[incfs] Use a more efficient getBlockCount() for incfs v2

v2 IncFS driver gives a very lightweight function to check the
loading progress on a file, use it instead of counting the
filled ranges

+ remove the unused mockable toString(IncFsFileId)

Bug: 183067554
Test: atest IncrementalServiceTest
Change-Id: Icd3bd891d671b27654f4194787a15a00cba1eb80
diff --git a/services/incremental/IncrementalService.cpp b/services/incremental/IncrementalService.cpp
index ebfcc32..34253f9 100644
--- a/services/incremental/IncrementalService.cpp
+++ b/services/incremental/IncrementalService.cpp
@@ -2860,7 +2860,7 @@
     dprintf(fd, "        lastPendingReads: \n");
     const auto control = mService.mIncFs->openMount(mHealthPath);
     for (auto&& pendingRead : mLastPendingReads) {
-        dprintf(fd, "          fileId: %s\n", mService.mIncFs->toString(pendingRead.id).c_str());
+        dprintf(fd, "          fileId: %s\n", IncFsWrapper::toString(pendingRead.id).c_str());
         const auto metadata = mService.mIncFs->getMetadata(control, pendingRead.id);
         dprintf(fd, "          metadataHex: %s\n", toHexString(metadata).c_str());
         dprintf(fd, "          blockIndex: %d\n", pendingRead.block);
diff --git a/services/incremental/ServiceWrappers.cpp b/services/incremental/ServiceWrappers.cpp
index eb204c5..7e85f9d 100644
--- a/services/incremental/ServiceWrappers.cpp
+++ b/services/incremental/ServiceWrappers.cpp
@@ -134,6 +134,10 @@
     } mLooper;
 };
 
+std::string IncFsWrapper::toString(FileId fileId) {
+    return incfs::toString(fileId);
+}
+
 class RealIncFs final : public IncFsWrapper {
 public:
     RealIncFs() = default;
@@ -173,9 +177,16 @@
     FileId getFileId(const Control& control, std::string_view path) const final {
         return incfs::getFileId(control, path);
     }
-    std::string toString(FileId fileId) const final { return incfs::toString(fileId); }
     std::pair<IncFsBlockIndex, IncFsBlockIndex> countFilledBlocks(
             const Control& control, std::string_view path) const final {
+        if (incfs::features() & Features::v2) {
+            const auto counts = incfs::getBlockCount(control, path);
+            if (!counts) {
+                return {-errno, -errno};
+            }
+            return {counts->filledDataBlocks + counts->filledHashBlocks,
+                    counts->totalDataBlocks + counts->totalHashBlocks};
+        }
         const auto fileId = incfs::getFileId(control, path);
         const auto fd = incfs::openForSpecialOps(control, fileId);
         int res = fd.get();
diff --git a/services/incremental/ServiceWrappers.h b/services/incremental/ServiceWrappers.h
index 2f3eb24..a787db5 100644
--- a/services/incremental/ServiceWrappers.h
+++ b/services/incremental/ServiceWrappers.h
@@ -84,6 +84,8 @@
             void(std::string_view root, std::string_view backingDir,
                  std::span<std::pair<std::string_view, std::string_view>> binds)>;
 
+    static std::string toString(FileId fileId);
+
     virtual ~IncFsWrapper() = default;
     virtual Features features() const = 0;
     virtual void listExistingMounts(const ExistingMountCallback& cb) const = 0;
@@ -99,7 +101,6 @@
     virtual incfs::RawMetadata getMetadata(const Control& control, FileId fileid) const = 0;
     virtual incfs::RawMetadata getMetadata(const Control& control, std::string_view path) const = 0;
     virtual FileId getFileId(const Control& control, std::string_view path) const = 0;
-    virtual std::string toString(FileId fileId) const = 0;
     virtual std::pair<IncFsBlockIndex, IncFsBlockIndex> countFilledBlocks(
             const Control& control, std::string_view path) const = 0;
     virtual incfs::LoadingState isFileFullyLoaded(const Control& control,
diff --git a/services/incremental/test/IncrementalServiceTest.cpp b/services/incremental/test/IncrementalServiceTest.cpp
index 50d1e36..fb3a8a0 100644
--- a/services/incremental/test/IncrementalServiceTest.cpp
+++ b/services/incremental/test/IncrementalServiceTest.cpp
@@ -362,7 +362,6 @@
     MOCK_CONST_METHOD2(getMetadata, RawMetadata(const Control& control, FileId fileid));
     MOCK_CONST_METHOD2(getMetadata, RawMetadata(const Control& control, std::string_view path));
     MOCK_CONST_METHOD2(getFileId, FileId(const Control& control, std::string_view path));
-    MOCK_CONST_METHOD1(toString, std::string(FileId fileId));
     MOCK_CONST_METHOD2(countFilledBlocks,
                        std::pair<IncFsBlockIndex, IncFsBlockIndex>(const Control& control,
                                                                    std::string_view path));