server/worker_task: improve newline handling in upid_read_status

improves upid_read_status with:
* ignore multiple newlines at the end
* remove all code that could panic (array index access)
  the one place where we access with '[pos+1..]' is ok since
  we explicitely test the len of the vector, this is done to
  let rust optimize away the range checks, so it cannot panic

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>
This commit is contained in:
Dominik Csapak 2021-01-25 12:32:29 +01:00 committed by Wolfgang Bumiller
parent 340c0bf9e3
commit 6864fd0149

View File

@ -190,20 +190,15 @@ pub fn upid_read_status(upid: &UPID) -> Result<TaskState, Error> {
let mut data = Vec::with_capacity(8192);
file.read_to_end(&mut data)?;
// task logs should end with newline, we do not want it here
if !data.is_empty() && data[data.len()-1] == b'\n' {
// strip newlines at the end of the task logs
while data.last() == Some(&b'\n') {
data.pop();
}
let last_line = {
let mut start = 0;
for pos in (0..data.len()).rev() {
if data[pos] == b'\n' {
start = data.len().min(pos + 1);
break;
}
}
&data[start..]
let last_line = match data.iter().rposition(|c| *c == b'\n') {
Some(start) if data.len() > (start+1) => &data[start+1..],
Some(_) => &data, // should not happen, since we removed all trailing newlines
None => &data,
};
let last_line = std::str::from_utf8(last_line)