/
load_balance.go
84 lines (74 loc) · 2.18 KB
/
load_balance.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
/*
* Copyright (C) 2020-2022, IrineSistiana
*
* This file is part of mosdns.
*
* mosdns is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* mosdns 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
package executable_seq
import (
"context"
"fmt"
"github.com/IrineSistiana/mosdns/v4/pkg/query_context"
"go.uber.org/zap"
"strconv"
"sync/atomic"
)
type LBNode struct {
prev, next ExecutableChainNode
branchNode []ExecutableChainNode
p uint32
}
func (lbn *LBNode) Next() ExecutableChainNode {
return lbn.next
}
func (lbn *LBNode) LinkNext(n ExecutableChainNode) {
lbn.next = n
for _, branch := range lbn.branchNode {
LastNode(branch).LinkNext(n)
}
}
type LBConfig struct {
LoadBalance []interface{} `yaml:"load_balance"`
}
func ParseLBNode(
c *LBConfig,
logger *zap.Logger,
execs map[string]Executable,
matchers map[string]Matcher,
) (*LBNode, error) {
if logger == nil {
logger = zap.NewNop()
}
ps := make([]ExecutableChainNode, 0, len(c.LoadBalance))
for i, subSequence := range c.LoadBalance {
es, err := BuildExecutableLogicTree(subSequence, logger.Named("lb_seq_"+strconv.Itoa(i)), execs, matchers)
if err != nil {
return nil, fmt.Errorf("invalid load balance command #%d: %w", i, err)
}
ps = append(ps, es)
}
return &LBNode{branchNode: ps}, nil
}
func (lbn *LBNode) Exec(ctx context.Context, qCtx *query_context.Context, next ExecutableChainNode) error {
if len(lbn.branchNode) == 0 {
return ExecChainNode(ctx, qCtx, next)
}
nextIdx := atomic.AddUint32(&lbn.p, 1) % uint32(len(lbn.branchNode))
err := ExecChainNode(ctx, qCtx, lbn.branchNode[nextIdx])
if err != nil {
return fmt.Errorf("command sequence #%d: %w", nextIdx, err)
}
return nil
}