refactor: call NascentGeneration::insert from ::insert_iter

This is a step towards getting rid of insert_iter entirely, which
would make it easier to make `obnam backup` use async.

I originally split insert_iter so I could use a single transaction for
inserting many rows, but it seems to not be needed for speed after
all. I've benchmarked backing up a large file with and without this
change, and there's no real difference. I've not benchmarked with a
large number of files.

Even if there's a performance hit from using multiple transactions, my
hope is that by being able to use more CPUs/threads for backing up
will outweigh that by far.

Sponsored-by: author

1 files changed, 1 insertions, 4 deletions

diff --git a/src/generation.rs b/src/generation.rs
index 5412ae7..45b8afa 100644
--- a/src/generation.rs
+++ b/src/generation.rs
@@ -94,7 +94,6 @@ impl NascentGeneration {
         &mut self,
         entries: impl Iterator<Item = Result<FsEntryBackupOutcome, BackupError>>,
     ) -> Result<Vec<BackupError>, NascentError> {
-        let t = self.conn.transaction().map_err(NascentError::Transaction)?;
         let mut warnings = vec![];
         for r in entries {
             match r {
@@ -108,12 +107,10 @@ impl NascentGeneration {
                     reason,
                     is_cachedir_tag,
                 }) => {
-                    self.fileno += 1;
-                    sql::insert_one(&t, entry, self.fileno, &ids[..], reason, is_cachedir_tag)?;
+                    self.insert(entry, &ids, reason, is_cachedir_tag)?;
                 }
             }
         }
-        t.commit().map_err(NascentError::Commit)?;
         Ok(warnings)
     }
 }