2 * Copyright 2004-present Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
18 #include <folly/Conv.h>
19 #include <folly/Format.h>
20 #include <folly/experimental/logging/LogCategory.h>
21 #include <folly/experimental/logging/LogLevel.h>
22 #include <folly/experimental/logging/LogStream.h>
23 #include <folly/experimental/logging/LogStreamProcessor.h>
26 * Helper macro for implementing FB_LOG() and FB_LOGF().
28 * This macro generally should not be used directly by end users.
30 #define FB_LOG_IMPL(logger, level, type, ...) \
31 (!(logger).getCategory()->logCheck(level)) \
33 : ::folly::LogStreamProcessor{(logger).getCategory(), \
42 * Log a message to the specified logger.
44 * This macro avoids evaluating the log arguments unless the log level check
47 * Beware that the logger argument is evaluated twice, so this argument should
48 * be an expression with no side-effects.
50 #define FB_LOG(logger, level, ...) \
53 ::folly::LogLevel::level, \
54 ::folly::LogStreamProcessor::APPEND, \
58 * Log a message to the specified logger, using a folly::format() string.
60 * The arguments will be processed using folly::format(). The format syntax
61 * is similar to Python format strings.
63 * This macro avoids evaluating the log arguments unless the log level check
66 * Beware that the logger argument is evaluated twice, so this argument should
67 * be an expression with no side-effects.
69 #define FB_LOGF(logger, level, fmt, arg1, ...) \
72 ::folly::LogLevel::level, \
73 ::folly::LogStreamProcessor::FORMAT, \
84 * Logger is the class you will normally use to log messages.
86 * The Logger is really just a small wrapper class that contains a pointer
87 * to the appropriate LogCategory object. It exists to allow for easy static
88 * initialization of log categories, as well as to provide fast checking of the
89 * current effective log level.
94 * Construct a Logger for the given category name.
96 * A LogCategory object for this category will be created if one does not
99 explicit Logger(folly::StringPiece name);
102 * Construct a Logger pointing to an existing LogCategory object.
104 explicit Logger(LogCategory* cat);
107 * Construct a Logger for a specific LoggerDB object, rather than the main
110 * This is primarily intended for use in unit tests.
112 Logger(LoggerDB* db, folly::StringPiece name);
115 * Get the LogCategory that this Logger refers to.
117 LogCategory* getCategory() const {
122 LogCategory* const category_{nullptr};