/
18_api_versions.go
81 lines (68 loc) · 2.2 KB
/
18_api_versions.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
package kfake
import (
"fmt"
"sort"
"sync"
"github.com/twmb/franz-go/pkg/kmsg"
)
func init() { regKey(18, 0, 3) }
func (c *Cluster) handleApiVersions(kreq kmsg.Request) (kmsg.Response, error) {
req := kreq.(*kmsg.ApiVersionsRequest)
resp := req.ResponseKind().(*kmsg.ApiVersionsResponse)
if resp.Version > 3 {
resp.Version = 0 // downgrades to 0 if the version is unknown
}
if err := checkReqVersion(req.Key(), req.Version); err != nil {
return nil, err
}
// If we are handling ApiVersions, our package is initialized and we
// build our response once.
apiVersionsOnce.Do(func() {
for _, v := range apiVersionsKeys {
apiVersionsSorted = append(apiVersionsSorted, v)
}
sort.Slice(apiVersionsSorted, func(i, j int) bool {
return apiVersionsSorted[i].ApiKey < apiVersionsSorted[j].ApiKey
})
})
resp.ApiKeys = apiVersionsSorted
return resp, nil
}
// Called at the beginning of every request, this validates that the client
// is sending requests within version ranges we can handle.
func checkReqVersion(key, version int16) error {
v, exists := apiVersionsKeys[key]
if !exists {
return fmt.Errorf("unsupported request key %d", key)
}
if version < v.MinVersion {
return fmt.Errorf("%s version %d below min supported version %d", kmsg.NameForKey(key), version, v.MinVersion)
}
if version > v.MaxVersion {
return fmt.Errorf("%s version %d above max supported version %d", kmsg.NameForKey(key), version, v.MaxVersion)
}
return nil
}
var (
apiVersionsMu sync.Mutex
apiVersionsKeys = make(map[int16]kmsg.ApiVersionsResponseApiKey)
apiVersionsOnce sync.Once
apiVersionsSorted []kmsg.ApiVersionsResponseApiKey
)
// Every request we implement calls regKey in an init function, allowing us to
// fully correctly build our ApiVersions response.
func regKey(key, min, max int16) {
apiVersionsMu.Lock()
defer apiVersionsMu.Unlock()
if key < 0 || min < 0 || max < 0 || max < min {
panic(fmt.Sprintf("invalid registration, key: %d, min: %d, max: %d", key, min, max))
}
if _, exists := apiVersionsKeys[key]; exists {
panic(fmt.Sprintf("doubly registered key %d", key))
}
apiVersionsKeys[key] = kmsg.ApiVersionsResponseApiKey{
ApiKey: key,
MinVersion: min,
MaxVersion: max,
}
}