/
z_eval.go
99 lines (85 loc) · 2.74 KB
/
z_eval.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
/*
* Copyright (c) 2017, 2020 ADLINK Technology Inc.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License 2.0 which is available at
* http://www.eclipse.org/legal/epl-2.0, or the Apache License, Version 2.0
* which is available at https://www.apache.org/licenses/LICENSE-2.0.
*
* SPDX-License-Identifier: EPL-2.0 OR Apache-2.0
*
* Contributors:
* ADLINK zenoh team, <zenoh@adlink-labs.tech>
*/
package main
import (
"fmt"
"os"
"github.com/alexflint/go-arg"
"github.com/eclipse-zenoh/zenoh-go"
)
func main() {
// --- Command line argument parsing --- --- --- --- --- ---
var args struct {
Path string `default:"/zenoh/examples/go/eval" arg:"-p" help:"the path representing the URI"`
Locator string `arg:"-l" help:"The locator to be used to boostrap the zenoh session. By default dynamic discovery is used"`
}
arg.MustParse(&args)
// zenoh-net code --- --- --- --- --- --- --- --- --- --- ---
p, err := zenoh.NewPath(args.Path)
if err != nil {
panic(err.Error())
}
fmt.Println("Login to Zenoh...")
y, err := zenoh.Login(&args.Locator, nil)
if err != nil {
panic(err.Error())
}
fmt.Println("Use Workspace on '/'")
root, _ := zenoh.NewPath("/")
w := y.WorkspaceWithExecutor(root)
fmt.Println("Register eval " + p.ToString())
err = w.RegisterEval(p,
func(path *zenoh.Path, props zenoh.Properties) zenoh.Value {
// In this Eval function, we choosed to get the name to be returned in the StringValue in 3 possible ways,
// depending the properties specified in the selector. For example, with the following selectors:
// - "/demo/example/zenoh-go-eval" : no properties are set, a default value is used for the name
// - "/demo/example/zenoh-go-eval?(name=Bob)" : "Bob" is used for the name
// - "/demo/example/zenoh-go-eval?(name=/demo/example/name)" :
// the Eval function does a GET on "/demo/example/name" an uses the 1st result for the name
fmt.Printf(">> Processing eval for path %s with properties: %s\n", path, props)
name := props["name"]
if name == "" {
name = "Zenoh Go!"
}
if name[0] == '/' {
fmt.Printf(" >> Get name to use from Zenoh at path: %s\n", name)
s, err := zenoh.NewSelector(name)
if err == nil {
kvs := w.Get(s)
if len(kvs) > 0 {
name = kvs[0].Value().ToString()
}
}
}
fmt.Printf(" >> Returning string: \"Eval from %s\"\n", name)
return zenoh.NewStringValue("Eval from " + name)
})
if err != nil {
panic(err.Error())
}
fmt.Println("Enter 'q' to quit...")
fmt.Println()
var b = make([]byte, 1)
for b[0] != 'q' {
os.Stdin.Read(b)
}
w.UnregisterEval(p)
if err != nil {
panic(err.Error())
}
err = y.Logout()
if err != nil {
panic(err.Error())
}
}