vendor/gix-ref/src/store/file/loose/reference/logiter.rs

   1 use crate::store_impl::{
   2     file,
   3     file::{log, loose, loose::Reference},
   4 };
   5
   6 pub(crate) fn must_be_io_err(err: loose::reflog::Error) -> std::io::Error {
   7     match err {
   8         loose::reflog::Error::Io(err) => err,
   9         loose::reflog::Error::RefnameValidation(_) => unreachable!("we are called from a valid ref"),
  10     }
  11 }
  12
  13 impl Reference {
  14     /// Returns true if a reflog exists in the given `store`.
  15     ///
  16     /// Please note that this method shouldn't be used to check if a log exists before trying to read it, but instead
  17     /// is meant to be the fastest possible way to determine if a log exists or not.
  18     /// If the caller needs to know if it's readable, try to read the log instead with a reverse or forward iterator.
  19     pub fn log_exists(&self, store: &file::Store) -> bool {
  20         store
  21             .reflog_exists(self.name.as_ref())
  22             .expect("name conversion infallible")
  23     }
  24     /// Return a reflog reverse iterator for this ref, reading chunks from the back into the fixed buffer `buf`, in the given `store`.
  25     ///
  26     /// The iterator will traverse log entries from most recent to oldest, reading the underlying file in chunks from the back.
  27     /// Return `Ok(None)` if no reflog exists.
  28     pub fn log_iter_rev<'b>(
  29         &self,
  30         store: &file::Store,
  31         buf: &'b mut [u8],
  32     ) -> std::io::Result<Option<log::iter::Reverse<'b, std::fs::File>>> {
  33         store.reflog_iter_rev(self.name.as_ref(), buf).map_err(must_be_io_err)
  34     }
  35
  36     /// Return a reflog forward iterator for this ref and write its file contents into `buf`, in the given `store`.
  37     ///
  38     /// The iterator will traverse log entries from oldest to newest.
  39     /// Return `Ok(None)` if no reflog exists.
  40     pub fn log_iter<'a, 'b: 'a>(
  41         &'a self,
  42         store: &file::Store,
  43         buf: &'b mut Vec<u8>,
  44     ) -> std::io::Result<Option<impl Iterator<Item = Result<log::LineRef<'b>, log::iter::decode::Error>> + 'a>> {
  45         store.reflog_iter(self.name.as_ref(), buf).map_err(must_be_io_err)
  46     }
  47 }