131 lines
3.2 KiB
Go
131 lines
3.2 KiB
Go
/*
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* indirect.go
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*
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* This source file is part of the FoundationDB open source project
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*
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* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package main
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import (
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"fmt"
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"github.com/apple/foundationdb/bindings/go/src/fdb"
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"github.com/apple/foundationdb/bindings/go/src/fdb/directory"
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"github.com/apple/foundationdb/bindings/go/src/fdb/subspace"
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"github.com/apple/foundationdb/bindings/go/src/fdb/tuple"
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"log"
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)
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func clear_subspace(trtr fdb.Transactor, sub subspace.Subspace) error {
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_, err := trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
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tr.ClearRange(sub)
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return nil, nil
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})
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return err
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}
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func print_subspace(trtr fdb.Transactor, sub subspace.Subspace) {
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trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
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k := tr.GetRange(sub, fdb.RangeOptions{0, -1, false}).Iterator()
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for k.Advance() {
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fmt.Println(_unpack(k.MustGet().Value))
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}
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return nil, nil
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})
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}
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func _pack(t interface{}) []byte {
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return tuple.Tuple{t}.Pack()
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}
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func _unpack(t []byte) tuple.Tuple {
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i, e := tuple.Unpack(t)
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if e != nil {
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return nil
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}
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return i
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}
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type Workspace struct {
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Dir directory.Directory
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db fdb.Database
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}
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func (wrkspc Workspace) _Update(trtr fdb.Transactor) {
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trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
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_, err := wrkspc.Dir.Remove(tr, []string{"current"})
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if err != nil {
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log.Fatal(err)
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}
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_, err = wrkspc.Dir.Move(tr, []string{"new"}, []string{"current"})
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return nil, err
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})
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}
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func (wrkspc Workspace) GetCurrent() (dir directory.DirectorySubspace, err error) {
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dir, err = wrkspc.Dir.CreateOrOpen(wrkspc.db, []string{"current"}, nil)
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return
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}
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func (wrkspc Workspace) Session(foo func(directory.DirectorySubspace)) (err error) {
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newdir, err := wrkspc.Dir.CreateOrOpen(wrkspc.db, []string{"new"}, nil)
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if err != nil {
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return
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}
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foo(newdir)
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wrkspc._Update(wrkspc.db)
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return
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}
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func main() {
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fdb.MustAPIVersion(710)
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db := fdb.MustOpenDefault()
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WorkspaceDemoDir, err := directory.CreateOrOpen(db, []string{"Workspace"}, nil)
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if err != nil {
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log.Fatal(err)
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}
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clear_subspace(db, WorkspaceDemoDir)
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w := Workspace{WorkspaceDemoDir, db}
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current, err := w.GetCurrent()
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clear_subspace(db, current)
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db.Transact(func(tr fdb.Transaction) (interface{}, error) {
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tr.Set(current.Pack(tuple.Tuple{"a"}), _pack("Hello"))
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return nil, nil
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})
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print_subspace(db, current)
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w.Session(func(dir directory.DirectorySubspace) {
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db.Transact(func(tr fdb.Transaction) (interface{}, error) {
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tr.Set(dir.Pack(tuple.Tuple{"b"}), _pack("World"))
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return nil, nil
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})
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})
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current, err = w.GetCurrent()
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if err != nil {
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log.Fatal(err)
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}
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print_subspace(db, current)
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}
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