pgx/internal/stmtcache/lru_test.go

293 lines
8.8 KiB
Go

package stmtcache_test
import (
"context"
"fmt"
"math/rand"
"os"
"regexp"
"testing"
"time"
"github.com/jackc/pgx/v5/internal/stmtcache"
"github.com/jackc/pgx/v5/pgconn"
"github.com/stretchr/testify/require"
)
func TestLRUModePrepare(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
cache := stmtcache.NewLRU(conn, stmtcache.ModePrepare, 2)
require.EqualValues(t, 0, cache.Len())
require.EqualValues(t, 2, cache.Cap())
require.EqualValues(t, stmtcache.ModePrepare, cache.Mode())
psd, err := cache.Get(ctx, "select 1")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 1"}, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 1")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 1"}, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 2")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 2, cache.Len())
require.ElementsMatch(t, []string{"select 1", "select 2"}, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 3")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 2, cache.Len())
require.ElementsMatch(t, []string{"select 2", "select 3"}, fetchServerStatements(t, ctx, conn))
err = cache.Clear(ctx)
require.NoError(t, err)
require.EqualValues(t, 0, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
}
func TestLRUStmtInvalidation(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
// we construct a fake error because its not super straightforward to actually call
// a prepared statement from the LRU cache without the helper routines which live
// in pgx proper.
fakeInvalidCachePlanError := &pgconn.PgError{
Severity: "ERROR",
Code: "0A000",
Message: "cached plan must not change result type",
}
cache := stmtcache.NewLRU(conn, stmtcache.ModePrepare, 2)
//
// outside of a transaction, we eagerly flush the statement
//
_, err = cache.Get(ctx, "select 1")
require.NoError(t, err)
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 1"}, fetchServerStatements(t, ctx, conn))
cache.StatementErrored("select 1", fakeInvalidCachePlanError)
_, err = cache.Get(ctx, "select 2")
require.NoError(t, err)
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 2"}, fetchServerStatements(t, ctx, conn))
err = cache.Clear(ctx)
require.NoError(t, err)
//
// within an errored transaction, we defer the flush to after the first get
// that happens after the transaction is rolled back
//
_, err = cache.Get(ctx, "select 1")
require.NoError(t, err)
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 1"}, fetchServerStatements(t, ctx, conn))
res := conn.Exec(ctx, "begin")
require.NoError(t, res.Close())
require.Equal(t, byte('T'), conn.TxStatus())
res = conn.Exec(ctx, "selec")
require.Error(t, res.Close())
require.Equal(t, byte('E'), conn.TxStatus())
cache.StatementErrored("select 1", fakeInvalidCachePlanError)
require.EqualValues(t, 1, cache.Len())
res = conn.Exec(ctx, "rollback")
require.NoError(t, res.Close())
_, err = cache.Get(ctx, "select 2")
require.EqualValues(t, 1, cache.Len())
require.ElementsMatch(t, []string{"select 2"}, fetchServerStatements(t, ctx, conn))
}
func TestLRUStmtInvalidationIntegration(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
cache := stmtcache.NewLRU(conn, stmtcache.ModePrepare, 2)
result := conn.ExecParams(ctx, "create temporary table stmtcache_table (a text)", nil, nil, nil, nil).Read()
require.NoError(t, result.Err)
sql := "select * from stmtcache_table"
sd1, err := cache.Get(ctx, sql)
require.NoError(t, err)
result = conn.ExecPrepared(ctx, sd1.Name, nil, nil, nil).Read()
require.NoError(t, result.Err)
result = conn.ExecParams(ctx, "alter table stmtcache_table add column b text", nil, nil, nil, nil).Read()
require.NoError(t, result.Err)
result = conn.ExecPrepared(ctx, sd1.Name, nil, nil, nil).Read()
require.EqualError(t, result.Err, "ERROR: cached plan must not change result type (SQLSTATE 0A000)")
cache.StatementErrored(sql, result.Err)
sd2, err := cache.Get(ctx, sql)
require.NoError(t, err)
require.NotEqual(t, sd1.Name, sd2.Name)
result = conn.ExecPrepared(ctx, sd2.Name, nil, nil, nil).Read()
require.NoError(t, result.Err)
}
func TestLRUModePrepareStress(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*10)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
cache := stmtcache.NewLRU(conn, stmtcache.ModePrepare, 8)
require.EqualValues(t, 0, cache.Len())
require.EqualValues(t, 8, cache.Cap())
require.EqualValues(t, stmtcache.ModePrepare, cache.Mode())
for i := 0; i < 1000; i++ {
psd, err := cache.Get(ctx, fmt.Sprintf("select %d", rand.Intn(50)))
require.NoError(t, err)
require.NotNil(t, psd)
result := conn.ExecPrepared(ctx, psd.Name, nil, nil, nil).Read()
require.NoError(t, result.Err)
}
}
func TestLRUModeDescribe(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
cache := stmtcache.NewLRU(conn, stmtcache.ModeDescribe, 2)
require.EqualValues(t, 0, cache.Len())
require.EqualValues(t, 2, cache.Cap())
require.EqualValues(t, stmtcache.ModeDescribe, cache.Mode())
psd, err := cache.Get(ctx, "select 1")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 1, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 1")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 1, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 2")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 2, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
psd, err = cache.Get(ctx, "select 3")
require.NoError(t, err)
require.NotNil(t, psd)
require.EqualValues(t, 2, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
err = cache.Clear(ctx)
require.NoError(t, err)
require.EqualValues(t, 0, cache.Len())
require.Empty(t, fetchServerStatements(t, ctx, conn))
}
func TestLRUContext(t *testing.T) {
t.Parallel()
ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
defer cancel()
conn, err := pgconn.Connect(ctx, os.Getenv("PGX_TEST_CONN_STRING"))
require.NoError(t, err)
defer conn.Close(ctx)
cache := stmtcache.NewLRU(conn, stmtcache.ModeDescribe, 2)
// test 1 : getting a value for the first time with a cancelled context returns an error
ctx1, cancel1 := context.WithCancel(ctx)
cancel1()
desc, err := cache.Get(ctx1, "SELECT 1")
require.Error(t, err)
require.Nil(t, desc)
// test 2 : when querying for the 2nd time a cached value, if the context is canceled return an error
ctx2, cancel2 := context.WithCancel(ctx)
desc, err = cache.Get(ctx2, "SELECT 2")
require.NoError(t, err)
require.NotNil(t, desc)
cancel2()
desc, err = cache.Get(ctx2, "SELECT 2")
require.Error(t, err)
require.Nil(t, desc)
}
func fetchServerStatements(t testing.TB, ctx context.Context, conn *pgconn.PgConn) []string {
result := conn.ExecParams(ctx, `select statement from pg_prepared_statements`, nil, nil, nil, nil).Read()
require.NoError(t, result.Err)
var statements []string
for _, r := range result.Rows {
statement := string(r[0])
if conn.ParameterStatus("crdb_version") != "" {
if statement == "PREPARE AS select statement from pg_prepared_statements" {
// CockroachDB includes the currently running unnamed prepared statement while PostgreSQL does not. Ignore it.
continue
}
// CockroachDB includes the "PREPARE ... AS" text in the statement even if it was prepared through the extended
// protocol will PostgreSQL does not. Normalize the statement.
re := regexp.MustCompile(`^PREPARE lrupsc[0-9_]+ AS `)
statement = re.ReplaceAllString(statement, "")
}
statements = append(statements, statement)
}
return statements
}