Hash table cleanup [1/n]

A few cleanups for the hashtable implementation:
1. Correct function header comments
2. Complete argument checking for a few functions
3. Remove trailing space

src/util/src/hash.c

@@ -155,11 +155,14 @@ static void pushfrontNodeInEntryList(SHashEntry *pEntry, SHashNode *pNode);
 static FORCE_INLINE bool taosHashTableEmpty(const SHashObj *pHashObj);
 
 /**
- * Get the next element in hash table for iterator
- * @param pIter
- * @return
+ * Initialize a hash table
+ *
+ * @param capacity   Initial capacity of the hash table
+ * @param fn         Hash function
+ * @param update     Whether the hash table allows in place update
+ * @param type       Whether the hash table has per entry lock
+ * @return           Hash table object
  */
-
 SHashObj *taosHashInit(size_t capacity, _hash_fn_t fn, bool update, SHashLockTypeE type) {
   assert(fn != NULL);
   if (capacity == 0) {
@@ -206,7 +209,7 @@ void taosHashSetEqualFp(SHashObj *pHashObj, _equal_fn_t fp) {
 }
 
 int32_t taosHashGetSize(const SHashObj *pHashObj) {
-  if (!pHashObj) {
+  if (pHashObj == NULL) {
     return 0;
   }
   return (int32_t)atomic_load_64(&pHashObj->size);
@@ -217,6 +220,10 @@ static FORCE_INLINE bool taosHashTableEmpty(const SHashObj *pHashObj) {
 }
 
 int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *data, size_t size) {
+  if (pHashObj == NULL || key == NULL || keyLen == 0 || data == NULL || size == 0) {
+    return -1;
+  }
+
   uint32_t   hashVal = (*pHashObj->hashFp)(key, (uint32_t)keyLen);
   SHashNode *pNewNode = doCreateHashNode(key, keyLen, data, size, hashVal);
   if (pNewNode == NULL) {
@@ -248,7 +255,9 @@ int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *da
 
   SHashNode* prev = NULL;
   while (pNode) {
-    if ((pNode->keyLen == keyLen) && ((*(pHashObj->equalFp))(GET_HASH_NODE_KEY(pNode), key, keyLen) == 0) && pNode->removed == 0) {
+    if ((pNode->keyLen == keyLen) &&
+        (*(pHashObj->equalFp))(GET_HASH_NODE_KEY(pNode), key, keyLen) == 0 &&
+        pNode->removed == 0) {
       assert(pNode->hashVal == hashVal);
       break;
     }
@@ -261,11 +270,7 @@ int32_t taosHashPut(SHashObj *pHashObj, const void *key, size_t keyLen, void *da
     // no data in hash table with the specified key, add it into hash table
     pushfrontNodeInEntryList(pe, pNewNode);
 
-    if (pe->num == 0) {
-      assert(pe->next == NULL);
-    } else {
     assert(pe->next != NULL);
-    }
 
     if (pHashObj->type == HASH_ENTRY_LOCK) {
       taosWUnLockLatch(&pe->latch);
@@ -300,7 +305,7 @@ void *taosHashGet(SHashObj *pHashObj, const void *key, size_t keyLen) {
 }
 //TODO(yihaoDeng), merge with taosHashGetClone
 void* taosHashGetCloneExt(SHashObj *pHashObj, const void *key, size_t keyLen, void (*fp)(void *), void** d, size_t *sz) {
-  if (taosHashTableEmpty(pHashObj) || keyLen == 0 || key == NULL) {
+  if (pHashObj == NULL || taosHashTableEmpty(pHashObj) || keyLen == 0 || key == NULL) {
     return NULL;
   }
 
@@ -362,7 +367,7 @@ void* taosHashGetCloneExt(SHashObj *pHashObj, const void *key, size_t keyLen, vo
 }
 
 void* taosHashGetClone(SHashObj *pHashObj, const void *key, size_t keyLen, void (*fp)(void *), void* d) {
-  if (taosHashTableEmpty(pHashObj) || keyLen == 0 || key == NULL) {
+  if (pHashObj == NULL || taosHashTableEmpty(pHashObj) || keyLen == 0 || key == NULL) {
     return NULL;
   }