Implemented new schema for charm revision handling in an

independent file in the Go port, including backwards
compatibility with the previous schema, and also SetVersion
methods that enable bundling and expanding charms with
custom revisions (necessary for store).

bundle.go

@@ -2,9 +2,11 @@ package charm
 
 import (
 	"archive/zip"
+	"fmt"
 	"io"
 	"os"
 	"path/filepath"
+	"strconv"
 	"strings"
 )
 
@@ -39,6 +41,7 @@ func readBundle(r io.ReaderAt, size int64) (bundle *Bundle, err os.Error) {
 	if err != nil {
 		return
 	}
+
 	reader, err := zipOpen(zipr, "metadata.yaml")
 	if err != nil {
 		return
@@ -48,6 +51,7 @@ func readBundle(r io.ReaderAt, size int64) (bundle *Bundle, err os.Error) {
 	if err != nil {
 		return
 	}
+
 	reader, err = zipOpen(zipr, "config.yaml")
 	if err != nil {
 		return
@@ -57,6 +61,19 @@ func readBundle(r io.ReaderAt, size int64) (bundle *Bundle, err os.Error) {
 	if err != nil {
 		return
 	}
+
+	reader, err = zipOpen(zipr, "revision")
+	if err != nil {
+		if _, ok := err.(noBundleFile); !ok {
+			return
+		}
+		b.revision = b.meta.OldRevision
+	} else {
+		_, err = fmt.Fscan(reader, &b.revision)
+		if err != nil {
+			return nil, os.NewError("invalid revision file")
+		}
+	}
 	return b, nil
 }
 
@@ -66,22 +83,44 @@ func zipOpen(zipr *zip.Reader, path string) (rc io.ReadCloser, err os.Error) {
 			return fh.Open()
 		}
 	}
-	return nil, errorf("bundle file not found: %s", path)
+	return nil, noBundleFile{path}
+}
+
+type noBundleFile struct {
+	path string
+}
+
+func (err noBundleFile) String() string {
+	return fmt.Sprintf("bundle file not found: %s", err.path)
 }
 
 // The Bundle type encapsulates access to data and operations
 // on a charm bundle.
 type Bundle struct {
-	Path   string // May be empty if Bundle wasn't read from a file
-	meta   *Meta
-	config *Config
-	r      io.ReaderAt
-	size   int64
+	Path     string // May be empty if Bundle wasn't read from a file
+	meta     *Meta
+	config   *Config
+	revision int
+	r        io.ReaderAt
+	size     int64
 }
 
 // Trick to ensure *Bundle implements the Charm interface.
 var _ Charm = (*Bundle)(nil)
 
+// Revision returns the revision number for the charm
+// expanded in dir.
+func (b *Bundle) Revision() int {
+	return b.revision
+}
+
+// SetRevision changes the charm revision number. This affects the
+// revision reported by Revision and the revision of the charm
+// directory created by ExpandTo.
+func (b *Bundle) SetRevision(revision int) {
+	b.revision = revision
+}
+
 // Meta returns the Meta representing the metadata.yaml file from bundle.
 func (b *Bundle) Meta() *Meta {
 	return b.meta
@@ -126,17 +165,32 @@ func (b *Bundle) ExpandTo(dir string) (err os.Error) {
 			lasterr = err
 		}
 	}
+
+	revFile, err := os.Create(filepath.Join(dir, "revision"))
+	if err != nil {
+		return err
+	}
+	_, err = revFile.Write([]byte(strconv.Itoa(b.revision)))
+	revFile.Close()
+	if err != nil {
+		return err
+	}
 	return lasterr
 }
 
 func (b *Bundle) expand(dir string, zfile *zip.File) os.Error {
+	cleanName := filepath.Clean(zfile.Name)
+	if cleanName == "revision" {
+		return nil
+	}
+
 	r, err := zfile.Open()
 	if err != nil {
 		return err
 	}
 	defer r.Close()
 
-	path := filepath.Join(dir, filepath.Clean(zfile.Name))
+	path := filepath.Join(dir, cleanName)
 	if strings.HasSuffix(zfile.Name, "/") {
 		err = os.MkdirAll(path, 0755)
 		if err != nil {

bundle_test.go

@@ -2,6 +2,8 @@ package charm_test
 
 import (
 	//"archive/zip"
+	"exec"
+	"fmt"
 	"io/ioutil"
 	. "launchpad.net/gocheck"
 	"launchpad.net/juju/go/charm"
@@ -19,13 +21,13 @@ func (s *BundleSuite) SetUpSuite(c *C) {
 	s.bundlePath = bundleDir(c, repoDir("dummy"))
 }
 
-func (s BundleSuite) TestReadBundle(c *C) {
+func (s *BundleSuite) TestReadBundle(c *C) {
 	bundle, err := charm.ReadBundle(s.bundlePath)
 	c.Assert(err, IsNil)
 	checkDummy(c, bundle, s.bundlePath)
 }
 
-func (s BundleSuite) TestReadBundleBytes(c *C) {
+func (s *BundleSuite) TestReadBundleBytes(c *C) {
 	data, err := ioutil.ReadFile(s.bundlePath)
 	c.Assert(err, IsNil)
 
@@ -34,17 +36,66 @@ func (s BundleSuite) TestReadBundleBytes(c *C) {
 	checkDummy(c, bundle, "")
 }
 
-func (s BundleSuite) TestExpandTo(c *C) {
+func (s *BundleSuite) TestExpandTo(c *C) {
 	bundle, err := charm.ReadBundle(s.bundlePath)
-	path := filepath.Join(c.MkDir(), "charm")
+	c.Assert(err, IsNil)
 
+	path := filepath.Join(c.MkDir(), "charm")
 	err = bundle.ExpandTo(path)
 	c.Assert(err, IsNil)
 
 	dir, err := charm.ReadDir(path)
 	c.Assert(err, IsNil)
 	checkDummy(c, dir, path)
+}
+
+func (s *BundleSuite) TestBundleRevisionFile(c *C) {
+	charmDir := c.MkDir()
+	copyCharmDir(charmDir, repoDir("dummy"))
+	revPath := filepath.Join(charmDir, "revision")
+
+	// Missing revision file
+	err := os.Remove(revPath)
+	c.Assert(err, IsNil)
+
+	bundle, err := charm.ReadBundle(extBundleDir(c, charmDir))
+	c.Assert(err, IsNil)
+	c.Assert(bundle.Revision(), Equals, 0)
+
+	// Missing revision file with old revision in metadata
+	file, err := os.OpenFile(filepath.Join(charmDir, "metadata.yaml"), os.O_WRONLY|os.O_APPEND, 0)
+	c.Assert(err, IsNil)
+	_, err = file.Write([]byte("\nrevision: 1234\n"))
+	c.Assert(err, IsNil)
+
+	bundle, err = charm.ReadBundle(extBundleDir(c, charmDir))
+	c.Assert(err, IsNil)
+	c.Assert(bundle.Revision(), Equals, 1234)
+
+	// Revision file with bad content
+	err = ioutil.WriteFile(revPath, []byte("garbage"), 0666)
+	c.Assert(err, IsNil)
 
+	bundle, err = charm.ReadBundle(extBundleDir(c, charmDir))
+	c.Assert(err, Matches, "invalid revision file")
+	c.Assert(bundle, IsNil)
+}
+
+func (s *BundleSuite) TestBundleSetRevision(c *C) {
+	bundle, err := charm.ReadBundle(s.bundlePath)
+	c.Assert(err, IsNil)
+
+	c.Assert(bundle.Revision(), Equals, 1)
+	bundle.SetRevision(42)
+	c.Assert(bundle.Revision(), Equals, 42)
+
+	path := filepath.Join(c.MkDir(), "charm")
+	err = bundle.ExpandTo(path)
+	c.Assert(err, IsNil)
+
+	dir, err := charm.ReadDir(path)
+	c.Assert(err, IsNil)
+	c.Assert(dir.Revision(), Equals, 42)
 }
 
 func bundleDir(c *C, dirpath string) (path string) {
@@ -63,3 +114,10 @@ func bundleDir(c *C, dirpath string) (path string) {
 	return path
 }
 
+func extBundleDir(c *C, dirpath string) (path string) {
+	path = filepath.Join(c.MkDir(), "bundle.charm")
+	cmd := exec.Command("/bin/sh", "-c", fmt.Sprintf("cd %s; zip -r %s .", dirpath, path))
+	output, err := cmd.CombinedOutput()
+	c.Assert(err, IsNil, Bug("Command output: %s", output))
+	return path
+}

charm.go

@@ -1,17 +1,10 @@
 package charm
 
-import (
-	"fmt"
-	"os"
-)
-
 // The Charm interface is implemented by any type that
 // may be handled as a charm.
 type Charm interface {
 	Meta() *Meta
 	Config() *Config
-}
-
-func errorf(format string, args ...interface{}) os.Error {
-	return os.NewError(fmt.Sprintf(format, args...))
+	Revision() int
+	SetRevision(revision int)
 }

charm_test.go

@@ -21,6 +21,7 @@ type S struct{}
 var _ = Suite(&S{})
 
 func checkDummy(c *C, f charm.Charm, path string) {
+	c.Assert(f.Revision(), Equals, 1)
 	c.Assert(f.Meta().Name, Equals, "dummy")
 	c.Assert(f.Config().Options["title"].Default, Equals, "My Title")
 	switch f := f.(type) {

config.go

@@ -1,6 +1,7 @@
 package charm
 
 import (
+	"fmt"
 	"io"
 	"io/ioutil"
 	"launchpad.net/juju/go/schema"
@@ -70,25 +71,25 @@ func (c *Config) Validate(values map[string]string) (processed map[string]interf
 	for k, v := range values {
 		opt, ok := c.Options[k]
 		if !ok {
-			return nil, errorf("Unknown configuration option: %q", k)
+			return nil, fmt.Errorf("Unknown configuration option: %q", k)
 		}
 		switch opt.Type {
 		case "string":
 			out[k] = v
 		case "int":
 			i, err := strconv.Atoi64(v)
 			if err != nil {
-				return nil, errorf("Value for %q is not an int: %q", k, v)
+				return nil, fmt.Errorf("Value for %q is not an int: %q", k, v)
 			}
 			out[k] = i
 		case "float":
 			f, err := strconv.Atof64(v)
 			if err != nil {
-				return nil, errorf("Value for %q is not a float: %q", k, v)
+				return nil, fmt.Errorf("Value for %q is not a float: %q", k, v)
 			}
 			out[k] = f
 		default:
-			panic(errorf("Internal error: option type %q is unknown to Validate", opt.Type))
+			panic(fmt.Errorf("Internal error: option type %q is unknown to Validate", opt.Type))
 		}
 	}
 	for k, opt := range c.Options {

config_test.go

@@ -32,7 +32,7 @@ options:
 `
 
 func repoConfig(name string) io.Reader {
-	file, err := os.Open(filepath.Join("testrepo", name, "config.yaml"))
+	file, err := os.Open(filepath.Join("testrepo", "series", name, "config.yaml"))
 	if err != nil {
 		panic(err)
 	}