surrealpatch/db/document.go
2018-05-02 03:05:03 +01:00

534 lines
11 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 (
"fmt"
"context"
"github.com/abcum/surreal/kvs"
"github.com/abcum/surreal/sql"
"github.com/abcum/surreal/util/data"
"github.com/abcum/surreal/util/diff"
"github.com/abcum/surreal/util/indx"
"github.com/abcum/surreal/util/keys"
)
type document struct {
i *iterator
ns string
db string
tb string
md map[string]interface{}
id *sql.Thing
key *keys.Thing
val kvs.KV
lck bool
doc *data.Doc
initial *data.Doc
current *data.Doc
store struct {
id int
tb bool
ev bool
fd bool
ix bool
ft bool
lv bool
}
cache struct {
tb *sql.DefineTableStatement
ev []*sql.DefineEventStatement
fd []*sql.DefineFieldStatement
ix []*sql.DefineIndexStatement
ft []*sql.DefineTableStatement
lv []*sql.LiveStatement
}
}
func newDocument(i *iterator, key *keys.Thing, val kvs.KV, doc *data.Doc) (d *document) {
d = documentPool.Get().(*document)
d.i = i
d.id = nil
d.key = key
d.val = val
d.doc = doc
d.lck = false
return
}
func (d *document) close() {
documentPool.Put(d)
}
func (d *document) clear() {
d.store.tb = false
d.store.ev = false
d.store.fd = false
d.store.ix = false
d.store.ft = false
d.store.lv = false
}
func (d *document) erase() (err error) {
d.current = data.Consume(nil)
return
}
func (d *document) getTB(ctx context.Context) (out *sql.DefineTableStatement, err error) {
if !d.store.tb {
d.store.tb = true
d.cache.tb, err = d.i.e.dbo.GetTB(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.tb, err
}
func (d *document) getEV(ctx context.Context) (out []*sql.DefineEventStatement, err error) {
if !d.store.ev {
d.store.ev = true
d.cache.ev, err = d.i.e.dbo.AllEV(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.ev, err
}
func (d *document) getFD(ctx context.Context) (out []*sql.DefineFieldStatement, err error) {
if !d.store.fd {
d.store.fd = true
d.cache.fd, err = d.i.e.dbo.AllFD(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.fd, err
}
func (d *document) getIX(ctx context.Context) (out []*sql.DefineIndexStatement, err error) {
if !d.store.ix {
d.store.ix = true
d.cache.ix, err = d.i.e.dbo.AllIX(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.ix, err
}
func (d *document) getFT(ctx context.Context) (out []*sql.DefineTableStatement, err error) {
if !d.store.ft {
d.store.ft = true
d.cache.ft, err = d.i.e.dbo.AllFT(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.ft, err
}
func (d *document) getLV(ctx context.Context) (out []*sql.LiveStatement, err error) {
if !d.store.lv {
d.store.lv = true
d.cache.lv, err = d.i.e.dbo.AllLV(ctx, d.key.NS, d.key.DB, d.key.TB)
}
return d.cache.lv, err
}
func (d *document) query(ctx context.Context, stm sql.Statement) (val interface{}, err error) {
defer func() {
if r := recover(); r != nil {
var ok bool
if err, ok = r.(error); !ok {
err = fmt.Errorf("%v", r)
}
}
d.ulock(ctx)
d.close()
}()
switch stm := stm.(type) {
default:
return nil, nil
case *sql.SelectStatement:
return d.runSelect(ctx, stm)
case *sql.CreateStatement:
return d.runCreate(ctx, stm)
case *sql.UpdateStatement:
return d.runUpdate(ctx, stm)
case *sql.DeleteStatement:
return d.runDelete(ctx, stm)
case *sql.RelateStatement:
return d.runRelate(ctx, stm)
case *sql.InsertStatement:
return d.runInsert(ctx, stm)
case *sql.UpsertStatement:
return d.runUpsert(ctx, stm)
}
}
func (d *document) init(ctx context.Context) (err error) {
// A table of records were requested
// so we have the values, but no key
// yet, so we need to decode the KV
// store key into a Thing key.
if d.key == nil && d.val != nil {
d.key = &keys.Thing{}
d.key.Decode(d.val.Key())
}
return
}
func (d *document) lock(ctx context.Context) (err error) {
if d.key != nil {
d.lck = true
d.i.e.lock.Lock(ctx, d.key)
}
return
}
func (d *document) ulock(ctx context.Context) (err error) {
if d.key != nil && d.lck {
d.lck = false
d.i.e.lock.Unlock(ctx, d.key)
}
return
}
func (d *document) setup(ctx context.Context) (err error) {
// A specific record has been requested
// and we have a key, but no value has
// been loaded yet, so the record needs
// to be loaded from the KV store.
if d.key != nil && d.val == nil {
d.val, err = d.i.e.dbo.Get(ctx, d.i.versn, d.key.Encode())
if err != nil {
return
}
}
// A subquery or data param has been
// loaded, and we might not have a key
// or a value, so let's load the data
// into a document, so that we can
// maniuplate the virtual document.
if d.doc != nil {
d.initial = d.doc
d.current = d.doc.Copy()
}
// The requested record has been loaded
// from the KV store (and not from a
// subquery or data variable), but does
// not exist. So we'll create a document
// for processing any record changes.
if d.doc == nil && d.val != nil && d.val.Exi() == false {
d.initial = data.New()
d.current = data.New()
}
// The requested record has been loaded
// from the KV store (and not from a
// subquery or data variable). So we'll
// load the KV data into a document for
// processing any record changes.
if d.doc == nil && d.val != nil && d.val.Exi() == true {
d.initial = data.New().Decode(d.val.Val())
d.current = data.New().Decode(d.val.Val())
}
// Finally if we are dealing with a record
// which is not data from the result of a
// subquery, then generate the ID from the
// key and re-calculate any cached data.
if d.key != nil {
// Check that the cached data for the
// current document belongs to the same
// NS, DB, and TB as the pooled document.
// If it doesn't then reset the cached data.
if d.ns != d.key.NS {
d.ns = d.key.NS
d.clear()
}
if d.db != d.key.DB {
d.db = d.key.DB
d.clear()
}
if d.tb != d.key.TB {
d.tb = d.key.TB
d.clear()
}
// Check that the cached data for the
// current document belongs to the same
// iterator as the pooled document. If
// it doesn't then reset the cached data.
if d.i.id != d.store.id {
d.store.id = d.i.id
d.clear()
}
// Finally, let's specify the ID of the
// current document, so we can use it
// for getting and setting data.
d.id = sql.NewThing(d.key.TB, d.key.ID)
}
return
}
func (d *document) forced(ctx context.Context) bool {
if val := ctx.Value(ctxKeyForce); val != nil {
return val.(bool)
}
return false
}
func (d *document) changed(ctx context.Context) bool {
a, _ := d.initial.Data().(map[string]interface{})
b, _ := d.current.Data().(map[string]interface{})
c := diff.Diff(a, b)
return len(c) > 0
}
func (d *document) shouldDrop(ctx context.Context) (bool, error) {
// Check whether it is specified
// that the table should drop
// writes, and if so, then return.
tb, err := d.getTB(ctx)
if err != nil {
return false, err
}
return tb.Drop, err
}
func (d *document) storeThing(ctx context.Context) (err error) {
defer d.ulock(ctx)
// Check that the rcord has been
// changed, and if not, return.
if ok := d.changed(ctx); !ok {
return
}
// Check that the table should
// drop data being written.
if ok, err := d.shouldDrop(ctx); ok {
return err
}
// Write the value to the data
// layer and return any errors.
_, err = d.i.e.dbo.Put(ctx, d.i.e.time, d.key.Encode(), d.current.Encode())
return
}
func (d *document) purgeThing(ctx context.Context) (err error) {
defer d.ulock(ctx)
// Check that the table should
// drop data being written.
if ok, err := d.shouldDrop(ctx); ok {
return err
}
// Reset the item by writing a
// nil value to the storage.
_, err = d.i.e.dbo.Put(ctx, d.i.e.time, d.key.Encode(), nil)
return
}
func (d *document) eraseThing(ctx context.Context) (err error) {
defer d.ulock(ctx)
// Check that the table should
// drop data being written.
if ok, err := d.shouldDrop(ctx); ok {
return err
}
// Delete the item entirely from
// storage, so no versions exist.
_, err = d.i.e.dbo.Clr(ctx, d.key.Encode())
return
}
func (d *document) storeIndex(ctx context.Context) (err error) {
// Check if this query has been run
// in forced mode, or return.
forced := d.forced(ctx)
// Check that the rcord has been
// changed, and if not, return.
if !forced && !d.changed(ctx) {
return
}
// Check that the table should
// drop data being written.
if ok, err := d.shouldDrop(ctx); ok {
return err
}
// Get the index values specified
// for this table, loop through
// them, and compute the changes.
ixs, err := d.getIX(ctx)
if err != nil {
return err
}
for _, ix := range ixs {
del := indx.Build(ix.Cols, d.initial)
add := indx.Build(ix.Cols, d.current)
if !forced {
del, add = indx.Diff(del, add)
}
if ix.Uniq == true {
for _, v := range del {
didx := &keys.Index{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v}
d.i.e.dbo.DelC(ctx, d.i.e.time, didx.Encode(), d.id.Bytes())
}
for _, v := range add {
aidx := &keys.Index{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v}
if _, err = d.i.e.dbo.PutC(ctx, 0, aidx.Encode(), d.id.Bytes(), nil); err != nil {
return &IndexError{tb: d.key.TB, name: ix.Name, cols: ix.Cols, vals: v}
}
}
}
if ix.Uniq == false {
for _, v := range del {
didx := &keys.Point{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v, ID: d.key.ID}
d.i.e.dbo.DelC(ctx, d.i.e.time, didx.Encode(), d.id.Bytes())
}
for _, v := range add {
aidx := &keys.Point{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v, ID: d.key.ID}
if _, err = d.i.e.dbo.PutC(ctx, 0, aidx.Encode(), d.id.Bytes(), nil); err != nil {
return &IndexError{tb: d.key.TB, name: ix.Name, cols: ix.Cols, vals: v}
}
}
}
}
return
}
func (d *document) purgeIndex(ctx context.Context) (err error) {
// Check if this query has been run
// in forced mode, or return.
forced := d.forced(ctx)
// Check that the rcord has been
// changed, and if not, return.
if !forced && !d.changed(ctx) {
return
}
// Check that the table should
// drop data being written.
if ok, err := d.shouldDrop(ctx); ok {
return err
}
// Get the index values specified
// for this table, loop through
// them, and compute the changes.
ixs, err := d.getIX(ctx)
if err != nil {
return err
}
for _, ix := range ixs {
del := indx.Build(ix.Cols, d.initial)
if ix.Uniq == true {
for _, v := range del {
key := &keys.Index{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v}
d.i.e.dbo.DelC(ctx, 0, key.Encode(), d.id.Bytes())
}
}
if ix.Uniq == false {
for _, v := range del {
key := &keys.Point{KV: d.key.KV, NS: d.key.NS, DB: d.key.DB, TB: d.key.TB, IX: ix.Name.ID, FD: v, ID: d.key.ID}
d.i.e.dbo.DelC(ctx, 0, key.Encode(), d.id.Bytes())
}
}
}
return
}