4 files changed, 44 insertions, 10 deletions
diff --git a/cmds/idmap2/idmap2/CommandUtils.cpp b/cmds/idmap2/idmap2/CommandUtils.cpp
index 63235ff7d199..d344d0f1c531 100644
--- a/cmds/idmap2/idmap2/CommandUtils.cpp
+++ b/cmds/idmap2/idmap2/CommandUtils.cpp
@@ -14,12 +14,13 @@
  * limitations under the License.
  */
 
+#include "idmap2/CommandUtils.h"
+
 #include <fstream>
 #include <memory>
 #include <string>
 #include <vector>
 
-#include "idmap2/CommandUtils.h"
 #include "idmap2/Idmap.h"
 #include "idmap2/Result.h"
 #include "idmap2/SysTrace.h"
diff --git a/cmds/idmap2/idmap2d/Idmap2Service.cpp b/cmds/idmap2/idmap2d/Idmap2Service.cpp
index 2cfbac3f2c26..a8d648917b08 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.cpp
+++ b/cmds/idmap2/idmap2d/Idmap2Service.cpp
@@ -297,17 +297,40 @@ Status Idmap2Service::createFabricatedOverlay(
   return ok();
 }
 
-Status Idmap2Service::getFabricatedOverlayInfos(
+Status Idmap2Service::acquireFabricatedOverlayIterator() {
+  if (frro_iter_.has_value()) {
+    LOG(WARNING) << "active ffro iterator was not previously released";
+  }
+  frro_iter_ = std::filesystem::directory_iterator(kIdmapCacheDir);
+  return ok();
+}
+
+Status Idmap2Service::releaseFabricatedOverlayIterator() {
+  if (!frro_iter_.has_value()) {
+    LOG(WARNING) << "no active ffro iterator to release";
+  }
+  return ok();
+}
+
+Status Idmap2Service::nextFabricatedOverlayInfos(
     std::vector<os::FabricatedOverlayInfo>* _aidl_return) {
-  for (const auto& entry : std::filesystem::directory_iterator(kIdmapCacheDir)) {
-    if (!android::IsFabricatedOverlay(entry.path())) {
+  constexpr size_t kMaxEntryCount = 100;
+  if (!frro_iter_.has_value()) {
+    return error("no active frro iterator");
+  }
+
+  size_t count = 0;
+  auto& entry_iter = *frro_iter_;
+  auto entry_iter_end = end(*frro_iter_);
+  for (; entry_iter != entry_iter_end && count < kMaxEntryCount; ++entry_iter) {
+    auto& entry = *entry_iter;
+    if (!entry.is_regular_file() || !android::IsFabricatedOverlay(entry.path())) {
       continue;
     }
 
     const auto overlay = FabricatedOverlayContainer::FromPath(entry.path());
     if (!overlay) {
-      // This is a sign something went wrong.
-      LOG(ERROR) << "Failed to open '" << entry.path() << "': " << overlay.GetErrorMessage();
+      LOG(WARNING) << "Failed to open '" << entry.path() << "': " << overlay.GetErrorMessage();
       continue;
     }
 
@@ -319,8 +342,8 @@ Status Idmap2Service::getFabricatedOverlayInfos(
     out_info.targetOverlayable = info.target_name;
     out_info.path = entry.path();
     _aidl_return->emplace_back(std::move(out_info));
+    count++;
   }
-
   return ok();
 }
 
diff --git a/cmds/idmap2/idmap2d/Idmap2Service.h b/cmds/idmap2/idmap2d/Idmap2Service.h
index c16c3c52155f..c61e4bc98a54 100644
--- a/cmds/idmap2/idmap2d/Idmap2Service.h
+++ b/cmds/idmap2/idmap2d/Idmap2Service.h
@@ -24,6 +24,7 @@
 #include <idmap2/ResourceContainer.h>
 #include <idmap2/Result.h>
 
+#include <filesystem>
 #include <memory>
 #include <string>
 #include <vector>
@@ -59,7 +60,11 @@ class Idmap2Service : public BinderService<Idmap2Service>, public BnIdmap2 {
   binder::Status deleteFabricatedOverlay(const std::string& overlay_path,
                                          bool* _aidl_return) override;
 
-  binder::Status getFabricatedOverlayInfos(
+  binder::Status acquireFabricatedOverlayIterator() override;
+
+  binder::Status releaseFabricatedOverlayIterator() override;
+
+  binder::Status nextFabricatedOverlayInfos(
       std::vector<os::FabricatedOverlayInfo>* _aidl_return) override;
 
   binder::Status dumpIdmap(const std::string& overlay_path, std::string* _aidl_return) override;
@@ -69,7 +74,7 @@ class Idmap2Service : public BinderService<Idmap2Service>, public BnIdmap2 {
   // be able to be recalculated if idmap2 dies and restarts.
   std::unique_ptr<idmap2::TargetResourceContainer> framework_apk_cache_;
 
-  std::vector<os::FabricatedOverlayInfo> fabricated_overlays_;
+  std::optional<std::filesystem::directory_iterator> frro_iter_;
 
   template <typename T>
   using MaybeUniquePtr = std::variant<std::unique_ptr<T>, T*>;
diff --git a/cmds/idmap2/idmap2d/aidl/services/android/os/IIdmap2.aidl b/cmds/idmap2/idmap2d/aidl/services/android/os/IIdmap2.aidl
index 48cee69ca779..0059cf293177 100644
--- a/cmds/idmap2/idmap2d/aidl/services/android/os/IIdmap2.aidl
+++ b/cmds/idmap2/idmap2d/aidl/services/android/os/IIdmap2.aidl
@@ -37,8 +37,13 @@ interface IIdmap2 {
                                           int fulfilledPolicies,
                                           boolean enforceOverlayable,
                                           int userId);
+
   @nullable FabricatedOverlayInfo createFabricatedOverlay(in FabricatedOverlayInternal overlay);
-  List<FabricatedOverlayInfo> getFabricatedOverlayInfos();
   boolean deleteFabricatedOverlay(@utf8InCpp String path);
+
+  void acquireFabricatedOverlayIterator();
+  void releaseFabricatedOverlayIterator();
+  List<FabricatedOverlayInfo> nextFabricatedOverlayInfos();
+
   @utf8InCpp String dumpIdmap(@utf8InCpp String overlayApkPath);
 }