From e55018a8ce0b83e3f1dbe17d0632062924e119ad Mon Sep 17 00:00:00 2001
From: bbkot <97723937+bbkot@users.noreply.github.com>
Date: Wed, 30 Mar 2022 15:55:31 -0700
Subject: [PATCH] fixing issue #8345 RocksDB does not work when using UNC
 network paths (#9384)

Summary:
Fix https://github.com/facebook/rocksdb/issues/8345
RocksDB does not work with network filesystem paths on Windows, e.g. "\\hostname\folder\..."

Pull Request resolved: https://github.com/facebook/rocksdb/pull/9384

Reviewed By: mrambacher

Differential Revision: D33830622

Pulled By: riversand963

fbshipit-source-id: 2a99dc3c94415eb1460e110784b97d71600218f1
---
 HISTORY.md          |  1 +
 db/filename_test.cc | 63 +++++++++++++++++++++++++++++++++++++++++++++
 file/filename.cc    |  6 +++++
 3 files changed, 70 insertions(+)

diff --git a/HISTORY.md b/HISTORY.md
index a406fea4a..154ee23f1 100644
--- a/HISTORY.md
+++ b/HISTORY.md
@@ -1,6 +1,7 @@
 # Rocksdb Change Log
 ## Unreleased
 ### Bug Fixes
+* Fixed bug which caused rocksdb failure in the situation when rocksdb was accessible using UNC path
 * Fixed a race condition when 2PC is disabled and WAL tracking in the MANIFEST is enabled. The race condition is between two background flush threads trying to install flush results, causing a WAL deletion not tracked in the MANIFEST. A future DB open may fail.
 * Fixed a heap use-after-free race with DropColumnFamily.
 * Fixed a bug that `rocksdb.read.block.compaction.micros` cannot track compaction stats (#9722).
diff --git a/db/filename_test.cc b/db/filename_test.cc
index d166876ba..23f6974b1 100644
--- a/db/filename_test.cc
+++ b/db/filename_test.cc
@@ -171,6 +171,69 @@ TEST_F(FileNameTest, Construction) {
   ASSERT_EQ(kMetaDatabase, type);
 }
 
+TEST_F(FileNameTest, NormalizePath) {
+  // No leading slash
+  const std::string sep = std::string(1, kFilePathSeparator);
+
+  std::string expected = "FOLDER" + sep + "filename.ext";
+  std::string given = "FOLDER" + sep + "filename.ext";
+
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // Two chars /a
+
+  expected = sep + "a";
+  given = expected;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // Two chars a/
+  expected = "a" + sep;
+  given = expected;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // Server only
+  expected = sep + sep + "a";
+  given = expected;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // Two slashes after character
+  expected = "a" + sep;
+  given = "a" + sep + sep;
+
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // slash only   /
+  expected = sep;
+  given = expected;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // UNC only   //
+  expected = sep;
+  given = sep + sep;
+
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // 3 slashesy   //
+  expected = sep + sep;
+  given = sep + sep + sep;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // 3 slashes   //
+  expected = sep + sep + "a" + sep;
+  given = sep + sep + sep + "a" + sep;
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // 2 separators in the middle
+  expected = "a" + sep + "b";
+  given = "a" + sep + sep + "b";
+  ASSERT_EQ(expected, NormalizePath(given));
+
+  // UNC with duplicate slashes
+  expected = sep + sep + "SERVER" + sep + "a" + sep + "b" + sep + "c";
+  given = sep + sep + "SERVER" + sep + "a" + sep + sep + "b" + sep + "c";
+  ASSERT_EQ(expected, NormalizePath(given));
+}
+
 }  // namespace ROCKSDB_NAMESPACE
 
 int main(int argc, char** argv) {
diff --git a/file/filename.cc b/file/filename.cc
index 358f88cf0..f63a469dd 100644
--- a/file/filename.cc
+++ b/file/filename.cc
@@ -491,6 +491,12 @@ Status GetInfoLogFiles(const std::shared_ptr<FileSystem>& fs,
 
 std::string NormalizePath(const std::string& path) {
   std::string dst;
+
+  if (path.length() > 2 && path[0] == kFilePathSeparator &&
+      path[1] == kFilePathSeparator) {  // Handle UNC names
+    dst.append(2, kFilePathSeparator);
+  }
+
   for (auto c : path) {
     if (!dst.empty() && (c == kFilePathSeparator || c == '/') &&
         (dst.back() == kFilePathSeparator || dst.back() == '/')) {