migrate syft/cataloger to syft/pkg/cataloger

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/cataloger/catalog.go

@@ -0,0 +1,80 @@
+package cataloger
+
+import (
+	"github.com/anchore/syft/internal/bus"
+	"github.com/anchore/syft/internal/log"
+	"github.com/anchore/syft/syft/distro"
+	"github.com/anchore/syft/syft/event"
+	"github.com/anchore/syft/syft/pkg"
+	"github.com/anchore/syft/syft/source"
+	"github.com/hashicorp/go-multierror"
+	"github.com/wagoodman/go-partybus"
+	"github.com/wagoodman/go-progress"
+)
+
+// Monitor provides progress-related data for observing the progress of a Catalog() call (published on the event bus).
+type Monitor struct {
+	FilesProcessed     progress.Monitorable // the number of files selected and contents analyzed from all registered catalogers
+	PackagesDiscovered progress.Monitorable // the number of packages discovered from all registered catalogers
+}
+
+// newMonitor creates a new Monitor object and publishes the object on the bus as a PackageCatalogerStarted event.
+func newMonitor() (*progress.Manual, *progress.Manual) {
+	filesProcessed := progress.Manual{}
+	packagesDiscovered := progress.Manual{}
+
+	bus.Publish(partybus.Event{
+		Type: event.PackageCatalogerStarted,
+		Value: Monitor{
+			FilesProcessed:     progress.Monitorable(&filesProcessed),
+			PackagesDiscovered: progress.Monitorable(&packagesDiscovered),
+		},
+	})
+	return &filesProcessed, &packagesDiscovered
+}
+
+// Catalog a given source (container image or filesystem) with the given catalogers, returning all discovered packages.
+// In order to efficiently retrieve contents from a underlying container image the content fetch requests are
+// done in bulk. Specifically, all files of interest are collected from each catalogers and accumulated into a single
+// request.
+func Catalog(resolver source.FileResolver, theDistro *distro.Distro, catalogers ...Cataloger) (*pkg.Catalog, error) {
+	catalog := pkg.NewCatalog()
+
+	filesProcessed, packagesDiscovered := newMonitor()
+
+	// perform analysis, accumulating errors for each failed analysis
+	var errs error
+	for _, theCataloger := range catalogers {
+		// find packages from the underlying raw data
+		packages, err := theCataloger.Catalog(resolver)
+		if err != nil {
+			errs = multierror.Append(errs, err)
+			continue
+		}
+
+		catalogedPackages := len(packages)
+
+		log.Debugf("cataloger '%s' discovered '%d' packages", theCataloger.Name(), catalogedPackages)
+		packagesDiscovered.N += int64(catalogedPackages)
+
+		for _, p := range packages {
+			// generate CPEs
+			p.CPEs = generatePackageCPEs(p)
+
+			// generate PURL
+			p.PURL = generatePackageURL(p, theDistro)
+
+			// add to catalog
+			catalog.Add(p)
+		}
+	}
+
+	if errs != nil {
+		return nil, errs
+	}
+
+	filesProcessed.SetCompleted()
+	packagesDiscovered.SetCompleted()
+
+	return catalog, nil
+}