Implement ZlibInputStream::Tell() by keeping track of the number of bytes

consumed by the reader.

PiperOrigin-RevId: 172634455

1 files changed, 5 insertions, 3 deletions

diff --git a/tensorflow/core/lib/io/zlib_inputstream.cc b/tensorflow/core/lib/io/zlib_inputstream.cc
index 4999d5cc90..984fbc2810 100644
--- a/tensorflow/core/lib/io/zlib_inputstream.cc
+++ b/tensorflow/core/lib/io/zlib_inputstream.cc
@@ -32,7 +32,8 @@ ZlibInputStream::ZlibInputStream(
       z_stream_input_(new Bytef[input_buffer_capacity_]),
       z_stream_output_(new Bytef[output_buffer_capacity_]),
       zlib_options_(zlib_options),
-      z_stream_(new z_stream) {
+      z_stream_(new z_stream),
+      bytes_read_(0) {
   InitZlibBuffer();
 }
 
@@ -45,6 +46,7 @@ ZlibInputStream::~ZlibInputStream() {
 Status ZlibInputStream::Reset() {
   TF_RETURN_IF_ERROR(input_stream_->Reset());
   InitZlibBuffer();
+  bytes_read_ = 0;
   return Status::OK();
 }
 
@@ -127,6 +129,7 @@ size_t ZlibInputStream::ReadBytesFromCache(size_t bytes_to_read,
     result->append(next_unread_byte_, can_read_bytes);
     next_unread_byte_ += can_read_bytes;
   }
+  bytes_read_ += can_read_bytes;
   return can_read_bytes;
 }
 
@@ -170,8 +173,7 @@ Status ZlibInputStream::ReadNBytes(int64 bytes_to_read, string* result) {
   return Status::OK();
 }
 
-// TODO(srbs): Implement this.
-int64 ZlibInputStream::Tell() const { return -1; }
+int64 ZlibInputStream::Tell() const { return bytes_read_; }
 
 Status ZlibInputStream::Inflate() {
   int error = inflate(z_stream_.get(), zlib_options_.flush_mode);