travail

VAISSE_rapport_td2.md

@@ -0,0 +1,165 @@
+# Complexité Cyclomatique
+## Calcul de la complexité cyclomatique pour chaque fonctions
+----------------
+Pour chaque fonction, un diagramme est proposé dans ping-report/diagrammes/*nom de la fonction approprié*.
+
+-- Dans daemon.c
+- create_daemon() : 4
+- ping_request() : 2 
+- send_check() : 2
+- check_keep_working() : 4
+- daemon_work() : 3
+- ping-report main() : 5
+- write_pid_file() : 2
+- get_ping_from_temp_log : 12
+- write_ping_log : 3
+- set_stats_ping() : 10
+
+Toute fonction non mentionnée dans la liste a une complexité cyclomatique de 1, et donc ne nécessite pas un diagramme.
+
+-------------------
+Dans un second temps, on va amélorier la complexité cyclomatique des fonctions les plus lourdes si possible. On va commencer par get_ping_from_temp_log.
+La méthode la plus efficace pour réduire la compléxité cyclomatique d'un programme, outre
+changer la nature du code, est de factoriser la fonction, c'est à dire d'écrire un segment
+du code coûteux dans une fonction à part puis de l'appeler.
+
+On a décidé de faire cela pour la boucle while de la fonction. Cela nous donne le code suivant :
+
+```c
+void while_from_gpftl(char* read_line, size_t* n, FILE* fd, regex_t* p_reg, regmatch_t* pmatch, size_t* nmatch, int* start, int* end, size_t* size_ping, char* ping){
+    while(getline(&read_line,n,fd) != -1){
+        
+        if(read_line == NULL){
+            break;
+        }
+
+        /* Exec regex to find ping */
+
+        if(regexec(p_reg,read_line,*nmatch,pmatch,0) == 0){
+
+            /* Extract ping position from read line */
+            *start = (int) pmatch[1].rm_so;
+            *end = (int) pmatch[1].rm_eo;
+            *size_ping = (size_t) ((*end) - (*start));
+
+            /* ping string memory allocation */
+            ping = malloc(sizeof(char) * ((*size_ping)+2));
+            if(ping == NULL){
+                free(read_line);
+                read_line = NULL;
+                *n = 0;
+                break;
+            }
+
+            /* Create ping string */
+            (void) strncpy(ping, &read_line[*start], *size_ping);
+            ping[*size_ping]='\n';
+            ping[*size_ping+1]='\0';
+
+            /* Free memory */
+            free(read_line);
+            read_line = NULL;
+            *n = 0;
+            break;
+        }
+}
+
+
+char* better_get_ping_from_temp_log(){
+    /* Variables */
+    FILE* fd = NULL;
+    char* read_line = NULL;
+    size_t n = 0;
+    size_t nmatch = 2;
+    regex_t* p_reg;
+    regmatch_t* pmatch;
+    char* ping = NULL;
+    int start;
+    int end;
+    size_t size_ping;
+
+    /* regex struct memory allocation */
+    p_reg = (regex_t *) malloc(sizeof(*p_reg));
+    if(p_reg == NULL){
+        return ping; /* NULL */
+    }
+
+    /* Open ping log file */
+    fd = fopen("/var/log/ping-report/last-ping.log","r");
+    if(fd == NULL){
+        free(p_reg);
+        return ping; /* NULL */
+    }
+
+    /* Construct regex to get ping from log file */
+    if(regcomp(p_reg,"time=(.*) ms",REG_EXTENDED) != 0){
+        if(p_reg != NULL){
+            free(p_reg);
+        }
+        (void) fclose(fd);
+        return ping; /* NULL */
+    }
+
+    /* match info memory allocation */
+    pmatch = malloc(sizeof(*pmatch) * nmatch);
+    if(pmatch == NULL){
+        (void) fclose(fd);
+        regfree(p_reg);
+        free(p_reg);
+        return ping; /* NULL */
+    }
+
+    while_from_gpftl(read_line, &n, fd, p_reg, pmatch, &nmatch, &start, &end, &size_ping, ping);
+
+    /* free allocated memory */
+    regfree(p_reg);
+    free(p_reg);
+    free(pmatch);
+    if(read_line != NULL){
+        free(read_line);
+    }
+
+    (void) fclose(fd);
+
+    /* ping may be null, then it must mean that the ping request was lost */
+    return ping;
+}
+```
+
+Vous pouvez retrouver le diagramme dans le répertoire ping-report/diagrammes/better_get_ping_from_temp_log.mdj. La complexité cyclomatique de l'algorithme sous cette forme est de 7.
+
+On peut appliquer le même principe à set_stats_ping en factorisant le segment suivant de la fonction :
+
+```c
+void trop_de_ifs(char* read_line, int* nb_loss, double* ping, int* nb_ping, double* max, double* min, int* nb_high, double* sum){
+    if(strcmp(read_line,"LOSS") == 0){
+        (*nb_loss)++;
+    }else{
+        /* Evaluate the ping as a double */
+        *ping = strtod(read_line,NULL);
+        /* Test null ping */
+        if(*ping < 0.1){
+            /* Ignore null ping */
+        }else{
+            /* Number of ping readed (for mean calculation) */
+            *nb_ping++;
+            /* Max ping */
+            if(*ping > *max){
+                *max = *ping;
+            }
+            /* Min ping */
+            if(*ping < *min){
+                *min = *ping;
+            }
+            /* Number of ping above 100 ms */
+            if(*ping > 100.0){
+                *nb_high++;
+            }
+            /* Sum (for mean calculation) */
+            sum += *ping;
+        }
+    } 
+}
+```
+
+Vous pouvez retrouver le diagramme dans le répertoire ping-report/diagrammes/better_set_stats_ping. La complexité cyclomatique de l'algorithme sous cette forme est de 4.

ping-report/src/stats.c

@@ -11,6 +11,105 @@
 #include "../include/stats.h"
 #include "../include/db-sqlite.h"
 
+void while_from_gpftl(char* read_line, size_t* n, FILE* fd, regex_t* p_reg, regmatch_t* pmatch, size_t* nmatch, int* start, int* end, size_t* size_ping, char* ping){
+    while(getline(&read_line,n,fd) != -1){
+        
+        if(read_line == NULL){
+            break;
+        }
+
+        /* Exec regex to find ping */
+
+        if(regexec(p_reg,read_line,*nmatch,pmatch,0) == 0){
+
+            /* Extract ping position from read line */
+            *start = (int) pmatch[1].rm_so;
+            *end = (int) pmatch[1].rm_eo;
+            *size_ping = (size_t) ((*end) - (*start));
+
+            /* ping string memory allocation */
+            ping = malloc(sizeof(char) * ((*size_ping)+2));
+            if(ping == NULL){
+                free(read_line);
+                read_line = NULL;
+                *n = 0;
+                break;
+            }
+
+            /* Create ping string */
+            (void) strncpy(ping, &read_line[*start], *size_ping);
+            ping[*size_ping]='\n';
+            ping[*size_ping+1]='\0';
+
+            /* Free memory */
+            free(read_line);
+            read_line = NULL;
+            *n = 0;
+            break;
+        }
+}
+
+
+char* better_get_ping_from_temp_log(){
+    /* Variables */
+    FILE* fd = NULL;
+    char* read_line = NULL;
+    size_t n = 0;
+    size_t nmatch = 2;
+    regex_t* p_reg;
+    regmatch_t* pmatch;
+    char* ping = NULL;
+    int start;
+    int end;
+    size_t size_ping;
+
+    /* regex struct memory allocation */
+    p_reg = (regex_t *) malloc(sizeof(*p_reg));
+    if(p_reg == NULL){
+        return ping; /* NULL */
+    }
+
+    /* Open ping log file */
+    fd = fopen("/var/log/ping-report/last-ping.log","r");
+    if(fd == NULL){
+        free(p_reg);
+        return ping; /* NULL */
+    }
+
+    /* Construct regex to get ping from log file */
+    if(regcomp(p_reg,"time=(.*) ms",REG_EXTENDED) != 0){
+        if(p_reg != NULL){
+            free(p_reg);
+        }
+        (void) fclose(fd);
+        return ping; /* NULL */
+    }
+
+    /* match info memory allocation */
+    pmatch = malloc(sizeof(*pmatch) * nmatch);
+    if(pmatch == NULL){
+        (void) fclose(fd);
+        regfree(p_reg);
+        free(p_reg);
+        return ping; /* NULL */
+    }
+
+    while_from_gpftl(read_line, &n, fd, p_reg, pmatch, &nmatch, &start, &end, &size_ping, ping);
+
+    /* free allocated memory */
+    regfree(p_reg);
+    free(p_reg);
+    free(pmatch);
+    if(read_line != NULL){
+        free(read_line);
+    }
+
+    (void) fclose(fd);
+
+    /* ping may be null, then it must mean that the ping request was lost */
+    return ping;
+}
+
 /*
     -- get_ping_from_temp_log --
     Desc :
@@ -171,6 +270,36 @@ void write_ping_log(char* new_ping){
     Return value :
         None
 */
+void trop_de_ifs(char* read_line, int* nb_loss, double* ping, int* nb_ping, double* max, double* min, int* nb_high, double* sum){
+    if(strcmp(read_line,"LOSS") == 0){
+        (*nb_loss)++;
+    }else{
+        /* Evaluate the ping as a double */
+        *ping = strtod(read_line,NULL);
+        /* Test null ping */
+        if(*ping < 0.1){
+            /* Ignore null ping */
+        }else{
+            /* Number of ping readed (for mean calculation) */
+            *nb_ping++;
+            /* Max ping */
+            if(*ping > *max){
+                *max = *ping;
+            }
+            /* Min ping */
+            if(*ping < *min){
+                *min = *ping;
+            }
+            /* Number of ping above 100 ms */
+            if(*ping > 100.0){
+                *nb_high++;
+            }
+            /* Sum (for mean calculation) */
+            sum += *ping;
+        }
+    } 
+}
+
 void set_stats_ping(){
     
     /* Variables */