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#pragma once
#include <string>
#include <Processors/IProcessor.h>
#include <Processors/RowsBeforeLimitCounter.h>
#include <IO/Progress.h>
#include <Common/Stopwatch.h>
namespace DB
{
class WriteBuffer;
/** Output format have three inputs and no outputs. It writes data from WriteBuffer.
*
* First input is for main resultset, second is for "totals" and third is for "extremes".
* It's not necessarily to connect "totals" or "extremes" ports (they may remain dangling).
*
* Data from input ports are pulled in order: first, from main input, then totals, then extremes.
*
* By default, data for "totals" and "extremes" is ignored.
*/
class IOutputFormat : public IProcessor
{
public:
enum PortKind { Main = 0, Totals = 1, Extremes = 2 };
IOutputFormat(const Block & header_, WriteBuffer & out_);
Status prepare() override;
void work() override;
/// Flush output buffers if any.
virtual void flush();
void setAutoFlush() { auto_flush = true; }
/// Value for rows_before_limit_at_least field.
virtual void setRowsBeforeLimit(size_t /*rows_before_limit*/) {}
/// Counter to calculate rows_before_limit_at_least in processors pipeline.
void setRowsBeforeLimitCounter(RowsBeforeLimitCounterPtr counter) override { rows_before_limit_counter.swap(counter); }
/// Notify about progress. Method could be called from different threads.
/// Passed value are delta, that must be summarized.
virtual void onProgress(const Progress & /*progress*/) {}
/// Content-Type to set when sending HTTP response.
virtual std::string getContentType() const { return "text/plain; charset=UTF-8"; }
InputPort & getPort(PortKind kind) { return *std::next(inputs.begin(), kind); }
/// Compatibility with old interface.
/// TODO: separate formats and processors.
void write(const Block & block);
void finalize();
virtual bool expectMaterializedColumns() const { return true; }
void setTotals(const Block & totals)
{
writeSuffixIfNeeded();
consumeTotals(Chunk(totals.getColumns(), totals.rows()));
are_totals_written = true;
}
void setExtremes(const Block & extremes)
{
writeSuffixIfNeeded();
consumeExtremes(Chunk(extremes.getColumns(), extremes.rows()));
}
virtual bool supportsWritingException() const { return false; }
virtual void setException(const String & /*exception_message*/) {}
size_t getResultRows() const { return result_rows; }
size_t getResultBytes() const { return result_bytes; }
void doNotWritePrefix() { need_write_prefix = false; }
void resetFormatter()
{
need_write_prefix = true;
need_write_suffix = true;
finalized = false;
resetFormatterImpl();
}
/// Reset the statistics watch to a specific point in time
/// If set to not running it will stop on the call (elapsed = now() - given start)
void setStartTime(UInt64 start, bool is_running)
{
statistics.watch = Stopwatch(CLOCK_MONOTONIC, start, true);
if (!is_running)
statistics.watch.stop();
}
void writePrefixIfNeeded()
{
if (need_write_prefix)
{
writePrefix();
need_write_prefix = false;
}
}
protected:
friend class ParallelFormattingOutputFormat;
void writeSuffixIfNeeded()
{
if (need_write_suffix)
{
writeSuffix();
need_write_suffix = false;
}
}
virtual void consume(Chunk) = 0;
virtual void consumeTotals(Chunk) {}
virtual void consumeExtremes(Chunk) {}
virtual void finalizeImpl() {}
virtual void finalizeBuffers() {}
virtual void writePrefix() {}
virtual void writeSuffix() {}
virtual void resetFormatterImpl() {}
/// Methods-helpers for parallel formatting.
/// Set the number of rows that was already read in
/// parallel formatting before creating this formatter.
void setRowsReadBefore(size_t first_row_number_)
{
rows_read_before = first_row_number_;
onRowsReadBeforeUpdate();
}
size_t getRowsReadBefore() const { return rows_read_before; }
/// Update state according to new rows_read_before.
virtual void onRowsReadBeforeUpdate() {}
/// Some formats outputs some statistics after the data,
/// in parallel formatting we collect these statistics outside the
/// underling format and then set it to format before finalizing.
struct Statistics
{
Stopwatch watch;
Progress progress;
bool applied_limit = false;
size_t rows_before_limit = 0;
Chunk totals;
Chunk extremes;
};
/// In some formats the way we print extremes depends on
/// were totals printed or not. In this case in parallel formatting
/// we should notify underling format if totals were printed.
void setTotalsAreWritten() { are_totals_written = true; }
bool areTotalsWritten() const { return are_totals_written; }
/// Return true if format saves totals and extremes in consumeTotals/consumeExtremes and
/// outputs them in finalize() method.
virtual bool areTotalsAndExtremesUsedInFinalize() const { return false; }
/// Derived classes can use some wrappers around out WriteBuffer
/// and can override this method to return wrapper
/// that should be used in its derived classes.
virtual WriteBuffer * getWriteBufferPtr() { return &out; }
WriteBuffer & out;
Chunk current_chunk;
PortKind current_block_kind = PortKind::Main;
bool has_input = false;
bool finished = false;
bool finalized = false;
/// Flush data on each consumed chunk. This is intended for interactive applications to output data as soon as it's ready.
bool auto_flush = false;
bool need_write_prefix = true;
bool need_write_suffix = true;
RowsBeforeLimitCounterPtr rows_before_limit_counter;
Statistics statistics;
private:
size_t rows_read_before = 0;
bool are_totals_written = false;
/// Counters for consumed chunks. Are used for QueryLog.
size_t result_rows = 0;
size_t result_bytes = 0;
};
}
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