ClickHouse/dbms/src/Dictionaries/HTTPDictionarySource.cpp

#include <Dictionaries/HTTPDictionarySource.h>

#include <Poco/Net/HTTPRequest.h>
#include <Interpreters/Context.h>
#include <DataStreams/OwningBlockInputStream.h>
#include <IO/ReadWriteBufferFromHTTP.h>
#include <DataStreams/IBlockOutputStream.h>
#include <IO/WriteBufferFromOStream.h>
#include <Dictionaries/DictionarySourceHelpers.h>
#include <common/logger_useful.h>
#include <IO/ConnectionTimeouts.h>

namespace DB
{

static const size_t max_block_size = 8192;


HTTPDictionarySource::HTTPDictionarySource(const DictionaryStructure & dict_struct_,
    const Poco::Util::AbstractConfiguration & config, const std::string & config_prefix,
    Block & sample_block, const Context & context)
    : log(&Logger::get("HTTPDictionarySource")),
    update_time{std::chrono::system_clock::from_time_t(0)},
    dict_struct{dict_struct_},
    url{config.getString(config_prefix + ".url", "")},
    update_field{config.getString(config_prefix + ".update_field", "")},
    format{config.getString(config_prefix + ".format")},
    sample_block{sample_block},
    context(context),
    timeouts(ConnectionTimeouts::getHTTPTimeouts(context.getSettingsRef()))
{
    if (update_field.empty())
        return;

    std::string::size_type option = url.find("?");
    if (option == std::string::npos) {
        update_field = "?&" + update_field;
    } else {
        update_field = '&' + update_field;
    }
}

HTTPDictionarySource::HTTPDictionarySource(const HTTPDictionarySource & other)
    : log(&Logger::get("HTTPDictionarySource")),
    update_time{other.update_time},
    dict_struct{other.dict_struct},
    url{other.url},
    update_field{other.update_field},
    format{other.format},
    sample_block{other.sample_block},
    context(other.context),
    timeouts(ConnectionTimeouts::getHTTPTimeouts(context.getSettingsRef()))
{
}

std::string HTTPDictionarySource::getUpdateFieldAndDate()
{
    if (update_time != std::chrono::system_clock::from_time_t(0))
    {
        auto tmp_time = update_time;
        update_time = std::chrono::system_clock::now();
        time_t hr_time = std::chrono::system_clock::to_time_t(tmp_time) - 1;
        char buffer [80];
        struct tm * timeinfo;
        timeinfo = localtime (&hr_time);
        strftime(buffer, 80, "=%Y-%m-%d%%20%H:%M:%S", timeinfo);
        std::string str_time(buffer);
        return url + update_field + str_time;
    }
    else
    {
        update_time = std::chrono::system_clock::now();
        return url + update_field + "=0000-00-00%2000:00:00"; ///for initial load
    }
}

BlockInputStreamPtr HTTPDictionarySource::loadAll()
{
    LOG_TRACE(log, "loadAll " + toString());
    Poco::URI uri(url);
    auto in_ptr = std::make_unique<ReadWriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_GET,
                                                            ReadWriteBufferFromHTTP::OutStreamCallback(), timeouts);
    auto input_stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);
    return std::make_shared<OwningBlockInputStream<ReadWriteBufferFromHTTP>>(input_stream, std::move(in_ptr));
}

BlockInputStreamPtr HTTPDictionarySource::loadUpdatedAll()
{
    std::string url_update = getUpdateFieldAndDate();
    LOG_TRACE(log, "loadUpdatedAll " + url_update);
    Poco::URI uri(url_update);
    auto in_ptr = std::make_unique<ReadWriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_GET,
                                                            ReadWriteBufferFromHTTP::OutStreamCallback(), timeouts);
    auto input_stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);
    return std::make_shared<OwningBlockInputStream<ReadWriteBufferFromHTTP>>(input_stream, std::move(in_ptr));
}

BlockInputStreamPtr HTTPDictionarySource::loadIds(const std::vector<UInt64> & ids)
{
    LOG_TRACE(log, "loadIds " << toString() << " size = " << ids.size());

    ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback = [&](std::ostream & ostr)
    {
        WriteBufferFromOStream out_buffer(ostr);
        auto output_stream = context.getOutputFormat(format, out_buffer, sample_block);
        formatIDs(output_stream, ids);
    };

    Poco::URI uri(url);
    auto in_ptr = std::make_unique<ReadWriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_POST,
                                                            out_stream_callback, timeouts);
    auto input_stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);
    return std::make_shared<OwningBlockInputStream<ReadWriteBufferFromHTTP>>(input_stream, std::move(in_ptr));
}

BlockInputStreamPtr HTTPDictionarySource::loadKeys(
    const Columns & key_columns, const std::vector<size_t> & requested_rows)
{
    LOG_TRACE(log, "loadKeys " << toString() << " size = " << requested_rows.size());

    ReadWriteBufferFromHTTP::OutStreamCallback out_stream_callback = [&](std::ostream & ostr)
    {
        WriteBufferFromOStream out_buffer(ostr);
        auto output_stream = context.getOutputFormat(format, out_buffer, sample_block);
        formatKeys(dict_struct, output_stream, key_columns, requested_rows);
    };

    Poco::URI uri(url);
    auto in_ptr = std::make_unique<ReadWriteBufferFromHTTP>(uri, Poco::Net::HTTPRequest::HTTP_POST,
                                                            out_stream_callback, timeouts);
    auto input_stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);
    return std::make_shared<OwningBlockInputStream<ReadWriteBufferFromHTTP>>(input_stream, std::move(in_ptr));
}

bool HTTPDictionarySource::isModified() const
{
    return true;
}

bool HTTPDictionarySource::supportsSelectiveLoad() const
{
    return true;
}

bool HTTPDictionarySource::hasUpdateField() const
{
    return !update_field.empty();
}

DictionarySourcePtr HTTPDictionarySource::clone() const
{
    return std::make_unique<HTTPDictionarySource>(*this);
}

std::string HTTPDictionarySource::toString() const
{
    Poco::URI uri(url);
    return uri.toString();
}

}