// Internally, only Feature additions/removals are stored for each layer. If a layer has a parent,
// the Feature list will be compared to the parent's Feature list and the difference will be stored.
// Note that when the Namespace of a layer differs from its parent, it is expected that several
// Feature that were already included a parent will have their Namespace updated as well
// (happens when Feature detectors relies on the detected layer Namespace). However, if the listed
// Feature has the same Name/Version as its parent, InsertLayer considers that the Feature hasn't
// been modified.
func (pgSQL *pgSQL) InsertLayer(layer database.Layer) error {
tf := time.Now()
// Verify parameters
if layer.Name == "" {
log.Warning("could not insert a layer which has an empty Name")
return cerrors.NewBadRequestError("could not insert a layer which has an empty Name")
}
// Get a potentially existing layer.
existingLayer, err := pgSQL.FindLayer(layer.Name, true, false)
if err != nil && err != cerrors.ErrNotFound {
return err
} else if err == nil {
if existingLayer.EngineVersion >= layer.EngineVersion {
// The layer exists and has an equal or higher engine version, do nothing.
return nil
}
layer.ID = existingLayer.ID
}
// We do `defer observeQueryTime` here because we don't want to observe existing layers.
defer observeQueryTime("InsertLayer", "all", tf)
// Get parent ID.
var parentID zero.Int
if layer.Parent != nil {
if layer.Parent.ID == 0 {
log.Warning("Parent is expected to be retrieved from database when inserting a layer.")
return cerrors.NewBadRequestError("Parent is expected to be retrieved from database when inserting a layer.")
}
parentID = zero.IntFrom(int64(layer.Parent.ID))
}
// Find or insert namespace if provided.
var namespaceID zero.Int
if layer.Namespace != nil {
n, err := pgSQL.insertNamespace(*layer.Namespace)
if err != nil {
return err
}
namespaceID = zero.IntFrom(int64(n))
} else if layer.Namespace == nil && layer.Parent != nil {
// Import the Namespace from the parent if it has one and this layer doesn't specify one.
if layer.Parent.Namespace != nil {
namespaceID = zero.IntFrom(int64(layer.Parent.Namespace.ID))
}
}
// Begin transaction.
tx, err := pgSQL.Begin()
if err != nil {
tx.Rollback()
return handleError("InsertLayer.Begin()", err)
}
if layer.ID == 0 {
// Insert a new layer.
err = tx.QueryRow(insertLayer, layer.Name, layer.EngineVersion, parentID, namespaceID).
Scan(&layer.ID)
if err != nil {
tx.Rollback()
if isErrUniqueViolation(err) {
// Ignore this error, another process collided.
log.Debug("Attempted to insert duplicate layer.")
return nil
}
return handleError("insertLayer", err)
}
} else {
// Update an existing layer.
_, err = tx.Exec(updateLayer, layer.ID, layer.EngineVersion, namespaceID)
if err != nil {
tx.Rollback()
return handleError("updateLayer", err)
}
// Remove all existing Layer_diff_FeatureVersion.
_, err = tx.Exec(removeLayerDiffFeatureVersion, layer.ID)
if err != nil {
tx.Rollback()
return handleError("removeLayerDiffFeatureVersion", err)
}
}
// Update Layer_diff_FeatureVersion now.
err = pgSQL.updateDiffFeatureVersions(tx, &layer, &existingLayer)
if err != nil {
tx.Rollback()
return err
}
// Commit transaction.
err = tx.Commit()
if err != nil {
tx.Rollback()
return handleError("InsertLayer.Commit()", err)
}
return nil
}
