Slowly begin to unpick storage functions

This commit is contained in:
Kegan Dougal 2020-09-07 17:45:01 +01:00
parent c992f4f1f4
commit 2e1374057b
10 changed files with 99 additions and 195 deletions

View file

@ -54,17 +54,10 @@ const insertEventSQL = `
const selectEventSQL = "" +
"SELECT event_nid, state_snapshot_nid FROM roomserver_events WHERE event_id = $1"
// Bulk lookup of events by string ID.
// Sort by the numeric IDs for event type and state key.
// This means we can use binary search to lookup entries by type and state key.
const bulkSelectStateEventByIDSQL = "" +
"SELECT event_type_nid, event_state_key_nid, event_nid FROM roomserver_events" +
" WHERE event_id IN ($1)" +
" ORDER BY event_type_nid, event_state_key_nid ASC"
const bulkSelectStateAtEventByIDSQL = "" +
"SELECT event_type_nid, event_state_key_nid, event_nid, state_snapshot_nid FROM roomserver_events" +
" WHERE event_id IN ($1)"
" WHERE event_id IN ($1)" +
" ORDER BY event_type_nid, event_state_key_nid ASC"
const updateEventStateSQL = "" +
"UPDATE roomserver_events SET state_snapshot_nid = $1 WHERE event_nid = $2"
@ -101,7 +94,6 @@ type eventStatements struct {
db *sql.DB
insertEventStmt *sql.Stmt
selectEventStmt *sql.Stmt
bulkSelectStateEventByIDStmt *sql.Stmt
bulkSelectStateAtEventByIDStmt *sql.Stmt
updateEventStateStmt *sql.Stmt
selectEventSentToOutputStmt *sql.Stmt
@ -126,7 +118,6 @@ func NewSqliteEventsTable(db *sql.DB) (tables.Events, error) {
return s, shared.StatementList{
{&s.insertEventStmt, insertEventSQL},
{&s.selectEventStmt, selectEventSQL},
{&s.bulkSelectStateEventByIDStmt, bulkSelectStateEventByIDSQL},
{&s.bulkSelectStateAtEventByIDStmt, bulkSelectStateAtEventByIDSQL},
{&s.updateEventStateStmt, updateEventStateSQL},
{&s.updateEventSentToOutputStmt, updateEventSentToOutputSQL},
@ -179,57 +170,6 @@ func (s *eventStatements) SelectEvent(
return types.EventNID(eventNID), types.StateSnapshotNID(stateNID), err
}
// bulkSelectStateEventByID lookups a list of state events by event ID.
// If any of the requested events are missing from the database it returns a types.MissingEventError
func (s *eventStatements) BulkSelectStateEventByID(
ctx context.Context, eventIDs []string,
) ([]types.StateEntry, error) {
///////////////
iEventIDs := make([]interface{}, len(eventIDs))
for k, v := range eventIDs {
iEventIDs[k] = v
}
selectOrig := strings.Replace(bulkSelectStateEventByIDSQL, "($1)", sqlutil.QueryVariadic(len(iEventIDs)), 1)
selectStmt, err := s.db.Prepare(selectOrig)
if err != nil {
return nil, err
}
///////////////
rows, err := selectStmt.QueryContext(ctx, iEventIDs...)
if err != nil {
return nil, err
}
defer internal.CloseAndLogIfError(ctx, rows, "bulkSelectStateEventByID: rows.close() failed")
// We know that we will only get as many results as event IDs
// because of the unique constraint on event IDs.
// So we can allocate an array of the correct size now.
// We might get fewer results than IDs so we adjust the length of the slice before returning it.
results := make([]types.StateEntry, len(eventIDs))
i := 0
for ; rows.Next(); i++ {
result := &results[i]
if err = rows.Scan(
&result.EventTypeNID,
&result.EventStateKeyNID,
&result.EventNID,
); err != nil {
return nil, err
}
}
if i != len(eventIDs) {
// If there are fewer rows returned than IDs then we were asked to lookup event IDs we don't have.
// We don't know which ones were missing because we don't return the string IDs in the query.
// However it should be possible debug this by replaying queries or entries from the input kafka logs.
// If this turns out to be impossible and we do need the debug information here, it would be better
// to do it as a separate query rather than slowing down/complicating the internal case.
return nil, types.MissingEventError(
fmt.Sprintf("storage: state event IDs missing from the database (%d != %d)", i, len(eventIDs)),
)
}
return results, err
}
// bulkSelectStateAtEventByID lookups the state at a list of events by event ID.
// If any of the requested events are missing from the database it returns a types.MissingEventError.
// If we do not have the state for any of the requested events it returns a types.MissingEventError.