.

wcfs/δbtail_test.go

@@ -20,9 +20,57 @@
 package main
 
 import (
+	"io"
+	"os"
+	"os/exec"
 	"testing"
+
+	"lab.nexedi.com/kirr/go123/xerr"
+	"lab.nexedi.com/kirr/neo/go/zodb"
 )
 
+// TreeGen represents connection to running `treegen trees`.
+//
+// Create it with StartTreeGen(zurl).
+// - Commit(treeTopology) ->
+type TreeGen struct {
+	zurl	  string
+	pysrv     *exec.Cmd      // spawned `treegen trees`
+	pyin      *io.PipeWriter // input to pysrv
+	pyout     *io.PipeReader // output from pysrv
+	treeRoot  zodb.Oid       // oid of the tree treegen works on
+}
+
+// StartTreeGen spawns `treegen trees` server.
+func StartTreeGen(zurl string) (_ *TreeGen, err error) {
+	defer xerr.Contextf(&err, "treegen %s: start", zurl)
+
+	tg := &TreeGen{zurl: zurl}
+	tg.pysrv = exec.Command("./testprog/treegen.py", "trees")
+	tg.pysrv.Stdin, tg.pyin   = io.Pipe()
+	tg.pyout, tg.pysrv.Stdout = io.Pipe()
+	tg.pysrv.Stderr = os.Stderr // no redirection
+
+	err = tg.pysrv.Start()
+	if err != nil {
+		return nil, err
+	}
+
+	// XXX wait for init message and set .treeRoot
+
+	return tg, nil
+}
+
+// Close shutdowns the generator.
+func (tg *TreeGen) Close() (err error) {
+	defer xerr.Contextf(&err, "treegen %s: close", tg.zurl)
+
+	err1 := tg.pyin.Close()
+	err2 := tg.pyout.Close()
+	err3 := tg.pysrv.Wait()
+	return xerr.Merge(err1, err2, err3)
+}
+
 // XXX
 func XXX(t *testing.T, tree1, tree2 string) {
 	// XXX commit tree1