From 63b6af2ac73e0862a0ae706f4dcf4dfa8afb3c55 Mon Sep 17 00:00:00 2001
From: Raul Marin <git@rmr.ninja>
Date: Mon, 15 Jul 2019 14:16:21 +0200
Subject: [PATCH] Query utils: Use webmercator utils, reuse code and always
 substitute tokens

---
 lib/cartodb/utils/query-utils.js | 99 ++++++++++++++------------------
 1 file changed, 42 insertions(+), 57 deletions(-)

diff --git a/lib/cartodb/utils/query-utils.js b/lib/cartodb/utils/query-utils.js
index 2fc00c5a..f5daf0e1 100644
--- a/lib/cartodb/utils/query-utils.js
+++ b/lib/cartodb/utils/query-utils.js
@@ -1,48 +1,41 @@
 'use strict';
 
-const SubstitutionTokens = require('./substitution-tokens');
+const windshaftUtils = require('windshaft').utils;
 
-function prepareQuery(sql) {
-    var affectedTableRegexCache = {
-        bbox: /!bbox!/g,
-        scale_denominator: /!scale_denominator!/g,
-        pixel_width: /!pixel_width!/g,
-        pixel_height: /!pixel_height!/g
-    };
-
-    return sql
-        .replace(affectedTableRegexCache.bbox, 'ST_MakeEnvelope(0,0,0,0)')
-        .replace(affectedTableRegexCache.scale_denominator, '0')
-        .replace(affectedTableRegexCache.pixel_width, '1')
-        .replace(affectedTableRegexCache.pixel_height, '1');
-}
-
-module.exports.extractTableNames = function extractTableNames(query) {
+module.exports.extractTableNames = function (query) {
     return [
         'SELECT * FROM CDB_QueryTablesText($windshaft$',
-        prepareQuery(query),
+        substituteDummyTokens(query),
         '$windshaft$) as tablenames'
     ].join('');
 };
 
 module.exports.getQueryActualRowCount = function (query) {
-    return `select COUNT(*) AS rows FROM (${query}) AS __cdb_query`;
+    return `select COUNT(*) AS rows FROM (${substituteDummyTokens(query)}) AS __cdb_query`;
 };
 
 function getQueryRowEstimation(query) {
-    return 'select CDB_EstimateRowCount($windshaft$' + query + '$windshaft$) as rows';
+    return 'select CDB_EstimateRowCount($windshaft$' + substituteDummyTokens(query) + '$windshaft$) as rows';
 }
-
 module.exports.getQueryRowEstimation = getQueryRowEstimation;
 
+function getQueryGeometryType(query, geometryColumn) {
+    return `
+        SELECT ST_GeometryType(${geometryColumn}) AS geom_type
+            FROM (${substituteDummyTokens(query)}) AS __cdb_query
+            WHERE ${geometryColumn} IS NOT NULL
+            LIMIT 1
+    `;
+}
+module.exports.getQueryGeometryType = getQueryGeometryType;
+
 module.exports.getAggregationMetadata = ctx => `
     WITH
     rowEstimation AS (
         ${getQueryRowEstimation(ctx.query)}
     ),
     geometryType AS (
-        SELECT ST_GeometryType(${ctx.geometryColumn}) as geom_type
-        FROM (${ctx.query}) AS __cdb_query WHERE ${ctx.geometryColumn} IS NOT NULL LIMIT 1
+        ${getQueryGeometryType(ctx.query, ctx.geometryColumn)}
     )
     SELECT
         rows AS count,
@@ -85,7 +78,7 @@ module.exports.getQueryTopCategories = function (query, column, topN, includeNul
     const where = includeNulls ? '' : `WHERE ${column} IS NOT NULL`;
     return `
         SELECT ${column} AS category, COUNT(*) AS frequency
-        FROM (${query}) AS __cdb_query
+        FROM (${substituteDummyTokens(query)}) AS __cdb_query
         ${where}
         GROUP BY ${column} ORDER BY 2 DESC
         LIMIT ${topN}
@@ -116,7 +109,7 @@ module.exports.getQuerySample = function (query, sampleProb, limit = null, rando
             SELECT setseed(${randomSeed})
         )
         SELECT ${columnSelector(columns)}
-            FROM (${query}) AS __cdb_query
+            FROM (${substituteDummyTokens(query)}) AS __cdb_query
             WHERE random() < ${sampleProb}
             ${limitClause}
     `;
@@ -157,19 +150,11 @@ function simpleQueryTable(sql) {
     return false;
 }
 
-module.exports.getQueryGeometryType = function (query, geometryColumn) {
-    return `
-        SELECT ST_GeometryType(${geometryColumn}) AS geom_type
-            FROM (${query}) AS __cdb_query
-            WHERE ${geometryColumn} IS NOT NULL
-            LIMIT 1
-    `;
-};
 
 function getQueryLimited(query, limit = 0) {
     return `
         SELECT *
-            FROM (${query}) AS __cdb_query
+            FROM (${substituteDummyTokens(query)}) AS __cdb_query
             LIMIT ${limit}
     `;
 }
@@ -181,32 +166,32 @@ function queryPromise(dbConnection, query) {
 }
 
 function substituteDummyTokens(sql) {
-    return sql && SubstitutionTokens.replace(sql, {
-        bbox: 'ST_MakeEnvelope(0,0,0,0)',
-        scale_denominator: '0',
-        pixel_width: '1',
-        pixel_height: '1'
-    });
+    return subsituteTokensForZoom(sql, 0);
 }
 
-function subsituteTokensForZoom(sql, zoom, singleTile=false) {
-    const tileRes = 256;
-    const wmSize = 6378137.0*2*Math.PI;
-    const nTiles = Math.pow(2, zoom);
-    const tileSize = wmSize / nTiles;
-    const resolution = tileSize / tileRes;
-    const scaleDenominator = resolution / 0.00028;
-    const x0 = -wmSize/2, y0 = -wmSize/2;
-    let bbox = `ST_MakeEnvelope(${x0}, ${y0}, ${x0+wmSize}, ${y0+wmSize})`;
-    if (singleTile) {
-        bbox = `ST_MakeEnvelope(${x0}, ${y0}, ${x0 + tileSize}, ${y0 + tileSize})`;
+function subsituteTokensForZoom(sql, zoom) {
+    if (!sql) {
+        return undefined;
     }
-    return SubstitutionTokens.replace(sql, {
-        bbox: bbox,
-        scale_denominator: scaleDenominator,
-        pixel_width: resolution,
-        pixel_height: resolution
-    });
+    const affectedTableRegexCache = {
+        bbox: /!bbox!/g,
+        scale_denominator: /!scale_denominator!/g,
+        pixel_width: /!pixel_width!/g,
+        pixel_height: /!pixel_height!/g
+    };
+
+    const webmercator = new windshaftUtils.WebMercatorHelper();
+    const resolution = webmercator.getResolution({ z : zoom });
+    const scaleDenominator = resolution.dividedBy(0.00028);
+    // We always use the whole world as the bbox
+    const extent = webmercator.getExtent({ x : 0, y : 0, z : 0 });
+
+    return sql
+        .replace(affectedTableRegexCache.bbox,
+                 `ST_MakeEnvelope(${extent.xmin}, ${extent.ymin}, ${extent.xmax}, ${extent.ymax}, 3857)`)
+        .replace(affectedTableRegexCache.scale_denominator, scaleDenominator)
+        .replace(affectedTableRegexCache.pixel_width, resolution)
+        .replace(affectedTableRegexCache.pixel_height, resolution);
 }
 
 module.exports.queryPromise = queryPromise;