:02:28 +00:00 committed by GitHub
commit a862dc6794
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194
3 changed files with 136 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
sys/bcd/bcd.c
View File

@ -56,3 +56,61 @@ int bcd_buf_from_u32(uint32_t val, void *dst, size_t len)
return (uintptr_t)tgt - (uintptr_t)dst;
}
/* Use the same code for 32 bit and 64 bit sum */
#define _BCD_CONVERT(sum, len) \
for (int i = len * 2 - 1; i >= 0; --i) { \
uint8_t digit = i & 1 \
? bcd[i >> 1] >> 4 \
: bcd[i >> 1] & 0xF; \
sum = sum * 10 + digit; \
}
uint32_t bcd_buf_to_u32(const void *src, size_t len)
{
const uint8_t *bcd = src;
uint32_t sum = 0;
_BCD_CONVERT(sum, len);
return sum;
}
uint64_t bcd_buf_to_u64(const void *src, size_t len)
{
const uint8_t *bcd = src;
uint64_t sum = 0;
_BCD_CONVERT(sum, len);
return sum;
}
static bool _is_digit(char c)
{
return c >= '0' && c <= '9';
}
int bcd_buf_from_str(const char *str, size_t len, void *dst, size_t dst_len)
{
uint8_t *bcd = dst;
memset(dst, 0, dst_len);
dst_len *= 2;
uint8_t i = 0;
for (int j = len; j >= 0; --j) {
if (i == dst_len) {
return -ENOBUFS;
}
if (!_is_digit(str[j])) {
continue;
}
uint8_t d = str[j] & 0xF;
bcd[i >> 1] |= i & 1
? d << 4
: d;
++i;
}
return (i & 1) + (i >> 1);
}

41
sys/include/bcd.h
View File

@ -16,10 +16,12 @@
* @brief BCD definitions
*
* @author Martine Lenders <m.lenders@fu-berlin.de>
* @author Benjamin Valentin <benjamin.valentin@ml-pa.com>
*/
#ifndef BCD_H
#define BCD_H
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
@ -64,11 +66,48 @@ static inline uint8_t bcd_to_byte(uint8_t bcd)
* @param[in] len Size of the destination buffer
*
* @return number of bytes written
* @return -ENOBUFS if @p dst is not large enough
* @retval -ENOBUFS if @p dst is not large enough
* In that case the state of @p dst is undefined.
*/
int bcd_buf_from_u32(uint32_t val, void *dst, size_t len);
/**
* @brief Convert a BCD buffer into it's binary representation
* (This will reverse @ref bcd_buf_from_u32)
*
* @param[in] src The BCD buffer to convert
* @param[in] len Bytes in @p src
*
* @returns decimal representation of @p src
*/
uint32_t bcd_buf_to_u32(const void *src, size_t len);
/**
* @brief Convert a BCD buffer into it's binary representation
*
* @param[in] src The BCD buffer to convert
* @param[in] len Bytes in @p src
*
* @returns decimal representation of @p src
*/
uint64_t bcd_buf_to_u64(const void *src, size_t len);
/**
* @brief Convert a string into a BCD buffer
* Digits may be separated by any character.
*
* @param[in] str Input string
* @param[in] str_len Length of the input string
* @param[out] dst Destination buffer
* @param[in] dst_len Size of the destination buffer
*
* @return number of bytes written
* @retval -ENOBUFS if @p dst is not large enough
* In that case the state of @p dst is undefined.
*/
int bcd_buf_from_str(const char *str, size_t str_len,
void *dst, size_t dst_len);
#ifdef __cplusplus
}
#endif

38
tests/unittests/tests-bcd/tests-bcd.c
View File

@ -85,6 +85,42 @@ static void test_bcd_buf_from_u32(void)
TEST_ASSERT_EQUAL_INT(-ENOBUFS, bcd_buf_from_u32(0, NULL, 0));
}
static void test_bcd_buf_to_u32(void)
{
char buf[4];
bcd_buf_from_u32(1, buf, sizeof(buf));
TEST_ASSERT_EQUAL_INT(1, bcd_buf_to_u32(buf, sizeof(buf)));
bcd_buf_from_u32(12, buf, sizeof(buf));
TEST_ASSERT_EQUAL_INT(12, bcd_buf_to_u32(buf, sizeof(buf)));
bcd_buf_from_u32(123, buf, sizeof(buf));
TEST_ASSERT_EQUAL_INT(123, bcd_buf_to_u32(buf, sizeof(buf)));
bcd_buf_from_u32(1234, buf, sizeof(buf));
TEST_ASSERT_EQUAL_INT(1234, bcd_buf_to_u32(buf, sizeof(buf)));
}
static void test_bcd_buf_from_str(void)
{
uint8_t buf[4];
TEST_ASSERT_EQUAL_INT(1, bcd_buf_from_str("1", 1, buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(1, bcd_buf_to_u32(buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(1, bcd_buf_from_str("12", 2, buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(12, bcd_buf_to_u32(buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(2, bcd_buf_from_str("123", 3, buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(123, bcd_buf_to_u32(buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(2, bcd_buf_from_str("1234", 4, buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(1234, bcd_buf_to_u32(buf, sizeof(buf)));
TEST_ASSERT_EQUAL_INT(-ENOBUFS, bcd_buf_from_str("1234567890", 10, buf, sizeof(buf)));
}
Test *tests_bcd_tests(void)
{
EMB_UNIT_TESTFIXTURES(fixtures) {
@ -95,6 +131,8 @@ Test *tests_bcd_tests(void)
new_TestFixture(test_bcd_to_byte__greater_0x99),
new_TestFixture(test_bcd_to_byte),
new_TestFixture(test_bcd_buf_from_u32),
new_TestFixture(test_bcd_buf_to_u32),
new_TestFixture(test_bcd_buf_from_str),
};
EMB_UNIT_TESTCALLER(bcd_tests, NULL, NULL, fixtures);