Allow to pass a custom instance of pcidb

pkg/option/option.go

@@ -10,6 +10,8 @@ import (
 	"io"
 	"log"
 	"os"
+
+	"github.com/jaypipes/pcidb"
 )
 
 const (
@@ -140,6 +142,12 @@ type Option struct {
 	// during a call to the `context.WithContext` function. Only used internally.
 	// This is an interface to get around recursive package import issues.
 	Context interface{}
+
+	// PCIDB allows users to provide a custom instance of the PCI database (pcidb.PCIDB)
+	// to be used by ghw. This can be useful for testing, supplying a preloaded database,
+	// or providing an instance created with custom pcidb.WithOption settings, instead of
+	// letting ghw load the PCI database automatically.
+	PCIDB *pcidb.PCIDB
 }
 
 // SnapshotOptions contains options for handling of ghw snapshots
@@ -195,6 +203,14 @@ func WithDisableTools() *Option {
 	return &Option{EnableTools: &false_}
 }
 
+// WithPCIDB allows you to provide a custom instance of the PCI database (pcidb.PCIDB)
+// to ghw. This is useful if you want to use a preloaded or specially configured
+// PCI database, such as one created with custom pcidb.WithOption settings, instead
+// of letting ghw load the PCI database automatically.
+func WithPCIDB(pcidb *pcidb.PCIDB) *Option {
+	return &Option{PCIDB: pcidb}
+}
+
 // PathOverrides is a map, keyed by the string name of a mount path, of override paths
 type PathOverrides map[string]string
 
@@ -233,6 +249,9 @@ func Merge(opts ...*Option) *Option {
 		if opt.Context != nil {
 			merged.Context = opt.Context
 		}
+		if opt.PCIDB != nil {
+			merged.PCIDB = opt.PCIDB
+		}
 	}
 	// Set the default value if missing from mergeOpts
 	if merged.Chroot == nil {

pkg/option/option_test.go

@@ -7,9 +7,11 @@
 package option_test
 
 import (
+	"runtime"
 	"testing"
 
 	"github.com/jaypipes/ghw/pkg/option"
+	"github.com/jaypipes/pcidb"
 )
 
 type optTestCase struct {
@@ -20,6 +22,25 @@ type optTestCase struct {
 
 // nolint: gocyclo
 func TestOption(t *testing.T) {
+	var pciTest *optTestCase
+	pcidb, err := pcidb.New()
+	if err != nil {
+		t.Fatalf("error creating new pcidb: %v", err)
+	}
+	if runtime.GOOS == "linux" {
+		pciTest = &optTestCase{
+			name: "pcidb",
+			opts: []*option.Option{
+				option.WithPCIDB(pcidb),
+				option.WithChroot("/my/chroot/dir"),
+			},
+			merged: &option.Option{
+				Chroot: stringPtr("/my/chroot/dir"),
+				PCIDB:  pcidb,
+			},
+		}
+	}
+
 	optTCases := []optTestCase{
 		{
 			name: "multiple chroots",
@@ -151,6 +172,9 @@ func TestOption(t *testing.T) {
 			},
 		},
 	}
+	if pciTest != nil {
+		optTCases = append(optTCases, *pciTest)
+	}
 	for _, optTCase := range optTCases {
 		t.Run(optTCase.name, func(t *testing.T) {
 			opt := option.Merge(optTCase.opts...)

pkg/pci/pci.go

@@ -149,6 +149,9 @@ func New(opts ...*option.Option) (*Info, error) {
 		} else {
 			ctx.Warn("error detecting system topology: %v", err)
 		}
+		if merged.PCIDB != nil {
+			info.db = merged.PCIDB
+		}
 		return info.load()
 	}
 

pkg/pci/pci_linux.go

@@ -39,11 +39,13 @@ func (i *Info) load() error {
 	if i.ctx.SnapshotPath != "" {
 		chroot = option.DefaultChroot
 	}
-	db, err := pcidb.New(pcidb.WithChroot(chroot))
-	if err != nil {
-		return err
+	if i.db == nil {
+		db, err := pcidb.New(pcidb.WithChroot(chroot))
+		if err != nil {
+			return err
+		}
+		i.db = db
 	}
-	i.db = db
 	i.Devices = i.getDevices()
 	return nil
 }