sqlite: generate seed

go.mod

@@ -27,6 +27,7 @@ require (
 	github.com/klauspost/compress v1.10.3 // indirect
 	github.com/kr/text v0.2.0 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.4 // indirect
+	github.com/pierrec/xxHash v0.1.5 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
 	github.com/prometheus/client_model v0.4.1-0.20230718164431-9a2bf3000d16 // indirect
 	github.com/prometheus/common v0.44.0 // indirect

go.sum

@@ -82,6 +82,8 @@ github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd/go.mod h1:6dJ
 github.com/modern-go/reflect2 v0.0.0-20180701023420-4b7aa43c6742/go.mod h1:bx2lNnkwVCuqBIxFjflWJWanXIb3RllmbCylyMrvgv0=
 github.com/modern-go/reflect2 v1.0.2 h1:xBagoLtFs94CBntxluKeaWgTMpvLxC4ur3nMaC9Gz0M=
 github.com/modern-go/reflect2 v1.0.2/go.mod h1:yWuevngMOJpCy52FWWMvUC8ws7m/LJsjYzDa0/r8luk=
+github.com/pierrec/xxHash v0.1.5 h1:n/jBpwTHiER4xYvK3/CdPVnLDPchj8eTJFFLUb4QHBo=
+github.com/pierrec/xxHash v0.1.5/go.mod h1:w2waW5Zoa/Wc4Yqe0wgrIYAGKqRMf7czn2HNKXmuL+I=
 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/prometheus/client_golang v1.17.0 h1:rl2sfwZMtSthVU752MqfjQozy7blglC+1SOtjMAMh+Q=

handler/sqlite/handle.go

@@ -17,16 +17,23 @@ const (
 type SQLiteHandler struct {
 	db      *sql.DB
 	eventCh chan *mocrelay.Event
+	seed    uint32
 }
 
 func NewSQLiteHandler(ctx context.Context, db *sql.DB) (*SQLiteHandler, error) {
 	if err := Migrate(ctx, db); err != nil {
 		return nil, fmt.Errorf("failed to migrate: %w", err)
 	}
 
+	seed, err := getOrSetSeed(ctx, db)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get or set seed: %w", err)
+	}
+
 	h := &SQLiteHandler{
 		db:      db,
 		eventCh: make(chan *mocrelay.Event, bulkInsertNum),
+		seed:    seed,
 	}
 
 	go h.serveBulkInsert(ctx)

handler/sqlite/insert.go

@@ -3,10 +3,13 @@ package sqlite
 import (
 	"bytes"
 	"context"
+	"crypto/rand"
 	"database/sql"
 	"encoding/json"
 	"errors"
 	"fmt"
+	"math"
+	"math/big"
 	"slices"
 	"text/template"
 
@@ -245,3 +248,36 @@ func buildInsertDeletedKeys(
 
 	return b.ToSQL()
 }
+
+func getOrSetSeed(ctx context.Context, db *sql.DB) (seed uint32, err error) {
+	tx, err := db.BeginTx(ctx, nil)
+	if err != nil {
+		return 0, fmt.Errorf("failed to begin transaction: %w", err)
+	}
+	defer func() {
+		if err != nil {
+			err = errors.Join(err, tx.Rollback())
+			return
+		}
+		err = tx.Commit()
+	}()
+
+	if err := tx.QueryRowContext(ctx, "select seed from hash_seed").Scan(&seed); err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			n, err := rand.Int(rand.Reader, big.NewInt(math.MaxUint32))
+			if err != nil {
+				return 0, fmt.Errorf("failed to generate random number: %w", err)
+			}
+			seed = uint32(n.Int64())
+
+			if _, err := tx.ExecContext(ctx, "insert into hash_seed (seed) values (?)", seed); err != nil {
+				return 0, fmt.Errorf("failed to insert seed: %w", err)
+			}
+
+		} else {
+			return 0, fmt.Errorf("failed to query seed: %w", err)
+		}
+	}
+
+	return
+}

handler/sqlite/migrate.go

@@ -49,5 +49,14 @@ func Migrate(ctx context.Context, db *sql.DB) error {
 		return fmt.Errorf("failed to create deleted_keys table: %w", err)
 	}
 
+	// table hash_seed
+	if _, err := db.ExecContext(ctx, `
+		create table if not exists hash_seed (
+			seed integer not null primary key
+		) strict, without rowid;
+	`); err != nil {
+		return fmt.Errorf("failed to create hash_seed table: %w", err)
+	}
+
 	return nil
 }