1 files changed, 42 insertions, 0 deletions
diff --git a/tensorflow/core/lib/io/record_writer.cc b/tensorflow/core/lib/io/record_writer.cc
new file mode 100644
index 0000000000..3d7f1509ab
--- /dev/null
+++ b/tensorflow/core/lib/io/record_writer.cc
@@ -0,0 +1,42 @@
+#include "tensorflow/core/lib/io/record_writer.h"
+
+#include "tensorflow/core/public/env.h"
+#include "tensorflow/core/lib/core/coding.h"
+#include "tensorflow/core/lib/hash/crc32c.h"
+
+namespace tensorflow {
+namespace io {
+
+RecordWriter::RecordWriter(WritableFile* dest) : dest_(dest) {}
+
+RecordWriter::~RecordWriter() {}
+
+static uint32 MaskedCrc(const char* data, size_t n) {
+  return crc32c::Mask(crc32c::Value(data, n));
+}
+
+Status RecordWriter::WriteRecord(StringPiece data) {
+  // Format of a single record:
+  //  uint64    length
+  //  uint32    masked crc of length
+  //  byte      data[length]
+  //  uint32    masked crc of data
+  char header[sizeof(uint64) + sizeof(uint32)];
+  core::EncodeFixed64(header + 0, data.size());
+  core::EncodeFixed32(header + sizeof(uint64),
+                      MaskedCrc(header, sizeof(uint64)));
+  Status s = dest_->Append(StringPiece(header, sizeof(header)));
+  if (!s.ok()) {
+    return s;
+  }
+  s = dest_->Append(data);
+  if (!s.ok()) {
+    return s;
+  }
+  char footer[sizeof(uint32)];
+  core::EncodeFixed32(footer, MaskedCrc(data.data(), data.size()));
+  return dest_->Append(StringPiece(footer, sizeof(footer)));
+}
+
+}  // namespace io
+}  // namespace tensorflow