gotosocial/internal/db/bundb/util.go

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// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package bundb
import (
"strings"
"github.com/superseriousbusiness/gotosocial/internal/db"
"github.com/uptrace/bun"
)
// likeEscaper is a thread-safe string replacer which escapes
// common SQLite + Postgres `LIKE` wildcard chars using the
// escape character `\`. Initialized as a var in this package
// so it can be reused.
var likeEscaper = strings.NewReplacer(
`\`, `\\`, // Escape char.
`%`, `\%`, // Zero or more char.
`_`, `\_`, // Exactly one char.
)
// whereSubqueryLike appends a WHERE clause to the
// given SelectQuery, which searches for matches
// of `search` in the given subQuery using LIKE.
func whereLike(
query *bun.SelectQuery,
subject interface{},
search string,
) *bun.SelectQuery {
// Escape existing wildcard + escape
// chars in the search query string.
search = likeEscaper.Replace(search)
// Add our own wildcards back in; search
// zero or more chars around the query.
search = `%` + search + `%`
// Append resulting WHERE
// clause to the main query.
return query.Where(
"(?) LIKE ? ESCAPE ?",
subject, search, `\`,
)
}
// updateWhere parses []db.Where and adds it to the given update query.
func updateWhere(q *bun.UpdateQuery, where []db.Where) {
for _, w := range where {
query, args := parseWhere(w)
q = q.Where(query, args...)
}
}
// selectWhere parses []db.Where and adds it to the given select query.
func selectWhere(q *bun.SelectQuery, where []db.Where) {
for _, w := range where {
query, args := parseWhere(w)
q = q.Where(query, args...)
}
}
// deleteWhere parses []db.Where and adds it to the given where query.
func deleteWhere(q *bun.DeleteQuery, where []db.Where) {
for _, w := range where {
query, args := parseWhere(w)
q = q.Where(query, args...)
}
}
// parseWhere looks through the options on a single db.Where entry, and
// returns the appropriate query string and arguments.
func parseWhere(w db.Where) (query string, args []interface{}) {
if w.Not {
if w.Value == nil {
query = "? IS NOT NULL"
args = []interface{}{bun.Ident(w.Key)}
return
}
query = "? != ?"
args = []interface{}{bun.Ident(w.Key), w.Value}
return
}
if w.Value == nil {
query = "? IS NULL"
args = []interface{}{bun.Ident(w.Key)}
return
}
query = "? = ?"
args = []interface{}{bun.Ident(w.Key), w.Value}
return
}