/
lzdatagen.h
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/
lzdatagen.h
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/*
* lzdatagen - LZ data generator
*
* Copyright 2016-2023 Joergen Ibsen
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef LZDATAGEN_H_INCLUDED
#define LZDATAGEN_H_INCLUDED
#include <stddef.h>
#ifdef __cplusplus
extern "C" {
#endif
#define LZDG_VER_MAJOR 0 /**< Major version number */
#define LZDG_VER_MINOR 2 /**< Minor version number */
#define LZDG_VER_PATCH 0 /**< Patch version number */
#define LZDG_VER_STRING "0.2.0" /**< Version number as a string */
/**
* Generate compressible data.
*
* Data is generated by inserting sequences of either random bytes or
* repetitions from a buffer of bytes, depending on the ratio parameter.
*
* Based on "SDGen: Mimicking Datasets for Content Generation in Storage
* Benchmarks" by Raúl Gracia-Tinedo et al. (https://www.usenix.org/node/188461)
*
* Instead of sampling actual data, this uses a simple power function to
* determine the distributions of literals values and match lenghts.
*
* @param ptr pointer to where to store generated data
* @param size number of bytes to generate
* @param ratio desired compression ratio
* @param len_exp exponent used for distribution of lenghts
* @param lit_exp exponent used for distribution of literals
*/
void
lzdg_generate_data(void *ptr, size_t size, double ratio, double len_exp, double lit_exp);
/**
* Generate compressible data in bulk.
*
* This uses a faster but less precise method of generating the literals,
* and is useful when generating large amounts of data.
*
* @see lzdg_generate_data
*
* @param ptr pointer to where to store generated data
* @param size number of bytes to generate
* @param ratio desired compression ratio
* @param len_exp exponent used for distribution of lenghts
* @param lit_exp exponent used for distribution of literals
*/
void
lzdg_generate_data_bulk(void *ptr, size_t size, double ratio, double len_exp, double lit_exp);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* LZDATAGEN_H_INCLUDED */