1 /*
2 * Copyright (C) 2024 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 table query module defines the package table file read from mapped bytes
18
19 use crate::AconfigStorageError;
20 use aconfig_storage_file::{
21 package_table::PackageTableHeader, package_table::PackageTableNode, read_u32_from_bytes,
22 MAX_SUPPORTED_FILE_VERSION,
23 };
24 use anyhow::anyhow;
25
26 /// Package table query return
27 #[derive(PartialEq, Debug)]
28 pub struct PackageReadContext {
29 pub package_id: u32,
30 pub boolean_start_index: u32,
31 pub fingerprint: u64,
32 }
33
34 /// Query package read context: package id and start index
find_package_read_context( buf: &[u8], package: &str, ) -> Result<Option<PackageReadContext>, AconfigStorageError>35 pub fn find_package_read_context(
36 buf: &[u8],
37 package: &str,
38 ) -> Result<Option<PackageReadContext>, AconfigStorageError> {
39 let interpreted_header = PackageTableHeader::from_bytes(buf)?;
40 if interpreted_header.version > MAX_SUPPORTED_FILE_VERSION {
41 return Err(AconfigStorageError::HigherStorageFileVersion(anyhow!(
42 "Cannot read storage file with a higher version of {} with lib version {}",
43 interpreted_header.version,
44 MAX_SUPPORTED_FILE_VERSION
45 )));
46 }
47
48 let num_buckets = (interpreted_header.node_offset - interpreted_header.bucket_offset) / 4;
49 let bucket_index = PackageTableNode::find_bucket_index(package, num_buckets);
50
51 let mut pos = (interpreted_header.bucket_offset + 4 * bucket_index) as usize;
52 let mut package_node_offset = read_u32_from_bytes(buf, &mut pos)? as usize;
53 if package_node_offset < interpreted_header.node_offset as usize
54 || package_node_offset >= interpreted_header.file_size as usize
55 {
56 return Ok(None);
57 }
58
59 loop {
60 let interpreted_node =
61 PackageTableNode::from_bytes(&buf[package_node_offset..], interpreted_header.version)?;
62 if interpreted_node.package_name == package {
63 return Ok(Some(PackageReadContext {
64 package_id: interpreted_node.package_id,
65 boolean_start_index: interpreted_node.boolean_start_index,
66 fingerprint: interpreted_node.fingerprint,
67 }));
68 }
69 match interpreted_node.next_offset {
70 Some(offset) => package_node_offset = offset as usize,
71 None => return Ok(None),
72 }
73 }
74 }
75
76 #[cfg(test)]
77 mod tests {
78 use super::*;
79 use aconfig_storage_file::{test_utils::create_test_package_table, DEFAULT_FILE_VERSION};
80
81 #[test]
82 // this test point locks down table query
test_package_query()83 fn test_package_query() {
84 let package_table = create_test_package_table(DEFAULT_FILE_VERSION).into_bytes();
85 let package_context =
86 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_1")
87 .unwrap()
88 .unwrap();
89 let expected_package_context =
90 PackageReadContext { package_id: 0, boolean_start_index: 0, fingerprint: 0 };
91 assert_eq!(package_context, expected_package_context);
92 let package_context =
93 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_2")
94 .unwrap()
95 .unwrap();
96 let expected_package_context =
97 PackageReadContext { package_id: 1, boolean_start_index: 3, fingerprint: 0 };
98 assert_eq!(package_context, expected_package_context);
99 let package_context =
100 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_4")
101 .unwrap()
102 .unwrap();
103 let expected_package_context =
104 PackageReadContext { package_id: 2, boolean_start_index: 6, fingerprint: 0 };
105 assert_eq!(package_context, expected_package_context);
106 }
107
108 #[test]
109 // this test point locks down table query
test_package_query_v2()110 fn test_package_query_v2() {
111 let package_table = create_test_package_table(2).into_bytes();
112 let package_context =
113 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_1")
114 .unwrap()
115 .unwrap();
116 let expected_package_context = PackageReadContext {
117 package_id: 0,
118 boolean_start_index: 0,
119 fingerprint: 15248948510590158086u64,
120 };
121 assert_eq!(package_context, expected_package_context);
122 let package_context =
123 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_2")
124 .unwrap()
125 .unwrap();
126 let expected_package_context = PackageReadContext {
127 package_id: 1,
128 boolean_start_index: 3,
129 fingerprint: 4431940502274857964u64,
130 };
131 assert_eq!(package_context, expected_package_context);
132 let package_context =
133 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_4")
134 .unwrap()
135 .unwrap();
136 let expected_package_context = PackageReadContext {
137 package_id: 2,
138 boolean_start_index: 6,
139 fingerprint: 16233229917711622375u64,
140 };
141 assert_eq!(package_context, expected_package_context);
142 }
143
144 #[test]
145 // this test point locks down table query of a non exist package
test_not_existed_package_query()146 fn test_not_existed_package_query() {
147 // this will land at an empty bucket
148 let package_table = create_test_package_table(DEFAULT_FILE_VERSION).into_bytes();
149 let package_context =
150 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_3")
151 .unwrap();
152 assert_eq!(package_context, None);
153 // this will land at the end of a linked list
154 let package_context =
155 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_5")
156 .unwrap();
157 assert_eq!(package_context, None);
158 }
159
160 #[test]
161 // this test point locks down query error when file has a higher version
test_higher_version_storage_file()162 fn test_higher_version_storage_file() {
163 let mut table = create_test_package_table(DEFAULT_FILE_VERSION);
164 table.header.version = MAX_SUPPORTED_FILE_VERSION + 1;
165 let package_table = table.into_bytes();
166 let error =
167 find_package_read_context(&package_table[..], "com.android.aconfig.storage.test_1")
168 .unwrap_err();
169 assert_eq!(
170 format!("{:?}", error),
171 format!(
172 "HigherStorageFileVersion(Cannot read storage file with a higher version of {} with lib version {})",
173 MAX_SUPPORTED_FILE_VERSION + 1,
174 MAX_SUPPORTED_FILE_VERSION
175 )
176 );
177 }
178 }
179