Send dates as unix epoch instead strings in .mvt files

This commit creates a new ConfigAdapter used in vector maps instantiations.
This adapter generates a new sql query for ONE SINGLE LAYER (carto-vl currently only supports one layer per mvt)
where the date columns are wrapped into a epoch using the `date_part` function.

Due this mvt files are smaller since we use numbers instead strings to represent dates, this is also faster in carto-gl
where we interpolate linearly between 0 and 1 to create animations.

Notice we should add a parameter to make this transformation optional.
We also should take into account the epoch precission.

lib/cartodb/api/api-router.js

@@ -35,6 +35,7 @@ const TurboCartoAdapter = require('../models/mapconfig/adapter/turbo-carto-adapt
 const DataviewsWidgetsAdapter = require('../models/mapconfig/adapter/dataviews-widgets-adapter');
 const AggregationMapConfigAdapter = require('../models/mapconfig/adapter/aggregation-mapconfig-adapter');
 const MapConfigAdapter = require('../models/mapconfig/adapter');
+const VectorMapConfigAdapter = require('../models/mapconfig/adapter/vector-mapconfig-adapter');
 
 const ResourceLocator = require('../models/resource-locator');
 const LayergroupMetadata = require('../utils/layergroup-metadata');
@@ -135,6 +136,7 @@ module.exports = class ApiRouter {
             new SqlWrapMapConfigAdapter(),
             new DataviewsWidgetsAdapter(),
             new AnalysisMapConfigAdapter(analysisBackend),
+            new VectorMapConfigAdapter(pgConnection),
             new AggregationMapConfigAdapter(pgConnection),
             new MapConfigOverviewsAdapter(overviewsMetadataBackend, filterStatsBackend),
             new TurboCartoAdapter()

lib/cartodb/models/dataview/histograms/date-histogram.js

@@ -2,6 +2,7 @@ const BaseHistogram = require('./base-histogram');
 const debug = require('debug')('windshaft:dataview:date-histogram');
 const utils = require('../../../utils/query-utils');
 
+
 /**
  * Gets the name of a timezone with the same offset as the required
  * using the pg_timezone_names table. We do this because it's simpler to pass

lib/cartodb/models/mapconfig/adapter/vector-mapconfig-adapter.js

@@ -0,0 +1,39 @@
+const AggregationMapConfig = require('../../aggregation/aggregation-mapconfig');
+const utilsService = require('../../../utils/get-column-types');
+
+// Generate query to detect time columns
+// For every column cast to unix timestamp
+module.exports = class VectorMapConfigAdapter {
+    constructor(pgConnection) {
+        this.pgConnection = pgConnection;
+    }
+
+    getMapConfig(user, requestMapConfig, params, context, callback) {
+        let mapConfig;
+        try {
+            mapConfig = new AggregationMapConfig(user, requestMapConfig, this.pgConnection);
+        } catch (err) {
+            return callback(err);
+        }
+
+        if (!mapConfig.isVectorOnlyMapConfig()) {
+            return callback(null, requestMapConfig);
+        }
+
+        if (requestMapConfig.layers.lenght > 1) {
+            return callback(new Error('Get column types for multiple vector layers is not implemented'));
+        }
+
+
+        // // Get columns
+        utilsService.getColumns(user, this.pgConnection, requestMapConfig.layers[0])
+            .then(result => {
+                const newSqlQuery = utilsService.wrapDates(requestMapConfig.layers[0].options.sql, result.fields);
+                requestMapConfig.layers[0].options.sql = newSqlQuery;
+                return callback(null, requestMapConfig);
+            })
+            .catch(err => {
+                return callback(err);
+            });
+    }
+};

lib/cartodb/utils/get-column-types.js

@@ -0,0 +1,60 @@
+// Postgress ID of date types
+const DATE_OIDS = {
+    1082: true,
+    1114: true,
+    1184: true
+};
+
+
+/**
+ * Wrap a query transforming all date columns into a unix epoch
+ * @param {*} originalQuery 
+ * @param {*} fields 
+ */
+function wrapDates(originalQuery, fields) {
+    return `
+        SELECT 
+            ${fields.map(field => DATE_OIDS.hasOwnProperty(field.dataTypeID) ? _castColumnToEpoch(field.name) : `${field.name}`).join(',')} 
+        FROM 
+            (${originalQuery}) _cdb_epoch_transformation `;
+}
+
+/**
+ * Return a list of all the columns in the query
+ * @param {*} dbConnection 
+ * @param {*} originalQuery 
+ */
+function getColumns(user, dbConnection, layer) {
+    return _getColumns(user, dbConnection, layer.options.sql);
+}
+
+/**
+ * Return a sql query to transform a date column into a unix epoch
+ * @param {string} column - The name of the date column
+ */
+function _castColumnToEpoch(columnName) {
+    return `date_part('epoch', ${columnName}) as ${columnName}`;
+}
+
+function _getColumns(user, dbConnection, originalQuery) {
+    return new Promise((resolve, reject) => {
+
+        dbConnection.getConnection(user, (err, connection) => {
+            if (err) {
+                return reject(err);
+            }
+            connection.query(`SELECT * FROM (${originalQuery}) _cdb_column_type limit 0`, (err, res) => {
+                if (err) {
+                    return reject(err);
+                }
+                resolve(res);
+            });
+        });
+    });
+}
+
+
+module.exports = {
+    wrapDates,
+    getColumns,
+};

lib/cartodb/utils/query-utils.js

@@ -59,25 +59,25 @@ module.exports.handleFloatColumn = function handleFloatColumn(ctx) {
 };
 
 /** Count NULL appearances */
-module.exports.countNULLs= function countNULLs(ctx) {
+module.exports.countNULLs = function countNULLs(ctx) {
     return `sum(CASE WHEN (${ctx.column} IS NULL) THEN 1 ELSE 0 END)`;
 };
 
 /** Count only infinity (positive and negative) appearances */
 module.exports.countInfinites = function countInfinites(ctx) {
-    return `${!ctx.isFloatColumn ? `0` :
+    return `${!ctx.isFloatColumn ? '0' :
         `sum(CASE WHEN (${ctx.column} = 'infinity'::float OR ${ctx.column} = '-infinity'::float) THEN 1 ELSE 0 END)`
     }`;
 };
 
 /** Count only NaNs appearances*/
 module.exports.countNaNs = function countNaNs(ctx) {
-    return `${!ctx.isFloatColumn ? `0` :
+    return `${!ctx.isFloatColumn ? '0' :
         `sum(CASE WHEN (${ctx.column} = 'NaN'::float) THEN 1 ELSE 0 END)`
     }`;
 };
 
-module.exports.getQueryTopCategories = function(query, column, topN, includeNulls=false) {
+module.exports.getQueryTopCategories = function (query, column, topN, includeNulls = false) {
     const where = includeNulls ? '' : `WHERE ${column} IS NOT NULL`;
     return `
         SELECT ${column} AS category, COUNT(*) AS frequency
@@ -101,7 +101,7 @@ function columnSelector(columns) {
     throw new TypeError(`Bad argument type for columns: ${typeof columns}`);
 }
 
-module.exports.getQuerySample = function(query, sampleProb, limit = null, randomSeed = 0.5, columns = null) {
+module.exports.getQuerySample = function (query, sampleProb, limit = null, randomSeed = 0.5, columns = null) {
     const singleTable = simpleQueryTable(query);
     if (singleTable) {
         return getTableSample(singleTable.table, columns || singleTable.columns, sampleProb, limit, randomSeed);
@@ -121,7 +121,7 @@ module.exports.getQuerySample = function(query, sampleProb, limit = null, random
 function getTableSample(table, columns, sampleProb, limit = null, randomSeed = 0.5) {
     const limitClause = limit ? `LIMIT ${limit}` : '';
     sampleProb *= 100;
-    randomSeed *= Math.pow(2, 31) -1;
+    randomSeed *= Math.pow(2, 31) - 1;
     return `
         SELECT ${columnSelector(columns)}
         FROM ${table}
@@ -132,12 +132,12 @@ function getTableSample(table, columns, sampleProb, limit = null, randomSeed = 0
 function simpleQueryTable(sql) {
     const basicQuery =
         /\s*SELECT\s+([\*a-z0-9_,\s]+?)\s+FROM\s+((\"[^"]+\"|[a-z0-9_]+)\.)?(\"[^"]+\"|[a-z0-9_]+)\s*;?\s*/i;
-    const unwrappedQuery = new RegExp("^"+basicQuery.source+"$", 'i');
+    const unwrappedQuery = new RegExp('^' + basicQuery.source + '$', 'i');
     // queries for named maps are wrapped like this:
     var wrappedQuery = new RegExp(
-        "^\\s*SELECT\\s+\\*\\s+FROM\\s+\\(" +
+        '^\\s*SELECT\\s+\\*\\s+FROM\\s+\\(' +
         basicQuery.source +
-        "\\)\\s+AS\\s+wrapped_query\\s+WHERE\\s+\\d+=1\\s*$",
+        '\\)\\s+AS\\s+wrapped_query\\s+WHERE\\s+\\d+=1\\s*$',
         'i'
     );
     let match = sql.match(unwrappedQuery);
@@ -153,7 +153,7 @@ function simpleQueryTable(sql) {
     return false;
 }
 
-module.exports.getQueryGeometryType = function(query, geometryColumn) {
+module.exports.getQueryGeometryType = function (query, geometryColumn) {
     return `
         SELECT ST_GeometryType(${geometryColumn}) AS geom_type
             FROM (${query}) AS __cdb_query
@@ -162,10 +162,12 @@ module.exports.getQueryGeometryType = function(query, geometryColumn) {
     `;
 };
 
-module.exports.getQueryLimited = function(query, limit=0) {
+function getQueryLimited(query, limit = 0) {
     return `
         SELECT *
             FROM (${query}) AS __cdb_query
             LIMIT ${limit}
     `;
-};
+}
+
+module.exports.getQueryLimited = getQueryLimited;