Changeset 350 in code for trunk/irc.go

Timestamp:

Jul 6, 2020, 9:06:20 AM (5 years ago)

Author:

contact

Message:

Sort and split JOIN messages

Sort channels so that channels with a key appear first. Split JOIN
messages so that we don't reach the message size limit.

File:

• trunk/irc.go (modified) (3 diffs)

trunk/irc.go

@@ -3 +3 @@
 import (
         "fmt"
+        "sort"
         "strings"
 
@@ -18 +19 @@
 
 const maxMessageLength = 512
+
+// The server-time layout, as defined in the IRCv3 spec.
+const serverTimeLayout = "2006-01-02T15:04:05.000Z"
 
 type userModes string
@@ -294 +298 @@
 }
 
-// The server-time layout, as defined in the IRCv3 spec.
-const serverTimeLayout = "2006-01-02T15:04:05.000Z"
+func join(channels, keys []string) []*irc.Message {
+        // Put channels with a key first
+        js := joinSorter{channels, keys}
+        sort.Sort(&js)
+
+        // Two spaces because there are three words (JOIN, channels and keys)
+        maxLength := maxMessageLength - (len("JOIN") + 2)
+
+        var msgs []*irc.Message
+        var channelsBuf, keysBuf strings.Builder
+        for i, channel := range channels {
+                key := keys[i]
+
+                n := channelsBuf.Len() + keysBuf.Len() + 1 + len(channel)
+                if key != "" {
+                        n += 1 + len(key)
+                }
+
+                if channelsBuf.Len() > 0 && n > maxLength {
+                        // No room for the new channel in this message
+                        params := []string{channelsBuf.String()}
+                        if keysBuf.Len() > 0 {
+                                params = append(params, keysBuf.String())
+                        }
+                        msgs = append(msgs, &irc.Message{Command: "JOIN", Params: params})
+                        channelsBuf.Reset()
+                        keysBuf.Reset()
+                }
+
+                if channelsBuf.Len() > 0 {
+                        channelsBuf.WriteByte(',')
+                }
+                channelsBuf.WriteString(channel)
+                if key != "" {
+                        if keysBuf.Len() > 0 {
+                                keysBuf.WriteByte(',')
+                        }
+                        keysBuf.WriteString(key)
+                }
+        }
+        if channelsBuf.Len() > 0 {
+                params := []string{channelsBuf.String()}
+                if keysBuf.Len() > 0 {
+                        params = append(params, keysBuf.String())
+                }
+                msgs = append(msgs, &irc.Message{Command: "JOIN", Params: params})
+        }
+
+        return msgs
+}
+
+type joinSorter struct {
+        channels []string
+        keys     []string
+}
+
+func (js *joinSorter) Len() int {
+        return len(js.channels)
+}
+
+func (js *joinSorter) Less(i, j int) bool {
+        if (js.keys[i] != "") != (js.keys[j] != "") {
+                // Only one of the channels has a key
+                return js.keys[i] != ""
+        }
+        return js.channels[i] < js.channels[j]
+}
+
+func (js *joinSorter) Swap(i, j int) {
+        js.channels[i], js.channels[j] = js.channels[j], js.channels[i]
+        js.keys[i], js.keys[j] = js.keys[j], js.keys[i]
+}