1 files changed, 68 insertions, 0 deletions
diff --git a/node_modules/mongodb/lib/operations/count.js b/node_modules/mongodb/lib/operations/count.js
new file mode 100644
index 0000000..a7216d6
--- /dev/null
+++ b/node_modules/mongodb/lib/operations/count.js
@@ -0,0 +1,68 @@
+'use strict';
+
+const buildCountCommand = require('./common_functions').buildCountCommand;
+const OperationBase = require('./operation').OperationBase;
+
+class CountOperation extends OperationBase {
+  constructor(cursor, applySkipLimit, options) {
+    super(options);
+
+    this.cursor = cursor;
+    this.applySkipLimit = applySkipLimit;
+  }
+
+  execute(callback) {
+    const cursor = this.cursor;
+    const applySkipLimit = this.applySkipLimit;
+    const options = this.options;
+
+    if (applySkipLimit) {
+      if (typeof cursor.cursorSkip() === 'number') options.skip = cursor.cursorSkip();
+      if (typeof cursor.cursorLimit() === 'number') options.limit = cursor.cursorLimit();
+    }
+
+    // Ensure we have the right read preference inheritance
+    if (options.readPreference) {
+      cursor.setReadPreference(options.readPreference);
+    }
+
+    if (
+      typeof options.maxTimeMS !== 'number' &&
+      cursor.cmd &&
+      typeof cursor.cmd.maxTimeMS === 'number'
+    ) {
+      options.maxTimeMS = cursor.cmd.maxTimeMS;
+    }
+
+    let finalOptions = {};
+    finalOptions.skip = options.skip;
+    finalOptions.limit = options.limit;
+    finalOptions.hint = options.hint;
+    finalOptions.maxTimeMS = options.maxTimeMS;
+
+    // Command
+    finalOptions.collectionName = cursor.namespace.collection;
+
+    let command;
+    try {
+      command = buildCountCommand(cursor, cursor.cmd.query, finalOptions);
+    } catch (err) {
+      return callback(err);
+    }
+
+    // Set cursor server to the same as the topology
+    cursor.server = cursor.topology.s.coreTopology;
+
+    // Execute the command
+    cursor.topology.command(
+      cursor.namespace.withCollection('$cmd'),
+      command,
+      cursor.options,
+      (err, result) => {
+        callback(err, result ? result.result.n : null);
+      }
+    );
+  }
+}
+
+module.exports = CountOperation;