graphvent/gql_node.go

153 lines
3.9 KiB
Go

package graphvent
import (
"reflect"
"fmt"
"time"
"github.com/graphql-go/graphql"
"github.com/graphql-go/graphql/language/ast"
)
func ResolveNodeID(p graphql.ResolveParams) (interface{}, error) {
node, ok := p.Source.(NodeResult)
if ok == false {
return nil, fmt.Errorf("Can't get NodeID from %+v", reflect.TypeOf(p.Source))
}
return node.NodeID, nil
}
func ResolveNodeType(p graphql.ResolveParams) (interface{}, error) {
node, ok := p.Source.(NodeResult)
if ok == false {
return nil, fmt.Errorf("Can't get TypeHash from %+v", reflect.TypeOf(p.Source))
}
return uint64(node.NodeType), nil
}
func GetFieldNames(ctx *Context, selection_set *ast.SelectionSet) []string {
names := []string{}
if selection_set == nil {
return names
}
for _, sel := range(selection_set.Selections) {
switch field := sel.(type) {
case *ast.Field:
names = append(names, field.Name.Value)
case *ast.InlineFragment:
default:
ctx.Log.Logf("gql", "Unknown selection type: %s", reflect.TypeOf(field))
}
}
return names
}
// Returns the fields that need to be resolved
func GetResolveFields(id NodeID, ctx *ResolveContext, p graphql.ResolveParams) (map[ExtType][]string, error) {
node_info, mapped := ctx.Context.NodeTypes[p.Info.ReturnType.Name()]
if mapped == false {
return nil, fmt.Errorf("No NodeType %s", p.Info.ReturnType.Name())
}
fields := map[ExtType][]string{}
names := []string{}
for _, field := range(p.Info.FieldASTs) {
names = append(names, GetFieldNames(ctx.Context, field.SelectionSet)...)
}
cache, node_cached := ctx.NodeCache[id]
for _, name := range(names) {
if name == "ID" || name == "Type" {
continue
}
ext_type, field_mapped := node_info.Fields[name]
if field_mapped == false {
return nil, fmt.Errorf("NodeType %s does not have field %s", p.Info.ReturnType.Name(), name)
}
ext_fields, exists := fields[ext_type]
if exists == false {
ext_fields = []string{}
}
if node_cached {
ext_cache, ext_cached := cache.Data[ext_type]
if ext_cached {
_, field_cached := ext_cache[name]
if field_cached {
continue
}
}
}
fields[ext_type] = append(ext_fields, name)
}
return fields, nil
}
func ResolveNode(id NodeID, p graphql.ResolveParams) (NodeResult, error) {
ctx, err := PrepResolve(p)
if err != nil {
return NodeResult{}, err
}
fields, err := GetResolveFields(id, ctx, p)
if err != nil {
return NodeResult{}, err
}
ctx.Context.Log.Logf("gql", "Resolving fields %+v on node %s", fields, id)
signal := NewReadSignal(fields)
response_chan := ctx.Ext.GetResponseChannel(signal.ID())
// TODO: TIMEOUT DURATION
err = ctx.Context.Send(ctx.Server, []SendMsg{{
Dest: id,
Signal: signal,
}})
if err != nil {
ctx.Ext.FreeResponseChannel(signal.ID())
return NodeResult{}, err
}
response, _, err := WaitForResponse(response_chan, 100*time.Millisecond, signal.ID())
ctx.Ext.FreeResponseChannel(signal.ID())
if err != nil {
return NodeResult{}, err
}
switch response := response.(type) {
case *ReadResultSignal:
cache, node_cached := ctx.NodeCache[id]
if node_cached == false {
cache = NodeResult{
NodeID: id,
NodeType: response.NodeType,
Data: response.Extensions,
}
} else {
for ext_type, ext_data := range(response.Extensions) {
cached_ext, ext_cached := cache.Data[ext_type]
if ext_cached {
for field_name, field := range(ext_data) {
cache.Data[ext_type][field_name] = field
}
} else {
cache.Data[ext_type] = ext_data
}
cache.Data[ext_type] = cached_ext
}
}
ctx.NodeCache[id] = cache
return ctx.NodeCache[id], nil
default:
return NodeResult{}, fmt.Errorf("Bad read response: %+v", response)
}
}