fix(lib): Improve context passing and visibility of internal structs

cmd/checkout.go

@@ -71,7 +71,7 @@ func (o *CheckoutOptions) Complete(f Factory, args []string) (err error) {
 
 // Run executes the `checkout` command
 func (o *CheckoutOptions) Run() (err error) {
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	if !o.Refs.IsExplicit() {

cmd/fsi.go

@@ -45,7 +45,8 @@ func NewFSICommand(f Factory, ioStreams ioes.IOStreams) *cobra.Command {
 			if err := o.Complete(f, args); err != nil {
 				return err
 			}
-			return o.Unlink()
+			ctx := context.TODO()
+			return o.Unlink(ctx)
 		},
 	}
 
@@ -87,7 +88,7 @@ func (o *FSIOptions) Link() (err error) {
 		return err
 	}
 
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	p := &lib.LinkParams{
@@ -104,8 +105,7 @@ func (o *FSIOptions) Link() (err error) {
 }
 
 // Unlink executes the fsi unlink command
-func (o *FSIOptions) Unlink() error {
-	ctx := context.Background()
+func (o *FSIOptions) Unlink(ctx context.Context) error {
 	inst := o.Instance
 
 	for _, ref := range o.Refs.RefList() {

cmd/init.go

@@ -88,7 +88,7 @@ func (o *InitOptions) Complete(f Factory, args []string) (err error) {
 
 // Run executes the `init` command
 func (o *InitOptions) Run() (err error) {
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	// An empty dir means the current dir

cmd/restore.go

@@ -124,7 +124,7 @@ func (o *RestoreOptions) Complete(f Factory, args []string) (err error) {
 func (o *RestoreOptions) Run() (err error) {
 	printRefSelect(o.ErrOut, o.Refs)
 
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	ref := o.Refs.Ref()

cmd/status.go

@@ -86,7 +86,7 @@ const ColumnPositionForMtime = 40
 func (o *StatusOptions) Run() (err error) {
 	printRefSelect(o.ErrOut, o.Refs)
 
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	params := lib.LinkParams{Dir: o.Refs.Dir()}

cmd/whatchanged.go

@@ -52,7 +52,7 @@ func (o *WhatChangedOptions) Complete(f Factory, args []string) (err error) {
 func (o *WhatChangedOptions) Run() (err error) {
 	printRefSelect(o.ErrOut, o.Refs)
 
-	ctx := context.Background()
+	ctx := context.TODO()
 	inst := o.Instance
 
 	params := lib.LinkParams{Refstr: o.Refs.Ref()}

lib/dispatch.go

@@ -7,7 +7,7 @@ import (
 	"strings"
 )
 
-// Dispatch is system for handling calls to lib. Currently only implemented for FSI methods.
+// Dispatch is a system for handling calls to lib. Should only be called by top-level lib methods.
 //
 // When programs are using qri as a library (such as the `cmd` package), calls to `lib` will
 // arrive at dispatch, before being routed to the actual implementation routine. This solves
@@ -22,13 +22,6 @@ import (
 // as the input and output parameters for those methods, and associates a string name for each
 // method. Dispatch works by looking up that method name, constructing the necessary input,
 // then invoking the actual implementation.
-
-// RegMethodSet represents a set of registered methods
-type RegMethodSet struct {
-	reg map[string]callable
-}
-
-// Dispatch looks up the method, and invokes it with the given input
 func (inst *Instance) Dispatch(ctx context.Context, method string, param interface{}) (res interface{}, err error) {
 	if inst == nil {
 		return nil, fmt.Errorf("instance is nil, cannot dispatch")
@@ -60,12 +53,12 @@ func (inst *Instance) Dispatch(ctx context.Context, method string, param interfa
 		// TODO(dustmop): Add user authentication, profile, identity, etc
 		// TODO(dustmop): Also determine if the method is read-only vs read-write,
 		// and only execute a single read-write method at a time
-		// Eventually, the data that lives in Scope should be immutable for its lifetime,
+		// Eventually, the data that lives in scope should be immutable for its lifetime,
 		// or use copy-on-write semantics, so that one method running at the same time as
 		// another cannot modify the out-of-scope data of the other. This will mostly
 		// involve making copies of the right things
-		scope := Scope{
-			ctx:  ctx,
+		scope := scope{
+			ctx: ctx,
 			inst: inst,
 		}
 
@@ -110,8 +103,13 @@ func (inst *Instance) NewInputParam(method string) interface{} {
 	return nil
 }
 
+// regMethodSet represents a set of registered methods
+type regMethodSet struct {
+	reg map[string]callable
+}
+
 // lookup finds the callable structure with the given method name
-func (r *RegMethodSet) lookup(method string) (*callable, bool) {
+func (r *regMethodSet) lookup(method string) (*callable, bool) {
 	if c, ok := r.reg[method]; ok {
 		return &c, true
 	}
@@ -129,7 +127,7 @@ type callable struct {
 func (inst *Instance) RegisterMethods() {
 	reg := make(map[string]callable)
 	inst.registerOne("fsi", &FSIImpl{}, reg)
-	inst.regMethods = &RegMethodSet{reg: reg}
+	inst.regMethods = &regMethodSet{reg: reg}
 }
 
 func (inst *Instance) registerOne(ourName string, impl interface{}, reg map[string]callable) {
@@ -139,51 +137,44 @@ func (inst *Instance) registerOne(ourName string, impl interface{}, reg map[stri
 	for k := 0; k < num; k++ {
 		m := implType.Method(k)
 		lowerName := strings.ToLower(m.Name)
-		funcName := ourName + "." + lowerName
+		funcName := fmt.Sprintf("%s.%s", ourName, lowerName)
 
 		// Validate the parameters to the method
 		// should have 3 input parameters: (receiver, scope, input struct)
 		// should have 2 output parametres: (output value, error)
 		// TODO(dustmop): allow variadic returns: error only, cursor for pagination
 		f := m.Type
 		if f.NumIn() != 3 {
-			log.Errorf("%s: bad number of inputs: %d", funcName, f.NumIn())
-			continue
+			log.Fatalf("%s: bad number of inputs: %d", funcName, f.NumIn())
 		}
 		if f.NumOut() != 2 {
-			log.Errorf("%s: bad number of outputs: %d", funcName, f.NumOut())
-			continue
+			log.Fatalf("%s: bad number of outputs: %d", funcName, f.NumOut())
 		}
 		// First input must be the receiver
 		inType := f.In(0)
 		if inType != implType {
-			log.Errorf("%s: first input param should be impl, got %v", funcName, inType)
-			continue
+			log.Fatalf("%s: first input param should be impl, got %v", funcName, inType)
 		}
 		// Second input must be a scope
 		inType = f.In(1)
-		if inType.Name() != "Scope" {
-			log.Errorf("%s: second input param should be scope, got %v", funcName, inType)
-			continue
+		if inType.Name() != "scope" {
+			log.Fatalf("%s: second input param should be scope, got %v", funcName, inType)
 		}
 		// Third input is a pointer to the input struct
 		inType = f.In(2)
 		if inType.Kind() != reflect.Ptr {
-			log.Errorf("%s: third input param must be a struct pointer, got %v", funcName, inType)
-			continue
+			log.Fatalf("%s: third input param must be a struct pointer, got %v", funcName, inType)
 		}
 		inType = inType.Elem()
 		if inType.Kind() != reflect.Struct {
-			log.Errorf("%s: third input param must be a struct pointer, got %v", funcName, inType)
-			continue
+			log.Fatalf("%s: third input param must be a struct pointer, got %v", funcName, inType)
 		}
 		// First output is anything
 		outType := f.Out(0)
 		// Second output must be an error
 		outErrType := f.Out(1)
 		if outErrType.Name() != "error" {
-			log.Errorf("%s: second output param should be error, got %v", funcName, inType)
-			continue
+			log.Fatalf("%s: second output param should be error, got %v", funcName, outErrType)
 		}
 
 		// Save the method to the registration table
@@ -193,12 +184,16 @@ func (inst *Instance) registerOne(ourName string, impl interface{}, reg map[stri
 			InType:  inType,
 			OutType: outType,
 		}
-		log.Infof("%d: registered %s(*%s) %v", k, funcName, inType, outType)
+		log.Debugf("%d: registered %s(*%s) %v", k, funcName, inType, outType)
 	}
 }
 
 // methodEndpoint returns a method name and returns the API endpoint for it
 func methodEndpoint(method string) APIEndpoint {
+	// TODO(dustmop): This is here temporarily. /fsi/write/ works differently than
+	// other methods; their http API endpoints are only their method name, for
+	// exmaple /status/. This should be replaced with an explicit mapping from
+	// method names to endpoints.
 	if method == "fsi.write" {
 		return "/fsi/write/"
 	}

lib/fsi.go

@@ -175,7 +175,7 @@ func (m *FSIMethods) EnsureRef(ctx context.Context, p *LinkParams) (*dsref.Versi
 type FSIImpl struct{}
 
 // CreateLink creates a connection between a working drirectory and a dataset history
-func (*FSIImpl) CreateLink(scope Scope, p *LinkParams) (*dsref.VersionInfo, error) {
+func (*FSIImpl) CreateLink(scope scope, p *LinkParams) (*dsref.VersionInfo, error) {
 	ctx := scope.Context()
 
 	ref, _, err := scope.ParseAndResolveRef(ctx, p.Refstr, "local")
@@ -189,7 +189,7 @@ func (*FSIImpl) CreateLink(scope Scope, p *LinkParams) (*dsref.VersionInfo, erro
 // Unlink removes the connection between a working directory and a dataset. If given only a
 // directory, will remove the link file from that directory. If given only a reference,
 // will remove the fsi path from that reference, and remove the link file from that fsi path
-func (*FSIImpl) Unlink(scope Scope, p *LinkParams) (string, error) {
+func (*FSIImpl) Unlink(scope scope, p *LinkParams) (string, error) {
 	ctx := scope.Context()
 
 	if p.Dir != "" && p.Refstr != "" {
@@ -225,7 +225,7 @@ func (*FSIImpl) Unlink(scope Scope, p *LinkParams) (string, error) {
 
 // Status checks for any modifications or errors in a linked directory against its previous
 // version in the repo. Must only be called if FSI is enabled for this dataset.
-func (*FSIImpl) Status(scope Scope, p *LinkParams) ([]StatusItem, error) {
+func (*FSIImpl) Status(scope scope, p *LinkParams) ([]StatusItem, error) {
 	ctx := scope.Context()
 
 	if p.Dir == "" && p.Refstr == "" {
@@ -252,7 +252,7 @@ func (*FSIImpl) Status(scope Scope, p *LinkParams) ([]StatusItem, error) {
 
 // WhatChanged gets changes that happened at a particular version in the history of the given
 // dataset reference.
-func (*FSIImpl) WhatChanged(scope Scope, p *LinkParams) ([]StatusItem, error) {
+func (*FSIImpl) WhatChanged(scope scope, p *LinkParams) ([]StatusItem, error) {
 	ctx := scope.Context()
 
 	ref, _, err := scope.ParseAndResolveRef(ctx, p.Refstr, "local")
@@ -265,7 +265,7 @@ func (*FSIImpl) WhatChanged(scope Scope, p *LinkParams) ([]StatusItem, error) {
 
 // Checkout method writes a dataset to a directory as individual files.
 // TODO(dustmop): Returned string is not used, remove it once dispatch is compatible
-func (*FSIImpl) Checkout(scope Scope, p *LinkParams) (string, error) {
+func (*FSIImpl) Checkout(scope scope, p *LinkParams) (string, error) {
 	ctx := scope.Context()
 
 	// Require a non-empty, absolute path for the checkout
@@ -330,7 +330,7 @@ func (*FSIImpl) Checkout(scope Scope, p *LinkParams) (string, error) {
 }
 
 // Write mutates a linked dataset on the filesystem
-func (*FSIImpl) Write(scope Scope, p *FSIWriteParams) ([]StatusItem, error) {
+func (*FSIImpl) Write(scope scope, p *FSIWriteParams) ([]StatusItem, error) {
 	ctx := scope.Context()
 
 	if p.Ds == nil {
@@ -363,7 +363,7 @@ func (*FSIImpl) Write(scope Scope, p *FSIWriteParams) ([]StatusItem, error) {
 
 // Restore method restores a component or all of the component files of a dataset from the repo
 // TODO(dustmop): Returned string is not used, remove it once dispatch is compatible
-func (*FSIImpl) Restore(scope Scope, p *RestoreParams) (string, error) {
+func (*FSIImpl) Restore(scope scope, p *RestoreParams) (string, error) {
 	ctx := scope.Context()
 
 	ref, _, err := scope.ParseAndResolveRef(ctx, p.Refstr, "local")
@@ -428,7 +428,7 @@ func (*FSIImpl) Restore(scope Scope, p *RestoreParams) (string, error) {
 }
 
 // Init creates a new dataset in a working directory
-func (*FSIImpl) Init(scope Scope, p *InitDatasetParams) (string, error) {
+func (*FSIImpl) Init(scope scope, p *InitDatasetParams) (string, error) {
 	ctx := scope.Context()
 
 	if p.UseDscache {
@@ -440,14 +440,14 @@ func (*FSIImpl) Init(scope Scope, p *InitDatasetParams) (string, error) {
 }
 
 // CanInitDatasetWorkDir returns nil if the directory can init a dataset, or an error if not
-func (*FSIImpl) CanInitDatasetWorkDir(scope Scope, p *InitDatasetParams) (bool, error) {
+func (*FSIImpl) CanInitDatasetWorkDir(scope scope, p *InitDatasetParams) (bool, error) {
 	// TODO(dustmop): Change dispatch so that implementations can only return 1 value
 	// if that value is an error
 	return true, scope.FSISubsystem().CanInitDatasetWorkDir(p.TargetDir, p.BodyPath)
 }
 
 // EnsureRef will modify the directory path in the repo for the given reference
-func (*FSIImpl) EnsureRef(scope Scope, p *LinkParams) (*dsref.VersionInfo, error) {
+func (*FSIImpl) EnsureRef(scope scope, p *LinkParams) (*dsref.VersionInfo, error) {
 	ctx := scope.Context()
 
 	ref, err := dsref.Parse(p.Refstr)

lib/lib.go

@@ -701,7 +701,7 @@ type Instance struct {
 	repoPath string
 	cfg      *config.Config
 
-	regMethods *RegMethodSet
+	regMethods *regMethodSet
 
 	streams         ioes.IOStreams
 	repo            repo.Repo