1/*
2 * Copyright (C) 2017 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@file:Suppress("NOTHING_TO_INLINE") // Aliases to other public API.
18
19package androidx.core.util
20
21import android.util.AtomicFile
22import androidx.annotation.RequiresApi
23import java.io.FileOutputStream
24import java.nio.charset.Charset
25
26/**
27 * Perform the write operations inside [block] on this file. If [block] throws an exception the
28 * write will be failed. Otherwise the write will be applied atomically to the file.
29 */
30@RequiresApi(17)
31inline fun AtomicFile.tryWrite(block: (out: FileOutputStream) -> Unit) {
32    val stream = startWrite()
33    var success = false
34    try {
35        block(stream)
36        success = true
37    } finally {
38        if (success) {
39            finishWrite(stream)
40        } else {
41            failWrite(stream)
42        }
43    }
44}
45
46/**
47 * Sets the content of this file as an [array] of bytes.
48 */
49@RequiresApi(17)
50fun AtomicFile.writeBytes(array: ByteArray) {
51    tryWrite {
52        it.write(array)
53    }
54}
55
56/**
57 * Sets the content of this file as [text] encoded using UTF-8 or specified [charset].
58 * If this file exists, it becomes overwritten.
59 */
60@RequiresApi(17)
61fun AtomicFile.writeText(text: String, charset: Charset = Charsets.UTF_8) {
62    writeBytes(text.toByteArray(charset))
63}
64
65/**
66 * Gets the entire content of this file as a byte array.
67 *
68 * This method is not recommended on huge files. It has an internal limitation of 2 GB file size.
69 */
70@RequiresApi(17)
71inline fun AtomicFile.readBytes(): ByteArray = readFully()
72
73/**
74 * Gets the entire content of this file as a String using UTF-8 or specified [charset].
75 *
76 * This method is not recommended on huge files. It has an internal limitation of 2 GB file size.
77 */
78@RequiresApi(17)
79fun AtomicFile.readText(charset: Charset = Charsets.UTF_8): String {
80    return readFully().toString(charset)
81}
82