foundationdb/recipes/go-recipes/table.go

172 lines
4.1 KiB
Go

/*
* table.go
*
* This source file is part of the FoundationDB open source project
*
* Copyright 2013-2018 Apple Inc. and the FoundationDB project authors
*
* 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 main
import (
"fmt"
"log"
"github.com/apple/foundationdb/bindings/go/src/fdb"
"github.com/apple/foundationdb/bindings/go/src/fdb/directory"
"github.com/apple/foundationdb/bindings/go/src/fdb/subspace"
"github.com/apple/foundationdb/bindings/go/src/fdb/tuple"
)
func clear_subspace(trtr fdb.Transactor, sub subspace.Subspace) error {
_, err := trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
tr.ClearRange(sub)
return nil, nil
})
return err
}
func _pack(t interface{}) []byte {
return tuple.Tuple{t}.Pack()
}
func _unpack(t []byte) tuple.Tuple {
i, e := tuple.Unpack(t)
if e != nil {
return nil
}
return i
}
type Table struct {
row, col subspace.Subspace
}
func (tbl *Table) NewTable(ss subspace.Subspace) {
tbl.row = ss.Sub("row")
tbl.col = ss.Sub("col")
}
func (tbl Table) TableSetCell(trtr fdb.Transactor, row, column int, value interface{}) {
trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
tr.Set(tbl.row.Pack(tuple.Tuple{row, column}), _pack(value))
tr.Set(tbl.col.Pack(tuple.Tuple{column, row}), _pack(value))
return nil, nil
})
}
func (tbl Table) TableGetCell(trtr fdb.Transactor, row, column int) interface{} {
item, _ := trtr.ReadTransact(func(rtr fdb.ReadTransaction) (interface{}, error) {
i := rtr.Get(tbl.row.Pack(tuple.Tuple{row, column})).MustGet()
return i, nil
})
return _unpack(item.([]byte))[0]
}
func (tbl Table) TableSetRow(trtr fdb.Transactor, row int, cols ...interface{}) {
trtr.Transact(func(tr fdb.Transaction) (interface{}, error) {
kr, err := fdb.PrefixRange(tbl.row.Pack(tuple.Tuple{row}))
if err != nil {
return nil, err
}
tr.ClearRange(kr)
for c, v := range cols {
tbl.TableSetCell(tr, row, c, v)
}
return nil, nil
})
return
}
func (tbl Table) TableGetRow(tr fdb.ReadTransactor, row int) ([]interface{}, error) {
item, err := tr.ReadTransact(func(rtr fdb.ReadTransaction) (interface{}, error) {
kr, e := fdb.PrefixRange(tbl.row.Pack(tuple.Tuple{row}))
if e != nil {
return nil, e
}
slice, e := rtr.GetRange(kr, fdb.RangeOptions{0, -1, false}).GetSliceWithError()
if e != nil {
return nil, e
}
ret := make([]interface{}, len(slice))
for i, v := range slice {
ret[i] = _unpack(v.Value)[0]
}
return ret, nil
})
if err != nil {
return nil, err
}
return item.([]interface{}), nil
}
func (tbl Table) TableGetCol(tr fdb.ReadTransactor, col int) ([]interface{}, error) {
item, err := tr.ReadTransact(func(rtr fdb.ReadTransaction) (interface{}, error) {
kr, e := fdb.PrefixRange(tbl.col.Pack(tuple.Tuple{col}))
if e != nil {
return nil, e
}
slice, e := rtr.GetRange(kr, fdb.RangeOptions{0, -1, false}).GetSliceWithError()
if e != nil {
return nil, e
}
ret := make([]interface{}, len(slice))
for i, v := range slice {
ret[i] = _unpack(v.Value)[0]
}
return ret, nil
})
if err != nil {
return nil, err
}
return item.([]interface{}), nil
}
func main() {
fdb.MustAPIVersion(710)
db := fdb.MustOpenDefault()
TableDemoDir, err := directory.CreateOrOpen(db, []string{"Graph"}, nil)
if err != nil {
log.Fatal(err)
}
clear_subspace(db, TableDemoDir)
var g Table
g.NewTable(TableDemoDir)
g.TableSetCell(db, 0, 0, "Hello")
g.TableSetCell(db, 0, 1, "World")
fmt.Println(g.TableGetCell(db, 0, 0).(string))
fmt.Println(g.TableGetCell(db, 0, 1).(string))
g.TableSetRow(db, 1, "Hello", "World", "Again!", 1)
fmt.Println(g.TableGetRow(db, 1))
}