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/*
* Copyright (c) 2005-2017 Lev Walkin <vlm@lionet.info>. All rights reserved.
* Redistribution and modifications are permitted subject to BSD license.
*/
#ifndef ASN_BIT_DATA
#define ASN_BIT_DATA
#include <asn_system.h> /* Platform-specific types */
#ifdef __cplusplus
extern "C" {
#endif
/*
* This structure describes a position inside an incoming PER bit stream.
*/
typedef struct asn_bit_data_s {
const uint8_t *buffer; /* Pointer to the octet stream */
size_t nboff; /* Bit offset to the meaningful bit */
size_t nbits; /* Number of bits in the stream */
size_t moved; /* Number of bits moved through this bit stream */
int (*refill)(struct asn_bit_data_s *);
void *refill_key;
} asn_bit_data_t;
/*
* Create a contiguous non-refillable bit data structure.
* Can be freed by FREEMEM().
*/
asn_bit_data_t *asn_bit_data_new_contiguous(const void *data, size_t size_bits);
/*
* Extract a small number of bits (<= 31) from the specified PER data pointer.
* This function returns -1 if the specified number of bits could not be
* extracted due to EOD or other conditions.
*/
int32_t asn_get_few_bits(asn_bit_data_t *, int get_nbits);
/* Undo the immediately preceeding "get_few_bits" operation */
void asn_get_undo(asn_bit_data_t *, int get_nbits);
/*
* Extract a large number of bits from the specified PER data pointer.
* This function returns -1 if the specified number of bits could not be
* extracted due to EOD or other conditions.
*/
int asn_get_many_bits(asn_bit_data_t *, uint8_t *dst, int right_align,
int get_nbits);
/* Non-thread-safe debugging function, don't use it */
char *asn_bit_data_string(asn_bit_data_t *);
/*
* This structure supports forming bit output.
*/
typedef struct asn_bit_outp_s {
uint8_t *buffer; /* Pointer into the (tmpspace) */
size_t nboff; /* Bit offset to the meaningful bit */
size_t nbits; /* Number of bits left in (tmpspace) */
uint8_t tmpspace[32]; /* Preliminary storage to hold data */
int (*output)(const void *data, size_t size, void *op_key);
void *op_key; /* Key for (output) data callback */
size_t flushed_bytes; /* Bytes already flushed through (output) */
} asn_bit_outp_t;
/* Output a small number of bits (<= 31) */
int asn_put_few_bits(asn_bit_outp_t *, uint32_t bits, int obits);
/* Output a large number of bits */
int asn_put_many_bits(asn_bit_outp_t *, const uint8_t *src, int put_nbits);
/*
* Flush whole bytes (0 or more) through (outper) member.
* The least significant bits which are not used are guaranteed to be set to 0.
* Returns -1 if callback returns -1. Otherwise, 0.
*/
int asn_put_aligned_flush(asn_bit_outp_t *);
#ifdef __cplusplus
}
#endif
#endif /* ASN_BIT_DATA */