Compresie ZLib char - fisier - Forumul Softpedia

#1
GabyF

Posted 28 February 2023 - 16:14

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Înscris: 27.09.2006

Am facut o functie care incarca datele existente intr-un fisier comprimat zlib intr-un char.

int uncomprCharLen(char *&output, char *infile) {
int nr_read, nr_out = 0; char buffer[512];
gzFile gzfile = gzopen(infile, "rb");
gzread(gzfile, buffer, 4);
char *tmp=new char[gzoffset(gzfile)*4];// uncompress data cannot be larger
gzseek(gzfile, 0, SEEK_SET);
while ((nr_read = gzread(gzfile, buffer, sizeof(buffer))) > 0) {
strncat(tmp, buffer, nr_read);
nr_out+=nr_read;
}
delete[] output;
output = new char[nr_out];
strncpy(output, tmp, nr_out);
delete[] tmp;
gzclose(gzfile);
return nr_out;
}
int main(int argc, char **argv) {
char *uncompr=new char[4];
uncomprCharLen(uncompr, argv[1]);
printf("uncompr %s\n", uncompr);
return 0;
}

Pare ca merge. Intrebarea mea este daca vi se pare ceva in neregula.
Zlib nu ofera posibilitatea de-a afla lungimea sirului decomprimat si nici n-as vrea sa folosesc gzread de doua ori. Asa ca am folosit un char temporar destul de mare si am redimensionat char-ul pe care o sa-l folosesc in afara functiei.

Edited by GabyF, 28 February 2023 - 16:14.

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#2
dani.user

Posted 28 February 2023 - 19:49

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std::vector

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#3
dani.user

Posted 28 February 2023 - 20:47

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Exista desigur si posibilitatea sa nici n-ai nevoie de toate caracterele deodata. De exemplu daca doar le copiez in alta parte sau faci procesari pe cate putine odata.

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#4
dani.user

Posted 02 March 2023 - 10:21

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Înscris: 24.02.2007

Ai reusit?

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Compresie ZLib char - fisier

#1 GabyF Posted 28 February 2023 - 16:14

#2 dani.user Posted 28 February 2023 - 19:49

#3 dani.user Posted 28 February 2023 - 20:47

#4 dani.user Posted 02 March 2023 - 10:21

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#1
GabyF

Posted 28 February 2023 - 16:14

#2
dani.user

Posted 28 February 2023 - 19:49

#3
dani.user

Posted 28 February 2023 - 20:47

#4
dani.user

Posted 02 March 2023 - 10:21