ARROW-410: [C++] Add virtual Writeable::Flush

wesm · wesm · commit be5d73f2cbcb · 2017-01-31T08:00:49.000-05:00
Author: Wes McKinney <wes.mckinney@twosigma.com> Closes apache#310 from wesm/ARROW-410 and squashes the following commits: 7352f0a [Wes McKinney] Add virtual Writeable::Flush, and move HDFS flush there
diff --git a/cpp/src/arrow/io/hdfs.cc b/cpp/src/arrow/io/hdfs.cc
@@ -238,15 +238,20 @@ class HdfsOutputStream::HdfsOutputStreamImpl : public HdfsAnyFileImpl {
 
   Status Close() {
     if (is_open_) {
-      int ret = driver_->Flush(fs_, file_);
-      CHECK_FAILURE(ret, "Flush");
-      ret = driver_->CloseFile(fs_, file_);
+      RETURN_NOT_OK(Flush());
+      int ret = driver_->CloseFile(fs_, file_);
       CHECK_FAILURE(ret, "CloseFile");
       is_open_ = false;
     }
     return Status::OK();
   }
 
+  Status Flush() {
+    int ret = driver_->Flush(fs_, file_);
+    CHECK_FAILURE(ret, "Flush");
+    return Status::OK();
+  }
+
   Status Write(const uint8_t* buffer, int64_t nbytes, int64_t* bytes_written) {
     tSize ret = driver_->Write(fs_, file_, reinterpret_cast<const void*>(buffer), nbytes);
     CHECK_FAILURE(ret, "Write");
@@ -277,6 +282,10 @@ Status HdfsOutputStream::Write(const uint8_t* buffer, int64_t nbytes) {
   return Write(buffer, nbytes, &bytes_written_dummy);
 }
 
+Status HdfsOutputStream::Flush() {
+  return impl_->Flush();
+}
+
 Status HdfsOutputStream::Tell(int64_t* position) {
   return impl_->Tell(position);
 }
diff --git a/cpp/src/arrow/io/hdfs.h b/cpp/src/arrow/io/hdfs.h
@@ -208,6 +208,8 @@ class ARROW_EXPORT HdfsOutputStream : public OutputStream {
 
   Status Write(const uint8_t* buffer, int64_t nbytes, int64_t* bytes_written);
 
+  Status Flush() override;
+
   Status Tell(int64_t* position) override;
 
  private:
diff --git a/cpp/src/arrow/io/interfaces.cc b/cpp/src/arrow/io/interfaces.cc
@@ -52,5 +52,9 @@ Status Writeable::Write(const std::string& data) {
       reinterpret_cast<const uint8_t*>(data.c_str()), static_cast<int64_t>(data.size()));
 }
 
+Status Writeable::Flush() {
+  return Status::OK();
+}
+
 }  // namespace io
 }  // namespace arrow
diff --git a/cpp/src/arrow/io/interfaces.h b/cpp/src/arrow/io/interfaces.h
@@ -73,6 +73,9 @@ class ARROW_EXPORT Writeable {
  public:
   virtual Status Write(const uint8_t* data, int64_t nbytes) = 0;
 
+  // Default implementation is a no-op
+  virtual Status Flush();
+
   Status Write(const std::string& data);
 };
 

Original file line number	Diff line number	Diff line change
`@@ -52,5 +52,9 @@ Status Writeable::Write(const std::string& data) {`
`52`	`52`	`reinterpret_cast<const uint8_t*>(data.c_str()), static_cast<int64_t>(data.size()));`
`53`	`53`	`}`
`54`	`54`
	`55`	`+Status Writeable::Flush() {`
	`56`	`+ return Status::OK();`
	`57`	`+}`
	`58`	`+`
`55`	`59`	`} // namespace io`
`56`	`60`	`} // namespace arrow`