From 8c60359ae52735faafbe9f9a8a24d94f9dbcca15 Mon Sep 17 00:00:00 2001
From: Konstantin Knizhnik <knizhnik@neon.tech>
Date: Tue, 12 Mar 2024 07:58:57 +0200
Subject: [PATCH] Emable iomage layer compression by default

---
 pageserver/src/tenant/blob_io.rs                   | 4 ++--
 pageserver/src/tenant/config.rs                    | 2 +-
 pageserver/src/tenant/storage_layer/image_layer.rs | 8 +-------
 3 files changed, 4 insertions(+), 10 deletions(-)

diff --git a/pageserver/src/tenant/blob_io.rs b/pageserver/src/tenant/blob_io.rs
index 4ba68bac1f..2e6c985158 100644
--- a/pageserver/src/tenant/blob_io.rs
+++ b/pageserver/src/tenant/blob_io.rs
@@ -237,7 +237,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
         (src_buf, Ok(()))
     }
 
-    pub async fn write_compressed_blob(&mut self, srcbuf: Bytes) -> Result<u64, Error> {
+    pub async fn write_compressed_blob(&mut self, srcbuf: Bytes, compress: bool) -> Result<u64, Error> {
         let offset = self.offset;
 
         let len = srcbuf.len();
@@ -257,7 +257,7 @@ impl<const BUFFERED: bool> BlobWriter<BUFFERED> {
                     format!("blob too large ({} bytes)", len),
                 ));
             }
-            if len == BLCKSZ as usize {
+            if compress && len == BLCKSZ as usize {
                 let compressed = lz4_flex::block::compress(&srcbuf);
                 if compressed.len() < len {
                     io_buf.put_u8(LZ4_COMPRESSION);
diff --git a/pageserver/src/tenant/config.rs b/pageserver/src/tenant/config.rs
index bcb1368911..b8fab30c97 100644
--- a/pageserver/src/tenant/config.rs
+++ b/pageserver/src/tenant/config.rs
@@ -546,7 +546,7 @@ impl Default for TenantConf {
             max_lsn_wal_lag: NonZeroU64::new(DEFAULT_MAX_WALRECEIVER_LSN_WAL_LAG)
                 .expect("cannot parse default max walreceiver Lsn wal lag"),
             trace_read_requests: false,
-            compress_image_layer: false,
+            compress_image_layer: true,
             eviction_policy: EvictionPolicy::NoEviction,
             min_resident_size_override: None,
             evictions_low_residence_duration_metric_threshold: humantime::parse_duration(
diff --git a/pageserver/src/tenant/storage_layer/image_layer.rs b/pageserver/src/tenant/storage_layer/image_layer.rs
index d7a000e549..c4d30cf1e3 100644
--- a/pageserver/src/tenant/storage_layer/image_layer.rs
+++ b/pageserver/src/tenant/storage_layer/image_layer.rs
@@ -668,13 +668,7 @@ impl ImageLayerWriterInner {
     ///
     async fn put_image(&mut self, key: Key, img: Bytes) -> anyhow::Result<()> {
         ensure!(self.key_range.contains(&key));
-        let off = if self.compression {
-            self.blob_writer.write_compressed_blob(img).await?
-        } else {
-            let (_img, res) = self.blob_writer.write_blob(img).await;
-            // TODO: re-use the buffer for `img` further upstack
-            res?
-        };
+        let off = self.blob_writer.write_compressed_blob(img, self.compression).await?;
         let mut keybuf: [u8; KEY_SIZE] = [0u8; KEY_SIZE];
         key.write_to_byte_slice(&mut keybuf);
         self.tree.append(&keybuf, off)?;