// Scan implements part of the graphstore.Service interface.
//
// TODO(fromberger): Maybe use prepared statements here.
func (db *DB) Scan(ctx context.Context, req *spb.ScanRequest, f graphstore.EntryFunc) (err error) {
var rows *sql.Rows
factPrefix := likeEscaper.Replace(req.FactPrefix) + "%"
if req.GetTarget() != nil {
if req.EdgeKind == "" {
rows, err = db.Query("SELECT "+columns+" FROM "+tableName+` WHERE fact LIKE ? ESCAPE '\t' AND source_signature = ? AND source_corpus = ? AND source_root = ? AND source_language = ? AND source_path = ? `+orderByClause, factPrefix, req.Target.Signature, req.Target.Corpus, req.Target.Root, req.Target.Language, req.Target.Path)
} else {
rows, err = db.Query("SELECT "+columns+" FROM "+tableName+` WHERE fact LIKE ? ESCAPE '\t' AND source_signature = ? AND source_corpus = ? AND source_root = ? AND source_language = ? AND source_path = ? AND kind = ? `+orderByClause, factPrefix, req.Target.Signature, req.Target.Corpus, req.Target.Root, req.Target.Language, req.Target.Path, req.EdgeKind)
}
} else {
if req.EdgeKind == "" {
rows, err = db.Query("SELECT "+columns+" FROM "+tableName+" WHERE fact LIKE ? ESCAPE '\t' "+orderByClause, factPrefix)
} else {
rows, err = db.Query("SELECT "+columns+" FROM "+tableName+` WHERE fact LIKE ? ESCAPE '\t' AND kind = ? `+orderByClause, factPrefix, req.EdgeKind)
}
}
if err != nil {
return err
}
return scanEntries(rows, f)
}
// EntryMatchesScan reports whether entry belongs in the result set for req.
func EntryMatchesScan(req *spb.ScanRequest, entry *spb.Entry) bool {
return (req.GetTarget() == nil || compare.VNamesEqual(entry.Target, req.Target)) &&
(req.EdgeKind == "" || entry.EdgeKind == req.EdgeKind) &&
strings.HasPrefix(entry.FactName, req.FactPrefix)
}
