| /* |
| * Copyright (C) 2021 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. |
| */ |
| |
| use anyhow::{anyhow, bail, Result}; |
| use nix::sys::stat::FileStat; |
| use std::fs::File; |
| use std::os::unix::fs::FileTypeExt; |
| use std::os::unix::io::AsRawFd; |
| use std::path::Path; |
| use std::thread; |
| use std::time::{Duration, Instant}; |
| |
| /// Returns when the file exists on the given `path` or timeout (1s) occurs. |
| pub fn wait_for_path<P: AsRef<Path>>(path: P) -> Result<()> { |
| const TIMEOUT: Duration = Duration::from_secs(1); |
| const INTERVAL: Duration = Duration::from_millis(10); |
| let begin = Instant::now(); |
| while !path.as_ref().exists() { |
| if begin.elapsed() > TIMEOUT { |
| bail!("{:?} not found. TIMEOUT.", path.as_ref()); |
| } |
| thread::sleep(INTERVAL); |
| } |
| Ok(()) |
| } |
| |
| /// Returns hexadecimal reprentation of a given byte array. |
| pub fn hexstring_from(s: &[u8]) -> String { |
| s.iter().map(|byte| format!("{:02x}", byte)).reduce(|i, j| i + &j).unwrap_or_default() |
| } |
| |
| /// Parses a hexadecimal string into a byte array |
| pub fn parse_hexstring(s: &str) -> Result<Vec<u8>> { |
| let len = s.len(); |
| if len % 2 != 0 { |
| bail!("length {} is not even", len) |
| } else { |
| (0..len) |
| .step_by(2) |
| .map(|i| u8::from_str_radix(&s[i..i + 2], 16).map_err(|e| anyhow!(e))) |
| .collect() |
| } |
| } |
| |
| /// fstat that accepts a path rather than FD |
| pub fn fstat(p: &Path) -> Result<FileStat> { |
| let f = File::open(p)?; |
| Ok(nix::sys::stat::fstat(f.as_raw_fd())?) |
| } |
| |
| // From include/uapi/linux/fs.h |
| const BLK: u8 = 0x12; |
| const BLKGETSIZE64: u8 = 114; |
| nix::ioctl_read!(_blkgetsize64, BLK, BLKGETSIZE64, libc::size_t); |
| |
| /// Gets the size of a block device |
| pub fn blkgetsize64(p: &Path) -> Result<u64> { |
| let f = File::open(p)?; |
| if !f.metadata()?.file_type().is_block_device() { |
| bail!("{:?} is not a block device", p); |
| } |
| let mut size: usize = 0; |
| // SAFETY: kernel copies the return value out to `size`. The file is kept open until the end of |
| // this function. |
| unsafe { _blkgetsize64(f.as_raw_fd(), &mut size) }?; |
| Ok(size as u64) |
| } |