surrealpatch/db/update.go
2016-05-11 20:23:21 +01:00

167 lines
3.5 KiB
Go

// Copyright © 2016 Abcum Ltd
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package db
import (
"github.com/abcum/surreal/kv"
"github.com/abcum/surreal/sql"
"github.com/abcum/surreal/util/json"
"github.com/abcum/surreal/util/keys"
"github.com/cockroachdb/cockroach/client"
)
func executeUpdateStatement(ast *sql.UpdateStatement) (out []interface{}, err error) {
db.Txn(func(txn *client.Txn) error {
bch := txn.NewBatch()
for _, w := range ast.What {
// var res []interface{}
switch what := w.(type) {
case *sql.Thing: // Update a thing
var res interface{}
key := &keys.Thing{
KV: ast.KV,
NS: ast.NS,
DB: ast.DB,
TB: what.Table,
ID: what.ID,
}
if res, err = update(txn, key, ast); err != nil {
return err
}
out = append(out, res)
case *sql.Table: // Update a table
var res []interface{}
beg := &keys.Thing{
KV: ast.KV,
NS: ast.NS,
DB: ast.DB,
TB: what.Name,
ID: keys.Prefix,
}
end := &keys.Thing{
KV: ast.KV,
NS: ast.NS,
DB: ast.DB,
TB: what.Name,
ID: keys.Suffix,
}
if res, err = updateMany(txn, beg, end, ast); err != nil {
return err
}
out = append(out, res...)
}
}
return txn.CommitInBatch(bch)
})
return
}
// update updates a single record in the database. Before the record is updated, all
// conditions are checked, and if successful, data is merged, and fields are computed.
func update(txn *client.Txn, key *keys.Thing, ast *sql.UpdateStatement) (res interface{}, err error) {
var kv *kv.KV
var old *json.Doc
var doc *json.Doc
// var dif *diff.DocumentChange
// Check conditions
if !match(txn, key, ast.Cond) {
return
}
// Select the record
if kv, err = get(txn, key); err != nil {
return
}
// Parse the record
if old, doc, err = new(txn, key, kv); err != nil {
return
}
// Modify the record
if err = mrg(txn, key, old, doc, ast.Data); err != nil {
return
}
// differ := diff.New()
// dif, _ = differ.Diff(old.Search("data").Data().(map[string]interface{}), doc.Search("data").Data().(map[string]interface{}))
// Update the record
if err = cput(txn, key, doc.Bytes(), kv.Actual()); err != nil {
return
}
// trl := &keys.Trail{KV: key.KV, NS: key.NS, DB: key.DB, TB: key.TB, ID: key.ID}
// if err = cput(txn, trl, "dif", nil); err != nil {
// return
// }
res = echo(key, old, doc, nil, ast.Echo, sql.AFTER)
return
}
// updateMany updates multiple records in the database. Before records are updated, all
// conditions are checked, and if successful, data is merged, and fields are computed.
func updateMany(txn *client.Txn, beg, end *keys.Thing, ast *sql.UpdateStatement) (res []interface{}, err error) {
kvs, err := rget(txn, beg, end, -1)
if err != nil {
return
}
for _, kv := range kvs {
var ret interface{}
key := &keys.Thing{}
key.Decode(kv.Key)
if ret, err = update(txn, key, ast); err != nil {
return
}
res = append(res, ret)
}
return
}