func (s *preallocSuite) TestPreallocFilesWriteErrors(c *gc.C) {
dir := c.MkDir()
prefix := filepath.Join(dir, "test.")
err := ioutil.WriteFile(prefix+"0", nil, 0644)
c.Assert(err, gc.IsNil)
err = ioutil.WriteFile(prefix+"1", nil, 0644)
c.Assert(err, gc.IsNil)
var called int
s.PatchValue(mongo.PreallocFile, func(filename string, size int) (bool, error) {
var created bool
var err error
called++
if called == 2 {
created = true
err = fmt.Errorf("failed to zero test.1")
}
return created, err
})
err = mongo.PreallocFiles(prefix, 4096, 8192)
c.Assert(err, gc.ErrorMatches, "failed to zero test.1")
// test.0 still exists because we said we didn't
// create it (i.e. it already existed)
_, err = os.Stat(prefix + "0")
c.Assert(err, gc.IsNil)
// test.1 no longer exists because we said we created
// it, but then failed to write to it.
_, err = os.Stat(prefix + "1")
c.Assert(err, jc.Satisfies, os.IsNotExist)
}
func (s *preallocSuite) TestPreallocFiles(c *gc.C) {
dir := c.MkDir()
prefix := filepath.Join(dir, "test.")
err := mongo.PreallocFiles(prefix, 0, 4096, 8192)
c.Assert(err, gc.IsNil)
zeroes := [8192]byte{}
for i := 0; i < 3; i++ {
filename := fmt.Sprintf("%s%d", prefix, i)
data, err := ioutil.ReadFile(filename)
c.Check(err, gc.IsNil)
c.Check(data, gc.DeepEquals, zeroes[:i*4096])
}
_, err = os.Stat(prefix + "3")
c.Assert(err, jc.Satisfies, os.IsNotExist)
}
func (s *preallocSuite) TestPreallocFilesErrors(c *gc.C) {
err := mongo.PreallocFiles("", 123)
c.Assert(err, gc.ErrorMatches, `specified size 123 for file "0" is not a multiple of 4096`)
}