diff options
author | Vincent Ambo <mail@tazj.in> | 2018-05-27T18·09+0200 |
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committer | Vincent Ambo <mail@tazj.in> | 2018-05-27T18·09+0200 |
commit | c5cd12b81f3a2908c3f8202dbc94dc535cf092c4 (patch) | |
tree | 6e3b0fdf87b198810bc6555c533bcee6c148912e /src/journald.rs | |
parent | 1ed238b4498f6d4f00216021cfa5be89e3cdf209 (diff) |
feat(journald): Implement initial libsystemd journal calls
Diffstat (limited to 'src/journald.rs')
-rw-r--r-- | src/journald.rs | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/src/journald.rs b/src/journald.rs new file mode 100644 index 000000000000..4892553ea57e --- /dev/null +++ b/src/journald.rs @@ -0,0 +1,71 @@ +//! This module contains FFI-bindings to the journald APi. See +//! sd-journal(3) for detailed information about the API. +//! +//! Only calls required by journaldriver are implemented. + +/// This type represents an opaque pointer to an `sd_journal` struct. +/// It should be changed to an `extern type` once RF1861 is +/// stabilized. +enum SdJournal {} + +use failure::Error; +use std::mem; + +extern { + fn sd_journal_open(sd_journal: *mut SdJournal, flags: usize) -> usize; + fn sd_journal_close(sd_journal: *mut SdJournal); + fn sd_journal_next(sd_journal: *mut SdJournal) -> usize; +} + +// Safe interface: + +/// This struct contains the opaque data used by libsystemd to +/// reference the journal. +pub struct Journal { + sd_journal: *mut SdJournal, +} + +impl Drop for Journal { + fn drop(&mut self) { + unsafe { + sd_journal_close(self.sd_journal); + } + } +} + +/// Open the journal for reading. No flags are supplied to libsystemd, +/// which means that all journal entries will become available. +pub fn open_journal() -> Result<Journal, Error> { + let (mut sd_journal, result) = unsafe { + let mut journal: SdJournal = mem::uninitialized(); + let result = sd_journal_open(&mut journal, 0); + (journal, result) + }; + + ensure!(result == 0, "Could not open journal (errno: {})", result); + Ok(Journal { sd_journal: &mut sd_journal }) +} + +#[derive(Debug)] +pub enum NextEntry { + /// If no new entries are available in the journal this variant is + /// returned. + NoEntry, + + Entry, +} + +impl Journal { + pub fn read_next(&self) -> Result<NextEntry, Error> { + let result = unsafe { + sd_journal_next(self.sd_journal) + }; + + match result { + 0 => Ok(NextEntry::NoEntry), + 1 => Ok(NextEntry::Entry), + n if n > 1 => bail!("Journal unexpectedly advanced by {} entries!", n), + _ => bail!("An error occured while advancing the journal (errno: {})", result), + } + } +} |