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/*
* Copyright (C) 2024 The Android Open Source Project
*
* 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
*
* http://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.
*/
//! flag value update module defines the flag value file write to mapped bytes
use aconfig_storage_file::{AconfigStorageError, FlagValueHeader, FILE_VERSION};
use anyhow::anyhow;
/// Set flag value
pub fn update_boolean_flag_value(
buf: &mut [u8],
flag_index: u32,
flag_value: bool,
) -> Result<(), AconfigStorageError> {
let interpreted_header = FlagValueHeader::from_bytes(buf)?;
if interpreted_header.version > FILE_VERSION {
return Err(AconfigStorageError::HigherStorageFileVersion(anyhow!(
"Cannot write to storage file with a higher version of {} with lib version {}",
interpreted_header.version,
FILE_VERSION
)));
}
// get byte offset to the flag
let head = (interpreted_header.boolean_value_offset + flag_index) as usize;
if head >= interpreted_header.file_size as usize {
return Err(AconfigStorageError::InvalidStorageFileOffset(anyhow!(
"Flag value offset goes beyond the end of the file."
)));
}
buf[head] = u8::from(flag_value).to_le_bytes()[0];
Ok(())
}
#[cfg(test)]
mod tests {
use super::*;
use aconfig_storage_file::test_utils::create_test_flag_value_list;
#[test]
// this test point locks down flag value update
fn test_boolean_flag_value_update() {
let flag_value_list = create_test_flag_value_list();
let value_offset = flag_value_list.header.boolean_value_offset;
let mut content = flag_value_list.into_bytes();
let true_byte = u8::from(true).to_le_bytes()[0];
let false_byte = u8::from(false).to_le_bytes()[0];
for i in 0..flag_value_list.header.num_flags {
let offset = (value_offset + i) as usize;
update_boolean_flag_value(&mut content, i, true).unwrap();
assert_eq!(content[offset], true_byte);
update_boolean_flag_value(&mut content, i, false).unwrap();
assert_eq!(content[offset], false_byte);
}
}
#[test]
// this test point locks down update beyond the end of boolean section
fn test_boolean_out_of_range() {
let mut flag_value_list = create_test_flag_value_list().into_bytes();
let error = update_boolean_flag_value(&mut flag_value_list[..], 8, true).unwrap_err();
assert_eq!(
format!("{:?}", error),
"InvalidStorageFileOffset(Flag value offset goes beyond the end of the file.)"
);
}
#[test]
// this test point locks down query error when file has a higher version
fn test_higher_version_storage_file() {
let mut value_list = create_test_flag_value_list();
value_list.header.version = FILE_VERSION + 1;
let mut flag_value = value_list.into_bytes();
let error = update_boolean_flag_value(&mut flag_value[..], 4, true).unwrap_err();
assert_eq!(
format!("{:?}", error),
format!(
"HigherStorageFileVersion(Cannot write to storage file with a higher version of {} with lib version {})",
FILE_VERSION + 1,
FILE_VERSION
)
);
}
}
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