feat: replace custom LRU cache with otter cache library

conn.go

@@ -39,8 +39,8 @@ import (
 	"sync/atomic"
 	"time"
 
-	"github.com/gocql/gocql/internal/lru"
 	"github.com/gocql/gocql/internal/streams"
+	"github.com/maypok86/otter/v2"
 )
 
 var (
@@ -1236,78 +1236,50 @@ type inflightPrepare struct {
 }
 
 func (c *Conn) prepareStatement(ctx context.Context, stmt string, tracer Tracer) (*preparedStatment, error) {
-	stmtCacheKey := c.session.stmtsLRU.keyFor(c.host.HostID(), c.currentKeyspace, stmt)
-	flight, ok := c.session.stmtsLRU.execIfMissing(stmtCacheKey, func(lru *lru.Cache) *inflightPrepare {
-		flight := &inflightPrepare{
-			done: make(chan struct{}),
+	loader := otter.LoaderFunc[string, *preparedStatment](func(ctx context.Context, key string) (*preparedStatment, error) {
+		prep := &writePrepareFrame{
+			statement: stmt,
+		}
+		if c.version > protoVersion4 {
+			prep.keyspace = c.currentKeyspace
 		}
-		lru.Add(stmtCacheKey, flight)
-		return flight
-	})
-
-	if !ok {
-		go func() {
-			defer close(flight.done)
-
-			prep := &writePrepareFrame{
-				statement: stmt,
-			}
-			if c.version > protoVersion4 {
-				prep.keyspace = c.currentKeyspace
-			}
-
-			// we won the race to do the load, if our context is canceled we shouldnt
-			// stop the load as other callers are waiting for it but this caller should get
-			// their context cancelled error.
-			framer, err := c.exec(c.ctx, prep, tracer)
-			if err != nil {
-				flight.err = err
-				c.session.stmtsLRU.remove(stmtCacheKey)
-				return
-			}
 
-			frame, err := framer.parseFrame()
-			if err != nil {
-				flight.err = err
-				c.session.stmtsLRU.remove(stmtCacheKey)
-				return
-			}
+		framer, err := c.exec(c.ctx, prep, tracer)
+		if err != nil {
+			return nil, err
+		}
 
-			// TODO(zariel): tidy this up, simplify handling of frame parsing so its not duplicated
-			// everytime we need to parse a frame.
-			if len(framer.traceID) > 0 && tracer != nil {
-				tracer.Trace(framer.traceID)
-			}
+		frame, err := framer.parseFrame()
+		if err != nil {
+			return nil, err
+		}
 
-			switch x := frame.(type) {
-			case *resultPreparedFrame:
-				flight.preparedStatment = &preparedStatment{
-					// defensively copy as we will recycle the underlying buffer after we
-					// return.
-					id: copyBytes(x.preparedID),
-					// the type info's should _not_ have a reference to the framers read buffer,
-					// therefore we can just copy them directly.
-					request:  x.reqMeta,
-					response: x.respMeta,
-				}
-			case error:
-				flight.err = x
-			default:
-				flight.err = NewErrProtocol("Unknown type in response to prepare frame: %s", x)
-			}
+		// TODO(zariel): tidy this up, simplify handling of frame parsing so its not duplicated
+		// everytime we need to parse a frame.
+		if len(framer.traceID) > 0 && tracer != nil {
+			tracer.Trace(framer.traceID)
+		}
 
-			if flight.err != nil {
-				c.session.stmtsLRU.remove(stmtCacheKey)
-			}
-		}()
-	}
+		switch x := frame.(type) {
+		case *resultPreparedFrame:
+			return &preparedStatment{
+				// defensively copy as we will recycle the underlying buffer after we
+				// return.
+				id: copyBytes(x.preparedID),
+				// the type info's should _not_ have a reference to the framers read buffer,
+				// therefore we can just copy them directly.
+				request:  x.reqMeta,
+				response: x.respMeta,
+			}, nil
+		case error:
+			return nil, x
+		default:
+			return nil, NewErrProtocol("Unknown type in response to prepare frame: %s", x)
+		}
+	})
+	stmtCacheKey := keyForPreparedStatement(c.host.HostID(), c.currentKeyspace, stmt)
 
-	select {
-	case <-ctx.Done():
-		return nil, ctx.Err()
-	case <-flight.done:
-		return flight.preparedStatment, flight.err
-	}
+	return c.session.stmtsLRU.Get(ctx, stmtCacheKey, loader)
 }
 
 func marshalQueryValue(typ TypeInfo, value interface{}, dst *queryValues) error {
@@ -1477,8 +1449,8 @@ func (c *Conn) executeQuery(ctx context.Context, qry *Query) *Iter {
 		// is not consistent with regards to its schema.
 		return iter
 	case *RequestErrUnprepared:
-		stmtCacheKey := c.session.stmtsLRU.keyFor(c.host.HostID(), c.currentKeyspace, qry.stmt)
-		c.session.stmtsLRU.evictPreparedID(stmtCacheKey, x.StatementId)
+		stmtCacheKey := keyForPreparedStatement(c.host.HostID(), c.currentKeyspace, qry.stmt)
+		c.session.stmtsLRU.Invalidate(stmtCacheKey)
 		return c.executeQuery(ctx, qry)
 	case error:
 		return &Iter{err: x, framer: framer}
@@ -1623,8 +1595,8 @@ func (c *Conn) executeBatch(ctx context.Context, batch *Batch) *Iter {
 	case *RequestErrUnprepared:
 		stmt, found := stmts[string(x.StatementId)]
 		if found {
-			key := c.session.stmtsLRU.keyFor(c.host.HostID(), c.currentKeyspace, stmt)
-			c.session.stmtsLRU.evictPreparedID(key, x.StatementId)
+			key := keyForPreparedStatement(c.host.HostID(), c.currentKeyspace, stmt)
+			c.session.stmtsLRU.Invalidate(key)
 		}
 		return c.executeBatch(ctx, batch)
 	case *resultRowsFrame:

go.mod

@@ -18,13 +18,17 @@
 module github.com/gocql/gocql
 
 require (
-	github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932 // indirect
-	github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 // indirect
 	github.com/golang/snappy v0.0.3
 	github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed
-	github.com/kr/pretty v0.1.0 // indirect
-	github.com/stretchr/testify v1.3.0 // indirect
+	github.com/maypok86/otter/v2 v2.2.1
 	gopkg.in/inf.v0 v0.9.1
 )
 
-go 1.13
+require (
+	github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932 // indirect
+	github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 // indirect
+	github.com/kr/pretty v0.1.0 // indirect
+	golang.org/x/sys v0.34.0 // indirect
+)
+
+go 1.24.6

go.sum

@@ -2,8 +2,8 @@ github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932 h1:mXoPYz/Ul5HYE
 github.com/bitly/go-hostpool v0.0.0-20171023180738-a3a6125de932/go.mod h1:NOuUCSz6Q9T7+igc/hlvDOUdtWKryOrtFyIVABv/p7k=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869 h1:DDGfHa7BWjL4YnC6+E63dPcxHo2sUxDIu8g3QgEJdRY=
 github.com/bmizerany/assert v0.0.0-20160611221934-b7ed37b82869/go.mod h1:Ekp36dRnpXw/yCqJaO+ZrUyxD+3VXMFFr56k5XYrpB4=
-github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
-github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/golang/snappy v0.0.3 h1:fHPg5GQYlCeLIPB9BZqMVR5nR9A+IM5zcgeTdjMYmLA=
 github.com/golang/snappy v0.0.3/go.mod h1:/XxbfmMg8lxefKM7IXC3fBNl/7bRcc72aCRzEWrmP2Q=
 github.com/hailocab/go-hostpool v0.0.0-20160125115350-e80d13ce29ed h1:5upAirOpQc1Q53c0bnx2ufif5kANL7bfZWcc6VJWJd8=
@@ -13,10 +13,15 @@ github.com/kr/pretty v0.1.0/go.mod h1:dAy3ld7l9f0ibDNOQOHHMYYIIbhfbHSm3C4ZsoJORN
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+github.com/maypok86/otter/v2 v2.2.1 h1:hnGssisMFkdisYcvQ8L019zpYQcdtPse+g0ps2i7cfI=
+github.com/maypok86/otter/v2 v2.2.1/go.mod h1:1NKY9bY+kB5jwCXBJfE59u+zAwOt6C7ni1FTlFFMqVs=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
-github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
-github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
+github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
+github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sys v0.34.0 h1:H5Y5sJ2L2JRdyv7ROF1he/lPdvFsd0mJHFw2ThKHxLA=
+golang.org/x/sys v0.34.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 gopkg.in/inf.v0 v0.9.1 h1:73M5CoZyi3ZLMOyDlQh031Cx6N9NDJ2Vvfl76EDAgDc=
 gopkg.in/inf.v0 v0.9.1/go.mod h1:cWUDdTG/fYaXco+Dcufb5Vnc6Gp2YChqWtbxRZE0mXw=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

prepared_cache.go

@@ -25,78 +25,19 @@
 package gocql
 
 import (
-	"bytes"
-	"sync"
-
-	"github.com/gocql/gocql/internal/lru"
+	"github.com/maypok86/otter/v2"
 )
 
 const defaultMaxPreparedStmts = 1000
 
-// preparedLRU is the prepared statement cache
-type preparedLRU struct {
-	mu  sync.Mutex
-	lru *lru.Cache
-}
-
-func (p *preparedLRU) clear() {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	for p.lru.Len() > 0 {
-		p.lru.RemoveOldest()
-	}
-}
-
-func (p *preparedLRU) add(key string, val *inflightPrepare) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-	p.lru.Add(key, val)
-}
-
-func (p *preparedLRU) remove(key string) bool {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-	return p.lru.Remove(key)
-}
-
-func (p *preparedLRU) execIfMissing(key string, fn func(lru *lru.Cache) *inflightPrepare) (*inflightPrepare, bool) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	val, ok := p.lru.Get(key)
-	if ok {
-		return val.(*inflightPrepare), true
-	}
-
-	return fn(p.lru), false
+func NewPreparedLRU(size int) *otter.Cache[string, *preparedStatment] {
+	return otter.Must(&otter.Options[string, *preparedStatment]{
+		InitialCapacity: size,
+		MaximumSize:     size,
+	})
 }
 
-func (p *preparedLRU) keyFor(hostID, keyspace, statement string) string {
+func keyForPreparedStatement(hostID, keyspace, statement string) string {
 	// TODO: we should just use a struct for the key in the map
 	return hostID + keyspace + statement
 }
-
-func (p *preparedLRU) evictPreparedID(key string, id []byte) {
-	p.mu.Lock()
-	defer p.mu.Unlock()
-
-	val, ok := p.lru.Get(key)
-	if !ok {
-		return
-	}
-
-	ifp, ok := val.(*inflightPrepare)
-	if !ok {
-		return
-	}
-
-	select {
-	case <-ifp.done:
-		if bytes.Equal(id, ifp.preparedStatment.id) {
-			p.lru.Remove(key)
-		}
-	default:
-	}
-
-}