From 6c008ff888c8c79c3322f8d06587407cf5a098b0 Mon Sep 17 00:00:00 2001
From: Dmitrii Merkurev <dimorinny@google.com>
Date: Fri, 2 Jun 2023 12:44:31 +0100
Subject: [PATCH] Avoid creating a storage folder for fastboot devices command

Bug: 284267164
Bug: 284786311
Test: fastboot devices doesn't create a .fastboot folder
Change-Id: I3e44c2a838e4287e6220c18f6e805cc71e0c9669
Signed-off-by: Dmitrii Merkurev <dimorinny@google.com>
---
 fastboot/fastboot.cpp |  2 +-
 fastboot/filesystem.h |  1 +
 fastboot/storage.cpp  | 22 ++++++++++------------
 fastboot/storage.h    |  4 +++-
 4 files changed, 15 insertions(+), 14 deletions(-)

diff --git a/fastboot/fastboot.cpp b/fastboot/fastboot.cpp
index bec4ef1e9..ee99c1788 100644
--- a/fastboot/fastboot.cpp
+++ b/fastboot/fastboot.cpp
@@ -396,7 +396,7 @@ static Transport* NetworkDeviceConnected(bool print = false) {
 
     ConnectedDevicesStorage storage;
     std::set<std::string> devices;
-    {
+    if (storage.Exists()) {
         FileLock lock = storage.Lock();
         devices = storage.ReadDevices(lock);
     }
diff --git a/fastboot/filesystem.h b/fastboot/filesystem.h
index 5f41fbc9f..c5f9c948d 100644
--- a/fastboot/filesystem.h
+++ b/fastboot/filesystem.h
@@ -31,6 +31,7 @@ const char kPathSeparator =
 #endif
 
 std::string GetHomeDirPath();
+bool FileExists(const std::string& path);
 bool EnsureDirectoryExists(const std::string& directory_path);
 
 class FileLock {
diff --git a/fastboot/storage.cpp b/fastboot/storage.cpp
index d6e00cffa..dc733b994 100644
--- a/fastboot/storage.cpp
+++ b/fastboot/storage.cpp
@@ -23,24 +23,19 @@
 #include "util.h"
 
 ConnectedDevicesStorage::ConnectedDevicesStorage() {
-    const std::string home_path = GetHomeDirPath();
-    if (home_path.empty()) {
-        return;
-    }
-
-    const std::string home_fastboot_path = home_path + kPathSeparator + ".fastboot";
-
-    if (!EnsureDirectoryExists(home_fastboot_path)) {
-        LOG(FATAL) << "Cannot create directory: " << home_fastboot_path;
-    }
+    home_fastboot_path_ = GetHomeDirPath() + kPathSeparator + ".fastboot";
+    devices_path_ = home_fastboot_path_ + kPathSeparator + "devices";
 
     // We're using a separate file for locking because the Windows LockFileEx does not
     // permit opening a file stream for the locked file, even within the same process. So,
     // we have to use fd or handle API to manipulate the storage files, which makes it
     // nearly impossible to fully rewrite a file content without having to recreate it.
     // Unfortunately, this is not an option during holding a lock.
-    devices_path_ = home_fastboot_path + kPathSeparator + "devices";
-    devices_lock_path_ = home_fastboot_path + kPathSeparator + "devices.lock";
+    devices_lock_path_ = home_fastboot_path_ + kPathSeparator + "devices.lock";
+}
+
+bool ConnectedDevicesStorage::Exists() const {
+    return FileExists(devices_path_);
 }
 
 void ConnectedDevicesStorage::WriteDevices(const FileLock&, const std::set<std::string>& devices) {
@@ -63,5 +58,8 @@ void ConnectedDevicesStorage::Clear(const FileLock&) {
 }
 
 FileLock ConnectedDevicesStorage::Lock() const {
+    if (!EnsureDirectoryExists(home_fastboot_path_)) {
+        LOG(FATAL) << "Cannot create directory: " << home_fastboot_path_;
+    }
     return FileLock(devices_lock_path_);
 }
\ No newline at end of file
diff --git a/fastboot/storage.h b/fastboot/storage.h
index 0cc3d86d6..ae9d846e6 100644
--- a/fastboot/storage.h
+++ b/fastboot/storage.h
@@ -24,13 +24,15 @@
 class ConnectedDevicesStorage {
   public:
     ConnectedDevicesStorage();
+
+    bool Exists() const;
     void WriteDevices(const FileLock&, const std::set<std::string>& devices);
     std::set<std::string> ReadDevices(const FileLock&);
     void Clear(const FileLock&);
-
     FileLock Lock() const;
 
   private:
+    std::string home_fastboot_path_;
     std::string devices_path_;
     std::string devices_lock_path_;
 };
\ No newline at end of file