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#pragma once
#include "clickhouse_config.h"
#include <Interpreters/Context.h>
#include <Interpreters/evaluateConstantExpression.h>
#include <Storages/StorageS3Cluster.h>
#include <Storages/checkAndGetLiteralArgument.h>
#include <TableFunctions/ITableFunction.h>
#include <TableFunctions/TableFunctionAzureBlobStorage.h>
#include <TableFunctions/TableFunctionS3.h>
namespace DB
{
namespace ErrorCodes
{
extern const int NUMBER_OF_ARGUMENTS_DOESNT_MATCH;
extern const int CLUSTER_DOESNT_EXIST;
extern const int LOGICAL_ERROR;
}
/// Base class for *Cluster table functions that require cluster_name for the first argument.
template <typename Base>
class ITableFunctionCluster : public Base
{
public:
String getName() const override = 0;
String getSignature() const override = 0;
static void addColumnsStructureToArguments(ASTs & args, const String & desired_structure, const ContextPtr & context)
{
if (args.empty())
throw Exception(ErrorCodes::LOGICAL_ERROR, "Unexpected empty list of arguments for {}Cluster table function", Base::name);
ASTPtr cluster_name_arg = args.front();
args.erase(args.begin());
Base::addColumnsStructureToArguments(args, desired_structure, context);
args.insert(args.begin(), cluster_name_arg);
}
protected:
void parseArguments(const ASTPtr & ast, ContextPtr context) override
{
/// Clone ast function, because we can modify its arguments like removing cluster_name
Base::parseArguments(ast->clone(), context);
}
void parseArgumentsImpl(ASTs & args, const ContextPtr & context) override
{
if (args.empty())
throw Exception(ErrorCodes::NUMBER_OF_ARGUMENTS_DOESNT_MATCH, "The signature of table function {} shall be the following:\n{}", getName(), getSignature());
/// Evaluate only first argument, everything else will be done Base class
args[0] = evaluateConstantExpressionOrIdentifierAsLiteral(args[0], context);
/// Cluster name is always the first
cluster_name = checkAndGetLiteralArgument<String>(args[0], "cluster_name");
if (!context->tryGetCluster(cluster_name))
throw Exception(ErrorCodes::CLUSTER_DOESNT_EXIST, "Requested cluster '{}' not found", cluster_name);
/// Just cut the first arg (cluster_name) and try to parse other table function arguments as is
args.erase(args.begin());
Base::parseArgumentsImpl(args, context);
}
String cluster_name;
};
}
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