changed the path where bottomless is storing gzipped db snapshot (#727)

* changed the path where bottomless is storing gzipped db snapshot

* fixed clippy suggestions

Author: Horusiath

bottomless/src/replicator.rs

@@ -18,7 +18,7 @@ use bytes::{Buf, Bytes};
 use chrono::{NaiveDateTime, TimeZone, Utc};
 use std::io::SeekFrom;
 use std::ops::Deref;
-use std::path::Path;
+use std::path::{Path, PathBuf};
 use std::sync::atomic::{AtomicU32, Ordering};
 use std::sync::Arc;
 use tokio::fs::{File, OpenOptions};
@@ -642,28 +642,40 @@ impl Replicator {
     // Returns the compressed database file path and its change counter, extracted
     // from the header of page1 at offset 24..27 (as per SQLite documentation).
     pub async fn maybe_compress_main_db_file(
-        mut reader: File,
+        db_path: &Path,
         compression: CompressionKind,
     ) -> Result<ByteStream> {
-        reader.seek(SeekFrom::Start(0)).await?;
         match compression {
-            CompressionKind::None => Ok(ByteStream::read_from().file(reader).build().await?),
+            CompressionKind::None => Ok(ByteStream::from_path(db_path).await?),
             CompressionKind::Gzip => {
+                let mut reader = File::open(db_path).await?;
+                let gzip_path = Self::db_gzip_path(db_path);
                 let compressed_file = OpenOptions::new()
                     .create(true)
                     .write(true)
                     .read(true)
                     .truncate(true)
-                    .open("db.gz")
+                    .open(&gzip_path)
                     .await?;
                 let mut writer = GzipEncoder::new(compressed_file);
                 let size = tokio::io::copy(&mut reader, &mut writer).await?;
-                tracing::trace!("Compressed database file ({} bytes) into db.gz", size);
                 writer.shutdown().await?;
-                Ok(ByteStream::from_path("db.gz").await?)
+                tracing::debug!(
+                    "Compressed database file ({} bytes) into `{}`",
+                    size,
+                    gzip_path.display()
+                );
+                Ok(ByteStream::from_path(gzip_path).await?)
             }
         }
     }
+
+    fn db_gzip_path(db_path: &Path) -> PathBuf {
+        let mut gzip_path = db_path.to_path_buf();
+        gzip_path.pop();
+        gzip_path.join("db.gz")
+    }
+
     // Replicates local WAL pages to S3, if local WAL is present.
     // This function is called under the assumption that if local WAL
     // file is present, it was already detected to be newer than its
@@ -729,8 +741,10 @@ impl Replicator {
         let generation = self.generation()?;
         let start_ts = Instant::now();
         let client = self.client.clone();
-        let mut db_file = File::open(&self.db_path).await?;
-        let change_counter = Self::read_change_counter(&mut db_file).await?;
+        let change_counter = {
+            let mut db_file = File::open(&self.db_path).await?;
+            Self::read_change_counter(&mut db_file).await?
+        };
         let snapshot_req = client.put_object().bucket(self.bucket.clone()).key(format!(
             "{}-{}/db.{}",
             self.db_name, generation, self.use_compression
@@ -753,14 +767,15 @@ impl Replicator {
             )));
         let snapshot_notifier = self.snapshot_notifier.clone();
         let compression = self.use_compression;
+        let db_path = PathBuf::from(self.db_path.clone());
         let handle = tokio::spawn(async move {
             tracing::trace!("Start snapshotting generation {}", generation);
             let start = Instant::now();
-            let body = match Self::maybe_compress_main_db_file(db_file, compression).await {
+            let body = match Self::maybe_compress_main_db_file(&db_path, compression).await {
                 Ok(file) => file,
                 Err(e) => {
                     tracing::error!(
-                        "Failed to compress db file (generation {}): {}",
+                        "Failed to compress db file (generation {}): {:?}",
                         generation,
                         e
                     );
@@ -791,7 +806,9 @@ impl Replicator {
             let _ = snapshot_notifier.send(Ok(Some(generation)));
             let elapsed = Instant::now() - start;
             tracing::debug!("Snapshot upload finished (took {:?})", elapsed);
-            let _ = tokio::fs::remove_file(format!("db.{}", compression)).await;
+            // cleanup gzip database snapshot if exists
+            let gzip_path = Self::db_gzip_path(&db_path);
+            let _ = tokio::fs::remove_file(gzip_path).await;
         });
         let elapsed = Instant::now() - start_ts;
         tracing::debug!("Scheduled DB snapshot {} (took {:?})", generation, elapsed);