super-graph/core/resolve.go
2020-04-11 02:45:06 -04:00

160 lines
3.2 KiB
Go

package core
import (
"fmt"
"io/ioutil"
"net/http"
"strings"
"github.com/dosco/super-graph/jsn"
)
var (
rmap map[uint64]*resolvFn
)
type resolvFn struct {
IDField []byte
Path [][]byte
Fn func(h http.Header, id []byte) ([]byte, error)
}
// func initResolvers() {
// var err error
// rmap = make(map[uint64]*resolvFn)
// for _, t := range conf.Tables {
// err = initRemotes(t)
// if err != nil {
// break
// }
// }
// if err != nil {
// errlog.Fatal().Err(err).Msg("failed to initialize resolvers")
// }
// }
// func initRemotes(t Table) error {
// h := xxhash.New()
// for _, r := range t.Remotes {
// // defines the table column to be used as an id in the
// // remote request
// idcol := r.ID
// // if no table column specified in the config then
// // use the primary key of the table as the id
// if len(idcol) == 0 {
// pcol, err := pcompile.IDColumn(t.Name)
// if err != nil {
// return err
// }
// idcol = pcol.Key
// }
// idk := fmt.Sprintf("__%s_%s", t.Name, idcol)
// // register a relationship between the remote data
// // and the database table
// val := &psql.DBRel{Type: psql.RelRemote}
// val.Left.Col = idcol
// val.Right.Col = idk
// err := pcompile.AddRelationship(strings.ToLower(r.Name), t.Name, val)
// if err != nil {
// return err
// }
// // the function thats called to resolve this remote
// // data request
// fn := buildFn(r)
// path := [][]byte{}
// for _, p := range strings.Split(r.Path, ".") {
// path = append(path, []byte(p))
// }
// rf := &resolvFn{
// IDField: []byte(idk),
// Path: path,
// Fn: fn,
// }
// // index resolver obj by parent and child names
// rmap[mkkey(h, r.Name, t.Name)] = rf
// // index resolver obj by IDField
// rmap[xxhash.Sum64(rf.IDField)] = rf
// }
// return nil
// }
func buildFn(r Remote) func(http.Header, []byte) ([]byte, error) {
reqURL := strings.Replace(r.URL, "$id", "%s", 1)
client := &http.Client{}
fn := func(hdr http.Header, id []byte) ([]byte, error) {
uri := fmt.Sprintf(reqURL, id)
req, err := http.NewRequest("GET", uri, nil)
if err != nil {
return nil, err
}
if host, ok := hdr["Host"]; ok {
req.Host = host[0]
}
for _, v := range r.SetHeaders {
req.Header.Set(v.Name, v.Value)
}
for _, v := range r.PassHeaders {
req.Header.Set(v, hdr.Get(v))
}
// logger.Debug().Str("uri", uri).Msg("Remote Join")
res, err := client.Do(req)
if err != nil {
// errlog.Error().Err(err).Msgf("Failed to connect to: %s", uri)
return nil, err
}
defer res.Body.Close()
if r.Debug {
// reqDump, err := httputil.DumpRequestOut(req, true)
// if err != nil {
// return nil, err
// }
// resDump, err := httputil.DumpResponse(res, true)
// if err != nil {
// return nil, err
// }
// logger.Debug().Msgf("Remote Request Debug:\n%s\n%s",
// reqDump, resDump)
}
if res.StatusCode != 200 {
return nil,
fmt.Errorf("server responded with a %d", res.StatusCode)
}
b, err := ioutil.ReadAll(res.Body)
if err != nil {
return nil, err
}
if err := jsn.ValidateBytes(b); err != nil {
return nil, err
}
return b, nil
}
return fn
}