1 files changed, 62 insertions, 0 deletions
diff --git a/tensorflow/core/lib/io/inputbuffer.h b/tensorflow/core/lib/io/inputbuffer.h
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+++ b/tensorflow/core/lib/io/inputbuffer.h
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+#ifndef TENSORFLOW_LIB_IO_INPUTBUFFER_H_
+#define TENSORFLOW_LIB_IO_INPUTBUFFER_H_
+
+#include <string>
+#include "tensorflow/core/public/env.h"
+#include "tensorflow/core/platform/port.h"
+#include "tensorflow/core/public/status.h"
+
+namespace tensorflow {
+namespace io {
+
+// An InputBuffer provides a buffer on top of a RandomAccessFile.
+// A given instance of an InputBuffer is NOT safe for concurrent use
+// by multiple threads
+class InputBuffer {
+ public:
+  // Create an InputBuffer for "file" with a buffer size of
+  // "buffer_bytes" bytes.  Takes ownership of "file" and will
+  // delete it when the InputBuffer is destroyed.
+  InputBuffer(RandomAccessFile* file, size_t buffer_bytes);
+  ~InputBuffer();
+
+  // Read one text line of data into "*result" until end-of-file or a
+  // \n is read.  (The \n is not included in the result.)  Overwrites
+  // any existing data in *result.
+  //
+  // If successful, returns OK.  If we are already at the end of the
+  // file, we return an OUT_OF_RANGE error.  Otherwise, we return
+  // some other non-OK status.
+  Status ReadLine(string* result);
+
+  // Reads bytes_to_read bytes into *result, overwriting *result.
+  //
+  // If successful, returns OK.  If we there are not enough bytes to
+  // read before the end of the file, we return an OUT_OF_RANGE error.
+  // Otherwise, we return some other non-OK status.
+  Status ReadNBytes(int64 bytes_to_read, string* result);
+
+  // Like ReadNBytes() without returning the bytes read.
+  Status SkipNBytes(int64 bytes_to_skip);
+
+  // Returns the position in the file.
+  int64 Tell() const { return file_pos_ - (limit_ - pos_); }
+
+ private:
+  Status FillBuffer();
+
+  RandomAccessFile* file_;  // Owned
+  int64 file_pos_;          // Next position to read from in "file_"
+  size_t size_;             // Size of "buf_"
+  char* buf_;               // The buffer itself
+  // [pos_,limit_) hold the "limit_ - pos_" bytes just before "file_pos_"
+  char* pos_;    // Current position in "buf"
+  char* limit_;  // Just past end of valid data in "buf"
+
+  TF_DISALLOW_COPY_AND_ASSIGN(InputBuffer);
+};
+
+}  // namespace io
+}  // namespace tensorflow
+
+#endif  // TENSORFLOW_LIB_IO_INPUTBUFFER_H_