pagers_core/
error.rs

1use std::{num::TryFromIntError, path::PathBuf};
2
3const MLOCK_HINT: &str = "\
4\n\nPossible fixes:\
5\n  ulimit -l unlimited\
6\n  setcap cap_ipc_lock+ep <binary>\
7\n  # Kubernetes:\
8\n  securityContext:\
9\n    capabilities:\
10\n      add: [\"IPC_LOCK\"]";
11
12#[derive(Debug, thiserror::Error)]
13pub enum MlockError {
14    #[error("{call} failed: permission denied (EPERM){}", MLOCK_HINT)]
15    PermissionDenied { call: &'static str },
16
17    #[error(
18        "{call} failed: cannot lock {len} bytes — RLIMIT_MEMLOCK too low (ENOMEM){}",
19        MLOCK_HINT
20    )]
21    OutOfMemory { call: &'static str, len: usize },
22
23    #[error("{call}: {source}")]
24    Other {
25        call: &'static str,
26        source: std::io::Error,
27    },
28}
29
30#[derive(Debug, thiserror::Error)]
31pub enum Error {
32    #[error("operation cancelled")]
33    Cancelled,
34
35    #[error("file worker thread panicked")]
36    WorkerPanic,
37
38    #[error("{context}: {source}")]
39    Io {
40        context: String,
41        source: std::io::Error,
42    },
43
44    #[error(transparent)]
45    Mlock(#[from] MlockError),
46
47    #[error("{0}")]
48    Syscall(#[from] nix::errno::Errno),
49
50    #[error("{0}")]
51    TryFromInt(#[from] TryFromIntError),
52
53    #[error("invalid path pattern: {0}")]
54    PathPattern(#[from] ignore::Error),
55
56    #[error("{path}: offset {offset} beyond file size {file_len}")]
57    OffsetBeyondFile {
58        path: PathBuf,
59        offset: u64,
60        file_len: u64,
61    },
62
63    #[error("range length must be greater than zero")]
64    EmptyRange,
65
66    #[error("range offset {offset} is not aligned to page size {page_size}")]
67    UnalignedRange { offset: u64, page_size: u64 },
68
69    #[error("range end overflows: offset {offset}, length {max_len}")]
70    RangeOverflow { offset: u64, max_len: u64 },
71}
72
73impl Error {
74    pub fn io(context: impl Into<String>, source: std::io::Error) -> Self {
75        Self::Io {
76            context: context.into(),
77            source,
78        }
79    }
80}
81
82impl From<std::io::Error> for Error {
83    fn from(source: std::io::Error) -> Self {
84        Self::Io {
85            context: String::new(),
86            source,
87        }
88    }
89}
90
91pub type Result<T> = std::result::Result<T, Error>;
92
93#[cfg(test)]
94mod tests {
95    use super::*;
96
97    #[test]
98    fn test_io_error_display_with_context() {
99        let err = Error::io(
100            "/tmp/test.dat",
101            std::io::Error::new(std::io::ErrorKind::NotFound, "file not found"),
102        );
103        let msg = err.to_string();
104        assert!(msg.contains("/tmp/test.dat"), "msg: {msg}");
105        assert!(msg.contains("file not found"), "msg: {msg}");
106    }
107
108    #[test]
109    fn test_io_error_from_std() {
110        let io_err = std::io::Error::new(std::io::ErrorKind::PermissionDenied, "denied");
111        let err: Error = io_err.into();
112        assert!(matches!(err, Error::Io { .. }));
113    }
114
115    #[test]
116    fn test_syscall_error_from_errno() {
117        let err: Error = nix::errno::Errno::EBADF.into();
118        assert!(matches!(err, Error::Syscall(_)));
119        assert!(err.to_string().contains("EBADF"));
120    }
121
122    #[test]
123    fn test_offset_beyond_file_display() {
124        let err = Error::OffsetBeyondFile {
125            path: PathBuf::from("/data/big.bin"),
126            offset: 1000,
127            file_len: 500,
128        };
129        let msg = err.to_string();
130        assert!(msg.contains("/data/big.bin"), "msg: {msg}");
131        assert!(msg.contains("1000"), "msg: {msg}");
132        assert!(msg.contains("500"), "msg: {msg}");
133    }
134}
pagers_core/error.rs

pagers_core/
error.rs
