Initial commit

node_modules/mongodb/lib/operations/distinct.js

@@ -0,0 +1,85 @@
+'use strict';
+
+const Aspect = require('./operation').Aspect;
+const defineAspects = require('./operation').defineAspects;
+const CommandOperationV2 = require('./command_v2');
+const decorateWithCollation = require('../utils').decorateWithCollation;
+const decorateWithReadConcern = require('../utils').decorateWithReadConcern;
+
+/**
+ * Return a list of distinct values for the given key across a collection.
+ *
+ * @class
+ * @property {Collection} a Collection instance.
+ * @property {string} key Field of the document to find distinct values for.
+ * @property {object} query The query for filtering the set of documents to which we apply the distinct filter.
+ * @property {object} [options] Optional settings. See Collection.prototype.distinct for a list of options.
+ */
+class DistinctOperation extends CommandOperationV2 {
+  /**
+   * Construct a Distinct operation.
+   *
+   * @param {Collection} a Collection instance.
+   * @param {string} key Field of the document to find distinct values for.
+   * @param {object} query The query for filtering the set of documents to which we apply the distinct filter.
+   * @param {object} [options] Optional settings. See Collection.prototype.distinct for a list of options.
+   */
+  constructor(collection, key, query, options) {
+    super(collection, options);
+
+    this.collection = collection;
+    this.key = key;
+    this.query = query;
+  }
+
+  /**
+   * Execute the operation.
+   *
+   * @param {Collection~resultCallback} [callback] The command result callback
+   */
+  execute(server, callback) {
+    const coll = this.collection;
+    const key = this.key;
+    const query = this.query;
+    const options = this.options;
+
+    // Distinct command
+    const cmd = {
+      distinct: coll.collectionName,
+      key: key,
+      query: query
+    };
+
+    // Add maxTimeMS if defined
+    if (typeof options.maxTimeMS === 'number') {
+      cmd.maxTimeMS = options.maxTimeMS;
+    }
+
+    // Do we have a readConcern specified
+    decorateWithReadConcern(cmd, coll, options);
+
+    // Have we specified collation
+    try {
+      decorateWithCollation(cmd, coll, options);
+    } catch (err) {
+      return callback(err, null);
+    }
+
+    super.executeCommand(server, cmd, (err, result) => {
+      if (err) {
+        callback(err);
+        return;
+      }
+
+      callback(null, this.options.full ? result : result.values);
+    });
+  }
+}
+
+defineAspects(DistinctOperation, [
+  Aspect.READ_OPERATION,
+  Aspect.RETRYABLE,
+  Aspect.EXECUTE_WITH_SELECTION
+]);
+
+module.exports = DistinctOperation;