syz-cluster: add pagination

Add simple Previous/Next navigation for the list of series.
For now, just rely on SQL's LIMIT/OFFSET functionality.

3 files changed, 29 insertions, 12 deletions

diff --git a/syz-cluster/pkg/db/series_repo.go b/syz-cluster/pkg/db/series_repo.go
index b21b82889..554a32b00 100644
--- a/syz-cluster/pkg/db/series_repo.go
+++ b/syz-cluster/pkg/db/series_repo.go
@@ -134,11 +134,13 @@ type SeriesWithSession struct {
 type SeriesFilter struct {
 	Cc     string
 	Status SessionStatus
+	Limit  int
+	Offset int
 }
 
 // ListLatest() returns the list of series ordered by the decreasing PublishedAt value.
 func (repo *SeriesRepository) ListLatest(ctx context.Context, filter SeriesFilter,
-	maxPublishedAt time.Time, limit int) ([]*SeriesWithSession, error) {
+	maxPublishedAt time.Time) ([]*SeriesWithSession, error) {
 	ro := repo.client.ReadOnlyTransaction()
 	defer ro.Close()
 
@@ -171,10 +173,14 @@ func (repo *SeriesRepository) ListLatest(ctx context.Context, filter SeriesFilte
 		}
 		stmt.SQL += ")"
 	}
-	stmt.SQL += " ORDER BY PublishedAt DESC"
-	if limit > 0 {
+	stmt.SQL += " ORDER BY PublishedAt DESC, ID"
+	if filter.Limit > 0 {
 		stmt.SQL += " LIMIT @limit"
-		stmt.Params["limit"] = limit
+		stmt.Params["limit"] = filter.Limit
+	}
+	if filter.Offset > 0 {
+		stmt.SQL += " OFFSET @offset"
+		stmt.Params["offset"] = filter.Offset
 	}
 	iter := ro.Query(ctx, stmt)
 	defer iter.Stop()
diff --git a/syz-cluster/pkg/db/series_repo_test.go b/syz-cluster/pkg/db/series_repo_test.go
index 222014113..694893514 100644
--- a/syz-cluster/pkg/db/series_repo_test.go
+++ b/syz-cluster/pkg/db/series_repo_test.go
@@ -84,22 +84,34 @@ func TestSeriesRepositoryList(t *testing.T) {
 	})
 
 	t.Run("all", func(t *testing.T) {
-		list, err := repo.ListLatest(ctx, SeriesFilter{}, time.Time{}, 0)
+		list, err := repo.ListLatest(ctx, SeriesFilter{}, time.Time{})
 		assert.NoError(t, err)
 		assert.Len(t, list, 3)
 	})
 
 	t.Run("with_limit", func(t *testing.T) {
-		list, err := repo.ListLatest(ctx, SeriesFilter{}, time.Time{}, 2)
+		list, err := repo.ListLatest(ctx, SeriesFilter{
+			Limit: 2,
+		}, time.Time{})
 		assert.NoError(t, err)
 		assert.Len(t, list, 2)
 		assert.Equal(t, "Series 3", list[0].Series.Title)
 		assert.Equal(t, "Series 2", list[1].Series.Title)
 	})
 
+	t.Run("with_offset", func(t *testing.T) {
+		list, err := repo.ListLatest(ctx, SeriesFilter{
+			Limit:  1,
+			Offset: 1,
+		}, time.Time{})
+		assert.NoError(t, err)
+		assert.Len(t, list, 1)
+		assert.Equal(t, "Series 2", list[0].Series.Title)
+	})
+
 	t.Run("with_from", func(t *testing.T) {
 		// Skips the latest series.
-		list, err := repo.ListLatest(ctx, SeriesFilter{}, time.Date(2020, time.January, 1, 3, 0, 0, 0, time.UTC), 0)
+		list, err := repo.ListLatest(ctx, SeriesFilter{}, time.Date(2020, time.January, 1, 3, 0, 0, 0, time.UTC))
 		assert.NoError(t, err)
 		assert.Len(t, list, 2)
 		assert.Equal(t, "Series 2", list[0].Series.Title)
@@ -107,8 +119,7 @@ func TestSeriesRepositoryList(t *testing.T) {
 	})
 
 	t.Run("filter_by_cc", func(t *testing.T) {
-		list, err := repo.ListLatest(ctx,
-			SeriesFilter{Cc: "a"}, time.Time{}, 0)
+		list, err := repo.ListLatest(ctx, SeriesFilter{Cc: "a"}, time.Time{})
 		assert.NoError(t, err)
 		assert.Len(t, list, 2)
 	})
@@ -125,7 +136,7 @@ func TestSeriesRepositoryList(t *testing.T) {
 	assert.NoError(t, err)
 
 	t.Run("filter_status_waiting", func(t *testing.T) {
-		list, err := repo.ListLatest(ctx, SeriesFilter{Status: SessionStatusWaiting}, time.Time{}, 0)
+		list, err := repo.ListLatest(ctx, SeriesFilter{Status: SessionStatusWaiting}, time.Time{})
 		assert.NoError(t, err)
 		assert.Len(t, list, 1)
 	})
@@ -134,7 +145,7 @@ func TestSeriesRepositoryList(t *testing.T) {
 	assert.NoError(t, err)
 
 	t.Run("filter_status_in_progress", func(t *testing.T) {
-		list, err := repo.ListLatest(ctx, SeriesFilter{Status: SessionStatusInProgress}, time.Time{}, 0)
+		list, err := repo.ListLatest(ctx, SeriesFilter{Status: SessionStatusInProgress}, time.Time{})
 		assert.NoError(t, err)
 		assert.Len(t, list, 1)
 	})
diff --git a/syz-cluster/pkg/db/session_repo_test.go b/syz-cluster/pkg/db/session_repo_test.go
index c6f79f975..eb688510a 100644
--- a/syz-cluster/pkg/db/session_repo_test.go
+++ b/syz-cluster/pkg/db/session_repo_test.go
@@ -20,7 +20,7 @@ func TestSeriesInsertSession(t *testing.T) {
 	assert.NoError(t, err)
 
 	withSession := func(need int) {
-		list, err := seriesRepo.ListLatest(ctx, SeriesFilter{}, time.Time{}, 10)
+		list, err := seriesRepo.ListLatest(ctx, SeriesFilter{Limit: 10}, time.Time{})
 		assert.NoError(t, err)
 		var cnt int
 		for _, item := range list {