feat: internal manifest package

internal/manifest/log.go

@@ -0,0 +1,53 @@
+package manifest
+
+import (
+	"fmt"
+	"sync"
+)
+
+// Avoid importing the log type information unnecessarily.  There's a small cost
+// associated with using an interface rather than the type.  Depending on how
+// often the logger is plugged in, it would be worth using the type instead.
+type log_Logger interface {
+	Output(calldepth int, s string) error
+}
+
+var globalLoggerLock sync.Mutex
+var globalLogger log_Logger
+var globalDebug bool
+
+// Specify the *log.Logger object where log messages should be sent to.
+func SetLogger(logger log_Logger) {
+	globalLoggerLock.Lock()
+	globalLogger = logger
+	globalLoggerLock.Unlock()
+}
+
+// Enable the delivery of debug messages to the logger.  Only meaningful
+// if a logger is also set.
+func SetDebug(debug bool) {
+	globalLoggerLock.Lock()
+	globalDebug = debug
+	globalLoggerLock.Unlock()
+}
+
+// logf sends to the logger registered via SetLogger the string resulting
+// from running format and args through Sprintf.
+func logf(format string, args ...interface{}) {
+	globalLoggerLock.Lock()
+	defer globalLoggerLock.Unlock()
+	if globalLogger != nil {
+		globalLogger.Output(2, fmt.Sprintf(format, args...))
+	}
+}
+
+// debugf sends to the logger registered via SetLogger the string resulting
+// from running format and args through Sprintf, but only if debugging was
+// enabled via SetDebug.
+func debugf(format string, args ...interface{}) {
+	globalLoggerLock.Lock()
+	defer globalLoggerLock.Unlock()
+	if globalDebug && globalLogger != nil {
+		globalLogger.Output(2, fmt.Sprintf(format, args...))
+	}
+}

internal/manifest/manifest.go

@@ -0,0 +1,245 @@
+package manifest
+
+import (
+	"fmt"
+	"os"
+	"slices"
+
+	"github.com/klauspost/compress/zstd"
+
+	"github.com/canonical/chisel/internal/jsonwall"
+	"github.com/canonical/chisel/internal/setup"
+)
+
+type Package struct {
+	Kind    string `json:"kind"`
+	Name    string `json:"name"`
+	Version string `json:"version"`
+	Digest  string `json:"sha256"`
+	Arch    string `json:"arch"`
+}
+
+type Slice struct {
+	Kind string `json:"kind"`
+	Name string `json:"name"`
+}
+
+type Path struct {
+	Kind      string   `json:"kind"`
+	Path      string   `json:"path"`
+	Mode      string   `json:"mode"`
+	Slices    []string `json:"slices"`
+	Hash      string   `json:"sha256,omitempty"`
+	FinalHash string   `json:"final_sha256,omitempty"`
+	Size      uint64   `json:"size,omitempty"`
+	Link      string   `json:"link,omitempty"`
+}
+
+type Content struct {
+	Kind  string `json:"kind"`
+	Slice string `json:"slice"`
+	Path  string `json:"path"`
+}
+
+type Manifest struct {
+	db *jsonwall.DB
+}
+
+func Read(absPath string) (manifest *Manifest, err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("cannot read manifest: %s", err)
+		}
+	}()
+
+	file, err := os.OpenFile(absPath, os.O_RDONLY, 0644)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+	r, err := zstd.NewReader(file)
+	if err != nil {
+		return nil, err
+	}
+	defer r.Close()
+	jsonwallDB, err := jsonwall.ReadDB(r)
+	if err != nil {
+		return nil, err
+	}
+
+	manifest = &Manifest{db: jsonwallDB}
+	err = validate(manifest)
+	if err != nil {
+		return nil, err
+	}
+	return manifest, nil
+}
+
+func (manifest *Manifest) IteratePath(prefix string, f func(Path) error) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("cannot read manifest: %s", err)
+		}
+	}()
+
+	iter, err := manifest.db.IteratePrefix(map[string]string{"kind": "path", "path": prefix})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var path Path
+		err := iter.Get(&path)
+		if err != nil {
+			return err
+		}
+		err = f(path)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (manifest *Manifest) IteratePkgs(f func(Package) error) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("cannot read manifest: %s", err)
+		}
+	}()
+
+	iter, err := manifest.db.Iterate(map[string]string{"kind": "package"})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var pkg Package
+		err := iter.Get(&pkg)
+		if err != nil {
+			return err
+		}
+		err = f(pkg)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (manifest *Manifest) IterateSlices(pkgName string, f func(Slice) error) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf("cannot read manifest: %s", err)
+		}
+	}()
+
+	iter, err := manifest.db.IteratePrefix(map[string]string{"kind": "slice", "name": pkgName})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var slice Slice
+		err := iter.Get(&slice)
+		if err != nil {
+			return err
+		}
+		err = f(slice)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func validate(manifest *Manifest) (err error) {
+	defer func() {
+		if err != nil {
+			err = fmt.Errorf(`invalid manifest: %s`, err)
+		}
+	}()
+
+	pkgExist := map[string]bool{}
+	iter, err := manifest.db.Iterate(map[string]string{"kind": "package"})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var pkg Package
+		err := iter.Get(&pkg)
+		if err != nil {
+			return err
+		}
+		if pkg.Kind != "package" {
+			return fmt.Errorf(`in packages expected kind "package", got %q`, pkg.Kind)
+		}
+		pkgExist[pkg.Name] = true
+	}
+
+	sliceExist := map[string]bool{}
+	iter, err = manifest.db.Iterate(map[string]string{"kind": "slice"})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var slice Slice
+		err := iter.Get(&slice)
+		if err != nil {
+			return err
+		}
+		sk, err := setup.ParseSliceKey(slice.Name)
+		if err != nil {
+			return err
+		}
+		if !pkgExist[sk.Package] {
+			return fmt.Errorf(`package %q not found in packages`, sk.Package)
+		}
+		sliceExist[slice.Name] = true
+	}
+
+	pathToSlices := map[string][]string{}
+	iter, err = manifest.db.Iterate(map[string]string{"kind": "content"})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var content Content
+		err := iter.Get(&content)
+		if err != nil {
+			return err
+		}
+		if content.Kind != "content" {
+			return fmt.Errorf(`in contents expected kind "content", got "%s"`, content.Kind)
+		}
+		if !sliceExist[content.Slice] {
+			return fmt.Errorf(`slice %s not found in slices`, content.Slice)
+		}
+		pathToSlices[content.Path] = append(pathToSlices[content.Path], content.Slice)
+	}
+
+	iter, err = manifest.db.Iterate(map[string]string{"kind": "path"})
+	if err != nil {
+		return err
+	}
+	for iter.Next() {
+		var path Path
+		err := iter.Get(&path)
+		if err != nil {
+			return err
+		}
+		if path.Kind != "path" {
+			return fmt.Errorf(`in paths expected kind "path", got "%s"`, path.Kind)
+		}
+		if pathSlices, ok := pathToSlices[path.Path]; !ok {
+			return fmt.Errorf(`path %s has no matching entry in contents`, path.Path)
+		} else if !slices.Equal(pathSlices, path.Slices) {
+			return fmt.Errorf(`path %s and content have diverging slices: %q != %q`, path.Path, path.Slices, pathSlices)
+		}
+		delete(pathToSlices, path.Path)
+	}
+
+	if len(pathToSlices) > 0 {
+		for path := range pathToSlices {
+			return fmt.Errorf(`content path %s has no matching entry in paths`, path)
+		}
+	}
+	return nil
+}