src/tools/time/tm_editor.rs: copied from proxmox backup

proxmox/src/tools/time.rs

@@ -1,6 +1,9 @@
 use anyhow::{bail, Error};
 use std::ffi::{CStr, CString};
 
+mod tm_editor;
+pub use tm_editor::*;
+
 /// Safe bindings to libc timelocal
 ///
 /// We set tm_isdst to -1.

proxmox/src/tools/time/tm_editor.rs

@@ -0,0 +1,140 @@
+use anyhow::Error;
+
+use super::{gmtime, localtime, timegm, timelocal};
+
+/// Safely Manipulate Date and Time
+pub struct TmEditor {
+    utc: bool,
+    t: libc::tm,
+}
+
+impl TmEditor {
+
+    /// Create a new instance initialize with epoch 0
+    pub fn new(utc: bool) -> Self {
+        let t = libc::tm { // epoch 0
+            tm_sec: 0,
+            tm_min: 0,
+            tm_hour: 0,
+            tm_mday: 1,
+            tm_mon: 0,
+            tm_year: 70,
+            tm_wday: 4,
+            tm_yday: 0,
+            tm_isdst: -1,
+            tm_gmtoff: -1,
+            tm_zone: std::ptr::null(),
+        };
+        Self { utc, t }
+    }
+
+    /// Create a new instance initialize with the specified epoch
+    pub fn with_epoch(epoch: i64, utc: bool) -> Result<Self, Error> {
+        let t = if utc { gmtime(epoch)? } else { localtime(epoch)? };
+        Ok(Self { utc, t })
+    }
+
+    /// Converts back into Unix epoch
+    pub fn into_epoch(mut self) -> Result<i64, Error> {
+        let epoch = if self.utc { timegm(&mut self.t)? } else { timelocal(&mut self.t)? };
+        Ok(epoch)
+    }
+
+    /// increases the year by 'years' and resets all smaller fields to their minimum
+    pub fn add_years(&mut self, years: libc::c_int) -> Result<(), Error> {
+        if years == 0 { return Ok(()); }
+        self.t.tm_mon = 0;
+        self.t.tm_mday = 1;
+        self.t.tm_hour = 0;
+        self.t.tm_min = 0;
+        self.t.tm_sec = 0;
+        self.t.tm_year += years;
+        self.normalize_time()
+    }
+
+    /// increases the month by 'months' and resets all smaller fields to their minimum
+    pub fn add_months(&mut self, months: libc::c_int) -> Result<(), Error> {
+        if months == 0 { return Ok(()); }
+        self.t.tm_mday = 1;
+        self.t.tm_hour = 0;
+        self.t.tm_min = 0;
+        self.t.tm_sec = 0;
+        self.t.tm_mon += months;
+        self.normalize_time()
+    }
+
+    /// increases the day by 'days' and resets all smaller fields to their minimum
+    pub fn add_days(&mut self, days: libc::c_int) -> Result<(), Error> {
+        if days == 0 { return Ok(()); }
+        self.t.tm_hour = 0;
+        self.t.tm_min = 0;
+        self.t.tm_sec = 0;
+        self.t.tm_mday += days;
+        self.normalize_time()
+    }
+
+    pub fn year(&self) -> libc::c_int { self.t.tm_year + 1900 } // see man mktime
+    pub fn month(&self) -> libc::c_int { self.t.tm_mon + 1 }
+    pub fn day(&self) -> libc::c_int { self.t.tm_mday }
+    pub fn hour(&self) -> libc::c_int { self.t.tm_hour }
+    pub fn min(&self) -> libc::c_int { self.t.tm_min }
+    pub fn sec(&self) -> libc::c_int { self.t.tm_sec }
+
+    // Note: tm_wday (0-6, Sunday = 0) => convert to Sunday = 6
+    pub fn day_num(&self) -> libc::c_int {
+        (self.t.tm_wday + 6) % 7
+    }
+
+    pub fn set_time(&mut self, hour: libc::c_int, min: libc::c_int, sec: libc::c_int) -> Result<(), Error> {
+        self.t.tm_hour = hour;
+        self.t.tm_min = min;
+        self.t.tm_sec = sec;
+        self.normalize_time()
+    }
+
+    pub fn set_min_sec(&mut self, min: libc::c_int, sec: libc::c_int) -> Result<(), Error> {
+        self.t.tm_min = min;
+        self.t.tm_sec = sec;
+        self.normalize_time()
+    }
+
+    fn normalize_time(&mut self) -> Result<(), Error> {
+        // libc normalizes it for us
+        if self.utc {
+            timegm(&mut self.t)?;
+        } else {
+            timelocal(&mut self.t)?;
+        }
+        Ok(())
+    }
+
+    pub fn set_sec(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_sec = v;
+        self.normalize_time()
+    }
+
+    pub fn set_min(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_min = v;
+        self.normalize_time()
+    }
+
+    pub fn set_hour(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_hour = v;
+        self.normalize_time()
+    }
+
+    pub fn set_mday(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_mday = v;
+        self.normalize_time()
+    }
+
+    pub fn set_mon(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_mon = v - 1;
+        self.normalize_time()
+    }
+
+    pub fn set_year(&mut self, v: libc::c_int) -> Result<(), Error> {
+        self.t.tm_year = v - 1900;
+        self.normalize_time()
+    }
+}