Added function "throwIf" [#CLICKHOUSE-2543]

dbms/src/Common/ErrorCodes.cpp

@@ -370,6 +370,7 @@ namespace ErrorCodes
     extern const int QUERY_IS_PROHIBITED = 392;
     extern const int THERE_IS_NO_QUERY = 393;
     extern const int QUERY_WAS_CANCELLED = 394;
+    extern const int FUNCTION_THROW_IF_VALUE_IS_NON_ZERO = 395;
 
 
     extern const int KEEPER_EXCEPTION = 999;

dbms/src/Functions/FunctionsMiscellaneous.cpp

@@ -41,6 +41,7 @@ namespace ErrorCodes
     extern const int FUNCTION_IS_SPECIAL;
     extern const int ARGUMENT_OUT_OF_BOUND;
     extern const int TOO_SLOW;
+    extern const int FUNCTION_THROW_IF_VALUE_IS_NON_ZERO;
 }
 
 /** Helper functions
@@ -1140,7 +1141,9 @@ public:
     {
         const auto in = block.getByPosition(arguments.front()).column.get();
 
-        if (!execute<UInt8>(block, in, result) && !execute<UInt16>(block, in, result) && !execute<UInt32>(block, in, result)
+        if (   !execute<UInt8>(block, in, result)
+            && !execute<UInt16>(block, in, result)
+            && !execute<UInt32>(block, in, result)
             && !execute<UInt64>(block, in, result)
             && !execute<Int8>(block, in, result)
             && !execute<Int16>(block, in, result)
@@ -1756,6 +1759,72 @@ void FunctionHasColumnInTable::executeImpl(Block & block, const ColumnNumbers &
 }
 
 
+/// Throw an exception if the argument is non zero.
+class FunctionThrowIf : public IFunction
+{
+public:
+    static constexpr auto name = "throwIf";
+    static FunctionPtr create(const Context &)
+    {
+        return std::make_shared<FunctionThrowIf>();
+    }
+
+    String getName() const override
+    {
+        return name;
+    }
+
+    size_t getNumberOfArguments() const override
+    {
+        return 1;
+    }
+
+    DataTypePtr getReturnTypeImpl(const DataTypes & arguments) const override
+    {
+        if (!arguments.front()->isNumber())
+            throw Exception{"Argument for function " + getName() + " must be number", ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT};
+
+        return std::make_shared<DataTypeUInt8>();
+    }
+
+    bool useDefaultImplementationForConstants() const override { return true; }
+
+    void executeImpl(Block & block, const ColumnNumbers & arguments, const size_t result) override
+    {
+        const auto in = block.getByPosition(arguments.front()).column.get();
+
+        if (   !execute<UInt8>(block, in, result)
+            && !execute<UInt16>(block, in, result)
+            && !execute<UInt32>(block, in, result)
+            && !execute<UInt64>(block, in, result)
+            && !execute<Int8>(block, in, result)
+            && !execute<Int16>(block, in, result)
+            && !execute<Int32>(block, in, result)
+            && !execute<Int64>(block, in, result)
+            && !execute<Float32>(block, in, result)
+            && !execute<Float64>(block, in, result))
+            throw Exception{"Illegal column " + in->getName() + " of first argument of function " + getName(), ErrorCodes::ILLEGAL_COLUMN};
+    }
+
+    template <typename T>
+    bool execute(Block & block, const IColumn * in_untyped, const size_t result)
+    {
+        if (const auto in = checkAndGetColumn<ColumnVector<T>>(in_untyped))
+        {
+            const auto & in_data = in->getData();
+            if (!memoryIsZero(in_data.data(), in_data.size() * sizeof(in_data[0])))
+                throw Exception("Value passed to 'throwIf' function is non zero", ErrorCodes::FUNCTION_THROW_IF_VALUE_IS_NON_ZERO);
+
+            /// We return non constant to avoid constant folding.
+            block.getByPosition(result).column = ColumnUInt8::create(in_data.size(), 0);
+            return true;
+        }
+
+        return false;
+    }
+};
+
+
 std::string FunctionVersion::getVersion() const
 {
     std::ostringstream os;
@@ -1797,6 +1866,7 @@ void registerFunctionsMiscellaneous(FunctionFactory & factory)
     factory.registerFunction<FunctionIsFinite>();
     factory.registerFunction<FunctionIsInfinite>();
     factory.registerFunction<FunctionIsNaN>();
+    factory.registerFunction<FunctionThrowIf>();
 
     factory.registerFunction<FunctionVersion>();
     factory.registerFunction<FunctionUptime>();

dbms/tests/queries/0_stateless/00602_throw_if.reference

@@ -0,0 +1,2 @@
+1
+1000000

dbms/tests/queries/0_stateless/00602_throw_if.sql

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+CURDIR=$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)
+. $CURDIR/../shell_config.sh
+
+exception_pattern="Value passed to 'throwIf' function is non zero"
+
+${CLICKHOUSE_CLIENT} --query="SELECT throwIf(number = 1000000) FROM system.numbers" 2>&1 | grep -cF "$exception_pattern"
+${CLICKHOUSE_CLIENT} --query="SELECT sum(x = 0) FROM (SELECT throwIf(number = 1000000) AS x FROM numbers(1000000))" 2>&1