147 lines
4.1 KiB
Go
147 lines
4.1 KiB
Go
package boil
|
|
|
|
import (
|
|
"database/sql"
|
|
"reflect"
|
|
|
|
"github.com/pkg/errors"
|
|
"github.com/vattle/sqlboiler/strmangle"
|
|
)
|
|
|
|
type loadRelationshipState struct {
|
|
exec Executor
|
|
loaded map[string]struct{}
|
|
toLoad []string
|
|
}
|
|
|
|
func (l loadRelationshipState) hasLoaded(depth int) bool {
|
|
_, ok := l.loaded[l.buildKey(depth)]
|
|
return ok
|
|
}
|
|
|
|
func (l loadRelationshipState) setLoaded(depth int) {
|
|
l.loaded[l.buildKey(depth)] = struct{}{}
|
|
}
|
|
|
|
func (l loadRelationshipState) buildKey(depth int) string {
|
|
buf := strmangle.GetBuffer()
|
|
|
|
for i, piece := range l.toLoad[:depth+1] {
|
|
if i != 0 {
|
|
buf.WriteByte('.')
|
|
}
|
|
buf.WriteString(piece)
|
|
}
|
|
|
|
str := buf.String()
|
|
strmangle.PutBuffer(buf)
|
|
return str
|
|
}
|
|
|
|
// loadRelationships dynamically calls the template generated eager load
|
|
// functions of the form:
|
|
//
|
|
// func (t *TableR) LoadRelationshipName(exec Executor, singular bool, obj interface{})
|
|
//
|
|
// The arguments to this function are:
|
|
// - t is not considered here, and is always passed nil. The function exists on a loaded
|
|
// struct to avoid a circular dependency with boil, and the receiver is ignored.
|
|
// - exec is used to perform additional queries that might be required for loading the relationships.
|
|
// - singular is passed in to identify whether or not this was a single object
|
|
// or a slice that must be loaded into.
|
|
// - obj is the object or slice of objects, always of the type *obj or *[]*obj as per bind.
|
|
//
|
|
// It takes list of nested relationships to load.
|
|
func (l loadRelationshipState) loadRelationships(depth int, obj interface{}, bkind bindKind) error {
|
|
typ := reflect.TypeOf(obj).Elem()
|
|
if bkind == kindPtrSliceStruct {
|
|
typ = typ.Elem().Elem()
|
|
}
|
|
|
|
if !l.hasLoaded(depth) {
|
|
current := l.toLoad[depth]
|
|
ln, found := typ.FieldByName(loaderStructName)
|
|
// It's possible a Loaders struct doesn't exist on the struct.
|
|
if !found {
|
|
return errors.Errorf("attempted to load %s but no L struct was found", current)
|
|
}
|
|
|
|
// Attempt to find the LoadRelationshipName function
|
|
loadMethod, found := ln.Type.MethodByName(loadMethodPrefix + current)
|
|
if !found {
|
|
return errors.Errorf("could not find %s%s method for eager loading", loadMethodPrefix, current)
|
|
}
|
|
|
|
// Hack to allow nil executors
|
|
execArg := reflect.ValueOf(l.exec)
|
|
if !execArg.IsValid() {
|
|
execArg = reflect.ValueOf((*sql.DB)(nil))
|
|
}
|
|
|
|
val := reflect.ValueOf(obj).Elem()
|
|
if bkind == kindPtrSliceStruct {
|
|
val = val.Index(0).Elem()
|
|
}
|
|
|
|
methodArgs := []reflect.Value{
|
|
val.FieldByName(loaderStructName),
|
|
execArg,
|
|
reflect.ValueOf(bkind == kindStruct),
|
|
reflect.ValueOf(obj),
|
|
}
|
|
resp := loadMethod.Func.Call(methodArgs)
|
|
if intf := resp[0].Interface(); intf != nil {
|
|
return errors.Wrapf(intf.(error), "failed to eager load %s", current)
|
|
}
|
|
|
|
l.setLoaded(depth)
|
|
}
|
|
|
|
// Pull one off the queue, continue if there's still some to go
|
|
depth++
|
|
if depth >= len(l.toLoad) {
|
|
return nil
|
|
}
|
|
|
|
loadedObject := reflect.ValueOf(obj)
|
|
// If we eagerly loaded nothing
|
|
if loadedObject.IsNil() {
|
|
return nil
|
|
}
|
|
loadedObject = reflect.Indirect(loadedObject)
|
|
|
|
// If it's singular we can just immediately call without looping
|
|
if bkind == kindStruct {
|
|
return l.loadRelationshipsRecurse(depth, loadedObject)
|
|
}
|
|
|
|
// Loop over all eager loaded objects
|
|
ln := loadedObject.Len()
|
|
if ln == 0 {
|
|
return nil
|
|
}
|
|
for i := 0; i < ln; i++ {
|
|
iter := loadedObject.Index(i).Elem()
|
|
if err := l.loadRelationshipsRecurse(depth, iter); err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
// loadRelationshipsRecurse is a helper function for taking a reflect.Value and
|
|
// Basically calls loadRelationships with: obj.R.EagerLoadedObj, and whether it's a string or slice
|
|
func (l loadRelationshipState) loadRelationshipsRecurse(depth int, obj reflect.Value) error {
|
|
r := obj.FieldByName(relationshipStructName)
|
|
if !r.IsValid() || r.IsNil() {
|
|
return errors.Errorf("could not traverse into loaded %s relationship to load more things", l.toLoad[depth])
|
|
}
|
|
newObj := reflect.Indirect(r).FieldByName(l.toLoad[depth])
|
|
bkind := kindStruct
|
|
if reflect.Indirect(newObj).Kind() != reflect.Struct {
|
|
bkind = kindPtrSliceStruct
|
|
newObj = newObj.Addr()
|
|
}
|
|
return l.loadRelationships(depth, newObj.Interface(), bkind)
|
|
}
|