orm/mapper.go

package orm

import (
	"fmt"
	"reflect"
	"strings"
	"sync"
)

type tblmap map[string]*tbl

func (t tblmap) String() string {
	s := make([]string, 0)
	for _, tbl := range t {
		s = append(s, tbl.String())
	}

	return strings.Join(s, "\n")
}

type mapper struct {
	lock *sync.Mutex
	wg   *sync.WaitGroup
	tbls tblmap
}

var ctx *mapper = &mapper{
	lock: &sync.Mutex{},
	wg:   &sync.WaitGroup{},
	tbls: make(tblmap),
}

func Map(tbl MappableInterface) *mapper {
	ctx.wg.Add(1)
	go func() {
		t := ctx.addTbl(tbl)
		if !t.isMapped() {
			ctx.mapTbl(t)
		}
		ctx.wg.Done()
		t.Unlock()
	}()
	return ctx
}

func WaitInit() {
	fmt.Println("Waiting in main")
	ctx.wg.Wait()
	fmt.Println(ctx.tbls)
}

func (m *mapper) addTbl(t MappableInterface) *tbl {
	rt := reflect.TypeOf(t).Elem()

	m.lock.Lock()
	defer m.lock.Unlock()

	if t, ok := m.tbls[rt.Name()]; ok {
		return t.ReadLock()
	}

	m.tbls[rt.Name()] = &tbl{
		rt:     rt,
		rv:     reflect.ValueOf(t).Elem(),
		lock:   &sync.RWMutex{},
		tFn:    t.GetTableMapperFn(),
		fFn:    t.GetFieldMapperFn(),
		mapped: false,
	}

	return m.tbls[rt.Name()].WriteLock()
}

func (m *mapper) mapTbl(t *tbl) {
	for n := 0; n < t.getType().NumField(); n++ {
		switch t.getType().Kind() {
		case reflect.Ptr:
		case reflect.Struct:
			if f := t.getType().Field(n); !f.Anonymous {
				t.add(t.getType().Field(n))
			} else if t.getType().Field(n).Anonymous && t.getValue().Field(n).CanInterface() {
				t.add(t.getType().Field(n))
			}
		default:
		}
	}
}