From 0b84c793bfc637e2a1f27b12fa931ddc74abd750 Mon Sep 17 00:00:00 2001
From: Olivier 'reivilibre <olivier@librepush.net>
Date: Wed, 15 Jun 2022 21:13:58 +0100
Subject: [PATCH] Flush chunk pointers in one transaction

---
 yama/src/pile/local_sqlitebloblogs.rs | 65 ++++++++++++++++-----------
 1 file changed, 39 insertions(+), 26 deletions(-)

diff --git a/yama/src/pile/local_sqlitebloblogs.rs b/yama/src/pile/local_sqlitebloblogs.rs
index 445226d..8d1ac5f 100644
--- a/yama/src/pile/local_sqlitebloblogs.rs
+++ b/yama/src/pile/local_sqlitebloblogs.rs
@@ -28,7 +28,7 @@ use anyhow::{bail, Context};
 use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use log::{info, warn};
 use nix::unistd::sync;
-use rusqlite::{params, Error, ErrorCode};
+use rusqlite::{params, Error, ErrorCode, Transaction};
 use rusqlite::{Connection, OptionalExtension};
 
 use crate::definitions::ChunkId;
@@ -145,47 +145,60 @@ pub struct Inner {
     queued_pointer_writes: HashMap<ChunkId, BloblogPointer>,
 }
 
+fn raw_put_chunk_pointer_txn(
+    txn: &Transaction,
+    chunk_id: &ChunkId,
+    bloblog: BloblogId,
+    offset_i64: i64,
+) -> anyhow::Result<()> {
+    match txn.execute(
+        "INSERT INTO chunks (chunk_id, bloblog, offset) VALUES (?1, ?2, ?3)",
+        params![&chunk_id[..], bloblog, offset_i64],
+    ) {
+        Ok(_) => Ok(()),
+        Err(Error::SqliteFailure(e, str)) => {
+            if e.code == ConstraintViolation {
+                warn!(
+                    "(ignoring) SQLite constraint violation on insertion... {:?}",
+                    str
+                );
+                Ok(())
+            } else {
+                Err(Error::SqliteFailure(e, str).into())
+            }
+        }
+        Err(other) => Err(other.into()),
+    }
+}
+
 impl Inner {
     pub fn raw_put_chunk_pointer(
-        &self,
+        &mut self,
         chunk_id: &ChunkId,
         bloblog: BloblogId,
         offset_i64: i64,
     ) -> anyhow::Result<()> {
-        match self.connection.execute(
-            "INSERT INTO chunks (chunk_id, bloblog, offset) VALUES (?1, ?2, ?3)",
-            params![&chunk_id[..], bloblog, offset_i64],
-        ) {
-            Ok(_) => Ok(()),
-            Err(Error::SqliteFailure(e, str)) => {
-                if e.code == ConstraintViolation {
-                    warn!(
-                        "(ignoring) SQLite constraint violation on insertion... {:?}",
-                        str
-                    );
-                    Ok(())
-                } else {
-                    Err(Error::SqliteFailure(e, str))?;
-                    unreachable!();
-                }
-            }
-            other => {
-                other?;
-                unreachable!();
-            }
-        }
+        let txn = self.connection.transaction()?;
+        raw_put_chunk_pointer_txn(&txn, chunk_id, bloblog, offset_i64)?;
+        txn.commit()?;
+        Ok(())
     }
 
     pub fn flush(&mut self) -> anyhow::Result<()> {
         // Create a non-allocated hashmap to satisfy borrow checker, then swap it in and out
         let mut queued_pointer_writes = HashMap::with_capacity(0);
         std::mem::swap(&mut self.queued_pointer_writes, &mut queued_pointer_writes);
+
+        let txn = self.connection.transaction()?;
+
         for (chunk_id, pointer) in queued_pointer_writes.drain() {
             let offset_i64 =
                 i64::try_from(pointer.offset).expect("ouch! can't turn u64 into i64...");
-            self.raw_put_chunk_pointer(&chunk_id, pointer.bloblog, offset_i64)?;
+            raw_put_chunk_pointer_txn(&txn, &chunk_id, pointer.bloblog, offset_i64)?;
         }
         std::mem::swap(&mut self.queued_pointer_writes, &mut queued_pointer_writes);
+
+        txn.commit()?;
         Ok(())
     }
 }
@@ -355,7 +368,7 @@ impl SqliteBloblogPile {
     }
 
     fn put_chunk_pointer(&self, chunk_id: &ChunkId, pointer: BloblogPointer) -> anyhow::Result<()> {
-        let inner = self.inner.lock().unwrap();
+        let mut inner = self.inner.lock().unwrap();
         let offset_i64 = i64::try_from(pointer.offset).expect("ouch! can't turn u64 into i64...");
         inner.raw_put_chunk_pointer(chunk_id, pointer.bloblog, offset_i64)
     }