libsnapshot: Add more feature flags to SnapshotMergeReport.

This patch also begins reducing the complexity of SnapshotMergeStats by
eliminating the indirection layer between the protobuf and
SnapshotManager.

Bug: 222117189
Test: statsd_testdrive
Change-Id: I15d740121c381da7d8311f0cbbd0da82db877555

fs_mgr/libsnapshot/android/snapshot/snapshot.proto

@@ -235,4 +235,13 @@ message SnapshotMergeReport {
 
     // The source fingerprint at the time the OTA was downloaded.
     string source_build_fingerprint = 10;
+
+    // Whether this update attempt uses userspace snapshots.
+    bool userspace_snapshots_used = 11;
+
+    // Whether this update attempt uses XOR compression.
+    bool xor_compression_used = 12;
+
+    // Whether this update attempt used io_uring.
+    bool iouring_used = 13;
 }

fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot.h

@@ -62,6 +62,7 @@ class MockSnapshotManager : public ISnapshotManager {
     MOCK_METHOD(std::unique_ptr<AutoDevice>, EnsureMetadataMounted, (), (override));
     MOCK_METHOD(ISnapshotMergeStats*, GetSnapshotMergeStatsInstance, (), (override));
     MOCK_METHOD(std::string, ReadSourceBuildFingerprint, (), (override));
+    MOCK_METHOD(void, SetMergeStatsFeatures, (ISnapshotMergeStats*), (override));
 };
 
 }  // namespace android::snapshot

fs_mgr/libsnapshot/include/libsnapshot/mock_snapshot_merge_stats.h

@@ -28,10 +28,7 @@ class MockSnapshotMergeStats final : public ISnapshotMergeStats {
     virtual ~MockSnapshotMergeStats() = default;
     // Called when merge starts or resumes.
     MOCK_METHOD(bool, Start, (), (override));
-    MOCK_METHOD(void, set_state, (android::snapshot::UpdateState, bool), (override));
-    MOCK_METHOD(void, set_cow_file_size, (uint64_t), ());
-    MOCK_METHOD(void, set_total_cow_size_bytes, (uint64_t), (override));
-    MOCK_METHOD(void, set_estimated_cow_size_bytes, (uint64_t), (override));
+    MOCK_METHOD(void, set_state, (android::snapshot::UpdateState), (override));
     MOCK_METHOD(void, set_boot_complete_time_ms, (uint32_t), (override));
     MOCK_METHOD(void, set_boot_complete_to_merge_start_time_ms, (uint32_t), (override));
     MOCK_METHOD(void, set_merge_failure_code, (MergeFailureCode), (override));
@@ -45,6 +42,7 @@ class MockSnapshotMergeStats final : public ISnapshotMergeStats {
     MOCK_METHOD(MergeFailureCode, merge_failure_code, (), (override));
     MOCK_METHOD(std::unique_ptr<Result>, Finish, (), (override));
     MOCK_METHOD(bool, WriteState, (), (override));
+    MOCK_METHOD(SnapshotMergeReport*, report, (), (override));
 
     using ISnapshotMergeStats::Result;
     // Return nullptr if any failure.

fs_mgr/libsnapshot/include/libsnapshot/snapshot.h

@@ -134,6 +134,9 @@ class ISnapshotManager {
     // may need to be merged before wiping.
     virtual bool FinishedSnapshotWrites(bool wipe) = 0;
 
+    // Set feature flags on an ISnapshotMergeStats object.
+    virtual void SetMergeStatsFeatures(ISnapshotMergeStats* stats) = 0;
+
     // Update an ISnapshotMergeStats object with statistics about COW usage.
     // This should be called before the merge begins as otherwise snapshots
     // may be deleted.
@@ -378,6 +381,7 @@ class SnapshotManager final : public ISnapshotManager {
     bool MapAllSnapshots(const std::chrono::milliseconds& timeout_ms = {}) override;
     bool UnmapAllSnapshots() override;
     std::string ReadSourceBuildFingerprint() override;
+    void SetMergeStatsFeatures(ISnapshotMergeStats* stats) override;
 
     // We can't use WaitForFile during first-stage init, because ueventd is not
     // running and therefore will not automatically create symlinks. Instead,

fs_mgr/libsnapshot/include/libsnapshot/snapshot_stats.h

@@ -28,10 +28,7 @@ class ISnapshotMergeStats {
     virtual ~ISnapshotMergeStats() = default;
     // Called when merge starts or resumes.
     virtual bool Start() = 0;
-    virtual void set_state(android::snapshot::UpdateState state, bool using_compression) = 0;
-    virtual void set_cow_file_size(uint64_t cow_file_size) = 0;
-    virtual void set_total_cow_size_bytes(uint64_t bytes) = 0;
-    virtual void set_estimated_cow_size_bytes(uint64_t bytes) = 0;
+    virtual void set_state(android::snapshot::UpdateState state) = 0;
     virtual void set_boot_complete_time_ms(uint32_t ms) = 0;
     virtual void set_boot_complete_to_merge_start_time_ms(uint32_t ms) = 0;
     virtual void set_merge_failure_code(MergeFailureCode code) = 0;
@@ -55,6 +52,9 @@ class ISnapshotMergeStats {
     // Return nullptr if any failure.
     virtual std::unique_ptr<Result> Finish() = 0;
 
+    // Return the underlying implementation.
+    virtual SnapshotMergeReport* report() = 0;
+
     // Write out the current state. This should be called when data might be lost that
     // cannot be recovered (eg the COW sizes).
     virtual bool WriteState() = 0;
@@ -67,11 +67,8 @@ class SnapshotMergeStats : public ISnapshotMergeStats {
 
     // ISnapshotMergeStats overrides
     bool Start() override;
-    void set_state(android::snapshot::UpdateState state, bool using_compression) override;
-    void set_cow_file_size(uint64_t cow_file_size) override;
+    void set_state(android::snapshot::UpdateState state) override;
     uint64_t cow_file_size() override;
-    void set_total_cow_size_bytes(uint64_t bytes) override;
-    void set_estimated_cow_size_bytes(uint64_t bytes) override;
     uint64_t total_cow_size_bytes() override;
     uint64_t estimated_cow_size_bytes() override;
     void set_boot_complete_time_ms(uint32_t ms) override;
@@ -85,6 +82,9 @@ class SnapshotMergeStats : public ISnapshotMergeStats {
     std::unique_ptr<Result> Finish() override;
     bool WriteState() override;
 
+    // Access the underlying report before it is finished.
+    SnapshotMergeReport* report() override { return &report_; }
+
   private:
     bool ReadState();
     bool DeleteState();

fs_mgr/libsnapshot/include/libsnapshot/snapshot_stub.h

@@ -59,6 +59,7 @@ class SnapshotManagerStub : public ISnapshotManager {
     bool MapAllSnapshots(const std::chrono::milliseconds& timeout_ms) override;
     bool UnmapAllSnapshots() override;
     std::string ReadSourceBuildFingerprint() override;
+    void SetMergeStatsFeatures(ISnapshotMergeStats* stats) override;
 };
 
 }  // namespace android::snapshot

fs_mgr/libsnapshot/snapshot.cpp

@@ -4120,9 +4120,20 @@ void SnapshotManager::UpdateCowStats(ISnapshotMergeStats* stats) {
         estimated_cow_size += status.estimated_cow_size();
     }
 
-    stats->set_cow_file_size(cow_file_size);
-    stats->set_total_cow_size_bytes(total_cow_size);
-    stats->set_estimated_cow_size_bytes(estimated_cow_size);
+    stats->report()->set_cow_file_size(cow_file_size);
+    stats->report()->set_total_cow_size_bytes(total_cow_size);
+    stats->report()->set_estimated_cow_size_bytes(estimated_cow_size);
+}
+
+void SnapshotManager::SetMergeStatsFeatures(ISnapshotMergeStats* stats) {
+    auto lock = LockExclusive();
+    if (!lock) return;
+
+    SnapshotUpdateStatus update_status = ReadSnapshotUpdateStatus(lock.get());
+    stats->report()->set_iouring_used(update_status.io_uring_enabled());
+    stats->report()->set_userspace_snapshots_used(update_status.userspace_snapshots());
+    stats->report()->set_xor_compression_used(
+            android::base::GetBoolProperty("ro.virtual_ab.compression.xor.enabled", false));
 }
 
 bool SnapshotManager::DeleteDeviceIfExists(const std::string& name,

fs_mgr/libsnapshot/snapshot_stats.cpp

@@ -84,27 +84,14 @@ bool SnapshotMergeStats::Start() {
     return WriteState();
 }
 
-void SnapshotMergeStats::set_state(android::snapshot::UpdateState state, bool using_compression) {
+void SnapshotMergeStats::set_state(android::snapshot::UpdateState state) {
     report_.set_state(state);
-    report_.set_compression_enabled(using_compression);
-}
-
-void SnapshotMergeStats::set_cow_file_size(uint64_t cow_file_size) {
-    report_.set_cow_file_size(cow_file_size);
 }
 
 uint64_t SnapshotMergeStats::cow_file_size() {
     return report_.cow_file_size();
 }
 
-void SnapshotMergeStats::set_total_cow_size_bytes(uint64_t bytes) {
-    report_.set_total_cow_size_bytes(bytes);
-}
-
-void SnapshotMergeStats::set_estimated_cow_size_bytes(uint64_t bytes) {
-    report_.set_estimated_cow_size_bytes(bytes);
-}
-
 uint64_t SnapshotMergeStats::total_cow_size_bytes() {
     return report_.total_cow_size_bytes();
 }

fs_mgr/libsnapshot/snapshot_stub.cpp

@@ -128,12 +128,9 @@ bool SnapshotManagerStub::UpdateUsesUserSnapshots() {
 
 class SnapshotMergeStatsStub : public ISnapshotMergeStats {
     bool Start() override { return false; }
-    void set_state(android::snapshot::UpdateState, bool) override {}
-    void set_cow_file_size(uint64_t) override {}
+    void set_state(android::snapshot::UpdateState) override {}
     uint64_t cow_file_size() override { return 0; }
     std::unique_ptr<Result> Finish() override { return nullptr; }
-    void set_total_cow_size_bytes(uint64_t) override {}
-    void set_estimated_cow_size_bytes(uint64_t) override {}
     uint64_t total_cow_size_bytes() override { return 0; }
     uint64_t estimated_cow_size_bytes() override { return 0; }
     void set_boot_complete_time_ms(uint32_t) override {}
@@ -145,6 +142,10 @@ class SnapshotMergeStatsStub : public ISnapshotMergeStats {
     void set_source_build_fingerprint(const std::string&) override {}
     std::string source_build_fingerprint() override { return {}; }
     bool WriteState() override { return false; }
+    SnapshotMergeReport* report() override { return &report_; }
+
+  private:
+    SnapshotMergeReport report_;
 };
 
 ISnapshotMergeStats* SnapshotManagerStub::GetSnapshotMergeStatsInstance() {
@@ -183,4 +184,8 @@ std::string SnapshotManagerStub::ReadSourceBuildFingerprint() {
     return {};
 }
 
+void SnapshotManagerStub::SetMergeStatsFeatures(ISnapshotMergeStats*) {
+    LOG(ERROR) << __FUNCTION__ << " should never be called.";
+}
+
 }  // namespace android::snapshot