// Copyright 2022 The Abseil Authors.

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//      https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

//

// -----------------------------------------------------------------------------

// File: log/globals.h

// -----------------------------------------------------------------------------

//

// This header declares global logging library configuration knobs.

#ifndef ABSL_LOG_GLOBALS_H_

#define ABSL_LOG_GLOBALS_H_

#include "absl/base/attributes.h"

#include "absl/base/config.h"

#include "absl/base/log_severity.h"

#include "absl/log/internal/vlog_config.h"

#include "absl/strings/string_view.h"

namespace absl {

ABSL_NAMESPACE_BEGIN

//------------------------------------------------------------------------------

//  Minimum Log Level

//------------------------------------------------------------------------------

//

// Messages logged at or above this severity are directed to all registered log

// sinks or skipped otherwise. This parameter can also be modified using

// command line flag --minloglevel.

// See absl/base/log_severity.h for descriptions of severity levels.

// MinLogLevel()

//

// Returns the value of the Minimum Log Level parameter.

// This function is async-signal-safe.

ABSL_MUST_USE_RESULT absl::LogSeverityAtLeast MinLogLevel();

// SetMinLogLevel()

//

// Updates the value of Minimum Log Level parameter.

// This function is async-signal-safe.

void SetMinLogLevel(absl::LogSeverityAtLeast severity);

namespace log_internal {

// ScopedMinLogLevel

//

// RAII type used to temporarily update the Min Log Level parameter.

class ScopedMinLogLevel final {

 public:

  explicit ScopedMinLogLevel(absl::LogSeverityAtLeast severity);

  ScopedMinLogLevel(const ScopedMinLogLevel&) = delete;

  ScopedMinLogLevel& operator=(const ScopedMinLogLevel&) = delete;

  ~ScopedMinLogLevel();

 private:

  absl::LogSeverityAtLeast saved_severity_;

};

}  // namespace log_internal

//------------------------------------------------------------------------------

// Stderr Threshold

//------------------------------------------------------------------------------

//

// Messages logged at or above this level are directed to stderr in

// addition to other registered log sinks. This parameter can also be modified

// using command line flag --stderrthreshold.

// See absl/base/log_severity.h for descriptions of severity levels.

// StderrThreshold()

//

// Returns the value of the Stderr Threshold parameter.

// This function is async-signal-safe.

ABSL_MUST_USE_RESULT absl::LogSeverityAtLeast StderrThreshold();

// SetStderrThreshold()

//

// Updates the Stderr Threshold parameter.

// This function is async-signal-safe.

void SetStderrThreshold(absl::LogSeverityAtLeast severity);

inline void SetStderrThreshold(absl::LogSeverity severity) {

  absl::SetStderrThreshold(static_cast<absl::LogSeverityAtLeast>(severity));

}

// ScopedStderrThreshold

//

// RAII type used to temporarily update the Stderr Threshold parameter.

class ScopedStderrThreshold final {

 public:

  explicit ScopedStderrThreshold(absl::LogSeverityAtLeast severity);

  ScopedStderrThreshold(const ScopedStderrThreshold&) = delete;

  ScopedStderrThreshold& operator=(const ScopedStderrThreshold&) = delete;

  ~ScopedStderrThreshold();

 private:

  absl::LogSeverityAtLeast saved_severity_;

};

//------------------------------------------------------------------------------

// Log Backtrace At

//------------------------------------------------------------------------------

//

// Users can request an existing `LOG` statement, specified by file and line

// number, to also include a backtrace when logged.

// ShouldLogBacktraceAt()

//

// Returns true if we should log a backtrace at the specified location.

namespace log_internal {

ABSL_MUST_USE_RESULT bool ShouldLogBacktraceAt(absl::string_view file,

                                               int line);

}  // namespace log_internal

// SetLogBacktraceLocation()

//

// Sets the location the backtrace should be logged at.  If the specified

// location isn't a `LOG` statement, the effect will be the same as

// `ClearLogBacktraceLocation` (but less efficient).

void SetLogBacktraceLocation(absl::string_view file, int line);

// ClearLogBacktraceLocation()

//

// Clears the set location so that backtraces will no longer be logged at it.

void ClearLogBacktraceLocation();

//------------------------------------------------------------------------------

// Prepend Log Prefix

//------------------------------------------------------------------------------

//

// This option tells the logging library that every logged message

// should include the prefix (severity, date, time, PID, etc.)

//

// ShouldPrependLogPrefix()

//

// Returns the value of the Prepend Log Prefix option.

// This function is async-signal-safe.

ABSL_MUST_USE_RESULT bool ShouldPrependLogPrefix();

// EnableLogPrefix()

//

// Updates the value of the Prepend Log Prefix option.

// This function is async-signal-safe.

void EnableLogPrefix(bool on_off);

//------------------------------------------------------------------------------

// `VLOG` Configuration

//------------------------------------------------------------------------------

//

// These methods set the `(ABSL_)VLOG(_IS_ON)` threshold.  They allow

// programmatic control of the thresholds set by the --v and --vmodule flags.

//

// Only `VLOG`s with a severity level LESS THAN OR EQUAL TO the threshold will

// be evaluated.

//

// For example, if the threshold is 2, then:

//

//   VLOG(2) << "This message will be logged.";

//   VLOG(3) << "This message will NOT be logged.";

//

// The default threshold is 0. Since `VLOG` levels must not be negative, a

// negative threshold value will turn off all VLOGs.

// SetGlobalVLogLevel()

//

// Sets the global `VLOG` level to threshold. Returns the previous global

// threshold.

inline int SetGlobalVLogLevel(int threshold) {

  return absl::log_internal::UpdateGlobalVLogLevel(threshold);

}

// SetVLogLevel()

//

// Sets the `VLOG` threshold for all files that match `module_pattern`,

// overwriting any prior value. Files that don't match aren't affected.

// Returns the threshold that previously applied to `module_pattern`.

inline int SetVLogLevel(absl::string_view module_pattern, int threshold) {

  return absl::log_internal::PrependVModule(module_pattern, threshold);

}

//------------------------------------------------------------------------------

// Configure Android Native Log Tag

//------------------------------------------------------------------------------

//

// The logging library forwards to the Android system log API when built for

// Android.  That API takes a string "tag" value in addition to a message and

// severity level.  The tag is used to identify the source of messages and to

// filter them.  This library uses the tag "native" by default.

// SetAndroidNativeTag()

//

// Stores a copy of the string pointed to by `tag` and uses it as the Android

// logging tag thereafter. `tag` must not be null.

// This function must not be called more than once!

void SetAndroidNativeTag(const char* tag);

namespace log_internal {

// GetAndroidNativeTag()

//

// Returns the configured Android logging tag.

const char* GetAndroidNativeTag();

}  // namespace log_internal

namespace log_internal {

using LoggingGlobalsListener = void (*)();

void SetLoggingGlobalsListener(LoggingGlobalsListener l);

// Internal implementation for the setter routines. These are used

// to break circular dependencies between flags and globals. Each "Raw"

// routine corresponds to the non-"Raw" counterpart and used to set the

// configuration parameter directly without calling back to the listener.

void RawSetMinLogLevel(absl::LogSeverityAtLeast severity);

void RawSetStderrThreshold(absl::LogSeverityAtLeast severity);

void RawEnableLogPrefix(bool on_off);

}  // namespace log_internal

ABSL_NAMESPACE_END

}  // namespace absl

#endif  // ABSL_LOG_GLOBALS_H_