Cannot retrieve all the data from Hashtable - c

Question

I am trying to code an algorithm in C that reads a huge file ( more than 750.000 lines) , separates each line by some specified delimiters , and saves the data into a structure , which is then saved into a Hashtable. Everything goes fine until I want to print one specific data for each row of the Hashtable: the output is good for some rows , but the console is just printing some random symbols for others (which means memory leaks maybe? ).
I am trying to figure what can cause this problem. If I isolate the code that separate the line and saves it into the structure, and execute it for each line separately, it works fine, everything is printed as expected.
I have also tried to do it without dynamic allocation but it works a bit better with it as I was getting the infamous "Segmentation fault"
Here is the code that splits the line and saves it:
unsigned int hash(unsigned int id) {
unsigned int hashage = 5381; //Valeur arbitraire
unsigned int mdop = 10; //faire un modulo obtenir l'unite
int idtmp = id;
while (mdop < id) {
idtmp = id%mdop;
hashage = ((hashage << 6) + hashage) + idtmp;
mdop *= 10;
}
return hashage % NB_CASES_HASH;
}
void initiate_hashtable(Hashtable hashtable) {
int i = 0;
for (; i < NB_CASES_HASH; i++) {
hashtable[i] = NULL;
}
}
void ajout_entete(Liste *liste, Oeuvre *oeuvre) {
Liste p = malloc(sizeof(Cellule));
if (!p) exit(EXIT_FAILURE);
p->oeuvre = *oeuvre;
p->suiv = *liste;
//Si on imprime ici , tout va bien , les données sont correctes
*liste = p;
}
void ajout_annee(Liste *liste, Oeuvre *oeuvre) { //ajout trié par année pour recherche plus rapide
if (!(*liste) || oeuvre->year <= (*liste)->oeuvre.year)
ajout_entete(liste,oeuvre);
else {
if (oeuvre->year >= (*liste)->oeuvre.year)
ajout_annee(&(*liste)->suiv, &oeuvre);
}
}
Oeuvre peuple_oeuvre(char line[MAX_CHARS_LINE]) {
int i = 0, j = 1, cmpt = 0;
char strings[CHAMPS_OEUVRE][MAX_SIZE];
char carac = *(line);
char mot[MAX_SIZE];
mot[0] = carac;
bool isSuivi = false;
Oeuvre oeuvre;
while (carac != '\n') {
if (carac == ',') {
if(isSuivi) {
mot[j - 1] = '\"';
mot[j] = '\0';
isSuivi = false;
} else
mot[j - 1] = '\0';
strcpy(strings[i], mot);
j = 0;
i++;
} else
if (carac == '\"') {
cmpt++;
carac = *(line + cmpt);
while (carac != '\"') {
mot[j] = carac;
j++;
cmpt++;
carac = *(line + cmpt);
}
isSuivi = true;
}
cmpt++;
carac = *(line + cmpt);
mot[j] = carac;
j++;
}
mot[j] = '\0';
strcpy(strings[i], mot);
//Assignation des valeurs :
oeuvre.id = atoi(strings[0]);
oeuvre.accession_number = strdup(strings[1]);
oeuvre.artiste.nomArtiste = strdup(strings[2]);
oeuvre.artiste.artistRole = strdup(strings[3]);
oeuvre.artiste.artistId = atoi(strings[4]);
oeuvre.titre = strdup(strings[5]);
oeuvre.url = strdup(strings[CHAMPS_OEUVRE]);
oeuvre.year = atoi(strings[9]);
return oeuvre;
}
void peuple_hashtable(Hashtable hashtable) { // Peuplement par redirection
char ligne[MAX_CHARS_LINE];
fgets(ligne, MAX_CHARS_LINE, stdin);
Oeuvre *oeuvre = malloc(sizeof(Oeuvre));
int hashNum;
while (fgets(ligne, MAX_CHARS_LINE, stdin)) {
*oeuvre = peuple_oeuvre(ligne);
hashNum = hash(oeuvre->artiste.artistId);
ajout_annee(&hashtable[hashNum], oeuvre);
}
}
int main() {
Hashtable hashtable;
initiate_hashtable(hashtable);
peuple_hashtable(hashtable);
return 0;
}
And the Oeuvre structure looks like this :
typedef struct oeuvre {
unsigned int id;
char *accession_number;
Artiste artiste;
char *titre;
int year;
char *url;
} Oeuvre;
typedef Liste Hashtable[NB_CASES_HASH];
Thanks in advance.

Answer 1

There are many problems in your code.
If line does not contain a newline or if a double quote is missing, the behavior is undefined.
You do not initialize the string array: if the description has missing fields, the behavior is undefined.
In the part where you save the structure fields, your allocation code is incorrect: you must allocate one more character than the length of the string, strlen(string[0]) + 1 instead of strlen(string[0]) * sizeof(char*).
It would be much simpler to use the POSIX function strdup():
// Assigning the values:
oeuvre.id = atoi(strings[0]);
oeuvre.accession_number = strdup(strings[1]);
oeuvre.artiste.nomArtiste = strdup(strings[2]);
oeuvre.artiste.artistRole = strdup(strings[3]);
oeuvre.artiste.artistId = atoi(strings[4]);
oeuvre.titre = strdup(strings[5]);
oeuvre.url = strdup(strings[CHAMPS_OEUVRE]));
oeuvre.year = atoi(strings[9]);

Answer 2

Solved my issue by declaring the Oeuvre structure like this
typedef struct oeuvre {
unsigned int id;
char accession_number[MAX_CHARS];
Artiste artiste;
char titre[MAX_CHARS];
int year;
char url[MAX_CHARS];
} Oeuvre;
with MAX_CHARS referring to a large number.
So I believe I was not properly allocating the strings before using them, which made them to point to random adresses , resulting in those weird outputs but no error. I also believe that another way of solving this would be to dynamically allocate the chars for each Oeuvre in my function.