forked from ava-labs/avalanchego
-
Notifications
You must be signed in to change notification settings - Fork 3
/
router.go
141 lines (116 loc) · 3.42 KB
/
router.go
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
// Copyright (C) 2019-2024, Ava Labs, Inc. All rights reserved.
// See the file LICENSE for licensing terms.
package server
import (
"errors"
"fmt"
"net/http"
"sync"
"github.com/gorilla/mux"
"github.com/MetalBlockchain/metalgo/utils/set"
)
var (
errUnknownBaseURL = errors.New("unknown base url")
errUnknownEndpoint = errors.New("unknown endpoint")
errAlreadyReserved = errors.New("route is either already aliased or already maps to a handle")
)
type router struct {
lock sync.RWMutex
router *mux.Router
routeLock sync.Mutex
reservedRoutes set.Set[string] // Reserves routes so that there can't be alias that conflict
aliases map[string][]string // Maps a route to a set of reserved routes
routes map[string]map[string]http.Handler // Maps routes to a handler
}
func newRouter() *router {
return &router{
router: mux.NewRouter(),
reservedRoutes: set.Set[string]{},
aliases: make(map[string][]string),
routes: make(map[string]map[string]http.Handler),
}
}
func (r *router) ServeHTTP(writer http.ResponseWriter, request *http.Request) {
r.lock.RLock()
defer r.lock.RUnlock()
r.router.ServeHTTP(writer, request)
}
func (r *router) GetHandler(base, endpoint string) (http.Handler, error) {
r.routeLock.Lock()
defer r.routeLock.Unlock()
urlBase, exists := r.routes[base]
if !exists {
return nil, errUnknownBaseURL
}
handler, exists := urlBase[endpoint]
if !exists {
return nil, errUnknownEndpoint
}
return handler, nil
}
func (r *router) AddRouter(base, endpoint string, handler http.Handler) error {
r.lock.Lock()
defer r.lock.Unlock()
r.routeLock.Lock()
defer r.routeLock.Unlock()
return r.addRouter(base, endpoint, handler)
}
func (r *router) addRouter(base, endpoint string, handler http.Handler) error {
if r.reservedRoutes.Contains(base) {
return fmt.Errorf("%w: %s", errAlreadyReserved, base)
}
return r.forceAddRouter(base, endpoint, handler)
}
func (r *router) forceAddRouter(base, endpoint string, handler http.Handler) error {
endpoints := r.routes[base]
if endpoints == nil {
endpoints = make(map[string]http.Handler)
}
url := base + endpoint
if _, exists := endpoints[endpoint]; exists {
return fmt.Errorf("failed to create endpoint as %s already exists", url)
}
endpoints[endpoint] = handler
r.routes[base] = endpoints
// Name routes based on their URL for easy retrieval in the future
route := r.router.Handle(url, handler)
if route == nil {
return fmt.Errorf("failed to create new route for %s", url)
}
route.Name(url)
var err error
if aliases, exists := r.aliases[base]; exists {
for _, alias := range aliases {
if innerErr := r.forceAddRouter(alias, endpoint, handler); err == nil {
err = innerErr
}
}
}
return err
}
func (r *router) AddAlias(base string, aliases ...string) error {
r.lock.Lock()
defer r.lock.Unlock()
r.routeLock.Lock()
defer r.routeLock.Unlock()
for _, alias := range aliases {
if r.reservedRoutes.Contains(alias) {
return fmt.Errorf("%w: %s", errAlreadyReserved, alias)
}
}
for _, alias := range aliases {
r.reservedRoutes.Add(alias)
}
r.aliases[base] = append(r.aliases[base], aliases...)
var err error
if endpoints, exists := r.routes[base]; exists {
for endpoint, handler := range endpoints {
for _, alias := range aliases {
if innerErr := r.forceAddRouter(alias, endpoint, handler); err == nil {
err = innerErr
}
}
}
}
return err
}