Monorepo for Tangled
tangled.org
appview/knotcompat: knot capability detection
Lewis: May this revision serve well! <lewis@tangled.org>
author
Lewis
committer
Tangled
date
(Jun 8, 2026, 4:18 PM +0300)
commit
db265537
db265537f1c013cebc36530a82bdb726cb1bec53
parent
d588ea08
d588ea08ca844226b162eb5fc49519fc7ba06ebd
change-id
xvnlplur
xvnlplurrmtryuxrkpnznmooksslrrlo
+232
-97
+1
-1
appview/compat113/compat.go
appview/knotcompat/compat.go
+1
-1
appview/compat113/compat.go
appview/knotcompat/compat.go
+1
-1
appview/compat113/compat_test.go
appview/knotcompat/compat_test.go
+1
-1
appview/compat113/compat_test.go
appview/knotcompat/compat_test.go
-60
appview/compat113/version.go
-60
appview/compat113/version.go
···
1
-
package compat113
2
-
3
-
import (
4
-
"context"
5
-
"fmt"
6
-
"net/http"
7
-
"strconv"
8
-
"strings"
9
-
"time"
10
-
11
-
indigoxrpc "github.com/bluesky-social/indigo/xrpc"
12
-
"tangled.org/core/api/tangled"
13
-
)
14
-
15
-
const versionProbeTimeout = 5 * time.Second
16
-
17
-
func KnotSupports114(ctx context.Context, host string, dev bool) bool {
18
-
scheme := "https"
19
-
if dev {
20
-
scheme = "http"
21
-
}
22
-
client := &indigoxrpc.Client{
23
-
Host: fmt.Sprintf("%s://%s", scheme, host),
24
-
Client: &http.Client{Timeout: versionProbeTimeout},
25
-
}
26
-
27
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ctx, cancel := context.WithTimeout(ctx, versionProbeTimeout)
28
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defer cancel()
29
-
30
-
resp, err := tangled.KnotVersion(ctx, client)
31
-
if err != nil || resp == nil {
32
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return true
33
-
}
34
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return atLeast114(resp.Version)
35
-
}
36
-
37
-
func atLeast114(v string) bool {
38
-
v = strings.TrimSpace(v)
39
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v = strings.TrimPrefix(v, "v")
40
-
if strings.HasPrefix(v, "(devel)") {
41
-
return true
42
-
}
43
-
if v == "" {
44
-
return false
45
-
}
46
-
parts := strings.SplitN(v, ".", 3)
47
-
if len(parts) < 2 {
48
-
return false
49
-
}
50
-
major, err := strconv.Atoi(parts[0])
51
-
if err != nil {
52
-
return false
53
-
}
54
-
minorRaw := strings.SplitN(parts[1], "-", 2)[0]
55
-
minor, err := strconv.Atoi(minorRaw)
56
-
if err != nil {
57
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return false
58
-
}
59
-
return major > 1 || (major == 1 && minor >= 14)
60
-
}
-35
appview/compat113/version_test.go
-35
appview/compat113/version_test.go
···
1
-
package compat113
2
-
3
-
import "testing"
4
-
5
-
func TestAtLeast114(t *testing.T) {
6
-
cases := []struct {
7
-
in string
8
-
want bool
9
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}{
10
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{"v1.14.0", true},
11
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{"v1.14.0-alpha", true},
12
-
{"v1.14.5", true},
13
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{"v1.13.0", false},
14
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{"v1.13.0-alpha", false},
15
-
{"v1.0.0", false},
16
-
{"v2.0.0", true},
17
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{"1.14.0", true},
18
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{"1.13.99", false},
19
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{"(devel)", true},
20
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{"", false},
21
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{"garbagio-furioso", false},
22
-
{"v1", false},
23
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{"vX.Y.Z", false},
24
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{"unknown", false},
25
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{"unknown-abc1234", false},
26
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{"unknown-abc1234-modified", false},
27
-
}
28
-
for _, c := range cases {
29
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t.Run(c.in, func(t *testing.T) {
30
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if got := atLeast114(c.in); got != c.want {
31
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t.Errorf("atLeast114(%q) = %v, want %v", c.in, got, c.want)
32
-
}
33
-
})
34
-
}
35
-
}
+230
appview/knotcompat/version.go
+230
appview/knotcompat/version.go
···
1
+
package knotcompat
2
+
3
+
import (
4
+
"context"
5
+
"fmt"
6
+
"net/http"
7
+
"slices"
8
+
"strconv"
9
+
"strings"
10
+
"sync"
11
+
"sync/atomic"
12
+
"time"
13
+
14
+
indigoxrpc "github.com/bluesky-social/indigo/xrpc"
15
+
"tangled.org/core/api/tangled"
16
+
"tangled.org/core/consts"
17
+
)
18
+
19
+
const (
20
+
versionProbeTimeout = 5 * time.Second
21
+
versionProbeFresh = 5 * time.Minute
22
+
versionProbeTrust = time.Hour
23
+
versionProbeCacheMax = 4096
24
+
)
25
+
26
+
type versionProbeEntry struct {
27
+
version string
28
+
probedAt time.Time
29
+
}
30
+
31
+
type versionProbeCache struct {
32
+
mu sync.Mutex
33
+
entries map[string]versionProbeEntry
34
+
}
35
+
36
+
func (c *versionProbeCache) get(host string) (versionProbeEntry, bool) {
37
+
c.mu.Lock()
38
+
defer c.mu.Unlock()
39
+
e, ok := c.entries[host]
40
+
return e, ok
41
+
}
42
+
43
+
func (c *versionProbeCache) put(host, version string, at time.Time) {
44
+
c.mu.Lock()
45
+
defer c.mu.Unlock()
46
+
if _, exists := c.entries[host]; !exists && len(c.entries) >= versionProbeCacheMax {
47
+
c.evictLocked(at)
48
+
}
49
+
c.entries[host] = versionProbeEntry{version: version, probedAt: at}
50
+
}
51
+
52
+
func (c *versionProbeCache) evictLocked(now time.Time) {
53
+
oldestHost := ""
54
+
var oldestAt time.Time
55
+
for h, e := range c.entries {
56
+
if now.Sub(e.probedAt) >= versionProbeTrust {
57
+
delete(c.entries, h)
58
+
continue
59
+
}
60
+
if oldestHost == "" || e.probedAt.Before(oldestAt) {
61
+
oldestHost, oldestAt = h, e.probedAt
62
+
}
63
+
}
64
+
if len(c.entries) >= versionProbeCacheMax && oldestHost != "" {
65
+
delete(c.entries, oldestHost)
66
+
}
67
+
}
68
+
69
+
func (c *versionProbeCache) supports(now time.Time, host string, minMajor, minMinor int, failOpen bool, probe func() (string, bool)) bool {
70
+
if e, ok := c.get(host); ok && now.Sub(e.probedAt) < versionProbeFresh {
71
+
return atLeast(e.version, minMajor, minMinor)
72
+
}
73
+
if version, ok := probe(); ok {
74
+
c.put(host, version, now)
75
+
return atLeast(version, minMajor, minMinor)
76
+
}
77
+
if e, ok := c.get(host); ok && now.Sub(e.probedAt) < versionProbeTrust {
78
+
return atLeast(e.version, minMajor, minMinor)
79
+
}
80
+
return failOpen
81
+
}
82
+
83
+
var probeCache = &versionProbeCache{entries: map[string]versionProbeEntry{}}
84
+
85
+
type NativeLatch interface {
86
+
IsNative(host string) bool
87
+
MarkNative(host string)
88
+
}
89
+
90
+
type latchBox struct{ l NativeLatch }
91
+
92
+
type nativeGate struct {
93
+
memo sync.Map
94
+
negMemo sync.Map
95
+
latch atomic.Pointer[latchBox]
96
+
useOnce sync.Once
97
+
now func() time.Time
98
+
}
99
+
100
+
func (g *nativeGate) clock() time.Time {
101
+
if g.now != nil {
102
+
return g.now()
103
+
}
104
+
return time.Now()
105
+
}
106
+
107
+
func (g *nativeGate) use(l NativeLatch) {
108
+
g.useOnce.Do(func() {
109
+
g.latch.Store(&latchBox{l: l})
110
+
})
111
+
}
112
+
113
+
func (g *nativeGate) currentLatch() NativeLatch {
114
+
if b := g.latch.Load(); b != nil {
115
+
return b.l
116
+
}
117
+
return nil
118
+
}
119
+
120
+
func (g *nativeGate) isNative(host string, probe func() bool) bool {
121
+
if _, ok := g.memo.Load(host); ok {
122
+
return true
123
+
}
124
+
if until, ok := g.negMemo.Load(host); ok {
125
+
if g.clock().Before(until.(time.Time)) {
126
+
return false
127
+
}
128
+
g.negMemo.Delete(host)
129
+
}
130
+
if l := g.currentLatch(); l != nil && l.IsNative(host) {
131
+
g.memo.Store(host, struct{}{})
132
+
return true
133
+
}
134
+
if !probe() {
135
+
g.negMemo.Store(host, g.clock().Add(versionProbeFresh))
136
+
return false
137
+
}
138
+
g.memo.Store(host, struct{}{})
139
+
if l := g.currentLatch(); l != nil {
140
+
l.MarkNative(host)
141
+
}
142
+
return true
143
+
}
144
+
145
+
var nativeProbeGate = &nativeGate{}
146
+
147
+
func UseNativeLatch(l NativeLatch) {
148
+
nativeProbeGate.use(l)
149
+
}
150
+
151
+
func KnotSupports114(ctx context.Context, host string, dev bool) bool {
152
+
return knotSupportsVersion(ctx, host, dev, 1, 14, true)
153
+
}
154
+
155
+
func KnotHasCapability(ctx context.Context, host string, dev bool, capability consts.Capability) bool {
156
+
return nativeProbeGate.isNative(host, func() bool {
157
+
return knotDeclares(ctx, host, dev, capability)
158
+
})
159
+
}
160
+
161
+
func knotDeclares(ctx context.Context, host string, dev bool, capability consts.Capability) bool {
162
+
scheme := "https"
163
+
if dev {
164
+
scheme = "http"
165
+
}
166
+
client := &indigoxrpc.Client{
167
+
Host: fmt.Sprintf("%s://%s", scheme, host),
168
+
Client: &http.Client{Timeout: versionProbeTimeout},
169
+
}
170
+
171
+
ctx, cancel := context.WithTimeout(ctx, versionProbeTimeout)
172
+
defer cancel()
173
+
174
+
resp, err := tangled.KnotVersion(ctx, client)
175
+
if err != nil || resp == nil {
176
+
return false
177
+
}
178
+
return slices.Contains(resp.Capabilities, string(capability))
179
+
}
180
+
181
+
func knotSupportsVersion(ctx context.Context, host string, dev bool, minMajor, minMinor int, failOpen bool) bool {
182
+
return probeCache.supports(time.Now(), host, minMajor, minMinor, failOpen, func() (string, bool) {
183
+
return probeVersion(ctx, host, dev)
184
+
})
185
+
}
186
+
187
+
func probeVersion(ctx context.Context, host string, dev bool) (string, bool) {
188
+
scheme := "https"
189
+
if dev {
190
+
scheme = "http"
191
+
}
192
+
client := &indigoxrpc.Client{
193
+
Host: fmt.Sprintf("%s://%s", scheme, host),
194
+
Client: &http.Client{Timeout: versionProbeTimeout},
195
+
}
196
+
197
+
ctx, cancel := context.WithTimeout(ctx, versionProbeTimeout)
198
+
defer cancel()
199
+
200
+
resp, err := tangled.KnotVersion(ctx, client)
201
+
if err != nil || resp == nil {
202
+
return "", false
203
+
}
204
+
return resp.Version, true
205
+
}
206
+
207
+
func atLeast(v string, minMajor, minMinor int) bool {
208
+
v = strings.TrimSpace(v)
209
+
v = strings.TrimPrefix(v, "v")
210
+
if strings.HasPrefix(v, "(devel)") {
211
+
return true
212
+
}
213
+
if v == "" {
214
+
return false
215
+
}
216
+
parts := strings.SplitN(v, ".", 3)
217
+
if len(parts) < 2 {
218
+
return false
219
+
}
220
+
major, err := strconv.Atoi(parts[0])
221
+
if err != nil {
222
+
return false
223
+
}
224
+
minorRaw := strings.SplitN(parts[1], "-", 2)[0]
225
+
minor, err := strconv.Atoi(minorRaw)
226
+
if err != nil {
227
+
return false
228
+
}
229
+
return major > minMajor || (major == minMajor && minor >= minMinor)
230
+
}