Entry: restore weak_ptr on Storage to avoid circular reference.

srouquette · Sep 5, 2015 · bc03f4d · bc03f4d
1 parent d477b15
commit bc03f4d
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Showing 3 changed files with 15 additions and 16 deletions.
diff --git a/include/filesystem/entry.h b/include/filesystem/entry.h
@@ -57,6 +57,7 @@ class Entry {
     const std::string& url() const noexcept;
 
  private:
+    storage_ptr_t storage() const;
     void throws_if_nonexistent() const;
     void throws_if_storage_null() const;
     void safe_update_status() const;
@@ -69,7 +70,7 @@ class Entry {
     const fs::path                  path_;
     mutable boost::shared_mutex     shared_mutex_;
     mutable fs::file_status         status_;
-    storage_ptr_t                   storage_;
+    std::weak_ptr<Storage>          storage_;  // weak_ptr to prevent circular ref
     const std::string               url_;
 };
 

diff --git a/src/filesystem/entry.cpp b/src/filesystem/entry.cpp
@@ -39,17 +39,15 @@ Entry::content_t Entry::content() const {
 bool Entry::exists() const {
     std::lock_guard<std::mutex> lock{ mutex_ };
     try {
-        throws_if_storage_null();
-        return storage_->exists(*this);
+        return storage()->exists(*this);
     } catch (const filesystem_error&) {
         return false;
     }
 }
 
 bool Entry::is_dir() const {
     std::lock_guard<std::mutex> lock{ mutex_ };
-    throws_if_storage_null();
-    return storage_->is_dir(*this);
+    return storage()->is_dir(*this);
 }
 
 void Entry::invalidate() noexcept {
@@ -58,7 +56,7 @@ void Entry::invalidate() noexcept {
 
 void Entry::ls() {
     safe_update_status();
-    auto content = storage_->ls(*this);
+    auto content = storage()->ls(*this);
     std::lock_guard<std::mutex> lock{ mutex_ };
     std::swap(content_, content);
     on_update_(*this);
@@ -84,16 +82,17 @@ const std::string& Entry::url() const noexcept {
     return url_;
 }
 
-void Entry::throws_if_nonexistent() const {
-    update_status();
-    if (!storage_->exists(*this)) {
-        throw EXCEPTION(__FUNCTION__, url_, no_such_file_or_directory);
+storage_ptr_t Entry::storage() const {
+    if (storage_.expired()) {
+        throw EXCEPTION(__FUNCTION__, url_, no_such_device);
     }
+    return storage_.lock();
 }
 
-void Entry::throws_if_storage_null() const {
-    if (!storage_) {
-        throw EXCEPTION(__FUNCTION__, url_, no_such_device);
+void Entry::throws_if_nonexistent() const {
+    update_status();
+    if (!storage()->exists(*this)) {
+        throw EXCEPTION(__FUNCTION__, url_, no_such_file_or_directory);
     }
 }
 
@@ -103,8 +102,7 @@ void Entry::safe_update_status() const {
 }
 
 void Entry::update_status() const {
-    throws_if_storage_null();
-    status_ = storage_->status(*this);
+    status_ = storage()->status(*this);
 }
 
 }  // namespace filesystem

diff --git a/test/filesystem/pattern/storage_helper.cpp b/test/filesystem/pattern/storage_helper.cpp
@@ -46,7 +46,7 @@ void StorageHelper::remove(const fs::path& path) const {
     entries_.erase(path);
     try {
         fs::remove_all(path);
-    } catch (const std::exception& e) {}
+    } catch (...) {}
 }
 
 }  // namespace filesystem