X-Git-Url: https://git.stg.codes/stg.git/blobdiff_plain/b27841d687ec9e84983340b5581376dfb24010ea..b2b89723a2427bba8290bd6967a1ab39cbb630be:/libs/smux/include/stg/asn_bit_data.h

diff --git a/libs/smux/include/stg/asn_bit_data.h b/libs/smux/include/stg/asn_bit_data.h
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+++ b/libs/smux/include/stg/asn_bit_data.h
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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 */