From ffe7558fe265189f04827233b42f712d00658024 Mon Sep 17 00:00:00 2001
From: Vitaliy Lyudvichenko <vludv@yandex-team.ru>
Date: Sun, 6 Aug 2017 23:26:23 +0300
Subject: [PATCH] Add SYSTEM KILL and SHUTDOWN implementations.
 [#CLICKHOUSE-2931]

---
 dbms/src/Core/ErrorCodes.cpp                  |  1 +
 .../Interpreters/InterpreterSystemQuery.cpp   | 50 ++++++++++++++++++-
 .../src/Interpreters/InterpreterSystemQuery.h |  3 +-
 dbms/src/Parsers/ASTSystemQuery.cpp           | 22 ++++++--
 dbms/src/Parsers/ASTSystemQuery.h             | 10 ++--
 5 files changed, 73 insertions(+), 13 deletions(-)

diff --git a/dbms/src/Core/ErrorCodes.cpp b/dbms/src/Core/ErrorCodes.cpp
index ceee11c9e2..8fbb195694 100644
--- a/dbms/src/Core/ErrorCodes.cpp
+++ b/dbms/src/Core/ErrorCodes.cpp
@@ -382,6 +382,7 @@ namespace ErrorCodes
     extern const int ILLEGAL_SYNTAX_FOR_DATA_TYPE = 377;
     extern const int DATA_TYPE_CANNOT_HAVE_ARGUMENTS = 378;
     extern const int UNKNOWN_STATUS_OF_DISTRIBUTED_DDL_TASK = 379;
+    extern const int CANNOT_KILL = 380;
 
     extern const int KEEPER_EXCEPTION = 999;
     extern const int POCO_EXCEPTION = 1000;
diff --git a/dbms/src/Interpreters/InterpreterSystemQuery.cpp b/dbms/src/Interpreters/InterpreterSystemQuery.cpp
index b454b5375e..e738f5978b 100644
--- a/dbms/src/Interpreters/InterpreterSystemQuery.cpp
+++ b/dbms/src/Interpreters/InterpreterSystemQuery.cpp
@@ -1,14 +1,62 @@
-#include "InterpreterSystemQuery.h"
+#include <Interpreters/InterpreterSystemQuery.h>
+#include <Parsers/ASTSystemQuery.h>
+#include <Common/typeid_cast.h>
+#include <csignal>
+
 
 namespace DB
 {
 
+
+namespace ErrorCodes
+{
+    extern const int BAD_ARGUMENTS;
+    extern const int CANNOT_KILL;
+}
+
+
 InterpreterSystemQuery::InterpreterSystemQuery(const ASTPtr & query_ptr_, Context & context_)
         : query_ptr(query_ptr_), context(context_) {}
 
+
 BlockIO InterpreterSystemQuery::execute()
 {
+    auto & query = typeid_cast<ASTSystemQuery &>(*query_ptr);
+
+    using Type = ASTSystemQuery::Type;
+
+    switch (query.type)
+    {
+        case Type::SHUTDOWN:
+            if (kill(0, SIGTERM))
+                throw Exception("System call kill() failed", ErrorCodes::CANNOT_KILL);
+            break;
+        case Type::KILL:
+            if (kill(0, SIGKILL))
+                throw Exception("System call kill() failed", ErrorCodes::CANNOT_KILL);
+            break;
+        case Type::DROP_DNS_CACHE:
+            break;
+        case Type::DROP_MARK_CACHE:
+            break;
+        case Type::DROP_UNCOMPRESSED_CACHE:
+            break;
+        case Type::STOP_LISTEN_QUERIES:break;
+        case Type::START_LISTEN_QUERIES:break;
+        case Type::RESTART_REPLICAS:break;
+        case Type::SYNC_REPLICA:break;
+        case Type::RELOAD_DICTIONARY:break;
+        case Type::RELOAD_DICTIONARIES:break;
+        case Type::STOP_MERGES:break;
+        case Type::START_MERGES:break;
+        case Type::STOP_REPLICATION_QUEUES:break;
+        case Type::START_REPLICATION_QUEUES:break;
+        default:
+            throw Exception("Unknown type of SYSTEM query", ErrorCodes::BAD_ARGUMENTS);
+    }
+
     return BlockIO();
 }
 
+
 }
\ No newline at end of file
diff --git a/dbms/src/Interpreters/InterpreterSystemQuery.h b/dbms/src/Interpreters/InterpreterSystemQuery.h
index f6010dafc5..9f797b9838 100644
--- a/dbms/src/Interpreters/InterpreterSystemQuery.h
+++ b/dbms/src/Interpreters/InterpreterSystemQuery.h
@@ -1,6 +1,7 @@
 #pragma once
 #include <Interpreters/IInterpreter.h>
 
+
 namespace DB
 {
 
@@ -9,8 +10,6 @@ class IAST;
 using ASTPtr = std::shared_ptr<IAST>;
 
 
-/** Return list of currently executing queries.
-  */
 class InterpreterSystemQuery : public IInterpreter
 {
 public:
diff --git a/dbms/src/Parsers/ASTSystemQuery.cpp b/dbms/src/Parsers/ASTSystemQuery.cpp
index 2eb45f5b5e..753b2c05a2 100644
--- a/dbms/src/Parsers/ASTSystemQuery.cpp
+++ b/dbms/src/Parsers/ASTSystemQuery.cpp
@@ -2,14 +2,15 @@
 #include <Parsers/ASTSystemQuery.h>
 
 
-namespace ErrorCodes
+namespace DB
 {
-    extern const int BAD_TYPE_OF_FIELD;
-}
 
 
-namespace DB
+namespace ErrorCodes
 {
+    extern const int BAD_TYPE_OF_FIELD;
+    extern const int NOT_IMPLEMENTED;
+}
 
 
 const char * ASTSystemQuery::typeToString(Type type)
@@ -52,4 +53,17 @@ const char * ASTSystemQuery::typeToString(Type type)
 }
 
 
+void ASTSystemQuery::formatImpl(const IAST::FormatSettings & settings, IAST::FormatState & state,
+                                IAST::FormatStateStacked frame) const
+{
+    settings.ostr << (settings.hilite ? hilite_keyword : "") << "SYSTEM " << (settings.hilite ? hilite_none : "");
+    settings.ostr << typeToString(type);
+
+    if (type == Type::RELOAD_DICTIONARY)
+        settings.ostr << " " << backQuoteIfNeed(target_dictionary);
+    else if (type == Type::SYNC_REPLICA)
+        throw Exception("SYNC_REPLICA isn't supported yet", ErrorCodes::NOT_IMPLEMENTED);
+}
+
+
 }
\ No newline at end of file
diff --git a/dbms/src/Parsers/ASTSystemQuery.h b/dbms/src/Parsers/ASTSystemQuery.h
index e4f08a4eb1..5573345ffa 100644
--- a/dbms/src/Parsers/ASTSystemQuery.h
+++ b/dbms/src/Parsers/ASTSystemQuery.h
@@ -36,12 +36,13 @@ public:
     Type type = Type::_UNKNOWN;
 
     String target_dictionary;
-    //String target_replica;
+    //String target_replica_database;
+    //String target_replica_table;
 
     ASTSystemQuery() = default;
     explicit ASTSystemQuery(const StringRange range) : IAST(range) {}
 
-    String getID() const override { return "SYSTEM"; };
+    String getID() const override { return "SYSTEM query"; };
 
     ASTPtr clone() const override { return std::make_shared<ASTSystemQuery>(*this); }
 
@@ -49,10 +50,7 @@ public:
 
 protected:
 
-    void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override
-    {
-        settings.ostr << (settings.hilite ? hilite_keyword : "") << "SYSTEM " << (settings.hilite ? hilite_none : "");
-    }
+    void formatImpl(const FormatSettings & settings, FormatState & state, FormatStateStacked frame) const override;
 };
 
 
-- 
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