add alpha parquet data files loading with parquets lib (#13)

Author: RandomFractals

package-lock.json

@@ -2,7 +2,7 @@
   "name": "vscode-data-preview",
   "displayName": "Data Preview",
   "description": "Data Preview 🈸 extension for importing 📤 viewing 🔎 slicing 🔪 dicing 🎲 charting 📊 & exporting 📥 large JSON array/config, YAML, Apache Arrow, Avro & Excel data files",
-  "version": "2.2.0",
+  "version": "2.3.0",
   "icon": "images/data-preview.png",
   "publisher": "RandomFractalsInc",
   "author": "Taras Novak a.k.a. dataPixy devTools maker :)",
@@ -416,8 +416,9 @@
     "json5": "^2.1.3",
     "jsonc-parser": "2.3.1",
     "json-spread": "0.3.2",
+    "parquets": "^0.10.10",
     "properties": "^1.2.1",
-    "snappy": "^6.3.4",
+    "snappy": "^6.3.5",
     "superagent": "^6.1.0",
     "xlsx": "^0.16.7"
   }

package.json

@@ -12,8 +12,9 @@ import {JsonDataProvider} from './data.providers/json.data.provider';
 import {Json5DataProvider} from './data.providers/json5.data.provider';
 import {JsonLineDataProvider} from './data.providers/json.line.data.provider';
 import {MarkdownDataProvider} from './data.providers/markdown.data.provider';
-import {TextDataProvider} from './data.providers/text.data.provider';
+import {ParquetDataProvider} from './data.providers/parquet.data.provider';
 import {PropertiesDataProvider} from './data.providers/properties.data.provider';
+import {TextDataProvider} from './data.providers/text.data.provider';
 import {YamlDataProvider} from './data.providers/yaml.data.provider';
 
 /**
@@ -143,8 +144,9 @@ export class DataManager implements IDataManager {
     this.addDataProvider(dataProviders, new Json5DataProvider());
     this.addDataProvider(dataProviders, new JsonLineDataProvider());
     this.addDataProvider(dataProviders, new MarkdownDataProvider());
-    this.addDataProvider(dataProviders, new TextDataProvider());
     this.addDataProvider(dataProviders, new PropertiesDataProvider());
+    this.addDataProvider(dataProviders, new ParquetDataProvider());
+    this.addDataProvider(dataProviders, new TextDataProvider());
     this.addDataProvider(dataProviders, new YamlDataProvider());
     this._logger.debug('loadDataProviders(): loaded data providers:', Object.keys(dataProviders));
     return dataProviders;

src/data.manager.ts

@@ -19,7 +19,6 @@ import {
 // fs data parsing imports
 import * as fs from 'fs';
 import * as path from 'path';
-//import * as parquet from 'parquetjs';
 
 // data preview imports
 import * as config from './config';
@@ -404,7 +403,7 @@ export class DataPreview {
     // update columns and rows state vars
     this._columns = columns;
     this._rowCount = rowCount;
-    let dataStats: string = `Rows: ${rowCount.toLocaleString()}\tColumns: ${columns.length.toLocaleString()}`;
+    let dataStats: string = `Rows: ${rowCount.toLocaleString()}\tColumns: ${columns?.length.toLocaleString()}`;
     if (this._tableNames.length > 0) {
       // add tables count to data preview data stats status display
       dataStats = `Tables: ${this._tableNames.length.toLocaleString()}\t${dataStats}`;
@@ -666,30 +665,23 @@ export class DataPreview {
    */
   private getData(dataUrl: string, dataTable: string = ''): any {
     let data: any = [];
-    if (this._fileExtension === '.parquet') {
-      // TODO: sort out node-gyp lzo lib loading for parquet data files parse
-      window.showInformationMessage('Parquet Data Preview 🈸 coming soon!');        
-      // data = this.getParquetData(dataFilePath);
-    }
-    else { // get data, table names, and data schema via data.manager api
-      dataManager.getData(dataUrl, {
-          dataTable: dataTable,
-          createJsonFiles: this.createJsonFiles,
-          createJsonSchema: this.createJsonSchema
-        }, (data: any) => {
-        this._tableNames = dataManager.getDataTableNames(dataUrl);
-        this._dataSchema = dataManager.getDataSchema(dataUrl);
-        this.loadData(data);
-        // log data stats
-        if (typeof data === 'string') {
-          const dataLines: Array<string> = data.split('\n');
-          this.logDataStats(dataLines);
-        }
-        else {
-          this.logDataStats(data, this._dataSchema);
-        }    
-      });
-    }
+    dataManager.getData(dataUrl, {
+        dataTable: dataTable,
+        createJsonFiles: this.createJsonFiles,
+        createJsonSchema: this.createJsonSchema
+      }, (data: any) => {
+      this._tableNames = dataManager.getDataTableNames(dataUrl);
+      this._dataSchema = dataManager.getDataSchema(dataUrl);
+      this.loadData(data);
+      // log data stats
+      if (typeof data === 'string') {
+        const dataLines: Array<string> = data.split('\n');
+        this.logDataStats(dataLines);
+      }
+      else {
+        this.logDataStats(data, this._dataSchema);
+      }    
+    });
     return data;
   } // end of getData()
 
@@ -716,29 +708,7 @@ export class DataPreview {
     }
   }
 
-  /**
-   * Gets binary Parquet file data.
-   * @param dataFilePath Parquet data file path.
-   * @returns Array of row objects.
-   */ /*
-  private async getParquetData(dataFilePath: string) {
-    let dataSchema: any = {};
-    let dataRows: Array<any> = [];
-    const parquetReader = await parquet.ParquetReader.openFile(dataFilePath);
-    const cursor = parquetReader.getCursor();
-    // read all records
-    let record = null;
-    while (record = await cursor.next()) {
-      dataRows.push(record);
-    }
-    await parquetReader.close();
-    dataRows = dataRows.map(rowObject => this.flattenObject(rowObject));    
-    this.logDataStats(dataRows, dataSchema);
-    // update web view
-    this.loadData(dataRows);
-    return dataRows;
-  } */
-
+  
   /**
    * Saves posted data from data view.
    * @param fileData File data to save.