Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 3/22/2024
Public
Document Table of Contents

EncodeLZ4HCHashTableGetSize

Calculates the size of the LZ4 HashTable and PrevTable for HC mode.

Syntax

IppStatus ippsEncodeLZ4HCHashTableGetSize(int* pHashTableSize, int* pPrevTableSize);

Include Files

ippdc.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

pHashTableSize

Pointer to the variable containing the size of the LZ4 HashTable.

pHashPrevSize

Pointer to the variable containing the size of the LZ4 PrevTable.

Description

This function calculates the size of the memory buffer that must be allocated for the LZ4 HashTable and PrevTable in HC mode.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error if pHashTableSize or pPrevTableSize is NULL.

Example

/*******************************************************************************
* Copyright 2017 Intel Corporation.
*
*
* This software and the related documents are Intel copyrighted materials, and your use of them is governed by
* the express license under which they were provided to you ('License'). Unless the License provides otherwise,
* you may not use, modify, copy, publish, distribute, disclose or transmit this software or the related
* documents without Intel's prior written permission.
* This software and the related documents are provided as is, with no express or implied warranties, other than
* those that are expressly stated in the License.
*******************************************************************************/

/*
 The example below shows how to use the functions:
     ippsEncodeLZ4HCHashTableGetSize_8u
     ippsEncodeLZ4HCHashTableInit_8u
     ippsEncodeLZ4HC_8u
     ippsDecodeLZ4_8u
*/

#include <stdio.h>
#include <string.h>

#include <ipp/ippdc.h>
#include <ipp/ipps.h>

/* Next two defines are created to simplify code reading and understanding */
#define EXIT_MAIN       exitLine:                              /* Label for Exit */
#define check_sts(st)   if((st) != ippStsNoErr) goto exitLine; /* Go to Exit if Intel(R) Integrated Performance Primitives (Intel(R) IPP) function returned status different from ippStsNoErr */

#define TEST_SIZE (1024)

static int checkDecompr(Ipp8u* decomprAddr, int decomprLen, Ipp8u* srcAddr, int srcLen);

int main(void)
{
    Ipp8u       *srcBuf = NULL, *comprBuf = NULL, *decomprBuf = NULL, *hashTable = NULL,
                *prevTable = NULL;
    Ipp8u       *tables[2];
    IppStatus   st = ippStsNoErr;
    int         hashSize = 0, prevSize = 0,
                srcLen = TEST_SIZE,
                comprLen = TEST_SIZE + TEST_SIZE / 255 + 16,    /* Extra bytes for 
                                                                    uncompressible data */
                decomprLen = TEST_SIZE + 33;                    /* Spare bytes for "wild"
                                                                (non-safe) decompression */
    int         i;

    srcBuf      = ippsMalloc_8u(TEST_SIZE);
    decomprBuf  = ippsMalloc_8u(decomprLen);
    comprBuf    = ippsMalloc_8u(comprLen);
    /* Initialize source buffer */
    check_sts(      st = ippsVectorJaehne_8u(srcBuf, TEST_SIZE, IPP_MAX_8U)         )
    for(i = 0; i < TEST_SIZE; i++)
        srcBuf[i] >>= 6;                                /* Decrease source data entropy */
    /* Init and allocate hash table */
    check_sts(      st = ippsEncodeLZ4HCHashTableGetSize_8u(&hashSize, &prevSize)       )
    hashTable   = ippsMalloc_8u(hashSize);
    prevTable   = ippsMalloc_8u(prevSize);
    tables[0]   = hashTable;
    tables[1]   = prevTable;
    check_sts(      st = ippsEncodeLZ4HCHashTableInit_8u(tables)      )
    /* Compress source data at level 1*/
    check_sts(      st = ippsEncodeLZ4HC_8u((const Ipp8u*)srcBuf, 0, &srcLen, comprBuf,
                                            &comprLen, tables, NULL, 0, 1)   )
    /* Print compression result */
    printf("Compression lev 1: %d bytes compressed into %d bytes\n", TEST_SIZE, comprLen);
    /* Decompression */
    decomprLen  = TEST_SIZE + 33;
    check_sts(  st = ippsDecodeLZ4_8u((const Ipp8u*)comprBuf, comprLen, decomprBuf, 
                                          &decomprLen)  )
    check_sts(  st = checkDecompr(decomprBuf, decomprLen, srcBuf, srcLen)   )

    /* Compress source data at level 6*/
    comprLen = TEST_SIZE + TEST_SIZE / 255 + 16;
    check_sts(  st = ippsEncodeLZ4HC_8u((const Ipp8u*)srcBuf, 0, &srcLen, comprBuf,
                                            &comprLen, tables, NULL, 0, 6)   )
    /* Print compression result */
    printf("Compression lev 6: %d bytes compressed into %d bytes\n", TEST_SIZE, comprLen);
    /* Decompression */
    decomprLen  = TEST_SIZE + 33;
    check_sts(  st = ippsDecodeLZ4_8u((const Ipp8u*)comprBuf, comprLen, decomprBuf,
                                          &decomprLen)      )
    check_sts(  st = checkDecompr(decomprBuf, decomprLen, srcBuf, srcLen)                             )

    /* Compress source data at level 9*/
    comprLen = TEST_SIZE + TEST_SIZE / 255 + 16;
    check_sts(  st = ippsEncodeLZ4HC_8u((const Ipp8u*)srcBuf, 0, &srcLen, comprBuf,
                                            &comprLen, tables, NULL, 0, 9)   )
    /* Print compression result */
    printf("Compression lev 9: %d bytes compressed into %d bytes\n", TEST_SIZE, comprLen);
    /* Decompression */
    decomprLen  = TEST_SIZE + 33;
    check_sts(  st = ippsDecodeLZ4_8u((const Ipp8u*)comprBuf, comprLen, decomprBuf,
                                          &decomprLen)  )
    st = checkDecompr(decomprBuf, decomprLen, srcBuf, srcLen);

EXIT_MAIN
    ippsFree(srcBuf);
    ippsFree(comprBuf);
    ippsFree(decomprBuf);
    ippsFree(hashTable);
    ippsFree(prevTable);
    return (int)st;
}
static IppStatus checkDecompr(Ipp8u* decomprAddr, int decomprLen, Ipp8u* srcAddr,
                              int srcLen)
{
    /* Check */
    if(decomprLen != srcLen || memcmp(decomprAddr, srcAddr, srcLen) != 0)
    {
            printf("Wrong decompression!\n");
            return ippStsErr;
    }
    printf("Decompressed OK into %d bytes\n", decomprLen);
    return ippStsNoErr;
}