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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
use crate::error::Result;
use payload_support::Fit;
use serde::Serialize;
/// Truncates `list` to fit within `payload_size_max_bytes` when serialized to
/// JSON.
pub fn shrink_to_fit<T: Serialize>(list: &mut Vec<T>, payload_size_max_bytes: usize) -> Result<()> {
match payload_support::try_fit_items(list, payload_size_max_bytes) {
Fit::All => {}
Fit::Some(count) => list.truncate(count.get()),
Fit::None => list.clear(),
Fit::Err(e) => Err(e)?,
};
Ok(())
}
#[cfg(test)]
mod tests {
use super::super::record::CommandRecord;
use super::*;
#[test]
fn test_shrink_to_fit() {
let mut commands = vec![
CommandRecord {
name: "wipeEngine".into(),
args: vec![Some("bookmarks".into())],
flow_id: Some("flow".into()),
},
CommandRecord {
name: "resetEngine".into(),
args: vec![Some("history".into())],
flow_id: Some("flow".into()),
},
CommandRecord {
name: "logout".into(),
args: Vec::new(),
flow_id: None,
},
];
// 4096 bytes is enough to fit all three commands.
shrink_to_fit(&mut commands, 4096).unwrap();
assert_eq!(commands.len(), 3);
// `logout` won't fit within 2168 bytes.
shrink_to_fit(&mut commands, 2168).unwrap();
assert_eq!(commands.len(), 2);
// `resetEngine` won't fit within 2084 bytes.
shrink_to_fit(&mut commands, 2084).unwrap();
assert_eq!(commands.len(), 1);
// `wipeEngine` won't fit at all.
shrink_to_fit(&mut commands, 1024).unwrap();
assert!(commands.is_empty());
}
}