59 lines
1.4 KiB
Rust
59 lines
1.4 KiB
Rust
use std::cell::RefCell;
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const LOG_MESSAGES_BYTES_LIMIT: usize = 10 * 1000;
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#[derive(Default)]
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struct LogCollectorInner {
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messages: Vec<String>,
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bytes_written: usize,
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limit_warning: bool,
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}
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#[derive(Default)]
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pub struct LogCollector {
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inner: RefCell<LogCollectorInner>,
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}
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impl LogCollector {
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pub fn log(&self, message: &str) {
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let mut inner = self.inner.borrow_mut();
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if inner.bytes_written + message.len() >= LOG_MESSAGES_BYTES_LIMIT {
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if !inner.limit_warning {
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inner.limit_warning = true;
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inner.messages.push(String::from("Log truncated"));
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}
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} else {
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inner.bytes_written += message.len();
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inner.messages.push(message.to_string());
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}
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}
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}
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impl From<LogCollector> for Vec<String> {
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fn from(log_collector: LogCollector) -> Self {
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log_collector.inner.into_inner().messages
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}
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}
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#[cfg(test)]
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pub(crate) mod tests {
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use super::*;
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#[test]
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fn test_log_messages_bytes_limit() {
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let lc = LogCollector::default();
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for _i in 0..LOG_MESSAGES_BYTES_LIMIT * 2 {
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lc.log("x");
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}
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let logs: Vec<_> = lc.into();
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assert_eq!(logs.len(), LOG_MESSAGES_BYTES_LIMIT);
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for log in logs.iter().take(LOG_MESSAGES_BYTES_LIMIT - 1) {
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assert_eq!(*log, "x".to_string());
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}
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assert_eq!(logs.last(), Some(&"Log truncated".to_string()));
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}
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}
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