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// to you under the Apache License, Version 2.0 (the
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//
//   http://www.apache.org/licenses/LICENSE-2.0
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#ifndef IMPALA_UTIL_ERROR_UTIL_INTERNAL_H
#define IMPALA_UTIL_ERROR_UTIL_INTERNAL_H

#include <google/protobuf/map.h>

#include "gen-cpp/control_service.pb.h"
#include "util/error-util.h"

/// Factor out the following structures from 'error-util.h' to prevent circular dependency
/// with code in kudu directory which is needed for generating 'control_service.pb.h'.
namespace impala {

/// Track log messages per error code. Using a map here instead of unordered_map
/// to ensure the output from PrintErrorLogMap() is deterministic.
typedef std::map<TErrorCode::type, ErrorLogEntryPB> ErrorLogMap;
typedef google::protobuf::Map<int32_t, ErrorLogEntryPB> ErrorLogMapPB;

/// Merge an error log entry 'entry' with 'error_code' into ErrorLogMap 'target_map'.
/// General log messages are simply appended, specific errors are deduplicated by either
/// appending a new instance or incrementing the count of an existing one.
void MergeErrorLogEntry(const TErrorCode::type error_code,
    const ErrorLogEntryPB& entry, ErrorLogMap* target_map);

/// Merge error map m1 into m2. Calls MergerErrorLogEntry() internally.
void MergeErrorMaps(const ErrorLogMap& m1, ErrorLogMap* m2);

/// Merge protobuf error map m1 into m2. Calls MergeErrorLogEntry() internally.
void MergeErrorMaps(const ErrorLogMapPB& m1, ErrorLogMap* m2);

/// Append an error to the error map. Performs the aggregation as follows: GENERAL errors
/// are appended to the list of GENERAL errors, to keep one item each in the map, while
/// for all other error codes only the count is incremented and only the first message
/// is kept as a sample.
void AppendError(ErrorLogMap* map, const ErrorMsg& e);

/// Helper method to print the contents of an ErrorMap to a stream.
void PrintErrorMap(std::ostream* stream, const ErrorLogMap& errors);

/// Reset all messages and count, but keep all keys to prevent sending already reported
/// general errors and counting the same non-general error multiple times.
void ClearErrorMap(ErrorLogMap& errors);

/// Return the number of errors within this error maps. General errors are counted
/// individually, while specific errors are counted once per distinct occurrence.
size_t ErrorCount(const ErrorLogMap& errors);

/// Generate a string representation of the error map. Produces the same output as
/// PrintErrorMap, but returns a string instead of using a stream.
std::string PrintErrorMapToString(const ErrorLogMap& errors);

} // namespace impala

#endif // IMPALA_UTIL_ERROR_UTIL_INTERNAL_H