[pmg-devel] [PATCH log-tracker] drop 'time' dependency
Wolfgang Bumiller
w.bumiller at proxmox.com
Tue Jan 4 14:57:23 CET 2022
We're using a very old version of it and the functions we
actually use are available in glibc anyway.
The only difference I found was that the result of
glibc's `strptime()`'s `%s` does *not* want an additional
`.to_local()` call anymore...
... which was weird anyway.
As a minor optimization I pass the format string as `&CStr`
to avoid the memcpy.
(The CString::new() call in `strptime()` only happens during
parameter parsing)
Signed-off-by: Wolfgang Bumiller <w.bumiller at proxmox.com>
---
Cargo.toml | 1 -
src/main.rs | 75 ++++++++---------------
src/time.rs | 169 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 194 insertions(+), 51 deletions(-)
create mode 100644 src/time.rs
diff --git a/Cargo.toml b/Cargo.toml
index a975d39..7c31157 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -14,4 +14,3 @@ anyhow = "1"
clap = "2.32"
flate2 = "1.0"
libc = "0.2.48"
-time = "0.1.42"
diff --git a/src/main.rs b/src/main.rs
index fb06463..bf9783b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -15,6 +15,9 @@ use libc::time_t;
use clap::{App, Arg};
+mod time;
+use time::{Tm, CAL_MTOD};
+
fn main() -> Result<(), Error> {
let matches = App::new(clap::crate_name!())
.version(clap::crate_version!())
@@ -114,7 +117,7 @@ fn main() -> Result<(), Error> {
)
.get_matches();
- let mut parser = Parser::new();
+ let mut parser = Parser::new()?;
parser.handle_args(matches)?;
println!("# LogReader: {}", std::process::id());
@@ -144,12 +147,12 @@ fn main() -> Result<(), Error> {
println!(
"# Start: {} ({})",
- time::strftime("%F %T", &parser.start_tm)?,
+ time::strftime(c_str!("%F %T"), &parser.start_tm)?,
parser.options.start
);
println!(
"# End: {} ({})",
- time::strftime("%F %T", &parser.end_tm)?,
+ time::strftime(c_str!("%F %T"), &parser.end_tm)?,
parser.options.end
);
@@ -1743,10 +1746,10 @@ struct Parser {
}
impl Parser {
- fn new() -> Self {
- let ltime = time::now();
+ fn new() -> Result<Self, Error> {
+ let ltime = Tm::now_local()?;
- Self {
+ Ok(Self {
sentries: HashMap::new(),
fentries: HashMap::new(),
qentries: HashMap::new(),
@@ -1760,12 +1763,12 @@ impl Parser {
count: 0,
buffered_stdout: BufWriter::with_capacity(4 * 1024 * 1024, std::io::stdout()),
options: Options::default(),
- start_tm: time::empty_tm(),
- end_tm: time::empty_tm(),
+ start_tm: Tm::zero(),
+ end_tm: Tm::zero(),
ctime: 0,
string_match: false,
lines: 0,
- }
+ })
}
fn free_sentry(&mut self, sentry_pid: u64) {
@@ -1976,40 +1979,38 @@ impl Parser {
}
if let Some(start) = args.value_of("start") {
- if let Ok(res) = time::strptime(start, "%F %T") {
- self.options.start = mkgmtime(&res);
+ if let Ok(res) = time::strptime(start, c_str!("%F %T")) {
+ self.options.start = res.as_utc_to_epoch();
self.start_tm = res;
- } else if let Ok(res) = time::strptime(start, "%s") {
- let res = res.to_local();
- self.options.start = mkgmtime(&res);
+ } else if let Ok(res) = time::strptime(start, c_str!("%s")) {
+ self.options.start = res.as_utc_to_epoch();
self.start_tm = res;
} else {
bail!("failed to parse start time");
}
} else {
- let mut ltime = time::now();
+ let mut ltime = Tm::now_local()?;
ltime.tm_sec = 0;
ltime.tm_min = 0;
ltime.tm_hour = 0;
- self.options.start = mkgmtime(<ime);
+ self.options.start = ltime.as_utc_to_epoch();
self.start_tm = ltime;
}
if let Some(end) = args.value_of("end") {
- if let Ok(res) = time::strptime(end, "%F %T") {
- self.options.end = mkgmtime(&res);
+ if let Ok(res) = time::strptime(end, c_str!("%F %T")) {
+ self.options.end = res.as_utc_to_epoch();
self.end_tm = res;
- } else if let Ok(res) = time::strptime(end, "%s") {
- let res = res.to_local();
- self.options.end = mkgmtime(&res);
+ } else if let Ok(res) = time::strptime(end, c_str!("%s")) {
+ self.options.end = res.as_utc_to_epoch();
self.end_tm = res;
} else {
bail!("failed to parse end time");
}
} else {
- let ltime = time::now();
- self.options.end = mkgmtime(<ime);
- self.end_tm = ltime;
+ // FIXME: just use libc::time(NULL) here
+ self.options.end = unsafe { libc::time(std::ptr::null_mut()) };
+ self.end_tm = Tm::at_local(self.options.end)?;
}
if self.options.end < self.options.start {
@@ -2171,30 +2172,6 @@ fn get_or_create_fentry(
}
}
-fn mkgmtime(tm: &time::Tm) -> time_t {
- let mut res: time_t;
-
- let mut year = tm.tm_year as i64 + 1900;
- let mon = tm.tm_mon;
-
- res = (year - 1970) * 365 + CAL_MTOD[mon as usize];
-
- if mon <= 1 {
- year -= 1;
- }
-
- res += (year - 1968) / 4;
- res -= (year - 1900) / 100;
- res += (year - 1600) / 400;
-
- res += (tm.tm_mday - 1) as i64;
- res = res * 24 + tm.tm_hour as i64;
- res = res * 60 + tm.tm_min as i64;
- res = res * 60 + tm.tm_sec as i64;
-
- res
-}
-
const LOGFILES: [&str; 32] = [
"/var/log/syslog",
"/var/log/syslog.1",
@@ -2397,8 +2374,6 @@ fn parse_time<'a>(
Some((ltime, data))
}
-const CAL_MTOD: [i64; 12] = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];
-
type ByteSlice<'a> = &'a [u8];
/// Parse Host, Service and PID at the beginning of data. Returns a tuple of (host, service, pid, remaining_text).
fn parse_host_service_pid(data: &[u8]) -> Option<(ByteSlice, ByteSlice, u64, ByteSlice)> {
diff --git a/src/time.rs b/src/time.rs
new file mode 100644
index 0000000..5851496
--- /dev/null
+++ b/src/time.rs
@@ -0,0 +1,169 @@
+//! Time support library.
+//!
+//! Contains wrappers for `strftime`, `strptime`, `libc::localtime_r`.
+
+use std::ffi::{CStr, CString};
+use std::fmt;
+use std::mem::MaybeUninit;
+
+use anyhow::{bail, format_err, Error};
+
+/// Calender month index to *non-leap-year* day-of-the-year.
+pub const CAL_MTOD: [i64; 12] = [0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334];
+
+/// Shortcut for generating an `&'static CStr`.
+#[macro_export]
+macro_rules! c_str {
+ ($data:expr) => {{
+ let bytes = concat!($data, "\0");
+ unsafe { ::std::ffi::CStr::from_bytes_with_nul_unchecked(bytes.as_bytes()) }
+ }};
+}
+
+// Wrapper around `libc::tm` providing `Debug` and some helper methods.
+pub struct Tm(libc::tm);
+
+impl std::ops::Deref for Tm {
+ type Target = libc::tm;
+
+ fn deref(&self) -> &libc::tm {
+ &self.0
+ }
+}
+
+impl std::ops::DerefMut for Tm {
+ fn deref_mut(&mut self) -> &mut libc::tm {
+ &mut self.0
+ }
+}
+
+// (or add libc feature 'extra-traits' but that's the only struct we need it for...)
+impl fmt::Debug for Tm {
+ fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+ f.debug_struct("Tm")
+ .field("tm_sec", &self.tm_sec)
+ .field("tm_min", &self.tm_min)
+ .field("tm_hour", &self.tm_hour)
+ .field("tm_mday", &self.tm_mday)
+ .field("tm_mon", &self.tm_mon)
+ .field("tm_year", &self.tm_year)
+ .field("tm_wday", &self.tm_wday)
+ .field("tm_yday", &self.tm_yday)
+ .field("tm_isdst", &self.tm_isdst)
+ .field("tm_gmtoff", &self.tm_gmtoff)
+ .field("tm_zone", &self.tm_zone)
+ .finish()
+ }
+}
+
+/// These are now exposed via `libc`, but they're part of glibc.
+mod imports {
+ extern "C" {
+ pub fn strftime(
+ s: *mut libc::c_char,
+ max: libc::size_t,
+ format: *const libc::c_char,
+ tm: *const libc::tm,
+ ) -> libc::size_t;
+
+ pub fn strptime(
+ s: *const libc::c_char,
+ format: *const libc::c_char,
+ tm: *mut libc::tm,
+ ) -> *const libc::c_char;
+ }
+}
+
+impl Tm {
+ /// A zero-initialized time struct.
+ #[inline(always)]
+ pub fn zero() -> Self {
+ unsafe { std::mem::zeroed() }
+ }
+
+ /// Get the current time in the local timezone.
+ pub fn now_local() -> Result<Self, Error> {
+ Self::at_local(unsafe { libc::time(std::ptr::null_mut()) })
+ }
+
+ /// Get a local time from a unix time stamp.
+ pub fn at_local(time: libc::time_t) -> Result<Self, Error> {
+ let mut out = MaybeUninit::<libc::tm>::uninit();
+ Ok(Self(unsafe {
+ if libc::localtime_r(&time, out.as_mut_ptr()).is_null() {
+ bail!("failed to convert timestamp to local time");
+ }
+ out.assume_init()
+ }))
+ }
+
+ /// Assume this is an UTC time and convert it to a unix time stamp.
+ ///
+ /// Equivalent to `timegm(3)`, the gmt equivalent of `mktime(3)`.
+ pub fn as_utc_to_epoch(&self) -> libc::time_t {
+ let mut year = self.0.tm_year as i64 + 1900;
+ let mon = self.0.tm_mon;
+
+ let mut res: libc::time_t = (year - 1970) * 365 + CAL_MTOD[mon as usize];
+
+ if mon <= 1 {
+ year -= 1;
+ }
+
+ res += (year - 1968) / 4;
+ res -= (year - 1900) / 100;
+ res += (year - 1600) / 400;
+
+ res += (self.0.tm_mday - 1) as i64;
+ res = res * 24 + self.0.tm_hour as i64;
+ res = res * 60 + self.0.tm_min as i64;
+ res = res * 60 + self.0.tm_sec as i64;
+
+ res
+ }
+}
+
+/// Wrapper around `strftime(3)` to format time strings.
+pub fn strftime(format: &CStr, tm: &Tm) -> Result<String, Error> {
+ let mut buf = MaybeUninit::<[u8; 64]>::uninit();
+
+ let size = unsafe {
+ imports::strftime(
+ buf.as_mut_ptr() as *mut libc::c_char,
+ 64,
+ format.as_ptr(),
+ &tm.0,
+ )
+ };
+ if size == 0 {
+ bail!("failed to format time");
+ }
+ let size = size as usize;
+
+ let buf = unsafe { buf.assume_init() };
+
+ std::str::from_utf8(&buf[..size])
+ .map_err(|_| format_err!("formatted time was not valid utf-8"))
+ .map(str::to_string)
+}
+
+/// Wrapper around `strptime(3)` to parse time strings.
+pub fn strptime(time: &str, format: &CStr) -> Result<Tm, Error> {
+ let mut out = MaybeUninit::<libc::tm>::uninit();
+
+ let time = CString::new(time).map_err(|_| format_err!("time string contains nul bytes"))?;
+
+ let end = unsafe {
+ imports::strptime(
+ time.as_ptr() as *const libc::c_char,
+ format.as_ptr(),
+ out.as_mut_ptr(),
+ )
+ };
+
+ if end.is_null() {
+ bail!("failed to parse time string {:?}", time);
+ }
+
+ Ok(Tm(unsafe { out.assume_init() }))
+}
--
2.30.2
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