function 'request' for handling readN serverside

lib/threadpool/apiFile.c

@@ -417,32 +417,33 @@ void readNFiles(int num, queueT *q, long fd_c, taglia_t *taglia) {
 
     int oldNum = num;
     int64_t ntosend = (num<=0 || num>getLen(q))? getLen(q) : num;
-    fileT **toSend = calloc(ntosend, sizeof(fileT *));
+    fileT **toSend = NULL;
 
     n += snprintf(tmp_buf+n, m-n, "Client %ld ha richiesto una readNFile (n = %d) e' terminata con successo. File inviati:\n",
 		  fd_c,
 		  num);
-    /* extract n files, we dont check if the client can actually modify
-     * the files since we add them back immediatly */
-    size_t tot = 0;
-    for(int i=0;i<ntosend;++i) {
-	toSend[i] = dequeue(q);
-	if(!toSend[i]) {
+    /* extract n files, but dont actually dequeue them */
+    toSend = request(q, (int) ntosend);
+    if(toSend == NULL) {
 	n = 0;
 	n += snprintf(tmp_buf+n, m-n, "Client %ld ha richiesto una readNFiles (n = %d) e' terminato con errore del server\n",
 		      fd_c,
 		      oldNum);
-	    perror("readNFiles: dequeue");
+	perror("readNFiles: request");
 	serror(MESE, fd_c, taglia, tmp_buf);
 	return;
     }
-	int tmp = enqueue(q, toSend[i]);
-	if(tmp<0) {
+
+    size_t tot = 0;
+    for(int i=0;i<ntosend;++i) {
+	if(toSend[i] == NULL) {
 	    n = 0;
-	    n += snprintf(tmp_buf+n, m-n, "Client %ld ha richiesto una readNFiles (n = %d) e' terminato con errore del server\n",
+	    n += snprintf(tmp_buf+n, m-n, "Client %ld ha richiesto una readNFiles (n = %d) e' terminato con errore del server (file estratti [%d] inferiori a file richiesti [%ld])\n",
 			  fd_c,
-			  oldNum);
-	    perror("readNFiles: enqueue");
+			  oldNum,
+			  i,
+			  ntosend);
+	    perror("readNFiles: request");
 	    serror(MESE, fd_c, taglia, tmp_buf);
 	    return;
 	}

lib/threadpool/fileQueue.c

@@ -198,7 +198,6 @@ _end_dequeue:
     return NULL;
 }
 
-
 /* dequeue until we have s free space and expand the file by s */
 fileT ** dequeueN(queueT *q, char *filepath, size_t s) {
     if(!q) {
@@ -211,6 +210,8 @@ fileT ** dequeueN(queueT *q, char *filepath, size_t s) {
 
     LOCK_RETURN(&q->m, NULL); /* begin me */
 
+    fileT **returnList = NULL; /* list of removed files */
+
     if (q->head == NULL || q->len == 0) { /* empty queue */
 	errno = ENOENT;
 	goto _end_dequeueN;
@@ -235,10 +236,13 @@ fileT ** dequeueN(queueT *q, char *filepath, size_t s) {
 	goto _end_dequeueN;
     }
 
-    fileT **returnList = NULL; /* list of removed files */
     tmp = NULL;
 
-    returnList = calloc(1, sizeof(fileT*));
+    returnList = calloc(1, sizeof(*returnList));
+    if(!returnList) {
+	perror("dequeueN: calloc");
+	goto _end_dequeueN;
+    }
     returnList[0] = NULL;
 
     int purged = 0;
@@ -272,6 +276,8 @@ fileT ** dequeueN(queueT *q, char *filepath, size_t s) {
 
 _end_dequeueN:
     UNLOCK_RETURN(&q->m, NULL);
+    if(returnList)
+	free(returnList);
     return NULL;
 }
 
@@ -765,6 +771,57 @@ _end_find_in_queue:
     return NULL;
 }
 
+/* return n files */
+fileT ** request(queueT *q, int n) {
+    if(!q) {
+	errno = EINVAL;
+	return NULL;
+    }
+    if(n<=0) {
+	return NULL;
+    }
+
+    LOCK_RETURN(&q->m, NULL); /* begin me */
+
+    fileT **returnList = NULL; /* list of requested files */
+
+    if (q->head == NULL || q->len == 0) { /* empty queue */
+	errno = ENOENT;
+	goto _end_request;
+    }
+
+    if(q->size < n) {
+	errno = EINVAL;
+	goto _end_request;
+    }
+
+    returnList = calloc(n+1, sizeof(*returnList));
+    if(!returnList) {
+	perror("dequeueN: calloc");
+	goto _end_request;
+    }
+    returnList[n] = NULL;
+
+    nodeT *tmp = q->head;
+    for(int i=0; i<n; ++i) {
+	if(tmp == NULL) {
+	    errno = ENOENT;
+	    goto _end_request;
+	}
+	returnList[i] = tmp->data;
+	tmp = tmp->next;
+    }
+
+    UNLOCK_RETURN(&q->m, NULL); /* end me */
+    return returnList;
+
+_end_request:
+    UNLOCK_RETURN(&q->m, NULL);
+    if(returnList)
+	free(returnList);
+    return NULL;
+}
+
 /* search for file and return result of search */
 int searchFile(queueT *q, char *filepath) {
     if(!q || !filepath) {

lib/threadpool/fileQueue.h

@@ -67,8 +67,7 @@ void destroyFile(fileT *f);
 
 
 /**
- * Alloca ed inizializza una coda di fileT. Deve essere chiamata da un solo
- * thread.
+ * Alloca ed inizializza una coda di fileT.
  * @param maxLen lunghezza massima della coda
  * @param maxSize dimensione massima della coda in bytes
  *
@@ -215,6 +214,15 @@ int removeFileFromQueue(queueT *q, char *filepath, int owner);
  */
 fileT* find(queueT *q, char *filepath);
 
+/**
+ * Estrae n fileT dalla coda senza eliminarli
+ * @param q puntatore alla coda
+ * @param n numero di file da estrarre
+ *
+ * @return puntatore i file estratti (NULL terminated), NULL se errore
+ */
+fileT ** request(queueT *q, int n);
+
 /**
  * Cerca il fileT nella coda e ritorna il siultato dell'operazione
  * @param q puntatore alla coda sulla quale cercare il fileT