class LogEntry

Pass `LogEntry` by reference, and do not store it as its state does not

outlive the call to `LogSink::Send()`.

Source file and line where the log message occurred. Taken from `__FILE__`

and `__LINE__` unless overridden by `LOG(...).AtLocation(...)`.

Take special care not to use the values returned by `source_filename()` and

`source_basename()` after the lifetime of the entry. This is always

incorrect, but it will often work in practice because they usually point

into a statically allocated character array obtained from `__FILE__`.

Statements like `LOG(INFO).AtLocation(std::string(...), ...)` will expose

the bug. If you need the data later, you must copy them.

LogEntry::prefix()

True unless the metadata prefix was suppressed once by

`LOG(...).NoPrefix()` or globally by `absl::EnableLogPrefix(false)`.

Implies `text_message_with_prefix() == text_message()`.

LogEntry::log_severity()

Returns this entry's severity. For `LOG`, taken from the first argument;

for `CHECK`, always `absl::LogSeverity::kFatal`.

LogEntry::verbosity()

Returns this entry's verbosity, or `kNoVerbosityLevel` for a non-verbose

entry. Taken from the argument to `VLOG` or from

`LOG(...).WithVerbosity(...)`.

LogEntry::timestamp()

Returns the time at which this entry was written. Captured during

evaluation of `LOG`, but can be overridden by

`LOG(...).WithTimestamp(...)`.

Take care not to rely on timestamps increasing monotonically, or even to

rely on timestamps having any particular relationship with reality (since

they can be overridden).

LogEntry::tid()

Returns the ID of the thread that wrote this entry. Captured during

evaluation of `LOG`, but can be overridden by `LOG(...).WithThreadID(...)`.

Take care not to *rely* on reported thread IDs as they can be overridden as

specified above.

Text-formatted version of the log message. An underlying buffer holds

these contiguous data:

* A prefix formed by formatting metadata (timestamp, filename, line number,

etc.)

The prefix may be empty - see `LogEntry::prefix()` - and may rarely be

truncated if the metadata are very long.

* The streamed data

The data may be empty if nothing was streamed, or may be truncated to fit

the buffer.

* A newline

* A nul terminator

The newline and nul terminator will be present even if the prefix and/or

data are truncated.

These methods give access to the most commonly useful substrings of the

buffer's contents. Other combinations can be obtained with substring

arithmetic.

The buffer does not outlive the entry; if you need the data later, you must

copy them.

Returns a serialized protobuf holding the operands streamed into this

log message. The message definition is not yet published.

The buffer does not outlive the entry; if you need the data later, you must

copy them.

LogEntry::stacktrace()

Optional stacktrace, e.g. for `FATAL` logs and failed `CHECK`s.

Fatal entries are dispatched to each sink twice: first with all data and

metadata but no stacktrace, and then with the stacktrace. This is done

because stacktrace collection is sometimes slow and fallible, and it's

critical to log enough information to diagnose the failure even if the

stacktrace collection hangs.

The buffer does not outlive the entry; if you need the data later, you must

copy them.