Function rdbSaveBinaryDoubleValue

app/redis-6.2.6/src/rdb.c:635–638

Saves a double for RDB 8 or greater, where IE754 binary64 format is assumed. * We just make sure the integer is always stored in little endian, otherwise * the value is copied verbatim from memory to disk. * * Return -1 on error, the size of the serialized value on success. */

 *
 * Return -1 on error, the size of the serialized value on success. */
int rdbSaveBinaryDoubleValue(rio *rdb, double val) {
    memrev64ifbe(&val);
    return rdbWriteRaw(rdb,&val,sizeof(val));
}

/* Loads a double from RDB 8 or greater. See rdbSaveBinaryDoubleValue() for
 * more info. On error -1 is returned, otherwise 0. */