178 lines
6.3 KiB
Rust
178 lines
6.3 KiB
Rust
//! In-session size-based rotation for `warp.log`.
|
|
//!
|
|
//! The existing startup rotation (`rotate_log_files`) handles the
|
|
//! per-execution boundary: each launch's `warp.log` becomes `warp.log.old.N`
|
|
//! at the next launch, with older files shifting up and the oldest dropping
|
|
//! off. That model bounds disk usage *per restart* but the active session's
|
|
//! log itself grows unboundedly.
|
|
//!
|
|
//! This module adds the orthogonal in-session bound: a `Write` wrapper that
|
|
//! rotates the active file once its byte count crosses a configured
|
|
//! threshold. Rotated copies land at `warp.log.in_session.N` (distinct from
|
|
//! the startup `.old.N` slots, which log-bundle uploads and other UX depend
|
|
//! on). When the configured number of `.in_session.N` slots is full, the
|
|
//! oldest is discarded — matching `rotate_log_files`'s overflow semantics.
|
|
//!
|
|
//! See warpdotdev/warp#10879.
|
|
|
|
use std::fs::{self, File, OpenOptions};
|
|
use std::io::{self, Write};
|
|
use std::path::{Path, PathBuf};
|
|
|
|
/// `Write` implementation that rotates its backing file once `max_bytes` of
|
|
/// writes have accumulated. On rotation, the active path is renamed to
|
|
/// `<base>.in_session.0`, existing `<base>.in_session.N` files shift up,
|
|
/// and the oldest beyond `max_rotation` is deleted. A fresh empty active
|
|
/// file is then opened.
|
|
pub(crate) struct RotatingFileWriter {
|
|
log_directory: PathBuf,
|
|
base_file_name: String,
|
|
max_bytes: u64,
|
|
max_rotation: usize,
|
|
bytes_written: u64,
|
|
file: File,
|
|
}
|
|
|
|
impl RotatingFileWriter {
|
|
/// Opens (or truncates) `<log_directory>/<base_file_name>` and starts
|
|
/// tracking byte counts toward `max_bytes`. `max_rotation` is the number
|
|
/// of `.in_session.N` slots to retain.
|
|
pub(crate) fn open(
|
|
log_directory: impl Into<PathBuf>,
|
|
base_file_name: impl Into<String>,
|
|
max_bytes: u64,
|
|
max_rotation: usize,
|
|
) -> io::Result<Self> {
|
|
let log_directory = log_directory.into();
|
|
let base_file_name = base_file_name.into();
|
|
let file = OpenOptions::new()
|
|
.write(true)
|
|
.create(true)
|
|
.truncate(true)
|
|
.open(log_directory.join(&base_file_name))?;
|
|
Ok(Self {
|
|
log_directory,
|
|
base_file_name,
|
|
max_bytes,
|
|
max_rotation,
|
|
bytes_written: 0,
|
|
file,
|
|
})
|
|
}
|
|
|
|
fn in_session_path(&self, index: usize) -> PathBuf {
|
|
self.log_directory
|
|
.join(format!("{}.in_session.{index}", self.base_file_name))
|
|
}
|
|
|
|
fn active_path(&self) -> PathBuf {
|
|
self.log_directory.join(&self.base_file_name)
|
|
}
|
|
|
|
/// Rotates the active file. Drops the oldest `.in_session.N`, shifts
|
|
/// the remaining slots up by one, renames the active file into slot 0,
|
|
/// and opens a fresh active file.
|
|
fn rotate(&mut self) -> io::Result<()> {
|
|
if self.max_rotation == 0 {
|
|
// Caller asked for zero retained rotations — just truncate and
|
|
// continue without producing a sidecar file.
|
|
self.file.flush()?;
|
|
self.file = OpenOptions::new()
|
|
.write(true)
|
|
.create(true)
|
|
.truncate(true)
|
|
.open(self.active_path())?;
|
|
self.bytes_written = 0;
|
|
return Ok(());
|
|
}
|
|
|
|
self.file.flush()?;
|
|
|
|
// Delete the oldest slot.
|
|
let oldest = self.in_session_path(self.max_rotation - 1);
|
|
if oldest.exists() {
|
|
fs::remove_file(&oldest)?;
|
|
}
|
|
|
|
// Shift remaining slots up: N-2 -> N-1, ..., 0 -> 1.
|
|
for n in (0..self.max_rotation - 1).rev() {
|
|
let src = self.in_session_path(n);
|
|
if src.exists() {
|
|
fs::rename(src, self.in_session_path(n + 1))?;
|
|
}
|
|
}
|
|
|
|
// Move the active file to slot 0 and open a fresh active file.
|
|
fs::rename(self.active_path(), self.in_session_path(0))?;
|
|
self.file = OpenOptions::new()
|
|
.write(true)
|
|
.create(true)
|
|
.truncate(true)
|
|
.open(self.active_path())?;
|
|
self.bytes_written = 0;
|
|
Ok(())
|
|
}
|
|
}
|
|
|
|
impl Write for RotatingFileWriter {
|
|
fn write(&mut self, buf: &[u8]) -> io::Result<usize> {
|
|
// Rotate only when the *current* active file already holds content;
|
|
// otherwise an oversized first write would promote an empty file to
|
|
// `.in_session.0` and burn a retention slot before any useful log
|
|
// data exists. The oversized payload still lands in the active file,
|
|
// and is preserved on the next real rotation.
|
|
if !buf.is_empty()
|
|
&& self.max_bytes > 0
|
|
&& self.bytes_written > 0
|
|
&& self.bytes_written.saturating_add(buf.len() as u64) > self.max_bytes
|
|
{
|
|
self.rotate()?;
|
|
}
|
|
let n = self.file.write(buf)?;
|
|
self.bytes_written = self.bytes_written.saturating_add(n as u64);
|
|
Ok(n)
|
|
}
|
|
|
|
fn flush(&mut self) -> io::Result<()> {
|
|
self.file.flush()
|
|
}
|
|
}
|
|
|
|
/// Wraps `file` in a [`RotatingFileWriter`] when `max_file_size_bytes` is
|
|
/// `Some(_)` and non-zero. Otherwise returns the raw file boxed as a
|
|
/// `Write` so callers can use a uniform target type.
|
|
///
|
|
/// The `file` argument is the already-opened active file at
|
|
/// `<log_directory>/<base_file_name>`. When rotation is enabled we discard
|
|
/// it and reopen via `RotatingFileWriter::open` so the rotation state
|
|
/// owns the file descriptor.
|
|
pub(crate) fn wrap_for_rotation(
|
|
file: File,
|
|
log_directory: &Path,
|
|
base_file_name: &str,
|
|
max_file_size_bytes: Option<u64>,
|
|
max_rotation: usize,
|
|
) -> io::Result<Box<dyn Write + Send + 'static>> {
|
|
match max_file_size_bytes {
|
|
Some(max_bytes) if max_bytes > 0 => {
|
|
// The file passed in was opened with truncate=true by the caller;
|
|
// we'll reopen via RotatingFileWriter::open which has the same
|
|
// semantics. Drop the existing handle first to keep file
|
|
// descriptors symmetric.
|
|
drop(file);
|
|
let writer = RotatingFileWriter::open(
|
|
log_directory.to_path_buf(),
|
|
base_file_name.to_string(),
|
|
max_bytes,
|
|
max_rotation,
|
|
)?;
|
|
Ok(Box::new(writer))
|
|
}
|
|
_ => Ok(Box::new(file)),
|
|
}
|
|
}
|
|
|
|
#[cfg(test)]
|
|
#[path = "rotation_tests.rs"]
|
|
mod tests;
|