Preparations, part 5: table functions are using const Context for execution [#CLICKHOUSE-31].

dbms/src/TableFunctions/ITableFunction.h

@@ -32,7 +32,7 @@ public:
     virtual std::string getName() const = 0;
 
     /// Create storage according to the query
-    virtual StoragePtr execute(ASTPtr ast_function, Context & context) const = 0;
+    virtual StoragePtr execute(ASTPtr ast_function, const Context & context) const = 0;
 
     virtual ~ITableFunction() {};
 };

dbms/src/TableFunctions/TableFunctionFactory.cpp

@@ -25,9 +25,9 @@ TableFunctionPtr TableFunctionFactory::get(
     if (context.getSettings().limits.readonly == 1)        /** For example, for readonly = 2 - allowed. */
         throw Exception("Table functions are forbidden in readonly mode", ErrorCodes::READONLY);
 
-         if (name == "merge")        return std::make_shared<TableFunctionMerge>();
-    else if (name == "remote")        return std::make_shared<TableFunctionRemote>();
-    else if (name == "shardByHash")    return std::make_shared<TableFunctionShardByHash>();
+         if (name == "merge")       return std::make_shared<TableFunctionMerge>();
+    else if (name == "remote")      return std::make_shared<TableFunctionRemote>();
+    else if (name == "shardByHash") return std::make_shared<TableFunctionShardByHash>();
     else
         throw Exception("Unknown table function " + name, ErrorCodes::UNKNOWN_FUNCTION);
 }

dbms/src/TableFunctions/TableFunctionMerge.cpp

@@ -53,7 +53,7 @@ static NamesAndTypesList chooseColumns(const String & source_database, const Str
 }
 
 
-StoragePtr TableFunctionMerge::execute(ASTPtr ast_function, Context & context) const
+StoragePtr TableFunctionMerge::execute(ASTPtr ast_function, const Context & context) const
 {
     ASTs & args_func = typeid_cast<ASTFunction &>(*ast_function).children;
 

dbms/src/TableFunctions/TableFunctionMerge.h

@@ -6,8 +6,7 @@
 namespace DB
 {
 
-/*
- * merge (db_name, tables_regexp) - creates a temporary StorageMerge.
+/* merge (db_name, tables_regexp) - creates a temporary StorageMerge.
  * The structure of the table is taken from the first table that came up, suitable for regexp.
  * If there is no such table, an exception is thrown.
  */
@@ -15,7 +14,7 @@ class TableFunctionMerge: public ITableFunction
 {
 public:
     std::string getName() const override { return "merge"; }
-    StoragePtr execute(ASTPtr ast_function, Context & context) const override;
+    StoragePtr execute(ASTPtr ast_function, const Context & context) const override;
 };
 
 

dbms/src/TableFunctions/TableFunctionRemote.cpp

@@ -146,7 +146,8 @@ static std::vector<String> parseDescription(const String & description, size_t l
                     }
                     buffer.push_back(cur);
                 }
-            } else if (have_splitter) /// If there is a current delimiter inside, then generate a set of resulting rows
+            }
+            else if (have_splitter) /// If there is a current delimiter inside, then generate a set of resulting rows
                 buffer = parseDescription(description, i + 1, m, separator, max_addresses);
             else                     /// Otherwise just copy, spawn will occur when you call with the correct delimiter
                 buffer.push_back(description.substr(i, m - i + 1));
@@ -168,15 +169,17 @@ static std::vector<String> parseDescription(const String & description, size_t l
             append(cur, buffer, max_addresses);
         }
     }
+
     res.insert(res.end(), cur.begin(), cur.end());
     if (res.size() > max_addresses)
         throw Exception("Storage Distributed, first argument generates too many result addresses",
-                        ErrorCodes::BAD_ARGUMENTS);
+            ErrorCodes::BAD_ARGUMENTS);
+
     return res;
 }
 
 
-StoragePtr TableFunctionRemote::execute(ASTPtr ast_function, Context & context) const
+StoragePtr TableFunctionRemote::execute(ASTPtr ast_function, const Context & context) const
 {
     ASTs & args_func = typeid_cast<ASTFunction &>(*ast_function).children;
 

dbms/src/TableFunctions/TableFunctionRemote.h

@@ -6,8 +6,7 @@
 namespace DB
 {
 
-/*
- * remote ('address', db, table) - creates a temporary StorageDistributed.
+/* remote ('address', db, table) - creates a temporary StorageDistributed.
  * To get the table structure, a DESC TABLE request is made to the remote server.
  * For example
  * SELECT count() FROM remote('example01-01-1', merge, hits) - go to `example01-01-1`, in the merge database, the hits table.
@@ -17,7 +16,7 @@ class TableFunctionRemote : public ITableFunction
 {
 public:
     std::string getName() const override { return "remote"; }
-    StoragePtr execute(ASTPtr ast_function, Context & context) const override;
+    StoragePtr execute(ASTPtr ast_function, const Context & context) const override;
 };
 
 }

dbms/src/TableFunctions/TableFunctionShardByHash.cpp

@@ -20,7 +20,7 @@ namespace ErrorCodes
     extern const int BAD_ARGUMENTS;
 }
 
-StoragePtr TableFunctionShardByHash::execute(ASTPtr ast_function, Context & context) const
+StoragePtr TableFunctionShardByHash::execute(ASTPtr ast_function, const Context & context) const
 {
     ASTs & args_func = typeid_cast<ASTFunction &>(*ast_function).children;
 

dbms/src/TableFunctions/TableFunctionShardByHash.h

@@ -15,7 +15,7 @@ class TableFunctionShardByHash : public ITableFunction
 {
 public:
     std::string getName() const override { return "shardByHash"; }
-    StoragePtr execute(ASTPtr ast_function, Context & context) const override;
+    StoragePtr execute(ASTPtr ast_function, const Context & context) const override;
 };
 
 }