From f8d1a77edd69e76ff26f0d548f4d47584599dc15 Mon Sep 17 00:00:00 2001
From: Alex Gaetano Padula <me@alexpadula.com>
Date: Fri, 21 Feb 2025 04:50:02 -0500
Subject: [PATCH] refactor handleTombstones we shouldn't need to iterate over
 any sstables, just update sstable filters on if a key is being deleted. 
 Optimization.  I've also added some minor comments

---
 bloomfilter/bloomfilter.go |  3 +-
 starskey.go                | 96 +++++++++++++-------------------------
 2 files changed, 34 insertions(+), 65 deletions(-)

diff --git a/bloomfilter/bloomfilter.go b/bloomfilter/bloomfilter.go
index bba4e10..3fd0b8b 100644
--- a/bloomfilter/bloomfilter.go
+++ b/bloomfilter/bloomfilter.go
@@ -21,11 +21,10 @@ import (
 	"bytes"
 	"encoding/gob"
 	"errors"
+	"github.com/zeebo/xxh3"
 	"hash"
 	"hash/fnv"
 	"math"
-
-	"github.com/zeebo/xxh3"
 	// We could compare against github.com/cespare/xxhash/v2 and github.com/zeebo/xxh3
 	// but may not be backwards compatible. We use both currently(cespare is used for SuRF) which may be redundant to import 2 packages doing same thing
 )
diff --git a/starskey.go b/starskey.go
index 1345879..95baf0f 100644
--- a/starskey.go
+++ b/starskey.go
@@ -352,7 +352,7 @@ func Open(config *Config) (*Starskey, error) {
 
 	log.Println("Write-ahead log opened successfully")
 
-	log.Println("Creating memory table")
+	log.Println("Creating memory table with threshold: ", config.FlushThreshold, "and min/max degree: ", config.Optional.TTreeMin, config.Optional.TTreeMax)
 
 	// We create the memtable
 	skey.memtable = ttree.New(TTreeMin, TTreeMax)
@@ -416,7 +416,7 @@ func (skey *Starskey) Close() error {
 
 	log.Println("Levels closed")
 
-	log.Println("Starskey closed")
+	log.Println("Starskey closed successfully")
 
 	if skey.logFile != nil { // If log configured, we close it
 		if err := skey.logFile.Close(); err != nil {
@@ -436,6 +436,7 @@ func (skey *Starskey) appendToWal(record *WALRecord) error {
 	}
 
 	// Write the WAL record to the write-ahead log
+	// Using the pager we are writing to end of file and with durable sync by default in background
 	if _, err = skey.wal.Write(walSerialized); err != nil {
 		return err
 	}
@@ -492,14 +493,11 @@ func (skey *Starskey) Put(key, value []byte) error {
 
 // handleTombstones handles tombstones
 func (skey *Starskey) handleTombstones(key, value []byte) error {
+
+	// We check if the value is a tombstone, if the case we must update the bloomfilter/surf filters
 	if bytes.Equal(value, Tombstone) {
 		for _, level := range skey.levels {
 			for _, sstable := range level.sstables {
-				klog := sstable.klog
-				vlog := sstable.vlog
-
-				// Create a new iterator for the key log
-				it := pager.NewIterator(klog)
 
 				// If bloom filter is configured we check if key is in the bloom filter
 				if skey.config.BloomFilter {
@@ -517,72 +515,44 @@ func (skey *Starskey) handleTombstones(key, value []byte) error {
 					}
 				}
 
-				for it.Next() {
-					data, err := it.Read()
-					if err != nil {
-						break
-					}
-					klogRecord, err := deserializeKLogRecord(data, skey.config.Compression, skey.config.CompressionOption)
+				// Delete from bloom filter
+				if skey.config.BloomFilter {
+					// Bloom filter we must recreate the bloom filter
+					err := sstable.createBloomFilter(skey)
 					if err != nil {
 						return err
 					}
 
-					if bytes.Equal(klogRecord.Key, key) {
-						// We found the key
-						// We read the value from the value log
-						read, _, err := vlog.Read(int(klogRecord.ValPageNum))
-						if err != nil {
-							return err
-						}
-						vlogRecord, err := deserializeVLogRecord(read, skey.config.Compression, skey.config.CompressionOption)
-						if err != nil {
-							return err
-						}
-
-						// Check if the value is a tombstone
-						if bytes.Equal(vlogRecord.Value, Tombstone) {
-							continue
-						}
-
-						// Delete from bloom filter
-						if skey.config.BloomFilter {
-							// Bloom filter we must recreate the bloom filter
-							err = sstable.createBloomFilter(skey)
-							if err != nil {
-								return err
-							}
-
-						}
+				}
 
-						// Delete from SuRF
-						if skey.config.SuRF {
-							sstable.surf.Delete(key)
-							// We update the surf file
-							surfFile, err := os.OpenFile(fmt.Sprintf("%s%s", strings.TrimSuffix(sstable.klog.Name(), KLogExtension), SuRFExtension), os.O_CREATE|os.O_RDWR, skey.config.Permission)
-							if err != nil {
-								return err
-							}
+				// Delete from SuRF
+				if skey.config.SuRF {
+					sstable.surf.Delete(key)
+					// We update the surf file
+					surfFile, err := os.OpenFile(fmt.Sprintf("%s%s", strings.TrimSuffix(sstable.klog.Name(), KLogExtension), SuRFExtension), os.O_CREATE|os.O_RDWR, skey.config.Permission)
+					if err != nil {
+						return err
+					}
 
-							// We truncate
-							err = surfFile.Truncate(0)
-							if err != nil {
-								return err
-							}
+					// We truncate
+					err = surfFile.Truncate(0)
+					if err != nil {
+						return err
+					}
 
-							// We serialize the surf
-							serializedSurf, err := sstable.surf.Serialize()
-							if err != nil {
-								return err
-							}
+					// We serialize the surf
+					serializedSurf, err := sstable.surf.Serialize()
+					if err != nil {
+						return err
+					}
 
-							// We write the surf to the file
-							_, err = surfFile.WriteAt(serializedSurf, 0)
-							if err != nil {
-								return err
-							}
-						}
+					// We write the surf to the file
+					_, err = surfFile.WriteAt(serializedSurf, 0)
+					if err != nil {
+						return err
 					}
 				}
+
 			}
 		}
 	}