Added Blob::flush() and test cases for it

src/blobstore/implementations/ondisk/OnDiskBlob.cpp

@@ -29,6 +29,7 @@ OnDiskBlob::OnDiskBlob(const bf::path &filepath, Data &&data)
 }
 
 OnDiskBlob::~OnDiskBlob() {
+  _storeToDisk();
 }
 
 void *OnDiskBlob::data() {
@@ -71,5 +72,9 @@ void OnDiskBlob::_storeToDisk() const {
   _data.StoreToFile(_filepath);
 }
 
+void OnDiskBlob::flush() {
+  _storeToDisk();
+}
+
 } /* namespace ondisk */
 } /* namespace blobstore */

src/blobstore/implementations/ondisk/OnDiskBlob.h

@@ -24,6 +24,8 @@ public:
   void *data() override;
   const void *data() const override;
 
+  void flush() override;
+
   size_t size() const override;
 
 private:

src/blobstore/interface/Blob.h

@@ -13,6 +13,8 @@ public:
   virtual void *data() = 0;
   virtual const void *data() const = 0;
 
+  virtual void flush() = 0;
+
   virtual size_t size() const = 0;
 };
 

src/test/blobstore/ondisk/OnDiskBlobCreateTest.cpp

@@ -53,3 +53,5 @@ TEST_P(OnDiskBlobCreateSizeTest, InMemorySizeIsCorrect) {
   EXPECT_EQ(GetParam(), blob->size());
 }
 
+//TODO Test File is zeroed out
+//TODO Test in-memory is zeroed out

src/test/blobstore/ondisk/OnDiskBlobFlushTest.cpp

@@ -0,0 +1,103 @@
+#include "gtest/gtest.h"
+
+#include "test/testutils/TempFile.h"
+#include "test/testutils/VirtualTestFile.h"
+
+#include "blobstore/implementations/ondisk/OnDiskBlob.h"
+#include "blobstore/implementations/ondisk/FileAlreadyExistsException.h"
+
+using ::testing::Test;
+using ::testing::WithParamInterface;
+using ::testing::Values;
+
+using std::unique_ptr;
+
+using namespace blobstore::ondisk;
+
+namespace bf = boost::filesystem;
+
+class OnDiskBlobFlushTest: public Test, public WithParamInterface<size_t> {
+public:
+  OnDiskBlobFlushTest()
+  // Don't create the temp file yet (therefore pass false to the TempFile constructor)
+  : file(false), randomData(GetParam()) {
+  }
+  TempFile file;
+
+  VirtualTestFile randomData;
+
+  unique_ptr<OnDiskBlob> CreateBlobAndLoadItFromDisk() {
+    {
+      auto blob = OnDiskBlob::CreateOnDisk(file.path(), randomData.size());
+    }
+    return OnDiskBlob::LoadFromDisk(file.path());
+  }
+
+  unique_ptr<OnDiskBlob> CreateBlob() {
+    return OnDiskBlob::CreateOnDisk(file.path(), randomData.size());
+  }
+
+  void WriteDataToBlob(const unique_ptr<OnDiskBlob> &blob) {
+    std::memcpy(blob->data(), randomData.data(), randomData.size());
+  }
+
+  void EXPECT_BLOB_DATA_CORRECT(const unique_ptr<OnDiskBlob> &blob) {
+    EXPECT_EQ(randomData.size(), blob->size());
+    EXPECT_EQ(0, std::memcmp(randomData.data(), blob->data(), randomData.size()));
+  }
+
+  void EXPECT_STORED_FILE_DATA_CORRECT() {
+    Data actual = Data::LoadFromFile(file.path());
+    EXPECT_EQ(randomData.size(), actual.size());
+    EXPECT_EQ(0, std::memcmp(randomData.data(), actual.data(), randomData.size()));
+  }
+};
+INSTANTIATE_TEST_CASE_P(OnDiskBlobFlushTest, OnDiskBlobFlushTest, Values((size_t)0, (size_t)1, (size_t)1024, (size_t)4096, (size_t)10*1024*1024));
+
+TEST_P(OnDiskBlobFlushTest, AfterCreate_FlushingDoesntChangeBlob) {
+  auto blob =  CreateBlob();
+  WriteDataToBlob(blob);
+  blob->flush();
+
+  EXPECT_BLOB_DATA_CORRECT(blob);
+}
+
+TEST_P(OnDiskBlobFlushTest, AfterLoad_FlushingDoesntChangeBlob) {
+  auto blob =  CreateBlobAndLoadItFromDisk();
+  WriteDataToBlob(blob);
+  blob->flush();
+
+  EXPECT_BLOB_DATA_CORRECT(blob);
+}
+
+TEST_P(OnDiskBlobFlushTest, AfterCreate_FlushingWritesCorrectData) {
+  auto blob = CreateBlob();
+  WriteDataToBlob(blob);
+  blob->flush();
+
+  EXPECT_STORED_FILE_DATA_CORRECT();
+}
+
+TEST_P(OnDiskBlobFlushTest, AfterLoad_FlushingWritesCorrectData) {
+  auto blob = CreateBlobAndLoadItFromDisk();
+  WriteDataToBlob(blob);
+  blob->flush();
+
+  EXPECT_STORED_FILE_DATA_CORRECT();
+}
+
+TEST_P(OnDiskBlobFlushTest, AfterCreate_DestructorFlushes) {
+  {
+    auto blob = CreateBlob();
+    WriteDataToBlob(blob);
+  }
+  EXPECT_STORED_FILE_DATA_CORRECT();
+}
+
+TEST_P(OnDiskBlobFlushTest, AfterLoad_DestructorFlushes) {
+  {
+    auto blob = CreateBlobAndLoadItFromDisk();
+    WriteDataToBlob(blob);
+  }
+  EXPECT_STORED_FILE_DATA_CORRECT();
+}

src/test/blobstore/ondisk/OnDiskBlobLoadTest.cpp

@@ -39,3 +39,7 @@ TEST_P(OnDiskBlobLoadSizeTest, FileSizeIsCorrect) {
 
   EXPECT_EQ(GetParam(), blob->size());
 }
+
+//TODO Load and compare actual data
+//TODO Test file doesn't exist
+