Free hash after usage and dont use it at all if no readline present

dbms/src/Client/Completion.cpp

@@ -26,10 +26,10 @@ namespace Completion
         ht->buckets = (Bucket **)calloc(size, sizeof(Bucket));
         if (!ht->buckets) {
             ht->initialized = false;
-            return FAILURE;
+            return HASH_FAILURE;
         }
         ht->initialized = true;
-        return SUCCESS;
+        return HASH_SUCCESS;
     }
 
     void hash_add_word(HashTable *ht, char *word)
@@ -48,7 +48,7 @@ namespace Completion
         Bucket *bucket;
 
         if (keyLength <= 0) {
-            return FAILURE;
+            return HASH_FAILURE;
         }
         hash = ht->hashFunction(key, keyLength);
         bucketIndex = hash % ht->tableSize;
@@ -58,20 +58,20 @@ namespace Completion
                 if (!memcmp(bucket->key, key, keyLength)) {
                     auto *entry = (HashEntry *) calloc(1, sizeof(HashEntry));
                     if (entry == nullptr) {
-                        return FAILURE;
+                        return HASH_FAILURE;
                     }
                     entry->text = word;
                     entry->next = bucket->entry;
                     bucket->entry = entry;
 
-                    return SUCCESS;
+                    return HASH_SUCCESS;
                 }
             }
             bucket = bucket->next;
         }
         bucket = (Bucket *) calloc(1, sizeof(Bucket));
         if (bucket == nullptr) {
-            return FAILURE;
+            return HASH_FAILURE;
         }
         bucket->key = key;
         bucket->keyLength = keyLength;
@@ -79,7 +79,7 @@ namespace Completion
 
         bucket->entry = (HashEntry *) calloc(1, sizeof(HashEntry));
         if (bucket->entry == nullptr) {
-            return FAILURE;
+            return HASH_FAILURE;
         }
 
         bucket->entry->text = word;
@@ -89,7 +89,7 @@ namespace Completion
 
         ht->buckets[bucketIndex] = bucket;
 
-        return SUCCESS;
+        return HASH_SUCCESS;
     }
 
     Bucket * hash_find_all_matches(HashTable *ht, const char *word, uint length, uint *res_length)
@@ -117,6 +117,11 @@ namespace Completion
 
         return (Bucket *) nullptr;
     }
+
+    void hash_free(HashTable *ht)
+    {
+        free(ht->buckets);
+    }
 }
 
 

dbms/src/Client/Completion.h

@@ -1,11 +1,12 @@
 #ifndef CLICKHOUSE_COMPLETION_H
 #define CLICKHOUSE_COMPLETION_H
 
-#define SUCCESS 0
-#define FAILURE 1
+#define HASH_SUCCESS 0
+#define HASH_FAILURE 1
 
 #include <sys/types.h>
 
+//All of functionality for hash was taken from mysql-server project from completion_hash.cpp file
 namespace Completion
 {
     struct HashEntry {
@@ -31,6 +32,7 @@ namespace Completion
     int init_hash_table(HashTable *ht, size_t size);
     void hash_add_word(HashTable *ht, char *word);
     int hash_insert_key(HashTable *ht, char *key, uint keyLength, char* word);
+    void hash_free(HashTable *ht);
     Bucket * hash_find_all_matches(HashTable *ht, const char *word, uint length, uint *res_length);
 }
 

dbms/src/Server/Client.cpp

@@ -58,8 +58,8 @@
 #include <ext/scope_guard.h>
 
 static Completion::HashTable ht;
-char ** commands_completion(const char *, int, int);
-char * commands_generator(const char *, int);
+char ** query_parts_completion(const char *, int, int);
+char * query_parts_generator(const char *, int);
 
 /// http://en.wikipedia.org/wiki/ANSI_escape_code
 
@@ -348,7 +348,7 @@ private:
             Completion::hash_add_word(ht, qP->name);
             qP++;
         }
-        rl_attempted_completion_function = commands_completion;
+        rl_attempted_completion_function = query_parts_completion;
     }
 
 
@@ -461,7 +461,9 @@ private:
                 throw Exception("query_id could be specified only in non-interactive mode", ErrorCodes::BAD_ARGUMENTS);
             if (print_time_to_stderr)
                 throw Exception("time option could be specified only in non-interactive mode", ErrorCodes::BAD_ARGUMENTS);
+#if USE_READLINE
             init_suggestions(&ht);
+#endif
 
             /// Turn tab completion off.
 //            rl_bind_key('\t', rl_insert);
@@ -487,6 +489,9 @@ private:
             }
 
             loop();
+#if USE_READLINE
+            Completion::hash_free(&ht);
+#endif
 
             std::cout << (isNewYearMode() ? "Happy new year." : "Bye.") << std::endl;
 
@@ -1566,13 +1571,13 @@ int mainEntryClickHouseClient(int argc, char ** argv)
     return client.run();
 }
 
-char ** commands_completion(const char *text, int start, int end)
+char ** query_parts_completion(const char *text, int start, int end)
 {
     rl_attempted_completion_over = start + end + 1;
-    return rl_completion_matches(text, commands_generator);
+    return rl_completion_matches(text, query_parts_generator);
 }
 
-char * commands_generator(const char * text, int state)
+char * query_parts_generator(const char *text, int state)
 {
     static int text_length;
     static Completion::Bucket *bucket;