bitvec: Add get/set byte sequences
The new functions bitvec_get_bytes and bitvec_set_bytes copy
byte sequences from bitvecs to uint8_t arrays and vice versa.
While the bytes in the bitvecs do not need to be aligned, the uint8_t
arrays always are. In case the bytes in the bitvec are aligned, the
implementation uses memcpy.
Note that the implementation like the other existing functions assume
MSB first encoding.
[hfreyther: Squash the comment fix into this commit as well]
Sponsored-by: On-Waves ehf
diff --git a/include/osmocom/core/bitvec.h b/include/osmocom/core/bitvec.h
index 62e2e7b..89eb784 100644
--- a/include/osmocom/core/bitvec.h
+++ b/include/osmocom/core/bitvec.h
@@ -28,6 +28,14 @@
/*! \file bitvec.h
* \brief Osmocom bit vector abstraction
+ *
+ * These functions assume a MSB (most significant bit) first layout of the
+ * bits, so that for instance the 5 bit number abcde (a is MSB) can be
+ * embedded into a byte sequence like in xxxxxxab cdexxxxx. The bit count
+ * starts with the MSB, so the bits in a byte are numbered (MSB) 01234567 (LSB).
+ * Note that there are other incompatible encodings, like it is used
+ * for the EGPRS RLC data block headers (there the bits are numbered from LSB
+ * to MSB).
*/
#include <stdint.h>
@@ -63,5 +71,7 @@
int bitvec_get_uint(struct bitvec *bv, int num_bits);
int bitvec_find_bit_pos(const struct bitvec *bv, unsigned int n, enum bit_value val);
int bitvec_spare_padding(struct bitvec *bv, unsigned int up_to_bit);
+int bitvec_get_bytes(struct bitvec *bv, uint8_t *bytes, int count);
+int bitvec_set_bytes(struct bitvec *bv, const uint8_t *bytes, int count);
/*! @} */