add split module

1 files changed, 57 insertions, 0 deletions

diff --git a/pkg/server/module/split.go b/pkg/server/module/split.go
new file mode 100644
index 0000000..138814f
--- /dev/null
+++ b/pkg/server/module/split.go
@@ -0,0 +1,57 @@
+package module
+
+import (
+	"errors"
+	"strconv"
+	"tunnel/pkg/server/env"
+	"tunnel/pkg/server/opts"
+	"tunnel/pkg/server/queue"
+)
+
+const splitDefaultSize = 1024
+
+var errBadSize = errors.New("bad size value")
+
+type splitModule struct {
+	size int
+}
+
+func (m *splitModule) Send(rq, wq queue.Q) error {
+	for b := range rq {
+		var upto int
+
+		for n := 0; n < len(b); n = upto {
+			upto += m.size
+
+			if upto > len(b) {
+				upto = len(b)
+			}
+
+			wq <- b[n:upto]
+		}
+	}
+
+	return nil
+}
+
+func (m *splitModule) Open(env.Env) (Pipe, Pipe) {
+	return m.Send, nil
+}
+
+func newSplitModule(opts opts.Opts, env env.Env) (module, error) {
+	size := splitDefaultSize
+
+	if s, ok := opts["size"]; ok {
+		var err error
+
+		if size, err = strconv.Atoi(s); err != nil || size <= 0 {
+			return nil, errBadSize
+		}
+	}
+
+	return &splitModule{size: size}, nil
+}
+
+func init() {
+	register("split", newSplitModule)
+}