1 /*
2  * Copyright (C) 2023 The Android Open Source Project
3  *
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
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
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.
15  */
16 
17 package com.android.systemui.log.core
18 
19 /**
20  * [MessageBuffer] is an interface that represents a buffer of log messages, and provides methods to
21  * [obtain] a log message and [commit] it to the buffer.
22  */
23 interface MessageBuffer {
24     /**
25      * Obtains the next [LogMessage] from the buffer.
26      *
27      * After calling [obtain], the caller must store any relevant data on the message and then call
28      * [commit].
29      */
30     fun obtain(
31         tag: String,
32         level: LogLevel,
33         messagePrinter: MessagePrinter,
34         exception: Throwable? = null,
35     ): LogMessage
36 
37     /**
38      * After acquiring a log message via [obtain], call this method to signal to the buffer that
39      * data fields have been filled.
40      */
41     fun commit(message: LogMessage)
42 }
43