EncodeLZ4HashTableGetSize

Syntax

Include Files

ippdc.h

Domain Dependencies

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

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

Parameters

Description

This function calculates the size of the memory buffer that must be allocated for the LZ4 hash table.

Return Values

Example

/*******************************************************************************
* Copyright 2015 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:
     ippsEncodeLZ4HashTableGetSize_8u
     ippsEncodeLZ4HashTableInit_8u
     ippsEncodeLZ4_8u
     ippsDecodeLZ4_8u
*/

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

#include <ippdc.h>
#include <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® Integrated Primitives (Intel® IPP) function returned status different from ippStsNoErr */

#define TEST_SIZE (1024)

int main(void)
{
    Ipp8u       *srcBuf = NULL, *comprBuf = NULL, *decomprBuf = NULL, *hashTable = NULL;
    IppStatus   st = ippStsNoErr;
    int         hashSize = 0, 
                comprLen = TEST_SIZE + TEST_SIZE / 255 + 16,    /* Extra bytes for
                                                                    uncompressible data */
                decomprLen = TEST_SIZE + 33;
    int         i;

    srcBuf      = ippsMalloc_8u(TEST_SIZE);
    decomprBuf  = ippsMalloc_8u(decomprLen);                    /* Spare bytes for "wild"
                                                            (non-safe) decompression */
    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 = ippsEncodeLZ4HashTableGetSize_8u(&hashSize)    )
    hashTable   = ippsMalloc_8u(hashSize);
    check_sts(  st = ippsEncodeLZ4HashTableInit_8u(hashTable, TEST_SIZE)    )
    /* Compress source data */
    check_sts(  st = ippsEncodeLZ4_8u((const Ipp8u*)srcBuf, TEST_SIZE, comprBuf,
                                      &comprLen, hashTable) )
    /* Print compression result */
    printf("Compression: %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 */
    if(decomprLen == TEST_SIZE)/* Decompressed size must be equal to source data size */
    {
        if(memcmp(srcBuf, decomprBuf, TEST_SIZE) != 0)
        {
            printf("Wrong decompression!\n");
            st = ippStsErr;
        }
        else
            printf("Decompressed by ippsDecodeLZ4_8u OK\n");
    }
    else
        printf("Invalid decompressed length %d\n", decomprLen);

EXIT_MAIN
    ippsFree(srcBuf);
    ippsFree(comprBuf);
    ippsFree(decomprBuf);
    ippsFree(hashTable);
    return (int)st;
}