implemented queue type "drivers"

2 files changed, 99 insertions, 30 deletions

diff --git a/queue.c b/queue.c
index 00292a42..2600871a 100644
--- a/queue.c
+++ b/queue.c
@@ -37,6 +37,79 @@
 
 /* methods */
 
+/* first, we define type-specific handlers. The provide a generic functionality,
+ * but for this specific type of queue. The mapping to these handlers happens during
+ * queue construction. Later on, handlers are called by pointers present in the
+ * queue instance object.
+ */
+
+/* -------------------- fixed array -------------------- */
+rsRetVal qConstructFixedArray(queue_t *pThis)
+{
+	DEFiRet;
+
+	assert(pThis != NULL);
+
+	if((pThis->tVars.farray.pBuf = malloc(sizeof(void *) * pThis->iMaxQueueSize)) == NULL) {
+		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
+	}
+
+	pThis->tVars.farray.head = 0;
+	pThis->tVars.farray.tail = 0;
+
+finalize_it:
+	return iRet;
+}
+
+
+rsRetVal qDestructFixedArray(queue_t *pThis)
+{
+	DEFiRet;
+	
+	assert(pThis != NULL);
+
+	if(pThis->tVars.farray.pBuf != NULL)
+		free(pThis->tVars.farray.pBuf);
+	free (pThis);
+
+	return iRet;
+}
+
+rsRetVal qAddFixedArray(queue_t *pThis, void* in)
+{
+	DEFiRet;
+
+	assert(pThis != NULL);
+	pThis->tVars.farray.pBuf[pThis->tVars.farray.tail] = in;
+	pThis->tVars.farray.tail++;
+	if (pThis->tVars.farray.tail == pThis->iMaxQueueSize)
+		pThis->tVars.farray.tail = 0;
+	if (pThis->tVars.farray.tail == pThis->tVars.farray.head)
+		pThis->full = 1;
+	pThis->empty = 0;
+
+	return iRet;
+}
+
+rsRetVal qDelFixedArray(queue_t *pThis, void **out)
+{
+	DEFiRet;
+
+	assert(pThis != NULL);
+	*out = (void*) pThis->tVars.farray.pBuf[pThis->tVars.farray.head];
+
+	pThis->tVars.farray.head++;
+	if (pThis->tVars.farray.head == pThis->iMaxQueueSize)
+		pThis->tVars.farray.head = 0;
+	if (pThis->tVars.farray.head == pThis->tVars.farray.tail)
+		pThis->empty = 1;
+	pThis->full = 0;
+
+	return iRet;
+}
+/* --------------- end type-specific handlers -------------------- */
+
+
 /* Constructor for the queue object */
 rsRetVal queueConstruct(queue_t **ppThis, queueType_t qType, int iMaxQueueSize)
 {
@@ -62,13 +135,18 @@ dbgprintf("queueConstruct in \n");
 	pthread_cond_init (pThis->notEmpty, NULL);
 	pThis->qType = qType;
 
-	/* type-specific initialization */
-	if((pThis->tVars.farray.pBuf = malloc(sizeof(void *) * pThis->iMaxQueueSize)) == NULL) {
-		ABORT_FINALIZE(RS_RET_OUT_OF_MEMORY);
+	/* set type-specific handlers */
+	switch(qType) {
+		case QUEUETYPE_FIXED_ARRAY:
+			pThis->qConstruct = qConstructFixedArray;
+			pThis->qDestruct = qDestructFixedArray;
+			pThis->qAdd = qAddFixedArray;
+			pThis->qDel = qDelFixedArray;
+			break;
 	}
 
-	pThis->tVars.farray.head = 0;
-	pThis->tVars.farray.tail = 0;
+	/* call type-specific constructor */
+	CHKiRet(pThis->qConstruct(pThis));
 	
 finalize_it:
 	if(iRet == RS_RET_OK) {
@@ -87,7 +165,6 @@ rsRetVal queueDestruct(queue_t *pThis)
 {
 	DEFiRet;
 
-dbgprintf("queueDestruct\n");
 	assert(pThis != NULL);
 	pthread_mutex_destroy (pThis->mut);
 	free (pThis->mut);
@@ -96,8 +173,7 @@ dbgprintf("queueDestruct\n");
 	pthread_cond_destroy (pThis->notEmpty);
 	free (pThis->notEmpty);
 	/* type-specific destructor */
-	free(pThis->tVars.farray.pBuf);
-	free (pThis);
+	iRet = pThis->qDestruct(pThis);
 
 	return iRet;
 }
@@ -122,15 +198,9 @@ rsRetVal queueAdd(queue_t *pThis, void* in)
 {
 	DEFiRet;
 
-dbgprintf("queueAdd\n");
-	pThis->tVars.farray.pBuf[pThis->tVars.farray.tail] = in;
-	pThis->tVars.farray.tail++;
-	if (pThis->tVars.farray.tail == pThis->iMaxQueueSize)
-		pThis->tVars.farray.tail = 0;
-	if (pThis->tVars.farray.tail == pThis->tVars.farray.head)
-		pThis->full = 1;
-	pThis->empty = 0;
-
+	assert(pThis != NULL);
+	CHKiRet(pThis->qAdd(pThis, in));
+finalize_it:
 	return iRet;
 }
 
@@ -138,16 +208,9 @@ rsRetVal queueDel(queue_t *pThis, void **out)
 {
 	DEFiRet;
 
-dbgprintf("queueDel\n");
-	*out = (void*) pThis->tVars.farray.pBuf[pThis->tVars.farray.head];
-
-	pThis->tVars.farray.head++;
-	if (pThis->tVars.farray.head == pThis->iMaxQueueSize)
-		pThis->tVars.farray.head = 0;
-	if (pThis->tVars.farray.head == pThis->tVars.farray.tail)
-		pThis->empty = 1;
-	pThis->full = 0;
-
+	assert(pThis != NULL);
+	CHKiRet(pThis->qDel(pThis, out));
+finalize_it:
 	return iRet;
 }
 
diff --git a/queue.h b/queue.h
index 1a1722a0..86499306 100644
--- a/queue.h
+++ b/queue.h
@@ -26,14 +26,20 @@
 
 /* queue types */
 typedef enum {
-	QUEUETYPE_FIXED_ARRAY,	/* a simple queue made out of a fixed (initially malloced) array fast but memoryhog */
-	QUEUETYPE_LINKEDLIST,	/* linked list used as buffer, lower fixed memory overhead but slower */
+	QUEUETYPE_FIXED_ARRAY,/* a simple queue made out of a fixed (initially malloced) array fast but memoryhog */
+	QUEUETYPE_LINKEDLIST,/* linked list used as buffer, lower fixed memory overhead but slower */
 } queueType_t;
 
 /* the queue object */
-typedef struct {
+typedef struct queue_s {
 	queueType_t	qType;
 	int	iMaxQueueSize;	/* how large can the queue grow? */
+	/* type-specific handlers (set during construction) */
+	rsRetVal (*qConstruct)(struct queue_s *pThis);
+	rsRetVal (*qDestruct)(struct queue_s *pThis);
+	rsRetVal (*qAdd)(struct queue_s *pThis, void *pUsr);
+	rsRetVal (*qDel)(struct queue_s *pThis, void **ppUsr);
+	/* end type-specific handler */
 	/* synchronization variables */
 	pthread_mutex_t *mut;
 	pthread_cond_t *notFull, *notEmpty;