WIP: MongoDB-like Filtering

package.json

@@ -55,6 +55,7 @@
     "handlebars": "^4.7.7",
     "handlebars-helpers": "^0.9.8",
     "logfmt": "^1.3.2",
+    "mongo-query-compiler": "^1.0.4",
     "json-stable-stringify": "^1.0.1",
     "jsonic": "^0.3.1",
     "patch-package": "^6.4.7",

plugins/mongo_filter/README.md

@@ -0,0 +1,21 @@
+## qryn-plugin
+
+### mongo
+
+This plugin uses the [Mongo Query Compiler](https://github.com/aptivator/mongo-query-compiler-docs) library to transpile mongodb-like 
+query objects into a JavaScript filtering functions to be used with any array's .filter() method to isolate the needed data subset.
+
+### Example
+
+Original LogQL Selector:
+```
+{type="people"} |="alive" | json
+```
+
+Mongo Filter:
+```
+mongo({stream: { event: { $exists: true }}}, {type="people"} |="alive" | json)
+```
+```
+mongo({$where: 'this.stream.event === "user"'},  {type="people"} |="alive" | json )
+```

plugins/mongo_filter/index.js

@@ -0,0 +1,62 @@
+const { PluginLoaderBase } = require('plugnplay')
+const { compileMongoQuery } = require('mongo-query-compiler')
+
+/**
+
+Mongodb-like JSON filtering output processor.
+Usage: mongo({age: {$exists: true}}, {type="people"}
+
+**/
+
+/**
+ * @class Plugin
+ * @property {string} query
+ * @property start {number} start in NS
+ * @property end {string} end in NS
+ * @property type {string} promql or logql
+ * @property limit {number}
+ * @property {{
+ *   logql: (query: string, startNS: number, endNS: number, limit: number) => Promise<Object>
+ * }} API
+ *   promql: (query: string, startNS: number, endNS: number, limit: number) => Promise<Object> //not implemented
+ */
+class Plugin {
+  /**
+   * @method
+   * @name check
+   * @this {Plg}
+   * @returns {boolean} if this plugin is usable for the query
+   */
+  check () {
+    return this.query.match(/^mongo\(.+\)\s*$/)
+  }
+
+  /**
+   * @method
+   * @name process
+   * @this {Plg}
+   * @returns {Promise<{type: string, out: string}>} The raw output
+   */
+  async process () {
+    const match = this.query.match(/^mongo\({(.+)},\s*(.+)\)$/)
+    let response = await this.API.logql(match[2], this.start, this.end, this.limit)
+
+    // Sanity Check. What error should this return?
+    if (!match || !match[1] || !match[2]) return response;
+
+    // Filter using Mongo Query Compiler
+    let filterer = compileMongoQuery(match[1]);
+    response.data.result = response.data.result.filter(filterer);
+    return {
+      type: 'application/json',
+      out: response
+    }
+  }
+}
+class Plg extends PluginLoaderBase {
+  exportSync (api) {
+    return new Plugin()
+  }
+}
+
+module.exports = Plg

plugins/mongo_filter/plugnplay.yml

@@ -0,0 +1,5 @@
+id: mongo_filter
+name: Format Output
+description: Filter JSON using MongoDB functions
+loader: index.js
+type: custom_processor