ClickHouse/src/Dictionaries/MySQLDictionarySource.cpp
2020-08-15 06:10:57 +03:00

270 lines
9.1 KiB
C++

#include "MySQLDictionarySource.h"
#include <Poco/Util/AbstractConfiguration.h>
#include "DictionarySourceFactory.h"
#include "DictionaryStructure.h"
#include "registerDictionaries.h"
namespace DB
{
namespace ErrorCodes
{
extern const int SUPPORT_IS_DISABLED;
}
void registerDictionarySourceMysql(DictionarySourceFactory & factory)
{
auto create_table_source = [=](const DictionaryStructure & dict_struct,
const Poco::Util::AbstractConfiguration & config,
const std::string & config_prefix,
Block & sample_block,
const Context & /* context */,
const std::string & /* default_database */,
bool /* check_config */) -> DictionarySourcePtr {
#if USE_MYSQL
return std::make_unique<MySQLDictionarySource>(dict_struct, config, config_prefix + ".mysql", sample_block);
#else
(void)dict_struct;
(void)config;
(void)config_prefix;
(void)sample_block;
throw Exception{"Dictionary source of type `mysql` is disabled because ClickHouse was built without mysql support.",
ErrorCodes::SUPPORT_IS_DISABLED};
#endif
};
factory.registerSource("mysql", create_table_source);
}
}
#if USE_MYSQL
# include <Columns/ColumnString.h>
# include <DataTypes/DataTypeString.h>
# include <IO/WriteBufferFromString.h>
# include <IO/WriteHelpers.h>
# include <common/LocalDateTime.h>
# include <common/logger_useful.h>
# include <Formats/MySQLBlockInputStream.h>
# include "readInvalidateQuery.h"
# include <mysqlxx/PoolFactory.h>
namespace DB
{
static const UInt64 max_block_size = 8192;
MySQLDictionarySource::MySQLDictionarySource(
const DictionaryStructure & dict_struct_,
const Poco::Util::AbstractConfiguration & config,
const std::string & config_prefix,
const Block & sample_block_)
: log(&Poco::Logger::get("MySQLDictionarySource"))
, update_time{std::chrono::system_clock::from_time_t(0)}
, dict_struct{dict_struct_}
, db{config.getString(config_prefix + ".db", "")}
, table{config.getString(config_prefix + ".table")}
, where{config.getString(config_prefix + ".where", "")}
, update_field{config.getString(config_prefix + ".update_field", "")}
, dont_check_update_time{config.getBool(config_prefix + ".dont_check_update_time", false)}
, sample_block{sample_block_}
, pool{mysqlxx::PoolFactory::instance().get(config, config_prefix)}
, query_builder{dict_struct, db, "", table, where, IdentifierQuotingStyle::Backticks}
, load_all_query{query_builder.composeLoadAllQuery()}
, invalidate_query{config.getString(config_prefix + ".invalidate_query", "")}
, close_connection{config.getBool(config_prefix + ".close_connection", false) || config.getBool(config_prefix + ".share_connection", false)}
{
}
/// copy-constructor is provided in order to support cloneability
MySQLDictionarySource::MySQLDictionarySource(const MySQLDictionarySource & other)
: log(&Poco::Logger::get("MySQLDictionarySource"))
, update_time{other.update_time}
, dict_struct{other.dict_struct}
, db{other.db}
, table{other.table}
, where{other.where}
, update_field{other.update_field}
, dont_check_update_time{other.dont_check_update_time}
, sample_block{other.sample_block}
, pool{other.pool}
, query_builder{dict_struct, db, "", table, where, IdentifierQuotingStyle::Backticks}
, load_all_query{other.load_all_query}
, last_modification{other.last_modification}
, invalidate_query{other.invalidate_query}
, invalidate_query_response{other.invalidate_query_response}
, close_connection{other.close_connection}
{
}
std::string MySQLDictionarySource::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;
std::string str_time = std::to_string(LocalDateTime(hr_time));
return query_builder.composeUpdateQuery(update_field, str_time);
}
else
{
update_time = std::chrono::system_clock::now();
return query_builder.composeLoadAllQuery();
}
}
BlockInputStreamPtr MySQLDictionarySource::loadAll()
{
auto connection = pool.get();
last_modification = getLastModification(connection, false);
LOG_TRACE(log, load_all_query);
return std::make_shared<MySQLBlockInputStream>(connection, load_all_query, sample_block, max_block_size, close_connection);
}
BlockInputStreamPtr MySQLDictionarySource::loadUpdatedAll()
{
auto connection = pool.get();
last_modification = getLastModification(connection, false);
std::string load_update_query = getUpdateFieldAndDate();
LOG_TRACE(log, load_update_query);
return std::make_shared<MySQLBlockInputStream>(connection, load_update_query, sample_block, max_block_size, close_connection);
}
BlockInputStreamPtr MySQLDictionarySource::loadIds(const std::vector<UInt64> & ids)
{
/// We do not log in here and do not update the modification time, as the request can be large, and often called.
const auto query = query_builder.composeLoadIdsQuery(ids);
return std::make_shared<MySQLBlockInputStream>(pool.get(), query, sample_block, max_block_size, close_connection);
}
BlockInputStreamPtr MySQLDictionarySource::loadKeys(const Columns & key_columns, const std::vector<size_t> & requested_rows)
{
/// We do not log in here and do not update the modification time, as the request can be large, and often called.
const auto query = query_builder.composeLoadKeysQuery(key_columns, requested_rows, ExternalQueryBuilder::AND_OR_CHAIN);
return std::make_shared<MySQLBlockInputStream>(pool.get(), query, sample_block, max_block_size, close_connection);
}
bool MySQLDictionarySource::isModified() const
{
if (!invalidate_query.empty())
{
auto response = doInvalidateQuery(invalidate_query);
if (response == invalidate_query_response)
return false;
invalidate_query_response = response;
return true;
}
if (dont_check_update_time)
return true;
auto connection = pool.get();
return getLastModification(connection, true) > last_modification;
}
bool MySQLDictionarySource::supportsSelectiveLoad() const
{
return true;
}
bool MySQLDictionarySource::hasUpdateField() const
{
return !update_field.empty();
}
DictionarySourcePtr MySQLDictionarySource::clone() const
{
return std::make_unique<MySQLDictionarySource>(*this);
}
std::string MySQLDictionarySource::toString() const
{
return "MySQL: " + db + '.' + table + (where.empty() ? "" : ", where: " + where);
}
std::string MySQLDictionarySource::quoteForLike(const std::string s)
{
std::string tmp;
tmp.reserve(s.size());
for (auto c : s)
{
if (c == '%' || c == '_' || c == '\\')
tmp.push_back('\\');
tmp.push_back(c);
}
WriteBufferFromOwnString out;
writeQuoted(tmp, out);
return out.str();
}
LocalDateTime MySQLDictionarySource::getLastModification(mysqlxx::Pool::Entry & connection, bool allow_connection_closure) const
{
LocalDateTime modification_time{std::time(nullptr)};
if (dont_check_update_time)
return modification_time;
try
{
auto query = connection->query("SHOW TABLE STATUS LIKE " + quoteForLike(table));
LOG_TRACE(log, query.str());
auto result = query.use();
size_t fetched_rows = 0;
if (auto row = result.fetch())
{
++fetched_rows;
static const auto UPDATE_TIME_IDX = 12;
const auto & update_time_value = row[UPDATE_TIME_IDX];
if (!update_time_value.isNull())
{
modification_time = update_time_value.getDateTime();
LOG_TRACE(log, "Got modification time: {}", modification_time);
}
/// fetch remaining rows to avoid "commands out of sync" error
while (result.fetch())
++fetched_rows;
}
if (close_connection && allow_connection_closure)
{
connection.disconnect();
}
if (0 == fetched_rows)
LOG_ERROR(log, "Cannot find table in SHOW TABLE STATUS result.");
if (fetched_rows > 1)
LOG_ERROR(log, "Found more than one table in SHOW TABLE STATUS result.");
}
catch (...)
{
tryLogCurrentException("MySQLDictionarySource");
}
/// we suppose failure to get modification time is not an error, therefore return current time
return modification_time;
}
std::string MySQLDictionarySource::doInvalidateQuery(const std::string & request) const
{
Block invalidate_sample_block;
ColumnPtr column(ColumnString::create());
invalidate_sample_block.insert(ColumnWithTypeAndName(column, std::make_shared<DataTypeString>(), "Sample Block"));
MySQLBlockInputStream block_input_stream(pool.get(), request, invalidate_sample_block, 1, close_connection);
return readInvalidateQuery(block_input_stream);
}
}
#endif