From 44480c5ea986673b098fddd1ca74c23bc2b7e5e1 Mon Sep 17 00:00:00 2001
From: Lucas Fernandes de Oliveira <lfoliveira@inf.ufpr.br>
Date: Wed, 12 Dec 2018 09:23:49 -0200
Subject: [PATCH] Issue #100: Topological sort the query partial views in SQL
adapter
Signed-off-by: Lucas Fernandes de Oliveira <lfoliveira@inf.ufpr.br>
---
src/adapter/sql.ts | 31 ++++++++++++++++++--------
src/util/tsort.ts | 55 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 77 insertions(+), 9 deletions(-)
diff --git a/src/adapter/sql.ts b/src/adapter/sql.ts
index 6bf00505..93c3bb96 100644
--- a/src/adapter/sql.ts
+++ b/src/adapter/sql.ts
@@ -27,6 +27,7 @@ import { Filter, FilterOperator } from "../core/filter";
import { AggregationType, RelationType, DataType } from "../common/types";
import { Operation, Opcode } from "../common/expression";
import { View } from "../core/view";
+import { Tsort } from "../util/tsort";
/**
* Information required to make a join clause.
@@ -62,6 +63,11 @@ interface QueryAndName {
name: string;
}
+/** Dictonary indexed by view name, that returns the QueryAndName object. */
+interface QNMap {
+ [key: string]: QueryAndName;
+}
+
/**
* Two Dictionaries, both indexed with a dimension name.
* Used to get the views where a dimension is.
@@ -90,7 +96,11 @@ export abstract class SQLAdapter extends Adapter {
* @param view - View to be translated.
*/
public getQueryFromView(view: View): string {
- const partials = this.buildPartials(view).filter((i) => {
+ const map = this.buildPartials(view);
+ const topSort = Tsort.view(view);
+ const partials = topSort.map((i) => {
+ return (map[i]) ? map[i] : {query : "", name: i};
+ }).filter((i) => {
return i.query !== "";
}).map((i) => {
return i.name + " AS (" + i.query + ")";
@@ -121,13 +131,14 @@ export abstract class SQLAdapter extends Adapter {
* partials can only have one metric.
* @param view - View which the partial will be built.
*/
- private buildPartials(view: View): QueryAndName[] {
+ private buildPartials(view: View): QNMap {
let op = view.operation;
let queue: View[] = op.values.map((i) => i);
- const output: QueryAndName[] = [{
+ const output: QNMap = {};
+ output[view.name] = {
query: this.operation(op, view),
- name: view.name,
- }];
+ name: view.name
+ };
const map: {[key: string]: boolean } = {};
@@ -137,10 +148,12 @@ export abstract class SQLAdapter extends Adapter {
const query = this.operation(partial.operation, partial);
if (query !== "") {
map[partial.id] = true;
- output.unshift({
- query: query,
- name: partial.name
- });
+ if (!output[partial.name]) {
+ output[partial.name] = {
+ query: query,
+ name: partial.name
+ };
+ }
queue = queue.concat(partial.operation.values);
}
}
diff --git a/src/util/tsort.ts b/src/util/tsort.ts
index a97f7f4b..2bff0690 100644
--- a/src/util/tsort.ts
+++ b/src/util/tsort.ts
@@ -22,6 +22,9 @@
* A representation of a dependency relation.
* Equivalent to a edge in a dependency graph.
*/
+
+import { View } from "../core/view";
+
export interface TsortDep {
/** The value (vertex). */
value: string;
@@ -60,6 +63,7 @@ export class Tsort {
* dependency graph).
*/
public static dependencies(deps: TsortDep[]): string[]{
+ // Graph Creation
let graph: Graph = {};
let mark: VertexMark = {};
for (let i = 0; i < deps.length; ++i) {
@@ -82,6 +86,57 @@ export class Tsort {
}
+ // Topological Sort
+ let output: string[] = [];
+ for (let vertex of Object.keys(graph)) {
+ if (!mark[vertex]) {
+ Tsort.markVertex(vertex, graph, mark, output);
+ }
+ }
+ return output;
+ }
+
+ /**
+ * Topologicaly sort view descendents names.
+ * @param view - View to construct dependency tree(graph) and sort it
+ */
+ public static view(view: View): string[] {
+ // Graph creation
+ const graph: Graph = {};
+ const mark: VertexMark = {};
+
+ let queue = [view];
+
+ while (queue.length > 0) {
+ const partial = queue.shift();
+
+ // If the dependent vertex does not exist, create it
+ // with a empty dependent list
+ if (!graph[partial.name]) {
+ graph[partial.name] = [];
+ mark[partial.name] = false;
+ }
+ for (let i = 0; i < partial.operation.values.length; ++i) {
+ const dep = partial.operation.values[i];
+
+ // If the required vertex does not exists create it
+ // and put the dependent vertex in the dependent list
+ if (!graph[dep.name]) {
+ graph[dep.name] = [partial.name];
+ mark[dep.name] = false;
+ }
+
+ // If the vertex already exists, add it in the dependent list
+ else {
+ graph[dep.name].push(partial.name);
+ }
+
+ // Add the other view. Could create replicated edges.
+ queue = queue.concat(partial.operation.values);
+ }
+ }
+
+ // Topological Sort
let output: string[] = [];
for (let vertex of Object.keys(graph)) {
if (!mark[vertex]) {
--
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