From 7924a94e77534766ab51be3a05054bd60219402f Mon Sep 17 00:00:00 2001
From: Matej Ferencevic <matej.ferencevic@memgraph.io>
Date: Thu, 21 Jun 2018 14:22:16 +0200
Subject: [PATCH] Add overwrite flag to mg_import_csv

Reviewers: teon.banek, buda

Reviewed By: teon.banek

Subscribers: pullbot

Differential Revision: https://phabricator.memgraph.io/D1442
---
 docs/user_technical/import-tools.md |  3 ++-
 tools/src/mg_import_csv/main.cpp    | 20 ++++++++++++++++++++
 2 files changed, 22 insertions(+), 1 deletion(-)

diff --git a/docs/user_technical/import-tools.md b/docs/user_technical/import-tools.md
index f9ab72afb..786d145aa 100644
--- a/docs/user_technical/import-tools.md
+++ b/docs/user_technical/import-tools.md
@@ -94,7 +94,7 @@ will load the new dataset.
 Use the following command:
 
 ```bash
-mg_import_csv --nodes=comment_nodes.csv --nodes=forum_nodes.csv --relationships=relationships.csv
+mg_import_csv --overwrite --nodes=comment_nodes.csv --nodes=forum_nodes.csv --relationships=relationships.csv
 ```
 
 If using Docker, things are a bit more complicated. First you need to move the
@@ -110,6 +110,7 @@ Then, run the importer with the following:
 ```bash
 docker run -v mg_lib:/var/lib/memgraph -v mg_etc:/etc/memgraph -v mg_import:/import-data \
   --entrypoint=mg_import_csv memgraph \
+  --overwrite \
   --nodes=/import-data/comment_nodes.csv --nodes=/import-data/forum_nodes.csv \
   --relationships=/import-data/relationships.csv
 ```
diff --git a/tools/src/mg_import_csv/main.cpp b/tools/src/mg_import_csv/main.cpp
index d6776a382..abfa7a0c3 100644
--- a/tools/src/mg_import_csv/main.cpp
+++ b/tools/src/mg_import_csv/main.cpp
@@ -470,6 +470,26 @@ std::string GetOutputPath() {
   } catch (const std::experimental::filesystem::filesystem_error &error) {
     LOG(FATAL) << error.what();
   }
+  // TODO: Remove this stupid hack which deletes WAL files just to make snapshot
+  // recovery work. Newest snapshot without accompanying WAL files should be
+  // detected in memgraph and correctly recovered (or error reported).
+  try {
+    auto wal_dir = durability_dir + "/wal";
+    if (std::experimental::filesystem::exists(wal_dir)) {
+      for (const auto &wal_file :
+           std::experimental::filesystem::directory_iterator(wal_dir)) {
+        if (!FLAGS_overwrite) {
+          LOG(FATAL) << "Durability directory isn't empty. Pass --overwrite to "
+                        "remove the old recovery data";
+        }
+        break;
+      }
+      LOG(WARNING) << "Removing old recovery data!";
+      std::experimental::filesystem::remove_all(wal_dir);
+    }
+  } catch (const std::experimental::filesystem::filesystem_error &error) {
+    LOG(FATAL) << error.what();
+  }
   int worker_id = 0;
   // TODO(dgleich): Remove this transaction id hack
   return std::string(