59 lines
1.6 KiB
C
59 lines
1.6 KiB
C
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/*
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* Copyright (c) Meta Platforms, Inc. and affiliates.
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* All rights reserved.
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*
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* This source code is licensed under both the BSD-style license (found in the
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* LICENSE file in the root directory of this source tree) and the GPLv2 (found
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* in the COPYING file in the root directory of this source tree).
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* You may select, at your option, one of the above-listed licenses.
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*/
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#ifndef SEQGEN_H
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#define SEQGEN_H
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#define XXH_STATIC_LINKING_ONLY
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#include "xxhash.h"
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#include <stddef.h> /* size_t */
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typedef enum {
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SEQ_gen_ml = 0,
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SEQ_gen_ll,
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SEQ_gen_of,
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SEQ_gen_max /* Must be the last value */
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} SEQ_gen_type;
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/* Internal state, do not use */
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typedef struct {
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XXH64_state_t xxh; /* xxh state for all the data produced so far (seed=0) */
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unsigned seed;
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int state; /* enum to control state machine (clean=0) */
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unsigned saved;
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size_t bytesLeft;
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} SEQ_stream;
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SEQ_stream SEQ_initStream(unsigned seed);
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typedef struct {
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void* dst;
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size_t size;
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size_t pos;
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} SEQ_outBuffer;
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/* Returns non-zero until the current type/value has been generated.
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* Must pass the same type/value until it returns 0.
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*
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* Recommended to pick a value in the middle of the range you want, since there
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* may be some noise that causes actual results to be slightly different.
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* We try to be more accurate for smaller values.
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*
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* NOTE: Very small values don't work well (< 6).
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*/
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size_t SEQ_gen(SEQ_stream* stream, SEQ_gen_type type, unsigned value,
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SEQ_outBuffer* out);
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/* Returns the xxhash of the data produced so far */
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XXH64_hash_t SEQ_digest(SEQ_stream const* stream);
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#endif /* SEQGEN_H */
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