triggers

aquery_parser/parser.py

@@ -33,6 +33,7 @@ def common_parser():
 
     return parser(ansi_string | aquery_doublequote_string, combined_ident)
 
+    
 def parser(literal_string, ident):
     with Whitespace() as engine:
         engine.add_ignore(Literal("--") + restOfLine)
@@ -569,8 +570,26 @@ def parser(literal_string, ident):
             + index_type
             + index_column_names
             + index_options
-        )("create index")
+        )("create_index")
 
+        create_trigger = (
+            keyword("create trigger")
+            + var_name("name")
+            + ((
+                ON
+                + var_name("table")
+                + keyword("action") 
+                + var_name("action")
+                + WHEN
+                + var_name("query")            )  
+            | (
+                keyword("action")
+                + var_name("action")
+                + INTERVAL 
+                + int_num("interval")
+            ))
+        )("create_trigger")
+        
         cache_options = Optional((
             keyword("options").suppress()
             + LB
@@ -693,7 +712,7 @@ def parser(literal_string, ident):
         sql_stmts = delimited_list( (
             query
             | (insert | update | delete | load)
-            | (create_table | create_view | create_cache | create_index)
+            | (create_table | create_view | create_cache | create_index | create_trigger)
             | (drop_table | drop_view | drop_index)
         )("stmts"), ";")
 
@@ -707,6 +726,5 @@ def parser(literal_string, ident):
             |other_stmt
             | keyword(";").suppress() # empty stmt
         )
-        
         return stmts.finalize()
-
+    

engine/utils.py

@@ -8,7 +8,7 @@ nums = '0123456789'
 base62alp = nums + lower_alp + upper_alp
 
 reserved_monet = ['month']
-
+session_context = None
 
 class CaseInsensitiveDict(MutableMapping):
     def __init__(self, data=None, **kwargs):
@@ -158,3 +158,35 @@ def get_innermost(sl):
         return get_innermost(sl[0])
     else:
         return sl
+
+
+def send_to_server(payload : str):
+    from prompt import PromptState
+    cxt : PromptState = session_context
+    if cxt is None:
+        raise RuntimeError("Error! no session specified.")
+    else:
+        from ctypes import c_char_p
+        cxt.payload = (c_char_p*1)(c_char_p(bytes(payload, 'utf-8')))
+        cxt.cfg.has_dll = 0
+        cxt.send(1, cxt.payload)
+        cxt.set_ready()
+
+def get_storedproc(name : str):
+    from prompt import PromptState, StoredProcedure
+    cxt : PromptState = session_context
+    if cxt is None:
+        raise RuntimeError("Error! no session specified.")
+    else:
+        ret : StoredProcedure = cxt.get_storedproc(bytes(name, 'utf-8'))
+        if (
+            ret.name.value and 
+            ret.name.value.decode('utf-8') != name
+        ):
+            print(f'Procedure {name} mismatch in server {ret.name.value}')
+            return None
+        else:
+            return ret
+
+def execute_procedure(proc):
+    pass

prompt.py

@@ -119,6 +119,15 @@ class Backend_Type(enum.Enum):
 	BACKEND_MonetDB = 1
 	BACKEND_MariaDB = 2
 
+class StoredProcedure(ctypes.Structure):
+    _fields_ = [
+            ('cnt', ctypes.c_uint32), 
+            ('postproc_modules', ctypes.c_uint32), 
+            ('queries', ctypes.POINTER(ctypes.c_char_p)), 
+            ('name', ctypes.c_char_p), 
+            ('__rt_loaded_modules', ctypes.POINTER(ctypes.c_void_p)), 
+        ]
+
 @dataclass 
 class QueryStats:
     last_time : int = time.time()
@@ -229,6 +238,7 @@ class PromptState():
     server_bin = 'server.bin' if server_mode == RunType.IPC else 'server.so'
     wait_engine = lambda: None
     wake_engine = lambda: None
+    get_storedproc = lambda : StoredProcedure()
     set_ready = lambda: None
     get_ready = lambda: None
     server_status = lambda: False
@@ -322,6 +332,8 @@ def init_threaded(state : PromptState):
         state.send = server_so['receive_args']
         state.wait_engine = server_so['wait_engine']
         state.wake_engine = server_so['wake_engine']
+        state.get_storedproc = server_so['get_procedure']
+        state.get_storedproc.restype = StoredProcedure
         aquery_config.have_hge = server_so['have_hge']()
         if aquery_config.have_hge != 0:
             from engine.types import get_int128_support
@@ -330,9 +342,11 @@ def init_threaded(state : PromptState):
         state.th.start() 
 
 def init_prompt() -> PromptState:
+    from engine.utils import session_context
     aquery_config.init_config()
     
     state = PromptState()
+    session_context = state
     # if aquery_config.rebuild_backend:
     #     try:
     #         os.remove(state.server_bin) 
@@ -454,7 +468,7 @@ def prompt(running = lambda:True, next = lambda:input('> '), state : Optional[Pr
                 continue
             elif q.startswith('xexec') or q.startswith('exec'): # generate build and run (MonetDB Engine)
                 state.cfg.backend_type = Backend_Type.BACKEND_MonetDB.value
-                cxt = xengine.exec(state.stmts, cxt, keep)
+                cxt = xengine.exec(state.stmts, cxt, keep, parser.parse)
                 
                 this_udf = cxt.finalize_udf()
                 if this_udf:
@@ -613,11 +627,7 @@ def prompt(running = lambda:True, next = lambda:input('> '), state : Optional[Pr
             elif q.startswith('procedure'):
                 qs = re.split(r'[ \t\r\n]', q)
                 procedure_help = '''Usage: procedure <procedure_name> [record|stop|run|remove|save|load]'''
-                def send_to_server(payload : str): 
-                    state.payload = (ctypes.c_char_p*1)(ctypes.c_char_p(bytes(payload, 'utf-8')))
-                    state.cfg.has_dll = 0
-                    state.send(1, state.payload)
-                    state.set_ready()
+                from engine.utils import send_to_server
                 if len(qs) > 2:
                     if qs[2].lower() =='record':
                         if state.current_procedure is not None and state.current_procedure != qs[1]:             

reconstruct/__init__.py

@@ -18,10 +18,11 @@ def generate(ast, cxt):
         if k in ast_node.types.keys():
             ast_node.types[k](None, ast, cxt)
 
-def exec(stmts, cxt = None, keep = False):
+def exec(stmts, cxt = None, keep = False, parser = None):
     if 'stmts' not in stmts:
         return
     cxt = initialize(cxt, keep)
+    cxt.parser = parser
     stmts_stmts = stmts['stmts']
     if type(stmts_stmts) is list:
         for s in stmts_stmts:

reconstruct/ast.py

@@ -1081,7 +1081,62 @@ class create_table(ast_node):
         self.sql += ')'
         if self.context.use_columnstore:
             self.sql += ' engine=ColumnStore'
-                    
+
+class create_trigger(ast_node):
+    name = 'create_trigger'
+    first_order = name
+    class Type (Enum):
+        Interval = auto()
+        Callback = auto()
+        
+    def produce(self, node):
+        from engine.utils import send_to_server, get_storedproc
+        node = node['create_trigger']
+        self.trigger_name = node['name']
+        self.action_name = node['action']
+        self.action = get_storedproc(self.action_name)
+        if self.trigger_name in self.context.triggers:
+            raise ValueError(f'trigger {self.trigger_name} exists')
+        elif self.action:
+            raise ValueError(f'Stored Procedure {self.action_name} do not exist')
+
+        if 'interval' in node: # executed periodically from server
+            self.type = self.Type.Interval
+            self.interval = node['interval']
+            send_to_server(f'TI{self.trigger_name}{self.action_name}{self.interval}')
+        else: # executed from sql backend
+            self.type = self.Type.Callback
+            self.query_name = node['query']
+            self.table_name = node['table']
+            self.procedure = get_storedproc(self.query_name)
+            if self.procedure and self.table_name in self.context.tables_byname:
+                self.table = self.context.tables_byname[self.table_name]
+                self.table.triggers.add(self)
+            else:
+                return
+        self.context.triggers[self.trigger_name] = self
+
+    # manually execute trigger
+    def register(self): 
+        if self.type != self.Type.Callback:
+            self.context.triggers.pop(self.trigger_name)
+            raise ValueError(f'Trigger {self.trigger_name} is not a callback based trigger')
+        self.context.triggers_active.add(self)
+
+    def execute(self): 
+        from engine.utils import send_to_server
+        send_to_server(f'TC{self.query_name}{self.action_name}')
+
+    def remove(self):
+        from engine.utils import send_to_server
+        send_to_server(f'TR{self.trigger_name}')
+
+class drop_trigger(ast_node):
+    name = 'create_trigger'
+    first_order = name
+    def produce(self, node):
+        ...
+
 class drop(ast_node):
     name = 'drop'
     first_order = name
@@ -1111,9 +1166,11 @@ class insert(ast_node):
             complex_query_kw = ['from', 'where', 'groupby', 'having', 'orderby', 'limit']
             if any([kw in values for kw in complex_query_kw]):
                 values['into'] = node['insert']
-                proj_cls = (select_distinct 
-                if 'select_distinct' in values 
-                else projection)
+                proj_cls = (
+                    select_distinct 
+                    if 'select_distinct' in values 
+                    else projection
+                )
                 proj_cls(None, values, self.context)
                 self.produce = lambda*_:None
                 self.spawn = lambda*_:None
@@ -1147,6 +1204,11 @@ class insert(ast_node):
             
         keys = f'({", ".join(keys)})' if keys else ''
         tbl = node['insert']
+        if tbl not in self.context.tables_byname:
+            print('Warning: {tbl} not registered in aquery compiler.')
+        tbl_obj = self.context.tables_byname[tbl]
+        for t in tbl_obj.triggers:
+            t.register()
         self.sql = f'INSERT INTO {tbl}{keys} VALUES'
         # if len(values) != table.n_cols:
         #     raise ValueError("Column Mismatch")
@@ -1161,7 +1223,7 @@ class insert(ast_node):
             list_values.append(f"({', '.join(inner_list_values)})")
             
         self.sql += ', '.join(list_values) 
-        
+
 
 class delete_from(ast_node):
     name = 'delete'
@@ -1624,6 +1686,11 @@ class passthru_sql(ast_node):
     seprator = re.compile(r'''((?:[^;"']|"[^"]*"|'[^']*')+)''')
     def __init__(self, _, node, context:Context):
         sqls = passthru_sql.seprator.split(node['sql'])
+        try:
+            if callable(context.parser):
+                parsed = context.parser(node['sql'])
+        except BaseException:
+            parsed = None
         for sql in sqls:
             sq = sql.strip(' \t\n\r;')
             if sq:

reconstruct/storage.py

@@ -64,12 +64,14 @@ class ColRef:
 
 class TableInfo:
     def __init__(self, table_name, cols, cxt:'Context'):
+        from reconstruct.ast import create_trigger
         # statics
         self.table_name : str = table_name
         self.contextname_cpp : str = ''
         self.alias : Set[str] = set([table_name])
         self.columns_byname : CaseInsensitiveDict[str, ColRef] = CaseInsensitiveDict() # column_name, type
         self.columns : List[ColRef] = []
+        self.triggers : Set[create_trigger] = set()
         self.cxt = cxt
         # keep track of temp vars
         self.rec = None 
@@ -83,7 +85,7 @@ class TableInfo:
     def add_cols(self, cols, new = True):
         for c in enlist(cols):
             self.add_col(c, new)
-            
+        
     def add_col(self, c, new = True):
         _ty = c['type']
         _ty_args = None
@@ -156,9 +158,11 @@ class Context:
         self.module_init_loc = 0
         self.special_gb = False
         self.has_dll = False
-         
+        self.triggers_active.clear()
+        
     def __init__(self):
-        self.tables_byname = dict()
+        from .ast import create_trigger
+        self.tables_byname : Dict[str, TableInfo] = dict()
         self.col_byname = dict()
         self.tables : Set[TableInfo] = set()
         self.cols = []
@@ -174,6 +178,9 @@ class Context:
         self.have_hge = False
         self.Error = lambda *args: print(*args)
         self.Info = lambda *_: None
+        self.triggers : Dict[str, create_trigger] = dict()
+        self.triggers_active = set()
+        self.stored_proceudres = dict()
         # self.new() called everytime new query batch is started
 
     def get_scan_var(self):
@@ -256,7 +263,14 @@ class Context:
         limit = limit.to_bytes(4, 'little').decode('latin-1')
         self.queries.append(
             'O' + limit + sep + end)
-    
+        
+    def remove_trigger(self, name : str):
+        from reconstruct.ast import create_trigger
+        val = self.triggers.pop(name, None)
+        if val.type == create_trigger.Type.Callback:
+            val.table.triggers.remove(val)
+        val.remove()
+
     def abandon_postproc(self):
         self.ccode = ''
         self.finalize_query()

server/server.cpp

@@ -86,7 +86,8 @@ extern "C" int __DLLEXPORT__ binary_info() {
 #endif
 }
 
-__AQEXPORT__(bool) have_hge(){
+__AQEXPORT__(bool) 
+have_hge() {
 #if defined(__MONETDB_CONN_H__)
     return Server::havehge();
 #else
@@ -94,6 +95,19 @@ __AQEXPORT__(bool) have_hge(){
 #endif
 }
 
+__AQEXPORT__(StoredProcedure)
+get_procedure(Context* cxt, const char* name) {
+    auto res = cxt->stored_proc.find(name);
+    if (res == cxt->stored_proc.end())
+        return { .cnt = 0, 
+            .postproc_modules = 0, 
+            .queries = nullptr, 
+            .name = nullptr, 
+            .__rt_loaded_modules = nullptr
+        };
+    return res->second;
+}
+
 using prt_fn_t = char* (*)(void*, char*);
 
 // This function contains heap allocations, free after use