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TMessagesProj/jni/voip/webrtc/absl/log/vlog_is_on.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/vlog_is_on.h
+// -----------------------------------------------------------------------------
+//
+// This header defines the `VLOG_IS_ON()` macro that controls the
+// variable-verbosity conditional logging.
+//
+// It's used by `VLOG` in log.h, or it can also be used directly like this:
+//
+//   if (VLOG_IS_ON(2)) {
+//     foo_server.RecomputeStatisticsExpensive();
+//     LOG(INFO) << foo_server.LastStatisticsAsString();
+//   }
+//
+// Each source file has an effective verbosity level that's a non-negative
+// integer computed from the `--vmodule` and `--v` flags.
+// `VLOG_IS_ON(n)` is true, and `VLOG(n)` logs, if that effective verbosity
+// level is greater than or equal to `n`.
+//
+// `--vmodule` takes a comma-delimited list of key=value pairs.  Each key is a
+// pattern matched against filenames, and the values give the effective severity
+// level applied to matching files.  '?' and '*' characters in patterns are
+// interpreted as single-character and zero-or-more-character wildcards.
+// Patterns including a slash character are matched against full pathnames,
+// while those without are matched against basenames only.  One suffix (i.e. the
+// last . and everything after it) is stripped from each filename prior to
+// matching, as is the special suffix "-inl".
+//
+// Example: --vmodule=module_a=1,module_b=2
+//
+// Files are matched against globs in `--vmodule` in order, and the first match
+// determines the verbosity level.
+//
+// Files which do not match any pattern in `--vmodule` use the value of `--v` as
+// their effective verbosity level.  The default is 0.
+//
+// SetVLogLevel helper function is provided to do limited dynamic control over
+// V-logging by appending to `--vmodule`. Because these go at the beginning of
+// the list, they take priority over any globs previously added.
+//
+// Resetting --vmodule will override all previous modifications to `--vmodule`,
+// including via SetVLogLevel.
+
+#ifndef ABSL_LOG_VLOG_IS_ON_H_
+#define ABSL_LOG_VLOG_IS_ON_H_
+
+#include "absl/log/absl_vlog_is_on.h"  // IWYU pragma: export
+
+// IWYU pragma: private, include "absl/log/log.h"
+
+// Each VLOG_IS_ON call site gets its own VLogSite that registers with the
+// global linked list of sites to asynchronously update its verbosity level on
+// changes to --v or --vmodule. The verbosity can also be set by manually
+// calling SetVLogLevel.
+//
+// VLOG_IS_ON is not async signal safe, but it is guaranteed not to allocate
+// new memory.
+#define VLOG_IS_ON(verbose_level) ABSL_VLOG_IS_ON(verbose_level)
+
+#endif  // ABSL_LOG_VLOG_IS_ON_H_