ClickHouse/dbms/programs/odbc-bridge/MainHandler.cpp
2019-12-16 23:19:50 +02:00

147 lines
4.7 KiB
C++

#include "MainHandler.h"
#include "validateODBCConnectionString.h"
#include <memory>
#include <DataStreams/copyData.h>
#include <DataTypes/DataTypeFactory.h>
#include "ODBCBlockInputStream.h"
#include <Formats/FormatFactory.h>
#include <IO/WriteBufferFromHTTPServerResponse.h>
#include <IO/WriteHelpers.h>
#include <IO/ReadHelpers.h>
#include <Interpreters/Context.h>
#include <Poco/Net/HTTPServerRequest.h>
#include <Poco/Net/HTTPServerResponse.h>
#include <Poco/Net/HTMLForm.h>
#include <common/logger_useful.h>
#include <mutex>
#include <Poco/ThreadPool.h>
namespace DB
{
namespace
{
std::unique_ptr<Block> parseColumns(std::string && column_string)
{
std::unique_ptr<Block> sample_block = std::make_unique<Block>();
auto names_and_types = NamesAndTypesList::parse(column_string);
for (const NameAndTypePair & column_data : names_and_types)
sample_block->insert({column_data.type, column_data.name});
return sample_block;
}
}
using PocoSessionPoolConstructor = std::function<std::shared_ptr<Poco::Data::SessionPool>()>;
/** Is used to adjust max size of default Poco thread pool. See issue #750
* Acquire the lock, resize pool and construct new Session.
*/
static std::shared_ptr<Poco::Data::SessionPool> createAndCheckResizePocoSessionPool(PocoSessionPoolConstructor pool_constr)
{
static std::mutex mutex;
Poco::ThreadPool & pool = Poco::ThreadPool::defaultPool();
/// NOTE: The lock don't guarantee that external users of the pool don't change its capacity
std::unique_lock lock(mutex);
if (pool.available() == 0)
pool.addCapacity(2 * std::max(pool.capacity(), 1));
return pool_constr();
}
ODBCHandler::PoolPtr ODBCHandler::getPool(const std::string & connection_str)
{
std::lock_guard lock(mutex);
if (!pool_map->count(connection_str))
{
pool_map->emplace(connection_str, createAndCheckResizePocoSessionPool([connection_str]
{
return std::make_shared<Poco::Data::SessionPool>("ODBC", validateODBCConnectionString(connection_str));
}));
}
return pool_map->at(connection_str);
}
void ODBCHandler::handleRequest(Poco::Net::HTTPServerRequest & request, Poco::Net::HTTPServerResponse & response)
{
Poco::Net::HTMLForm params(request, request.stream());
LOG_TRACE(log, "Request URI: " + request.getURI());
auto process_error = [&response, this](const std::string & message)
{
response.setStatusAndReason(Poco::Net::HTTPResponse::HTTP_INTERNAL_SERVER_ERROR);
if (!response.sent())
response.send() << message << std::endl;
LOG_WARNING(log, message);
};
if (!params.has("query"))
{
process_error("No 'query' in request body");
return;
}
if (!params.has("columns"))
{
process_error("No 'columns' in request URL");
return;
}
if (!params.has("connection_string"))
{
process_error("No 'connection_string' in request URL");
return;
}
UInt64 max_block_size = DEFAULT_BLOCK_SIZE;
if (params.has("max_block_size"))
{
std::string max_block_size_str = params.get("max_block_size", "");
if (max_block_size_str.empty())
{
process_error("Empty max_block_size specified");
return;
}
max_block_size = parse<size_t>(max_block_size_str);
}
std::string columns = params.get("columns");
std::unique_ptr<Block> sample_block;
try
{
sample_block = parseColumns(std::move(columns));
}
catch (const Exception & ex)
{
process_error("Invalid 'columns' parameter in request body '" + ex.message() + "'");
LOG_WARNING(log, ex.getStackTrace().toString());
return;
}
std::string format = params.get("format", "RowBinary");
std::string query = params.get("query");
LOG_TRACE(log, "Query: " << query);
std::string connection_string = params.get("connection_string");
LOG_TRACE(log, "Connection string: '" << connection_string << "'");
WriteBufferFromHTTPServerResponse out(request, response, keep_alive_timeout);
try
{
BlockOutputStreamPtr writer = FormatFactory::instance().getOutput(format, out, *sample_block, *context);
auto pool = getPool(connection_string);
ODBCBlockInputStream inp(pool->get(), query, *sample_block, max_block_size);
copyData(inp, *writer);
}
catch (...)
{
auto message = getCurrentExceptionMessage(true);
response.setStatusAndReason(
Poco::Net::HTTPResponse::HTTP_INTERNAL_SERVER_ERROR); // can't call process_error, bacause of too soon response sending
writeStringBinary(message, out);
tryLogCurrentException(log);
}
}
}