Remove WritableFile(FSWritableFile)::GetFileSize default implementation (#12303)

Summary:
As titled. This changes public API behavior, and subclasses of `WritableFile` and `FSWritableFile` need to explicitly provide an implementation for the `GetFileSize` method after this change.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/12303

Reviewed By: ajkr

Differential Revision: D53205769

Pulled By: jowlyzhang

fbshipit-source-id: 2e613ca3650302913821b33159b742bdf1d24bc7

1 files changed, 18 insertions, 0 deletions

diff --git a/test_util/testutil.h b/test_util/testutil.h
index c484db649..5643c82b6 100644
--- a/test_util/testutil.h
+++ b/test_util/testutil.h
@@ -189,6 +189,11 @@ class StringSink : public FSWritableFile {
     }
   }
 
+  uint64_t GetFileSize(const IOOptions& /*options*/,
+                       IODebugContext* /*dbg*/) override {
+    return contents_.size();
+  }
+
  private:
   Slice* reader_contents_;
   size_t last_flush_;
@@ -285,6 +290,11 @@ class OverwritingStringSink : public FSWritableFile {
     if (last_flush_ > contents_.size()) last_flush_ = contents_.size();
   }
 
+  uint64_t GetFileSize(const IOOptions& /*options*/,
+                       IODebugContext* /*dbg*/) override {
+    return contents_.size();
+  }
+
  private:
   std::string contents_;
   Slice* reader_contents_;
@@ -562,6 +572,14 @@ class StringFS : public FileSystemWrapper {
       return IOStatus::OK();
     }
 
+    uint64_t GetFileSize(const IOOptions& /*options*/,
+                         IODebugContext* /*dbg*/) override {
+      if (contents_ != nullptr) {
+        return contents_->size();
+      }
+      return 0;
+    }
+
    private:
     std::string* contents_;
   };