Fix lifetime of leveldb::MojoEnv instances.

components/leveldb/env_mojo.cc

Index: components/leveldb/env_mojo.cc
diff --git a/components/leveldb/env_mojo.cc b/components/leveldb/env_mojo.cc
index 82af93a997036fa73be861228083b196b93f85f9..178f7672747484dde25f81ebe2af1e5ad5d829ce 100644
--- a/components/leveldb/env_mojo.cc
+++ b/components/leveldb/env_mojo.cc
@@ -8,7 +8,10 @@
 
 #include <memory>
 
+#include "base/lazy_instance.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
+#include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "third_party/leveldatabase/chromium_logger.h"
 #include "third_party/leveldatabase/src/include/leveldb/status.h"
@@ -217,20 +220,35 @@ class MojoWritableFile : public leveldb::WritableFile {
 
 }  // namespace
 
-MojoEnv::MojoEnv(const std::string& name,
-                 scoped_refptr<LevelDBMojoProxy> file_thread,
-                 LevelDBMojoProxy::OpaqueDir* dir)
-    : ChromiumEnv(name), thread_(file_thread), dir_(dir) {}
+MojoEnv::Directory::~Directory() {
+  env_->UnregisterDirectory(prefix_);
+}
+
+MojoEnv::Directory::Directory(MojoEnv* env, std::string prefix)
+    : env_(env), prefix_(std::move(prefix)) {}
 
-MojoEnv::~MojoEnv() {
-  thread_->UnregisterDirectory(dir_);
+MojoEnv::MojoEnv(scoped_refptr<base::SingleThreadTaskRunner> file_task_runner)
+    : ChromiumEnv("LevelDBEnv.Mojo"),
+      thread_(new LevelDBMojoProxy(std::move(file_task_runner))) {}
+
+std::unique_ptr<MojoEnv::Directory> MojoEnv::RegisterDirectory(
+    filesystem::mojom::DirectoryPtr directory) {
+  LevelDBMojoProxy::OpaqueDir* dir =
+      thread_->RegisterDirectory(std::move(directory));
+  int dir_id = dirs_.Add(dir);
+  std::string prefix = base::StringPrintf("%d:", dir_id);
+  return base::WrapUnique(new Directory(this, prefix));
 }
 
 Status MojoEnv::NewSequentialFile(const std::string& fname,
                                   SequentialFile** result) {
   TRACE_EVENT1("leveldb", "MojoEnv::NewSequentialFile", "fname", fname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
   base::File f = thread_->OpenFileHandle(
-      dir_, fname, filesystem::mojom::kFlagOpen | filesystem::mojom::kFlagRead);
+      dir, path, filesystem::mojom::kFlagOpen | filesystem::mojom::kFlagRead);
   if (!f.IsValid()) {
     *result = nullptr;
     return MakeIOError(fname, "Unable to create sequential file",
@@ -244,105 +262,152 @@ Status MojoEnv::NewSequentialFile(const std::string& fname,
 Status MojoEnv::NewRandomAccessFile(const std::string& fname,
                                     RandomAccessFile** result) {
   TRACE_EVENT1("leveldb", "MojoEnv::NewRandomAccessFile", "fname", fname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
   base::File f = thread_->OpenFileHandle(
-      dir_, fname, filesystem::mojom::kFlagRead | filesystem::mojom::kFlagOpen);
+      dir, path, filesystem::mojom::kFlagRead | filesystem::mojom::kFlagOpen);
   if (!f.IsValid()) {
     *result = nullptr;
     base::File::Error error_code = f.error_details();
-    return MakeIOError(fname, FileErrorString(error_code),
+    return MakeIOError(path, FileErrorString(error_code),
                        leveldb_env::kNewRandomAccessFile, error_code);
   }
 
-  *result = new MojoRandomAccessFile(fname, std::move(f));
+  *result = new MojoRandomAccessFile(path, std::move(f));
   return Status::OK();
 }
 
 Status MojoEnv::NewWritableFile(const std::string& fname,
                                 WritableFile** result) {
   TRACE_EVENT1("leveldb", "MojoEnv::NewWritableFile", "fname", fname);
-  base::File f =
-      thread_->OpenFileHandle(dir_, fname, filesystem::mojom::kCreateAlways |
-                                               filesystem::mojom::kFlagWrite);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
+  base::File f = thread_->OpenFileHandle(
+      dir, path,
+      filesystem::mojom::kCreateAlways | filesystem::mojom::kFlagWrite);
   if (!f.IsValid()) {
     *result = nullptr;
-    return MakeIOError(fname, "Unable to create writable file",
+    return MakeIOError(path, "Unable to create writable file",
                        leveldb_env::kNewWritableFile, f.error_details());
   }
 
-  *result = new MojoWritableFile(dir_, fname, std::move(f), thread_);
+  *result = new MojoWritableFile(dir, path, std::move(f), thread_);
   return Status::OK();
 }
 
 Status MojoEnv::NewAppendableFile(const std::string& fname,
                                   WritableFile** result) {
   TRACE_EVENT1("leveldb", "MojoEnv::NewAppendableFile", "fname", fname);
-  base::File f =
-      thread_->OpenFileHandle(dir_, fname, filesystem::mojom::kFlagOpenAlways |
-                                               filesystem::mojom::kFlagAppend);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
+  base::File f = thread_->OpenFileHandle(
+      dir, path,
+      filesystem::mojom::kFlagOpenAlways | filesystem::mojom::kFlagAppend);
   if (!f.IsValid()) {
     *result = nullptr;
-    return MakeIOError(fname, "Unable to create appendable file",
+    return MakeIOError(path, "Unable to create appendable file",
                        leveldb_env::kNewAppendableFile, f.error_details());
   }
 
-  *result = new MojoWritableFile(dir_, fname, std::move(f), thread_);
+  *result = new MojoWritableFile(dir, path, std::move(f), thread_);
   return Status::OK();
 }
 
 bool MojoEnv::FileExists(const std::string& fname) {
   TRACE_EVENT1("leveldb", "MojoEnv::FileExists", "fname", fname);
-  return thread_->FileExists(dir_, fname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
+  return thread_->FileExists(dir, path);
 }
 
-Status MojoEnv::GetChildren(const std::string& path,
+Status MojoEnv::GetChildren(const std::string& dirname,
                             std::vector<std::string>* result) {
-  TRACE_EVENT1("leveldb", "MojoEnv::GetChildren", "path", path);
-  return FilesystemErrorToStatus(thread_->GetChildren(dir_, path, result), path,
+  TRACE_EVENT1("leveldb", "MojoEnv::GetChildren", "dirname", dirname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(dirname, &dir, &path);
+
+  return FilesystemErrorToStatus(thread_->GetChildren(dir, path, result), path,
                                  leveldb_env::kGetChildren);
 }
 
 Status MojoEnv::DeleteFile(const std::string& fname) {
   TRACE_EVENT1("leveldb", "MojoEnv::DeleteFile", "fname", fname);
-  return FilesystemErrorToStatus(thread_->Delete(dir_, fname, 0), fname,
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
+  return FilesystemErrorToStatus(thread_->Delete(dir, path, 0), path,
                                  leveldb_env::kDeleteFile);
 }
 
 Status MojoEnv::CreateDir(const std::string& dirname) {
   TRACE_EVENT1("leveldb", "MojoEnv::CreateDir", "dirname", dirname);
-  return FilesystemErrorToStatus(thread_->CreateDir(dir_, dirname), dirname,
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(dirname, &dir, &path);
+
+  return FilesystemErrorToStatus(thread_->CreateDir(dir, path), path,
                                  leveldb_env::kCreateDir);
 }
 
 Status MojoEnv::DeleteDir(const std::string& dirname) {
   TRACE_EVENT1("leveldb", "MojoEnv::DeleteDir", "dirname", dirname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(dirname, &dir, &path);
+
   return FilesystemErrorToStatus(
-      thread_->Delete(dir_, dirname, filesystem::mojom::kDeleteFlagRecursive),
-      dirname, leveldb_env::kDeleteDir);
+      thread_->Delete(dir, path, filesystem::mojom::kDeleteFlagRecursive), path,
+      leveldb_env::kDeleteDir);
 }
 
 Status MojoEnv::GetFileSize(const std::string& fname, uint64_t* file_size) {
   TRACE_EVENT1("leveldb", "MojoEnv::GetFileSize", "fname", fname);
-  return FilesystemErrorToStatus(thread_->GetFileSize(dir_, fname, file_size),
-                                 fname,
-                                 leveldb_env::kGetFileSize);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
+  return FilesystemErrorToStatus(thread_->GetFileSize(dir, path, file_size),
+                                 path, leveldb_env::kGetFileSize);
 }
 
 Status MojoEnv::RenameFile(const std::string& src, const std::string& target) {
   TRACE_EVENT2("leveldb", "MojoEnv::RenameFile", "src", src, "target", target);
-  return FilesystemErrorToStatus(thread_->RenameFile(dir_, src, target), src,
-                                 leveldb_env::kRenameFile);
+  LevelDBMojoProxy::OpaqueDir* src_dir;
+  std::string src_path;
+  ParsePath(src, &src_dir, &src_path);
+  LevelDBMojoProxy::OpaqueDir* target_dir;
+  std::string target_path;
+  ParsePath(target, &target_dir, &target_path);
+  DCHECK_EQ(src_dir, target_dir);
+
+  return FilesystemErrorToStatus(
+      thread_->RenameFile(src_dir, src_path, target_path), src_path,
+      leveldb_env::kRenameFile);
 }
 
 Status MojoEnv::LockFile(const std::string& fname, FileLock** lock) {
   TRACE_EVENT1("leveldb", "MojoEnv::LockFile", "fname", fname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
 
   std::pair<filesystem::mojom::FileError, LevelDBMojoProxy::OpaqueLock*> p =
-      thread_->LockFile(dir_, fname);
+      thread_->LockFile(dir, path);
 
   if (p.second)
     *lock = new MojoFileLock(p.second, fname);
 
-  return FilesystemErrorToStatus(p.first, fname, leveldb_env::kLockFile);
+  return FilesystemErrorToStatus(p.first, path, leveldb_env::kLockFile);
 }
 
 Status MojoEnv::UnlockFile(FileLock* lock) {
@@ -368,12 +433,16 @@ Status MojoEnv::GetTestDirectory(std::string* path) {
 
 Status MojoEnv::NewLogger(const std::string& fname, Logger** result) {
   TRACE_EVENT1("leveldb", "MojoEnv::NewLogger", "fname", fname);
+  LevelDBMojoProxy::OpaqueDir* dir;
+  std::string path;
+  ParsePath(fname, &dir, &path);
+
   base::File f(thread_->OpenFileHandle(
-      dir_, fname,
+      dir, path,
       filesystem::mojom::kCreateAlways | filesystem::mojom::kFlagWrite));
   if (!f.IsValid()) {
     *result = NULL;
-    return MakeIOError(fname, "Unable to create log file",
+    return MakeIOError(path, "Unable to create log file",
                        leveldb_env::kNewLogger, f.error_details());
   } else {
     *result = new leveldb::ChromiumLogger(std::move(f));
@@ -381,4 +450,35 @@ Status MojoEnv::NewLogger(const std::string& fname, Logger** result) {
   }
 }
 
+MojoEnv::~MojoEnv() {}
+
+void MojoEnv::ParsePath(const std::string& path,
+                        LevelDBMojoProxy::OpaqueDir** out_dir,
+                        std::string* out_path) {
+  size_t colon_pos = path.find(':');
+  DCHECK_NE(colon_pos, std::string::npos);
+
+  int dir_id;
+  bool result = base::StringToInt(
+      base::StringPiece(path.begin(), path.begin() + colon_pos), &dir_id);
+  DCHECK(result) << "Invalid directory id in path '" << path << "'";
+  *out_dir = dirs_.Lookup(dir_id);
+  DCHECK(*out_dir) << "Invalid directory id " << dir_id;
+
+  *out_path = std::string(path.begin() + colon_pos + 1, path.end());
+}
+
+void MojoEnv::UnregisterDirectory(base::StringPiece prefix) {
+  DCHECK(!prefix.empty());
+  DCHECK_EQ(prefix.back(), ':');
+  prefix.remove_suffix(1);
+  int dir_id;
+  bool result = base::StringToInt(prefix, &dir_id);
+  DCHECK(result) << "Invalid directory id '" << prefix << "'";
+  LevelDBMojoProxy::OpaqueDir* dir = dirs_.Lookup(dir_id);
+  DCHECK(dir) << "Invalid directory id " << dir_id;
+  dirs_.Remove(dir_id);
+  thread_->UnregisterDirectory(dir);
+}
+
 }  // namespace leveldb