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author | Wim <wim@42.be> | 2022-04-01 00:23:19 +0200 |
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committer | GitHub <noreply@github.com> | 2022-04-01 00:23:19 +0200 |
commit | c6716e030c02f316b887c1d3ee4b443aa3ab6afd (patch) | |
tree | 470461fe2d29662e7a69834ed21fce30beed65ab /vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go | |
parent | 4ab72acec656dafd304f88359b509b1f27c06604 (diff) | |
download | matterbridge-msglm-c6716e030c02f316b887c1d3ee4b443aa3ab6afd.tar.gz matterbridge-msglm-c6716e030c02f316b887c1d3ee4b443aa3ab6afd.tar.bz2 matterbridge-msglm-c6716e030c02f316b887c1d3ee4b443aa3ab6afd.zip |
Update dependencies (#1784)
Diffstat (limited to 'vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go')
-rw-r--r-- | vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go | 381 |
1 files changed, 381 insertions, 0 deletions
diff --git a/vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go b/vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go new file mode 100644 index 00000000..6b478487 --- /dev/null +++ b/vendor/github.com/graph-gophers/graphql-go/internal/exec/exec.go @@ -0,0 +1,381 @@ +package exec + +import ( + "bytes" + "context" + "encoding/json" + "fmt" + "reflect" + "sync" + "time" + + "github.com/graph-gophers/graphql-go/errors" + "github.com/graph-gophers/graphql-go/internal/exec/resolvable" + "github.com/graph-gophers/graphql-go/internal/exec/selected" + "github.com/graph-gophers/graphql-go/internal/query" + "github.com/graph-gophers/graphql-go/log" + "github.com/graph-gophers/graphql-go/trace" + "github.com/graph-gophers/graphql-go/types" +) + +type Request struct { + selected.Request + Limiter chan struct{} + Tracer trace.Tracer + Logger log.Logger + PanicHandler errors.PanicHandler + SubscribeResolverTimeout time.Duration +} + +func (r *Request) handlePanic(ctx context.Context) { + if value := recover(); value != nil { + r.Logger.LogPanic(ctx, value) + r.AddError(r.PanicHandler.MakePanicError(ctx, value)) + } +} + +type extensionser interface { + Extensions() map[string]interface{} +} + +func (r *Request) Execute(ctx context.Context, s *resolvable.Schema, op *types.OperationDefinition) ([]byte, []*errors.QueryError) { + var out bytes.Buffer + func() { + defer r.handlePanic(ctx) + sels := selected.ApplyOperation(&r.Request, s, op) + r.execSelections(ctx, sels, nil, s, s.Resolver, &out, op.Type == query.Mutation) + }() + + if err := ctx.Err(); err != nil { + return nil, []*errors.QueryError{errors.Errorf("%s", err)} + } + + return out.Bytes(), r.Errs +} + +type fieldToExec struct { + field *selected.SchemaField + sels []selected.Selection + resolver reflect.Value + out *bytes.Buffer +} + +func resolvedToNull(b *bytes.Buffer) bool { + return bytes.Equal(b.Bytes(), []byte("null")) +} + +func (r *Request) execSelections(ctx context.Context, sels []selected.Selection, path *pathSegment, s *resolvable.Schema, resolver reflect.Value, out *bytes.Buffer, serially bool) { + async := !serially && selected.HasAsyncSel(sels) + + var fields []*fieldToExec + collectFieldsToResolve(sels, s, resolver, &fields, make(map[string]*fieldToExec)) + + if async { + var wg sync.WaitGroup + wg.Add(len(fields)) + for _, f := range fields { + go func(f *fieldToExec) { + defer wg.Done() + defer r.handlePanic(ctx) + f.out = new(bytes.Buffer) + execFieldSelection(ctx, r, s, f, &pathSegment{path, f.field.Alias}, true) + }(f) + } + wg.Wait() + } else { + for _, f := range fields { + f.out = new(bytes.Buffer) + execFieldSelection(ctx, r, s, f, &pathSegment{path, f.field.Alias}, true) + } + } + + out.WriteByte('{') + for i, f := range fields { + // If a non-nullable child resolved to null, an error was added to the + // "errors" list in the response, so this field resolves to null. + // If this field is non-nullable, the error is propagated to its parent. + if _, ok := f.field.Type.(*types.NonNull); ok && resolvedToNull(f.out) { + out.Reset() + out.Write([]byte("null")) + return + } + + if i > 0 { + out.WriteByte(',') + } + out.WriteByte('"') + out.WriteString(f.field.Alias) + out.WriteByte('"') + out.WriteByte(':') + out.Write(f.out.Bytes()) + } + out.WriteByte('}') +} + +func collectFieldsToResolve(sels []selected.Selection, s *resolvable.Schema, resolver reflect.Value, fields *[]*fieldToExec, fieldByAlias map[string]*fieldToExec) { + for _, sel := range sels { + switch sel := sel.(type) { + case *selected.SchemaField: + field, ok := fieldByAlias[sel.Alias] + if !ok { // validation already checked for conflict (TODO) + field = &fieldToExec{field: sel, resolver: resolver} + fieldByAlias[sel.Alias] = field + *fields = append(*fields, field) + } + field.sels = append(field.sels, sel.Sels...) + + case *selected.TypenameField: + _, ok := fieldByAlias[sel.Alias] + if !ok { + res := reflect.ValueOf(typeOf(sel, resolver)) + f := s.FieldTypename + f.TypeName = res.String() + + sf := &selected.SchemaField{ + Field: f, + Alias: sel.Alias, + FixedResult: res, + } + + field := &fieldToExec{field: sf, resolver: resolver} + *fields = append(*fields, field) + fieldByAlias[sel.Alias] = field + } + + case *selected.TypeAssertion: + out := resolver.Method(sel.MethodIndex).Call(nil) + if !out[1].Bool() { + continue + } + collectFieldsToResolve(sel.Sels, s, out[0], fields, fieldByAlias) + + default: + panic("unreachable") + } + } +} + +func typeOf(tf *selected.TypenameField, resolver reflect.Value) string { + if len(tf.TypeAssertions) == 0 { + return tf.Name + } + for name, a := range tf.TypeAssertions { + out := resolver.Method(a.MethodIndex).Call(nil) + if out[1].Bool() { + return name + } + } + return "" +} + +func execFieldSelection(ctx context.Context, r *Request, s *resolvable.Schema, f *fieldToExec, path *pathSegment, applyLimiter bool) { + if applyLimiter { + r.Limiter <- struct{}{} + } + + var result reflect.Value + var err *errors.QueryError + + traceCtx, finish := r.Tracer.TraceField(ctx, f.field.TraceLabel, f.field.TypeName, f.field.Name, !f.field.Async, f.field.Args) + defer func() { + finish(err) + }() + + err = func() (err *errors.QueryError) { + defer func() { + if panicValue := recover(); panicValue != nil { + r.Logger.LogPanic(ctx, panicValue) + err = r.PanicHandler.MakePanicError(ctx, panicValue) + err.Path = path.toSlice() + } + }() + + if f.field.FixedResult.IsValid() { + result = f.field.FixedResult + return nil + } + + if err := traceCtx.Err(); err != nil { + return errors.Errorf("%s", err) // don't execute any more resolvers if context got cancelled + } + + res := f.resolver + if f.field.UseMethodResolver() { + var in []reflect.Value + if f.field.HasContext { + in = append(in, reflect.ValueOf(traceCtx)) + } + if f.field.ArgsPacker != nil { + in = append(in, f.field.PackedArgs) + } + callOut := res.Method(f.field.MethodIndex).Call(in) + result = callOut[0] + if f.field.HasError && !callOut[1].IsNil() { + resolverErr := callOut[1].Interface().(error) + err := errors.Errorf("%s", resolverErr) + err.Path = path.toSlice() + err.ResolverError = resolverErr + if ex, ok := callOut[1].Interface().(extensionser); ok { + err.Extensions = ex.Extensions() + } + return err + } + } else { + // TODO extract out unwrapping ptr logic to a common place + if res.Kind() == reflect.Ptr { + res = res.Elem() + } + result = res.FieldByIndex(f.field.FieldIndex) + } + return nil + }() + + if applyLimiter { + <-r.Limiter + } + + if err != nil { + // If an error occurred while resolving a field, it should be treated as though the field + // returned null, and an error must be added to the "errors" list in the response. + r.AddError(err) + f.out.WriteString("null") + return + } + + r.execSelectionSet(traceCtx, f.sels, f.field.Type, path, s, result, f.out) +} + +func (r *Request) execSelectionSet(ctx context.Context, sels []selected.Selection, typ types.Type, path *pathSegment, s *resolvable.Schema, resolver reflect.Value, out *bytes.Buffer) { + t, nonNull := unwrapNonNull(typ) + + // a reflect.Value of a nil interface will show up as an Invalid value + if resolver.Kind() == reflect.Invalid || ((resolver.Kind() == reflect.Ptr || resolver.Kind() == reflect.Interface) && resolver.IsNil()) { + // If a field of a non-null type resolves to null (either because the + // function to resolve the field returned null or because an error occurred), + // add an error to the "errors" list in the response. + if nonNull { + err := errors.Errorf("graphql: got nil for non-null %q", t) + err.Path = path.toSlice() + r.AddError(err) + } + out.WriteString("null") + return + } + + switch t.(type) { + case *types.ObjectTypeDefinition, *types.InterfaceTypeDefinition, *types.Union: + r.execSelections(ctx, sels, path, s, resolver, out, false) + return + } + + // Any pointers or interfaces at this point should be non-nil, so we can get the actual value of them + // for serialization + if resolver.Kind() == reflect.Ptr || resolver.Kind() == reflect.Interface { + resolver = resolver.Elem() + } + + switch t := t.(type) { + case *types.List: + r.execList(ctx, sels, t, path, s, resolver, out) + + case *types.ScalarTypeDefinition: + v := resolver.Interface() + data, err := json.Marshal(v) + if err != nil { + panic(errors.Errorf("could not marshal %v: %s", v, err)) + } + out.Write(data) + + case *types.EnumTypeDefinition: + var stringer fmt.Stringer = resolver + if s, ok := resolver.Interface().(fmt.Stringer); ok { + stringer = s + } + name := stringer.String() + var valid bool + for _, v := range t.EnumValuesDefinition { + if v.EnumValue == name { + valid = true + break + } + } + if !valid { + err := errors.Errorf("Invalid value %s.\nExpected type %s, found %s.", name, t.Name, name) + err.Path = path.toSlice() + r.AddError(err) + out.WriteString("null") + return + } + out.WriteByte('"') + out.WriteString(name) + out.WriteByte('"') + + default: + panic("unreachable") + } +} + +func (r *Request) execList(ctx context.Context, sels []selected.Selection, typ *types.List, path *pathSegment, s *resolvable.Schema, resolver reflect.Value, out *bytes.Buffer) { + l := resolver.Len() + entryouts := make([]bytes.Buffer, l) + + if selected.HasAsyncSel(sels) { + // Limit the number of concurrent goroutines spawned as it can lead to large + // memory spikes for large lists. + concurrency := cap(r.Limiter) + sem := make(chan struct{}, concurrency) + for i := 0; i < l; i++ { + sem <- struct{}{} + go func(i int) { + defer func() { <-sem }() + defer r.handlePanic(ctx) + r.execSelectionSet(ctx, sels, typ.OfType, &pathSegment{path, i}, s, resolver.Index(i), &entryouts[i]) + }(i) + } + for i := 0; i < concurrency; i++ { + sem <- struct{}{} + } + } else { + for i := 0; i < l; i++ { + r.execSelectionSet(ctx, sels, typ.OfType, &pathSegment{path, i}, s, resolver.Index(i), &entryouts[i]) + } + } + + _, listOfNonNull := typ.OfType.(*types.NonNull) + + out.WriteByte('[') + for i, entryout := range entryouts { + // If the list wraps a non-null type and one of the list elements + // resolves to null, then the entire list resolves to null. + if listOfNonNull && resolvedToNull(&entryout) { + out.Reset() + out.WriteString("null") + return + } + + if i > 0 { + out.WriteByte(',') + } + out.Write(entryout.Bytes()) + } + out.WriteByte(']') +} + +func unwrapNonNull(t types.Type) (types.Type, bool) { + if nn, ok := t.(*types.NonNull); ok { + return nn.OfType, true + } + return t, false +} + +type pathSegment struct { + parent *pathSegment + value interface{} +} + +func (p *pathSegment) toSlice() []interface{} { + if p == nil { + return nil + } + return append(p.parent.toSlice(), p.value) +} |