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