skiplist minor correction on node Size() method; We must take into accout time, and handle 32 bit or 64 bit. New EscalateFlush and EscalateCompaction methods

Author: guycipher

README.md

@@ -272,6 +272,13 @@ func (txn *Transaction) Commit(k4 *K4) error
 // Recover from WAL file
 // WAL file must be placed in the data directory
 func (k4 *K4) RecoverFromWAL() error
+
+// EscalateFlush escalates the memtable flush to the background queue
+func (k4 *K4) EscalateFlush() error
+
+// EscalateCompaction escalates a compaction operation
+func (k4 *K4) EscalateCompaction() error
+
 ```
 
 ### What can you build with K4?

skiplist/skiplist.go

@@ -34,6 +34,7 @@ import (
 	"bytes"
 	"math/rand"
 	"time"
+	"unsafe"
 )
 
 const TOMBSTONE_VALUE = "$tombstone" // This is specific to k4
@@ -87,7 +88,12 @@ func NewNode(level int, key, value []byte, ttl *time.Duration) *Node {
 
 // Size returns the size of the node in bytes
 func (n *Node) Size() int {
-	return len(n.key) + len(n.value) + len(n.forward)*8 // assuming 64-bit pointers
+	size := len(n.key) + len(n.value) + len(n.forward)*int(unsafe.Sizeof(uintptr(0)))
+	if n.ttl != nil {
+		size += int(unsafe.Sizeof(*n.ttl))
+	}
+
+	return size
 }
 
 // IsExpired checks if the node is expired

v2/k4.go

@@ -1166,7 +1166,7 @@ func (txn *Transaction) Commit(k4 *K4) error {
 	}
 
 	// Check if memtable needs to be flushed
-	if k4.memtable.Size() > k4.memtableFlushThreshold {
+	if k4.memtable.Size() >= k4.memtableFlushThreshold {
 		k4.appendMemtableToFlushQueue() // Append memtable to flush queue
 	}
 
@@ -1369,7 +1369,7 @@ func (k4 *K4) Put(key, value []byte, ttl *time.Duration) error {
 	k4.memtable.Insert(key, value, ttl) // insert the key value pair into the memtable
 
 	// Check if memtable needs to be flushed
-	if k4.memtable.Size() > k4.memtableFlushThreshold {
+	if k4.memtable.Size() >= k4.memtableFlushThreshold {
 		k4.appendMemtableToFlushQueue()
 	}
 
@@ -2065,3 +2065,20 @@ func (it *Iterator) Reset() {
 	it.prevStarted = false // We reset the prevStarted to false
 
 }
+
+// EscalateFlush is a public method to force flush memtable to queue
+func (k4 *K4) EscalateFlush() error {
+	// Lock the memtable
+	k4.memtableLock.Lock()
+	defer k4.memtableLock.Unlock()
+
+	// Append memtable to flush queue
+	k4.appendMemtableToFlushQueue()
+
+	return nil
+}
+
+// EscalateCompaction is a public method to force compaction
+func (k4 *K4) EscalateCompaction() error {
+	return k4.compact()
+}

v2/k4_test.go

@@ -1303,7 +1303,7 @@ func TestCompressCompaction(t *testing.T) {
 	dir := setup(t)
 	defer teardown(dir)
 
-	k4, err := Open(dir, 12196/4, 2, true, true)
+	k4, err := Open(dir, 12196/4, 3000, true, true)
 	if err != nil {
 		t.Fatalf("Failed to open K4: %v", err)
 	}
@@ -1320,7 +1320,7 @@ func TestCompressCompaction(t *testing.T) {
 
 	}
 
-	time.Sleep(8 * time.Second)
+	k4.compact() // now we will compact and close
 
 	k4.Close()