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TMessagesProj/jni/voip/webrtc/absl/log/log_entry.h

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+// 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/log_entry.h
+// -----------------------------------------------------------------------------
+//
+// This header declares `class absl::LogEntry`, which represents a log record as
+// passed to `LogSink::Send`. Data returned by pointer or by reference or by
+// `absl::string_view` must be copied if they are needed after the lifetime of
+// the `absl::LogEntry`.
+
+#ifndef ABSL_LOG_LOG_ENTRY_H_
+#define ABSL_LOG_LOG_ENTRY_H_
+
+#include <cstddef>
+#include <string>
+
+#include "absl/base/attributes.h"
+#include "absl/base/config.h"
+#include "absl/base/log_severity.h"
+#include "absl/log/internal/config.h"
+#include "absl/strings/string_view.h"
+#include "absl/time/time.h"
+#include "absl/types/span.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+
+namespace log_internal {
+// Test only friend.
+class LogEntryTestPeer;
+class LogMessage;
+}  // namespace log_internal
+
+// LogEntry
+//
+// Represents a single entry in a log, i.e., one `LOG` statement or failed
+// `CHECK`.
+//
+// `LogEntry` is thread-compatible.
+class LogEntry final {
+ public:
+  using tid_t = log_internal::Tid;
+
+  // For non-verbose log entries, `verbosity()` returns `kNoVerbosityLevel`.
+  static constexpr int kNoVerbosityLevel = -1;
+  static constexpr int kNoVerboseLevel = -1;  // TO BE removed
+
+  // Pass `LogEntry` by reference, and do not store it as its state does not
+  // outlive the call to `LogSink::Send()`.
+  LogEntry(const LogEntry&) = delete;
+  LogEntry& operator=(const LogEntry&) = delete;
+
+  // 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.
+  absl::string_view source_filename() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return full_filename_;
+  }
+  absl::string_view source_basename() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return base_filename_;
+  }
+  int source_line() const { return line_; }
+
+  // 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()`.
+  bool prefix() const { return prefix_; }
+
+  // LogEntry::log_severity()
+  //
+  // Returns this entry's severity.  For `LOG`, taken from the first argument;
+  // for `CHECK`, always `absl::LogSeverity::kFatal`.
+  absl::LogSeverity log_severity() const { return severity_; }
+
+  // LogEntry::verbosity()
+  //
+  // Returns this entry's verbosity, or `kNoVerbosityLevel` for a non-verbose
+  // entry. Taken from the argument to `VLOG` or from
+  // `LOG(...).WithVerbosity(...)`.
+  int verbosity() const { return verbose_level_; }
+
+  // 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).
+  absl::Time timestamp() const { return timestamp_; }
+
+  // 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.
+  tid_t tid() const { return tid_; }
+
+  // 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.
+  absl::string_view text_message_with_prefix_and_newline() const
+      ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return absl::string_view(
+        text_message_with_prefix_and_newline_and_nul_.data(),
+        text_message_with_prefix_and_newline_and_nul_.size() - 1);
+  }
+  absl::string_view text_message_with_prefix() const
+      ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return absl::string_view(
+        text_message_with_prefix_and_newline_and_nul_.data(),
+        text_message_with_prefix_and_newline_and_nul_.size() - 2);
+  }
+  absl::string_view text_message_with_newline() const
+      ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return absl::string_view(
+        text_message_with_prefix_and_newline_and_nul_.data() + prefix_len_,
+        text_message_with_prefix_and_newline_and_nul_.size() - prefix_len_ - 1);
+  }
+  absl::string_view text_message() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return absl::string_view(
+        text_message_with_prefix_and_newline_and_nul_.data() + prefix_len_,
+        text_message_with_prefix_and_newline_and_nul_.size() - prefix_len_ - 2);
+  }
+  const char* text_message_with_prefix_and_newline_c_str() const
+      ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return text_message_with_prefix_and_newline_and_nul_.data();
+  }
+
+  // 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.
+  absl::string_view encoded_message() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return encoding_;
+  }
+
+  // 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.
+  absl::string_view stacktrace() const ABSL_ATTRIBUTE_LIFETIME_BOUND {
+    return stacktrace_;
+  }
+
+ private:
+  LogEntry() = default;
+
+  absl::string_view full_filename_;
+  absl::string_view base_filename_;
+  int line_;
+  bool prefix_;
+  absl::LogSeverity severity_;
+  int verbose_level_;  // >=0 for `VLOG`, etc.; otherwise `kNoVerbosityLevel`.
+  absl::Time timestamp_;
+  tid_t tid_;
+  absl::Span<const char> text_message_with_prefix_and_newline_and_nul_;
+  size_t prefix_len_;
+  absl::string_view encoding_;
+  std::string stacktrace_;
+
+  friend class log_internal::LogEntryTestPeer;
+  friend class log_internal::LogMessage;
+};
+
+ABSL_NAMESPACE_END
+}  // namespace absl
+
+#endif  // ABSL_LOG_LOG_ENTRY_H_