Changeset 408 in code for trunk/logger.go

Timestamp:

Aug 20, 2020, 6:05:01 PM (5 years ago)

Author:

contact

Message:

Introduce loadHistoryLatestID

This loads latest messages from logs up to a given message ID. This is
similar to the IRCv3 CHATHISTORY LATEST command [1].

[1]: ​https://github.com/ircv3/ircv3-specifications/blob/0c271a5f1df4f93b5ae4c7597422821c40a8cfeb/extensions/chathistory.md#latest

File:

• trunk/logger.go (modified) (4 diffs)

trunk/logger.go

@@ -234 +234 @@
 }
 
-func parseMessagesBefore(network *network, entity string, ref time.Time, limit int) ([]*irc.Message, error) {
+func parseMessagesBefore(network *network, entity string, ref time.Time, limit int, afterOffset int64) ([]*irc.Message, error) {
         path := logPath(network, entity, ref)
         f, err := os.Open(path)
@@ -249 +249 @@
 
         sc := bufio.NewScanner(f)
+
+        if afterOffset >= 0 {
+                if _, err := f.Seek(afterOffset, io.SeekStart); err != nil {
+                        return nil, nil
+                }
+                sc.Scan() // skip till next newline
+        }
+
         for sc.Scan() {
                 msg, t, err := parseMessage(sc.Text(), entity, ref)
@@ -317 +325 @@
         tries := 0
         for remaining > 0 && tries < messageLoggerMaxTries {
-                buf, err := parseMessagesBefore(network, entity, t, remaining)
+                buf, err := parseMessagesBefore(network, entity, t, remaining, -1)
                 if err != nil {
                         return nil, err
@@ -357 +365 @@
         return history, nil
 }
+
+func truncateDay(t time.Time) time.Time {
+        year, month, day := t.Date()
+        return time.Date(year, month, day, 0, 0, 0, 0, t.Location())
+}
+
+func loadHistoryLatestID(network *network, entity, id string, limit int) ([]*irc.Message, error) {
+        var afterTime time.Time
+        var afterOffset int64
+        if id != "" {
+                var idNet, idEntity string
+                var err error
+                idNet, idEntity, afterTime, afterOffset, err = parseMsgID(id)
+                if err != nil {
+                        return nil, err
+                }
+                if idNet != network.GetName() || idEntity != entity {
+                        return nil, fmt.Errorf("cannot find message ID: message ID doesn't match network/entity")
+                }
+        }
+
+        history := make([]*irc.Message, limit)
+        t := time.Now()
+        remaining := limit
+        tries := 0
+        for remaining > 0 && tries < messageLoggerMaxTries && !truncateDay(t).Before(afterTime) {
+                var offset int64 = -1
+                if afterOffset >= 0 && truncateDay(t).Equal(afterTime) {
+                        offset = afterOffset
+                }
+
+                buf, err := parseMessagesBefore(network, entity, t, remaining, offset)
+                if err != nil {
+                        return nil, err
+                }
+                if len(buf) == 0 {
+                        tries++
+                } else {
+                        tries = 0
+                }
+                copy(history[remaining-len(buf):], buf)
+                remaining -= len(buf)
+                year, month, day := t.Date()
+                t = time.Date(year, month, day, 0, 0, 0, 0, t.Location()).Add(-1)
+        }
+
+        return history[remaining:], nil
+}