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Diffstat (limited to '')
-rw-r--r-- | wsp.go | 85 |
1 files changed, 85 insertions, 0 deletions
@@ -0,0 +1,85 @@ +/* + * WebSocket-based protocol auxiliary functions + * + * Copyright (C) 2024 Runxi Yu <https://runxiyu.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 <https://www.gnu.org/licenses/>. + */ + +package main + +import ( + "context" + "fmt" + + "github.com/coder/websocket" +) + +/* + * Split an IRC-style message of type []byte into type []string where each + * element is a complete argument. Generally, arguments are separated by + * spaces, and an argument that begins with a ':' causes the rest of the + * line to be treated as a single argument. + */ +func splitMsg(b *[]byte) []string { + mar := make([]string, 0, config.Perf.MessageArgumentsCap) + elem := make([]byte, 0, config.Perf.MessageBytesCap) + for i, c := range *b { + switch c { + case ' ': + if (*b)[i+1] == ':' { + mar = append(mar, string(elem)) + mar = append(mar, string((*b)[i+2:])) + goto endl + } + mar = append(mar, string(elem)) + elem = make([]byte, 0, config.Perf.MessageBytesCap) + default: + elem = append(elem, c) + } + } + mar = append(mar, string(elem)) +endl: + return mar +} + +func baseReportError(ctx context.Context, conn *websocket.Conn, e string) error { + err := writeText(ctx, conn, "E :"+e) + if err != nil { + return fmt.Errorf("error reporting protocol violation: %w", err) + } + err = conn.Close(websocket.StatusProtocolError, e) + if err != nil { + return fmt.Errorf("error closing websocket: %w", err) + } + return nil +} + +type reportErrorT func(e string) error + +func makeReportError(ctx context.Context, conn *websocket.Conn) reportErrorT { + return func(e string) error { + return baseReportError(ctx, conn, e) + } +} + +func propagateSelectedUpdate(courseID int) { + course := courses[courseID] + course.UsemsLock.RLock() + defer course.UsemsLock.RUnlock() + for _, usem := range course.Usems { + usem.set() + } +} |