ClickHouse/src/Interpreters/AsynchronousMetricLog.h

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#pragma once
#include <Interpreters/SystemLog.h>
#include <Common/ProfileEvents.h>
#include <Common/CurrentMetrics.h>
#include <Core/NamesAndTypes.h>
#include <Core/NamesAndAliases.h>
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#include <vector>
#include <atomic>
#include <ctime>
namespace DB
{
using AsynchronousMetricValue = double;
using AsynchronousMetricValues = std::unordered_map<std::string, AsynchronousMetricValue>;
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/** AsynchronousMetricLog is a log of metric values measured at regular time interval.
*/
struct AsynchronousMetricLogElement
{
UInt16 event_date;
time_t event_time;
std::string metric_name;
double value;
static std::string name() { return "AsynchronousMetricLog"; }
static NamesAndTypesList getNamesAndTypes();
static NamesAndAliases getNamesAndAliases() { return {}; }
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void appendToBlock(MutableColumns & columns) const;
/// Returns the list of columns as in CREATE TABLE statement or nullptr.
/// If it's not nullptr, this list of columns will be used to create the table.
/// Otherwise the list will be constructed from LogElement::getNamesAndTypes and LogElement::getNamesAndAliases.
static const char * getCustomColumnList()
{
return "event_date Date CODEC(Delta(2), ZSTD(1)), "
"event_time DateTime CODEC(Delta(4), ZSTD(1)), "
"metric LowCardinality(String) CODEC(ZSTD(1)), "
"value Float64 CODEC(Gorilla, ZSTD(3))";
}
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};
class AsynchronousMetricLog : public SystemLog<AsynchronousMetricLogElement>
{
public:
using SystemLog<AsynchronousMetricLogElement>::SystemLog;
void addValues(const AsynchronousMetricValues &);
/// This table is usually queried for fixed metric name.
static const char * getDefaultOrderBy() { return "(metric, event_date, event_time)"; }
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};
}