c-multicodec/varint.h
2016-11-17 16:52:27 +02:00

51 lines
No EOL
1.1 KiB
C

#ifndef VARINT
#define VARINT
#include <stddef.h> /* size_t */
#include <stdint.h> /* uint8_t, uint64_t */
#define DEFN_ENCODER(SIZE) \
size_t \
uvarint_encode##SIZE (uint##SIZE##_t val, uint8_t buf[], size_t bufsize) \
{ \
size_t i = 0; \
for (; i < (SIZE/8) && i < bufsize; i++) { \
buf[i] = (uint8_t) ((val & 0xFF) | 0x80); \
val >>= 7; \
if (!val) \
return i + 1; \
} \
return -1; \
}
#define DEFN_DECODER(SIZE) \
size_t \
uvarint_decode##SIZE (uint8_t buf[], size_t bufsize, uint##SIZE##_t *val) \
{ \
*val = 0; \
size_t i = 0; \
for (; i < (SIZE/8) && i < bufsize; i++) { \
*val |= ((buf[i] & 0x7f) << (7 * i)); \
if (!(buf[i] & 0x80)) \
return i + 1; \
} \
return -1; \
}
#define DECL_ENCODER(SIZE) \
size_t \
uvarint_encode##SIZE (uint##SIZE##_t val, uint8_t buf[], size_t bufsize);
#define DECL_DECODER(SIZE) \
size_t \
uvarint_decode##SIZE (uint8_t buf[], size_t bufsize, uint##SIZE##_t *val);
DECL_ENCODER(32)
DECL_DECODER(32)
DECL_ENCODER(64)
DECL_DECODER(64)
#endif