Add Android asset manager. (#3151)

b/302715109

Change-Id: I3f22470821c1c77695d7c740c66ae227944e87c5

starboard/android/shared/BUILD.gn

@@ -279,6 +279,8 @@ static_library("starboard_platform") {
     "android_media_session_client.cc",
     "application_android.cc",
     "application_android.h",
+    "asset_manager.cc",
+    "asset_manager.h",
     "atomic_public.h",
     "audio_decoder.cc",
     "audio_decoder.h",
@@ -379,6 +381,7 @@ static_library("starboard_platform") {
     "player_set_max_video_input_size.h",
     "player_set_playback_rate.cc",
     "posix_emu/errno.cc",
+    "posix_emu/file.cc",
     "posix_emu/pthread.cc",
     "posix_emu/stat.cc",
     "sanitizer_options.cc",

starboard/android/shared/asset_manager.cc

@@ -0,0 +1,138 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// 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 specific language governing permissions and
+// limitations under the License.
+
+#include "starboard/android/shared/asset_manager.h"
+
+#include <android/asset_manager.h>
+#include <fcntl.h>
+#include <ftw.h>
+#include <linux/limits.h>
+#include <stdio.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include "starboard/android/shared/file_internal.h"
+#include "starboard/common/log.h"
+#include "starboard/common/mutex.h"
+#include "starboard/common/once.h"
+#include "starboard/common/string.h"
+#include "starboard/system.h"
+
+namespace starboard {
+namespace android {
+namespace shared {
+
+// static
+SB_ONCE_INITIALIZE_FUNCTION(AssetManager, AssetManager::GetInstance);
+
+AssetManager::AssetManager() {
+  const int kPathSize = PATH_MAX / 2;
+  char path[kPathSize] = {0};
+  SB_CHECK(SbSystemGetPath(kSbSystemPathTempDirectory, path, kPathSize))
+      << "Unable to get system temp path for AssetManager.";
+  SB_CHECK(starboard::strlcat(path, "/asset_tmp", kPathSize) < kPathSize)
+      << "Unable to construct temp path for AssetManager.";
+  tmp_root_ = path;
+  ClearTempDir();
+}
+
+uint64_t AssetManager::AcquireInternalFd() {
+  ScopedLock scoped_lock(mutex_);
+  do {
+    ++internal_fd_;
+  } while (in_use_internal_fd_set_.count(internal_fd_) == 1);
+  in_use_internal_fd_set_.insert(internal_fd_);
+  return internal_fd_;
+}
+
+std::string AssetManager::TempFilepath(uint64_t internal_fd) const {
+  return tmp_root_ + "/" + std::to_string(internal_fd);
+}
+
+int AssetManager::Open(const char* path) {
+  if (!path) {
+    return -1;
+  }
+
+  AAsset* asset = OpenAndroidAsset(path);
+  if (!asset) {
+    SB_LOG(WARNING) << "Asset path not found within package: " << path;
+    return -1;
+  }
+
+  // Create temporary POSIX file for the asset
+  uint64_t internal_fd = AcquireInternalFd();
+  std::string filepath = TempFilepath(internal_fd);
+  int fd = open(filepath.c_str(), O_RDWR | O_TRUNC | O_CREAT);
+  if (fd < 0) {
+    mutex_.Acquire();
+    in_use_internal_fd_set_.erase(internal_fd);
+    mutex_.Release();
+    return -1;
+  }
+
+  // Copy contents of asset into temporary file and then seek to start of file.
+  const off_t size = AAsset_getLength(asset);
+  const void* const data = AAsset_getBuffer(asset);
+  if (write(fd, data, size) != size || lseek(fd, 0, SEEK_SET) != 0) {
+    SB_LOG(WARNING) << "Failed to write temporary file for asset: " << path;
+    mutex_.Acquire();
+    in_use_internal_fd_set_.erase(internal_fd);
+    mutex_.Release();  // Can't hold lock when calling close();
+    close(fd);
+    return -1;
+  }
+  AAsset_close(asset);
+
+  // Keep track of the internal fd so we can delete its file on close();
+  mutex_.Acquire();
+  fd_to_internal_fd_map_[fd] = internal_fd;
+  mutex_.Release();
+  return fd;
+}
+
+bool AssetManager::IsAssetFd(int fd) const {
+  ScopedLock scoped_lock(mutex_);
+  return fd_to_internal_fd_map_.count(fd) == 1;
+}
+
+int AssetManager::Close(int fd) {
+  mutex_.Acquire();
+  if (auto search = fd_to_internal_fd_map_.find(fd);
+      search != fd_to_internal_fd_map_.end()) {
+    uint64_t internal_fd = search->second;
+    fd_to_internal_fd_map_.erase(search);
+    in_use_internal_fd_set_.erase(internal_fd);
+    mutex_.Release();  // Can't hold lock when calling close();
+    int retval = close(fd);
+    std::string filepath = TempFilepath(internal_fd);
+    if (unlink(filepath.c_str()) != 0) {
+      SB_LOG(WARNING) << "Failed to delete temporary file: " << filepath;
+    }
+    return retval;
+  }
+  mutex_.Release();
+  return -1;
+}
+
+void AssetManager::ClearTempDir() {
+  auto callback = [](const char* child, const struct stat*, int file_type,
+                     struct FTW*) -> int { return remove(child); };
+  nftw(tmp_root_.c_str(), callback, 32, FTW_DEPTH | FTW_PHYS);
+  mkdir(tmp_root_.c_str(), 0700);
+}
+
+}  // namespace shared
+}  // namespace android
+}  // namespace starboard

starboard/android/shared/asset_manager.h

@@ -0,0 +1,54 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// 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 specific language governing permissions and
+// limitations under the License.
+
+#ifndef STARBOARD_ANDROID_SHARED_ASSET_MANAGER_H_
+#define STARBOARD_ANDROID_SHARED_ASSET_MANAGER_H_
+
+#include <map>
+#include <set>
+#include <string>
+
+#include "starboard/common/mutex.h"
+
+namespace starboard {
+namespace android {
+namespace shared {
+
+// This class handles opening/closing Android asset files as POSIX filehandles.
+class AssetManager {
+ public:
+  static AssetManager* GetInstance();
+  int Open(const char* path);
+  int Close(int fd);
+  bool IsAssetFd(int fd) const;
+
+ private:
+  AssetManager();
+  ~AssetManager() { ClearTempDir(); }
+  uint64_t AcquireInternalFd();
+  std::string TempFilepath(uint64_t internal_fd) const;
+  void ClearTempDir();
+
+  std::string tmp_root_;
+  mutable Mutex mutex_;
+  uint64_t internal_fd_ = 0;                       // Guarded by |mutex_|.
+  std::set<uint64_t> in_use_internal_fd_set_;      // Guarded by |mutex_|.
+  std::map<int, uint64_t> fd_to_internal_fd_map_;  // Guarded by |mutex_|.
+};
+
+}  // namespace shared
+}  // namespace android
+}  // namespace starboard
+
+#endif  // STARBOARD_ANDROID_SHARED_ASSET_MANAGER_H_

starboard/android/shared/platform_configuration/BUILD.gn

@@ -169,7 +169,11 @@ config("platform_configuration") {
     "-Wl,--wrap=eglSwapBuffers",
   ]
   if (!is_native_target_build) {
-    ldflags += [ "-Wl,--wrap=stat" ]
+    ldflags += [
+      "-Wl,--wrap=close",
+      "-Wl,--wrap=open",
+      "-Wl,--wrap=stat",
+    ]
   }
 }
 

starboard/android/shared/posix_emu/file.cc

@@ -0,0 +1,61 @@
+// Copyright 2024 The Cobalt Authors. All Rights Reserved.
+//
+// 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 specific language governing permissions and
+// limitations under the License.
+
+#include <fcntl.h>
+
+#include <vector>
+
+#include "starboard/android/shared/asset_manager.h"
+#include "starboard/android/shared/file_internal.h"
+#include "starboard/common/log.h"
+#include "starboard/configuration_constants.h"
+#include "starboard/directory.h"
+#include "starboard/log.h"
+
+using starboard::android::shared::AssetManager;
+using starboard::android::shared::IsAndroidAssetPath;
+using starboard::android::shared::OpenAndroidAsset;
+
+// ///////////////////////////////////////////////////////////////////////////////
+// // Implementations below exposed externally in pure C for emulation.
+// ///////////////////////////////////////////////////////////////////////////////
+
+extern "C" {
+int __real_close(int fildes);
+int __real_open(const char* path, int oflag, ...);
+
+int __wrap_close(int fildes) {
+  AssetManager* asset_manager = AssetManager::GetInstance();
+  if (asset_manager->IsAssetFd(fildes)) {
+    return asset_manager->Close(fildes);
+  }
+  return __real_close(fildes);
+}
+
+int __wrap_open(const char* path, int oflag, ...) {
+  if (!IsAndroidAssetPath(path)) {
+    va_list args;
+    va_start(args, oflag);
+    int fd;
+    if (oflag & O_CREAT) {
+      mode_t mode = va_arg(args, int);
+      return __real_open(path, oflag, mode);
+    } else {
+      return __real_open(path, oflag);
+    }
+  }
+  return AssetManager::GetInstance()->Open(path);
+}
+
+}  // extern "C"

starboard/android/shared/test_filters.py

@@ -65,12 +65,6 @@
         'PosixDirectoryOpenTest.SunnyDayStaticContent',
         'PosixFileGetPathInfoTest.WorksOnStaticContentDirectories',
 
-        # These POSIX tests should be disabled until asset manager starboard
-        # extension is implemented.
-        'PosixFileGetInfoTest.WorksOnStaticContentFiles',
-        'PosixFileReadTest/*.ReadStaticContent',
-        'PosixFileSeekTest.FromEndInStaticContentWorks',
-
         # These tests are disabled due to not receiving the kEndOfStream
         # player state update within the specified timeout.
         'SbPlayerGetAudioConfigurationTests/SbPlayerGetAudioConfigurationTest.NoInput/*',