refactor to SQL builder iterators and standard iterator wrapper

This commit is contained in:
Barak Michener 2015-07-29 15:56:15 -04:00
parent b754810c6e
commit 3e02bb2b71
5 changed files with 453 additions and 593 deletions

View file

@ -15,22 +15,25 @@
package sql
import (
"database/sql"
"fmt"
"strings"
"sync/atomic"
"github.com/barakmich/glog"
"github.com/google/cayley/graph"
"github.com/google/cayley/graph/iterator"
"github.com/google/cayley/quad"
)
var sqlNodeType graph.Type
var sqlNodeTableID uint64
type sqlQueryType int
const (
node sqlQueryType = iota
link
)
func init() {
sqlNodeType = graph.RegisterIterator("sqlnode")
atomic.StoreUint64(&sqlNodeTableID, 0)
}
@ -40,34 +43,20 @@ func newNodeTableName() string {
}
type SQLNodeIterator struct {
uid uint64
qs *QuadStore
tagger graph.Tagger
tableName string
err error
cursor *sql.Rows
linkIts []sqlItDir
nodetables []string
size int64
tagger graph.Tagger
result map[string]string
resultIndex int
resultList [][]string
resultNext [][]string
cols []string
result string
}
func (n *SQLNodeIterator) sqlClone() sqlIterator {
return n.Clone().(*SQLNodeIterator)
}
func (n *SQLNodeIterator) Clone() graph.Iterator {
m := &SQLNodeIterator{
uid: iterator.NextUID(),
qs: n.qs,
size: n.size,
tableName: n.tableName,
size: n.size,
}
for _, i := range n.linkIts {
m.linkIts = append(m.linkIts, sqlItDir{
@ -75,109 +64,39 @@ func (n *SQLNodeIterator) Clone() graph.Iterator {
it: i.it.sqlClone(),
})
}
m.tagger.CopyFrom(n)
m.tagger.CopyFromTagger(n.Tagger())
return m
}
func (n *SQLNodeIterator) UID() uint64 {
return n.uid
}
func (n *SQLNodeIterator) Reset() {
n.err = nil
n.Close()
}
func (n *SQLNodeIterator) Err() error {
return n.err
}
func (n *SQLNodeIterator) Close() error {
if n.cursor != nil {
err := n.cursor.Close()
if err != nil {
return err
}
n.cursor = nil
}
return nil
}
func (n *SQLNodeIterator) Tagger() *graph.Tagger {
return &n.tagger
}
func (n *SQLNodeIterator) Result() graph.Value {
return n.result["__execd"]
return n.result
}
func (n *SQLNodeIterator) TagResults(dst map[string]graph.Value) {
for tag, value := range n.result {
if tag == "__execd" {
for _, tag := range n.tagger.Tags() {
dst[tag] = value
}
continue
func (n *SQLNodeIterator) Type() sqlQueryType {
return node
}
func (n *SQLNodeIterator) Size(qs *QuadStore) (int64, bool) {
return qs.Size() / int64(len(n.linkIts)+1), true
}
func (n *SQLNodeIterator) Describe() string {
return fmt.Sprintf("SQL_NODE_QUERY: %#v", n)
}
func (n *SQLNodeIterator) buildResult(result []string, cols []string) map[string]string {
m := make(map[string]string)
for i, c := range cols {
if c == "__execd" {
n.result = result[i]
}
dst[tag] = value
}
for tag, value := range n.tagger.Fixed() {
dst[tag] = value
}
}
func (n *SQLNodeIterator) Type() graph.Type {
return sqlNodeType
}
func (n *SQLNodeIterator) SubIterators() []graph.Iterator {
// TODO(barakmich): SQL Subiterators shouldn't count? If it makes sense,
// there's no reason not to expose them though.
return nil
}
func (n *SQLNodeIterator) Sorted() bool { return false }
func (n *SQLNodeIterator) Optimize() (graph.Iterator, bool) { return n, false }
func (n *SQLNodeIterator) Size() (int64, bool) {
return n.qs.Size() / int64(len(n.linkIts)+1), true
}
func (n *SQLNodeIterator) Describe() graph.Description {
size, _ := n.Size()
return graph.Description{
UID: n.UID(),
Name: fmt.Sprintf("SQL_NODE_QUERY: %#v", n),
Type: n.Type(),
Size: size,
}
}
func (n *SQLNodeIterator) Stats() graph.IteratorStats {
size, _ := n.Size()
return graph.IteratorStats{
ContainsCost: 1,
NextCost: 5,
Size: size,
}
}
func (n *SQLNodeIterator) NextPath() bool {
n.resultIndex += 1
if n.resultIndex >= len(n.resultList) {
return false
}
n.buildResult(n.resultIndex)
return true
}
func (n *SQLNodeIterator) buildResult(i int) {
container := n.resultList[i]
n.result = make(map[string]string)
for i, c := range n.cols {
n.result[c] = container[i]
m[c] = result[i]
}
return m
}
func (n *SQLNodeIterator) makeNodeTableNames() {
@ -215,7 +134,6 @@ func (n *SQLNodeIterator) buildSubqueries() []tableDef {
// separate SQL iterators to build a similar tree as we're doing here, and
// have a single graph.Iterator 'caddy' structure around it.
subNode := &SQLNodeIterator{
uid: iterator.NextUID(),
tableName: newTableName(),
linkIts: []sqlItDir{it},
}
@ -351,144 +269,8 @@ func (n *SQLNodeIterator) buildSQL(next bool, val graph.Value) (string, []string
return query, values
}
func (n *SQLNodeIterator) Next() bool {
var err error
graph.NextLogIn(n)
if n.cursor == nil {
err = n.makeCursor(true, nil)
n.cols, err = n.cursor.Columns()
if err != nil {
glog.Errorf("Couldn't get columns")
n.err = err
n.cursor.Close()
return false
}
// iterate the first one
if !n.cursor.Next() {
glog.V(4).Infoln("sql: No next")
err := n.cursor.Err()
if err != nil {
glog.Errorf("Cursor error in SQL: %v", err)
n.err = err
}
n.cursor.Close()
return false
}
s, err := scan(n.cursor, len(n.cols))
if err != nil {
n.err = err
n.cursor.Close()
return false
}
n.resultNext = append(n.resultNext, s)
}
if n.resultList != nil && n.resultNext == nil {
// We're on something and there's no next
return false
}
n.resultList = n.resultNext
n.resultNext = nil
n.resultIndex = 0
for {
if !n.cursor.Next() {
glog.V(4).Infoln("sql: No next")
err := n.cursor.Err()
if err != nil {
glog.Errorf("Cursor error in SQL: %v", err)
n.err = err
}
n.cursor.Close()
break
}
s, err := scan(n.cursor, len(n.cols))
if err != nil {
n.err = err
n.cursor.Close()
return false
}
if n.resultList[0][0] != s[0] {
n.resultNext = append(n.resultNext, s)
break
} else {
n.resultList = append(n.resultList, s)
}
}
if len(n.resultList) == 0 {
return graph.NextLogOut(n, nil, false)
}
n.buildResult(0)
return graph.NextLogOut(n, n.Result(), true)
func (n *SQLNodeIterator) sameTopResult(target []string, test []string) bool {
return target[0] == test[0]
}
func (n *SQLNodeIterator) makeCursor(next bool, value graph.Value) error {
if n.cursor != nil {
n.cursor.Close()
}
var q string
var values []string
q, values = n.buildSQL(next, value)
q = convertToPostgres(q, values)
ivalues := make([]interface{}, 0, len(values))
for _, v := range values {
ivalues = append(ivalues, v)
}
cursor, err := n.qs.db.Query(q, ivalues...)
if err != nil {
glog.Errorf("Couldn't get cursor from SQL database: %v", err)
glog.Errorf("Query: %v", q)
cursor = nil
return err
}
n.cursor = cursor
return nil
}
func (n *SQLNodeIterator) Contains(v graph.Value) bool {
var err error
//if it.preFilter(v) {
//return false
//}
err = n.makeCursor(false, v)
if err != nil {
glog.Errorf("Couldn't make query: %v", err)
n.err = err
n.cursor.Close()
return false
}
n.cols, err = n.cursor.Columns()
if err != nil {
glog.Errorf("Couldn't get columns")
n.err = err
n.cursor.Close()
return false
}
n.resultList = nil
for {
if !n.cursor.Next() {
glog.V(4).Infoln("sql: No next")
err := n.cursor.Err()
if err != nil {
glog.Errorf("Cursor error in SQL: %v", err)
n.err = err
}
n.cursor.Close()
break
}
s, err := scan(n.cursor, len(n.cols))
if err != nil {
n.err = err
n.cursor.Close()
return false
}
n.resultList = append(n.resultList, s)
}
n.cursor.Close()
n.cursor = nil
if len(n.resultList) != 0 {
n.resultIndex = 0
n.buildResult(0)
return true
}
return false
}
func (n *SQLNodeIterator) quickContains(_ graph.Value) (bool, bool) { return false, false }