feat(benchmark): Allow mailboxes to be populated from directory

Use `-imap-mbox-file-dir` to load all `*.eml` from that directory to use
as input for the mailbox creation on all existing IMAP benches.

benchmarks/gluon_bench/flags/imap_benchmarks.go

@@ -8,4 +8,5 @@ var (
 	IMAPRandomSeqSetIntervals = flag.Bool("imap-random-seqset-intervals", false, "When set, generate random sequence intervals rather than single numbers.")
 	IMAPUIDMode               = flag.Bool("imap-uid-mode", false, "When set, will run benchmarks in UID mode if available.")
 	IMAPParallelClients       = flag.Uint("imap-parallel-clients", 1, "Set the number of clients to be run in parallel during the benchmark.")
+	IMAPMailboxMessageDir     = flag.String("imap-mbox-file-dir", "", "Folder path to load *.eml messages instead of builtin selection.")
 )

benchmarks/gluon_bench/imap_benchmarks/build_mailbox.go

@@ -1,20 +1,41 @@
 package imap_benchmarks
 
 import (
+	"fmt"
+	"github.com/ProtonMail/gluon/benchmarks/gluon_bench/flags"
 	"time"
 
 	"github.com/ProtonMail/gluon/benchmarks/gluon_bench/utils"
 	"github.com/emersion/go-imap/client"
-	"golang.org/x/exp/rand"
 )
 
 // BuildMailbox creates a mailbox of name `mailbox` and fills it up with `messageCount` random messages.
 func BuildMailbox(cl *client.Client, mailbox string, messageCount int) error {
-	messages := []string{utils.MessageAfterNoonMeeting, utils.MessageMultiPartMixed, utils.MessageEmbedded}
+	var messages []string
+
+	if len(*flags.IMAPMailboxMessageDir) != 0 {
+		msgs, err := utils.LoadEMLFilesFromDirectory(*flags.IMAPMailboxMessageDir)
+		if err != nil {
+			return err
+		}
+
+		if *flags.Verbose {
+			fmt.Printf("Loaded %v messages from '%v'\n", len(msgs), *flags.IMAPMailboxMessageDir)
+		}
+
+		messages = msgs
+	} else {
+		messages = []string{utils.MessageAfterNoonMeeting, utils.MessageMultiPartMixed, utils.MessageEmbedded}
+	}
+
+	return BuildMailboxWithMessages(cl, mailbox, messageCount, messages)
+}
+
+func BuildMailboxWithMessages(cl *client.Client, mailbox string, messageCount int, messages []string) error {
 	messagesLen := len(messages)
 
 	for i := 0; i < messageCount; i++ {
-		if err := AppendToMailbox(cl, mailbox, messages[rand.Intn(messagesLen)], time.Now()); err != nil {
+		if err := AppendToMailbox(cl, mailbox, messages[i%messagesLen], time.Now()); err != nil {
 			return err
 		}
 	}

benchmarks/gluon_bench/utils/utils.go

@@ -2,7 +2,10 @@ package utils
 
 import (
 	"bufio"
+	"io/fs"
 	"os"
+	"path/filepath"
+	"strings"
 )
 
 func ReadLinesFromFile(path string) ([]string, error) {
@@ -24,3 +27,36 @@ func ReadLinesFromFile(path string) ([]string, error) {
 
 	return lines, nil
 }
+
+func LoadFilesFromDirectory(path string, filter func(string, fs.FileInfo) bool) ([]string, error) {
+	var files []string
+
+	if err := filepath.Walk(path, func(path string, info fs.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if !filter(path, info) {
+			return nil
+		}
+
+		bytes, err := os.ReadFile(path)
+		if err != nil {
+			return err
+		}
+
+		files = append(files, string(bytes))
+
+		return nil
+	}); err != nil {
+		return nil, err
+	}
+
+	return files, nil
+}
+
+func LoadEMLFilesFromDirectory(path string) ([]string, error) {
+	return LoadFilesFromDirectory(path, func(s string, info fs.FileInfo) bool {
+		return !info.IsDir() && strings.HasSuffix(s, ".eml")
+	})
+}