ClickHouse/programs/library-bridge/Handlers.h

#pragma once

#include <Interpreters/Context.h>
#include <Server/HTTP/HTTPRequestHandler.h>
#include <common/logger_useful.h>
#include "SharedLibraryHandler.h"


namespace DB
{


/// Handler for requests to Library Dictionary Source, returns response in RowBinary format.
/// When a library dictionary source is created, it sends libNew request to library bridge (which is started on first
/// request to it, if it was not yet started). On this request a new sharedLibrayHandler is added to a
/// sharedLibraryHandlerFactory by a dictionary uuid. With libNew request come: library_path, library_settings,
/// names of dictionary attributes, sample block to parse block of null values, block of null values. Everything is
/// passed in binary format and is urlencoded. When dictionary is cloned, a new handler is created.
/// Each handler is unique to dictionary.
class LibraryRequestHandler : public HTTPRequestHandler
{
public:

    LibraryRequestHandler(
        size_t keep_alive_timeout_,
        Context & context_)
        : log(&Poco::Logger::get("LibraryRequestHandler"))
        , keep_alive_timeout(keep_alive_timeout_)
        , context(context_)
    {
    }

    void handleRequest(HTTPServerRequest & request, HTTPServerResponse & response) override;

private:
    static constexpr inline auto FORMAT = "RowBinary";

    void processError(HTTPServerResponse & response, const std::string & message);

    Poco::Logger * log;
    size_t keep_alive_timeout;
    Context & context;
};


class PingHandler : public HTTPRequestHandler
{
public:
    explicit PingHandler(size_t keep_alive_timeout_)
        : keep_alive_timeout(keep_alive_timeout_)
    {
    }

    void handleRequest(HTTPServerRequest & request, HTTPServerResponse & response) override;

private:
    const size_t keep_alive_timeout;
};

}