{"record":{"id":"978b10ba3c7e1702","repo":"Hmbown/CodeWhale","slug":"event-recovery-chunk-length-fits-u64","errorCode":null,"errorMessage":"event recovery chunk length fits u64","messagePattern":"event recovery chunk length fits u64","errorType":"panic","errorClass":null,"httpStatus":null,"severity":"info","filePath":"crates/tui/src/runtime_threads.rs","lineNumber":14024,"sourceCode":"    if len == 0 {\n        return Ok(());\n    }\n\n    file.seek(SeekFrom::End(-1))?;\n    let mut last = [0_u8; 1];\n    file.read_exact(&mut last)?;\n    if last[0] == b'\\n' {\n        return Ok(());\n    }\n\n    let mut search_end = len;\n    let mut truncate_at = 0_u64;\n    let mut buffer = [0_u8; 8 * 1024];\n    let buffer_len = u64::try_from(buffer.len()).expect(\"event recovery buffer fits u64\");\n    while search_end > 0 {\n        let chunk_len = usize::try_from(search_end.min(buffer_len))\n            .expect(\"event recovery chunk length fits usize\");\n        let chunk_len_u64 = u64::try_from(chunk_len).expect(\"event recovery chunk length fits u64\");\n        let chunk_start = search_end - chunk_len_u64;\n        file.seek(SeekFrom::Start(chunk_start))?;\n        file.read_exact(&mut buffer[..chunk_len])?;\n        if let Some(index) = buffer[..chunk_len].iter().rposition(|byte| *byte == b'\\n') {\n            truncate_at = chunk_start\n                + u64::try_from(index).expect(\"event recovery newline index fits u64\")\n                + 1;\n            break;\n        }\n        search_end = chunk_start;\n    }\n\n    file.set_len(truncate_at)\n        .with_context(|| format!(\"Failed to truncate torn tail in {}\", path.display()))?;\n    file.sync_all()\n        .with_context(|| format!(\"Failed to sync repaired {}\", path.display()))?;\n    tracing::warn!(\n        path = %path.display(),","sourceCodeStart":14006,"sourceCodeEnd":14042,"githubUrl":"https://github.com/Hmbown/CodeWhale/blob/73e0f67d83c59909b571efdfc88c4bc28c309cb1/crates/tui/src/runtime_threads.rs#L14006-L14042","documentation":"Panic from `u64::try_from(chunk_len)` where `chunk_len` is the usize chunk length just computed (bounded by the 8 KiB buffer). Conversion to u64 cannot fail for any chunk the previous line produced; the expect asserts the recovery loop's internal sizing invariant.","triggerScenarios":"Unreachable with the current 8 KiB chunking; only a refactor producing chunk_len > u64::MAX (impossible for usize-derived values on supported targets) would fire it.","commonSituations":"Refactors that change the chunk-size source without revalidating the usize→u64 round trip.","solutions":["No action needed; keep the expect as a documented invariant","If chunk sizing changes, re-verify the bound before the try_from"],"exampleFix":null,"handlingStrategy":"validation","validationCode":"// chunk_len <= 8192 by construction, so u64::try_from always succeeds","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Derive chunk_len only from the bounded buffer length","Keep the usize→u64 round trip in one function so bounds stay provable"],"tags":["rust","panic","integer-conversion","filesystem"],"backgroundTag":"value-out-of-range","analyzedSha":"73e0f67d83c59909b571efdfc88c4bc28c309cb1","analyzedAt":"2026-09-22T01:30:00.501Z","contentChangedAt":"2026-09-22T01:30:00.501Z","schemaVersion":2},"datasetVersion":"2026-09-22T11:17:16.035Z"}