Reader.h

#pragma once

#include <chrono>
#include <memory>
#include <vector>

#include <folly/Range.h>

#include "logdevice/include/Record.h"
#include "logdevice/include/types.h"

namespace facebook { namespace logdevice {

struct ReadStreamAttributes;

class Reader {
 public:
  virtual int startReading(logid_t log_id,
                           lsn_t from,
                           lsn_t until = LSN_MAX,
                           const ReadStreamAttributes* attrs = nullptr) = 0;

  virtual int stopReading(logid_t log_id) = 0;

  virtual bool isReading(logid_t log_id) const = 0;

  virtual bool isReadingAny() const = 0;

  virtual int setTimeout(std::chrono::milliseconds timeout) = 0;

  const std::chrono::milliseconds MAX_TIMEOUT{(1LL << 31) - 1};

  virtual ssize_t read(size_t nrecords,
                       std::vector<std::unique_ptr<DataRecord>>* data_out,
                       GapRecord* gap_out) = 0;

  virtual void waitOnlyWhenNoData() = 0;

  virtual void addMonitoringTag(std::string tag) = 0;

  virtual void withoutPayload() = 0;

  virtual void forceNoSingleCopyDelivery() = 0;

  virtual void includeByteOffset() = 0;

  virtual void doNotSkipPartiallyTrimmedSections() = 0;

  virtual int isConnectionHealthy(logid_t) const = 0;

  virtual void doNotDecodeBufferedWrites() = 0;

  virtual void setReaderName(const std::string&) = 0;

  static lsn_t nextFromLsnWhenStuck(lsn_t stuck_lsn = LSN_INVALID,
                                    lsn_t tail_lsn = LSN_INVALID);

  virtual ~Reader() {}
};

}} // namespace facebook::logdevice