/* * Copyright (C) 2020 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specic language governing permissions and * limitations under the License. */ #include "node-inl.h" static std::vector<std::string> GetPathSegments(int segment_start, const std::string& path) { std::vector<std::string> segments; int segment_end = path.find_first_of('/', segment_start); while (segment_end != std::string::npos) { if (segment_end == segment_start) { // First character is '/' ignore segment_end = path.find_first_of('/', ++segment_start); continue; } segments.push_back(path.substr(segment_start, segment_end - segment_start)); segment_start = segment_end + 1; segment_end = path.find_first_of('/', segment_start); } if (segment_start < path.size()) { segments.push_back(path.substr(segment_start)); } return segments; } namespace mediaprovider { namespace fuse { // Assumes that |node| has at least one child. void node::BuildPathForNodeRecursive(bool safe, const node* node, std::stringstream* path) const { if (node->parent_) { BuildPathForNodeRecursive(safe, node->parent_, path); } if (safe && node->parent_) { (*path) << reinterpret_cast<uintptr_t>(node); } else { (*path) << node->GetName(); } if (node != this) { // Must not add a '/' to the last segment (*path) << "/"; } } std::string node::BuildPath() const { std::lock_guard<std::recursive_mutex> guard(*lock_); std::stringstream path; BuildPathForNodeRecursive(false, this, &path); return path.str(); } std::string node::BuildSafePath() const { std::lock_guard<std::recursive_mutex> guard(*lock_); std::stringstream path; BuildPathForNodeRecursive(true, this, &path); return path.str(); } const node* node::LookupAbsolutePath(const node* root, const std::string& absolute_path) { if (absolute_path.find(root->GetName()) != 0) { return nullptr; } std::vector<std::string> segments = GetPathSegments(root->GetName().size(), absolute_path); std::lock_guard<std::recursive_mutex> guard(*root->lock_); const node* node = root; for (const std::string& segment : segments) { node = node->LookupChildByName(segment, false /* acquire */); if (!node) { return nullptr; } } return node; } const node* node::LookupInode(const node* root, ino_t ino) { CHECK(root); std::lock_guard<std::recursive_mutex> guard(*root->lock_); if ((root->ino_ == ino) && !root->deleted_ && !(root->handles_.empty())) { return root; } for (node* child : root->children_) { const node* node = LookupInode(child, ino); if (node) { return node; } } return nullptr; } void node::DeleteTree(node* tree) { std::lock_guard<std::recursive_mutex> guard(*tree->lock_); if (tree) { // Make a copy of the list of children because calling Delete tree // will modify the list of children, which will cause issues while // iterating over them. std::vector<node*> children(tree->children_.begin(), tree->children_.end()); for (node* child : children) { DeleteTree(child); } CHECK(tree->children_.empty()); delete tree; } } } // namespace fuse } // namespace mediaprovider