mount: able to write to any part of a file

weed/filesys/dirty_page_interval_test.go

@@ -5,7 +5,7 @@ import (
 	"testing"
 )
 
-func TestContinuousIntervals_AddInterval(t *testing.T) {
+func TestContinuousIntervals_AddIntervalAppend(t *testing.T) {
 
 	c := &ContinuousIntervals{}
 
@@ -15,6 +15,38 @@ func TestContinuousIntervals_AddInterval(t *testing.T) {
 	c.AddInterval(getBytes(23, 4), 2)
 
 	expectedData(t, c, 0, 25, 25, 23, 23, 23, 23)
+
+}
+
+func TestContinuousIntervals_AddIntervalInnerOverwrite(t *testing.T) {
+
+	c := &ContinuousIntervals{}
+
+	// 25, 25, 25, 25, 25
+	c.AddInterval(getBytes(25, 5), 0)
+	//  _,  _, 23, 23
+	c.AddInterval(getBytes(23, 2), 2)
+
+	expectedData(t, c, 0, 25, 25, 23, 23, 25)
+
+}
+
+func TestContinuousIntervals_AddIntervalFullOverwrite(t *testing.T) {
+
+	c := &ContinuousIntervals{}
+
+	// 25,
+	c.AddInterval(getBytes(25, 1), 0)
+	//  _,  _,  _,  _, 23, 23
+	c.AddInterval(getBytes(23, 2), 4)
+	//  _,  _,  _, 24, 24, 24, 24
+	c.AddInterval(getBytes(24, 4), 3)
+
+	//  _,  22, 22
+	c.AddInterval(getBytes(22, 2), 1)
+
+	expectedData(t, c, 0, 25, 22, 22, 24, 24, 24, 24)
+
 }
 
 func expectedData(t *testing.T, c *ContinuousIntervals, offset int, data ...byte) {