-
Notifications
You must be signed in to change notification settings - Fork 0
/
responsebuffer.go
191 lines (161 loc) · 6.47 KB
/
responsebuffer.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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
// Copyright (c) 2016-2017 Daniel Oaks <daniel@danieloaks.net>
// released under the MIT license
package irc
import (
"runtime/debug"
"time"
"github.com/goshuirc/irc-go/ircmsg"
"github.com/oragono/oragono/irc/caps"
"github.com/oragono/oragono/irc/utils"
)
const (
// https://ircv3.net/specs/extensions/labeled-response.html
defaultBatchType = "draft/labeled-response"
)
// ResponseBuffer - put simply - buffers messages and then outputs them to a given client.
//
// Using a ResponseBuffer lets you really easily implement labeled-response, since the
// buffer will silently create a batch if required and label the outgoing messages as
// necessary (or leave it off and simply tag the outgoing message).
type ResponseBuffer struct {
Label string
batchID string
target *Client
messages []ircmsg.IrcMessage
finalized bool
}
// GetLabel returns the label from the given message.
func GetLabel(msg ircmsg.IrcMessage) string {
return msg.Tags[caps.LabelTagName].Value
}
// NewResponseBuffer returns a new ResponseBuffer.
func NewResponseBuffer(target *Client) *ResponseBuffer {
return &ResponseBuffer{
target: target,
}
}
// Add adds a standard new message to our queue.
func (rb *ResponseBuffer) Add(tags *map[string]ircmsg.TagValue, prefix string, command string, params ...string) {
if rb.finalized {
rb.target.server.logger.Error("internal", "message added to finalized ResponseBuffer, undefined behavior")
debug.PrintStack()
// TODO(dan): send a NOTICE to the end user with a string representation of the message,
// for debugging purposes
return
}
message := ircmsg.MakeMessage(tags, prefix, command, params...)
rb.messages = append(rb.messages, message)
}
// AddFromClient adds a new message from a specific client to our queue.
func (rb *ResponseBuffer) AddFromClient(msgid string, fromNickMask string, fromAccount string, tags *map[string]ircmsg.TagValue, command string, params ...string) {
// attach account-tag
if rb.target.capabilities.Has(caps.AccountTag) {
if fromAccount != "*" {
tags = ensureTag(tags, "account", fromAccount)
}
}
// attach message-id
if len(msgid) > 0 && rb.target.capabilities.Has(caps.MessageTags) {
tags = ensureTag(tags, "draft/msgid", msgid)
}
rb.Add(tags, fromNickMask, command, params...)
}
// AddSplitMessageFromClient adds a new split message from a specific client to our queue.
func (rb *ResponseBuffer) AddSplitMessageFromClient(msgid string, fromNickMask string, fromAccount string, tags *map[string]ircmsg.TagValue, command string, target string, message utils.SplitMessage) {
if rb.target.capabilities.Has(caps.MaxLine) || message.Wrapped == nil {
rb.AddFromClient(msgid, fromNickMask, fromAccount, tags, command, target, message.Original)
} else {
for _, str := range message.Wrapped {
rb.AddFromClient(msgid, fromNickMask, fromAccount, tags, command, target, str)
}
}
}
// InitializeBatch forcibly starts a batch of batch `batchType`.
// Normally, Send/Flush will decide automatically whether to start a batch
// of type draft/labeled-response. This allows changing the batch type
// and forcing the creation of a possibly empty batch.
func (rb *ResponseBuffer) InitializeBatch(batchType string, blocking bool) {
rb.sendBatchStart(batchType, blocking)
}
func (rb *ResponseBuffer) sendBatchStart(batchType string, blocking bool) {
if rb.batchID != "" {
// batch already initialized
return
}
// formerly this combined time.Now.UnixNano() in base 36 with an incrementing counter,
// also in base 36. but let's just use a uuidv4-alike (26 base32 characters):
rb.batchID = utils.GenerateSecretToken()
message := ircmsg.MakeMessage(nil, rb.target.server.name, "BATCH", "+"+rb.batchID, batchType)
if rb.Label != "" {
message.Tags[caps.LabelTagName] = ircmsg.MakeTagValue(rb.Label)
}
rb.target.SendRawMessage(message, blocking)
}
func (rb *ResponseBuffer) sendBatchEnd(blocking bool) {
if rb.batchID == "" {
// we are not sending a batch, skip this
return
}
message := ircmsg.MakeMessage(nil, rb.target.server.name, "BATCH", "-"+rb.batchID)
rb.target.SendRawMessage(message, blocking)
}
// Send sends all messages in the buffer to the client.
// Afterwards, the buffer is in an undefined state and MUST NOT be used further.
// If `blocking` is true you MUST be sending to the client from its own goroutine.
func (rb *ResponseBuffer) Send(blocking bool) error {
return rb.flushInternal(true, blocking)
}
// Flush sends all messages in the buffer to the client.
// Afterwards, the buffer can still be used. Client code MUST subsequently call Send()
// to ensure that the final `BATCH -` message is sent.
// If `blocking` is true you MUST be sending to the client from its own goroutine.
func (rb *ResponseBuffer) Flush(blocking bool) error {
return rb.flushInternal(false, blocking)
}
// flushInternal sends the contents of the buffer, either blocking or nonblocking
// It sends the `BATCH +` message if the client supports it and it hasn't been sent already.
// If `final` is true, it also sends `BATCH -` (if necessary).
func (rb *ResponseBuffer) flushInternal(final bool, blocking bool) error {
if rb.finalized {
return nil
}
useLabel := rb.target.capabilities.Has(caps.LabeledResponse) && rb.Label != ""
// use a batch if we have a label, and we either currently have multiple messages,
// or we are doing a Flush() and we have to assume that there will be more messages
// in the future.
useBatch := useLabel && (len(rb.messages) > 1 || !final)
// if label but no batch, add label to first message
if useLabel && !useBatch && len(rb.messages) == 1 && rb.batchID == "" {
rb.messages[0].Tags[caps.LabelTagName] = ircmsg.MakeTagValue(rb.Label)
} else if useBatch {
rb.sendBatchStart(defaultBatchType, blocking)
}
// send each message out
for _, message := range rb.messages {
// attach server-time if needed
if rb.target.capabilities.Has(caps.ServerTime) {
if !message.Tags["time"].HasValue {
t := time.Now().UTC().Format(IRCv3TimestampFormat)
message.Tags["time"] = ircmsg.MakeTagValue(t)
}
}
// attach batch ID
if rb.batchID != "" {
message.Tags["batch"] = ircmsg.MakeTagValue(rb.batchID)
}
// send message out
rb.target.SendRawMessage(message, blocking)
}
// end batch if required
if final {
rb.sendBatchEnd(blocking)
rb.finalized = true
}
// clear out any existing messages
rb.messages = rb.messages[:0]
return nil
}
// Notice sends the client the given notice from the server.
func (rb *ResponseBuffer) Notice(text string) {
rb.Add(nil, rb.target.server.name, "NOTICE", rb.target.nick, text)
}