first commit

internal/winmd/store.go

@@ -0,0 +1,89 @@
+package winmd
+
+import (
+	"fmt"
+
+	"github.com/go-kit/log"
+	"github.com/tdakkota/win32metadata/md"
+	"github.com/tdakkota/win32metadata/types"
+)
+
+// ClassNotFoundError is returned when a class is not found.
+type ClassNotFoundError struct {
+	Class string
+}
+
+func (e *ClassNotFoundError) Error() string {
+	return fmt.Sprintf("class %s was not found", e.Class)
+}
+
+// Store holds the windows metadata contexts. It can be used to get the metadata across multiple files.
+type Store struct {
+	contexts map[string]*types.Context
+	logger   log.Logger
+}
+
+// NewStore loads all windows metadata files and returns a new Store.
+func NewStore(logger log.Logger) (*Store, error) {
+	contexts := make(map[string]*types.Context)
+
+	winmdFiles, err := allFiles()
+	if err != nil {
+		return nil, err
+	}
+
+	// parse and store all files in memory
+	for _, f := range winmdFiles {
+		winmdCtx, err := parseWinMDFile(f.Name())
+		if err != nil {
+			return nil, err
+		}
+		contexts[f.Name()] = winmdCtx
+	}
+
+	return &Store{
+		contexts: contexts,
+		logger:   logger,
+	}, nil
+}
+
+func parseWinMDFile(path string) (*types.Context, error) {
+	f, err := open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer func() { _ = f.Close() }()
+
+	return types.FromPE(f)
+}
+
+// TypeDefByName returns a type definition that matches the given name.
+func (mds *Store) TypeDefByName(class string) (*TypeDef, error) {
+	// the type can belong to any of the contexts
+	for _, ctx := range mds.contexts {
+		if td := mds.typeDefByNameAndCtx(class, ctx); td != nil {
+			return td, nil // return the first match
+		}
+	}
+	return nil, &ClassNotFoundError{Class: class}
+}
+
+func (mds *Store) typeDefByNameAndCtx(class string, ctx *types.Context) *TypeDef {
+	typeDefTable := ctx.Table(md.TypeDef)
+	for i := uint32(0); i < typeDefTable.RowCount(); i++ {
+		var typeDef types.TypeDef
+		if err := typeDef.FromRow(typeDefTable.Row(i)); err != nil {
+			continue // keep searching instead of failing
+		}
+
+		if typeDef.TypeNamespace+"."+typeDef.TypeName == class {
+			return &TypeDef{
+				TypeDef:    typeDef,
+				HasContext: HasContext{ctx},
+				logger:     mds.logger,
+			}
+		}
+	}
+
+	return nil
+}