text: /*
   *  Copyright (c) 2018 The WebRTC project authors. All Rights Reserved.
   *
   *  Use of this source code is governed by a BSD-style license
   *  that can be found in the LICENSE file in the root of the source
   *  tree. An additional intellectual property rights grant can be found
   *  in the file PATENTS.  All contributing project authors may
   *  be found in the AUTHORS file in the root of the source tree.
   */
  
  #ifndef LOGGING_RTC_EVENT_LOG_ENCODER_BLOB_ENCODING_H_
  #define LOGGING_RTC_EVENT_LOG_ENCODER_BLOB_ENCODING_H_
  
  #include <stddef.h>
  #include <string>
  #include <vector>
  
  #include "absl/strings/string_view.h"
  
  namespace webrtc {
  
  // Encode/decode a sequence of strings, whose length is not known to be
  // discernable from the blob itself (i.e. without being transmitted OOB),
  // in a way that would allow us to separate them again on the decoding side.
  // The number of blobs is assumed to be transmitted OOB. For example, if
  // multiple sequences of different blobs are sent, but all sequences contain
  // the same number of blobs, it is beneficial to not encode the number of blobs.
  //
  // EncodeBlobs() must be given a non-empty vector. The blobs themselves may
  // be equal to "", though.
  // EncodeBlobs() may not fail.
  // EncodeBlobs() never returns the empty string.
  //
  // Calling DecodeBlobs() on an empty string, or with |num_of_blobs| set to 0,
  // is an error.
  // DecodeBlobs() returns an empty vector if it fails, e.g. due to a mismatch
  // between |num_of_blobs| and |encoded_blobs|, which can happen if
  // |encoded_blobs| is corrupted.
  // When successful, DecodeBlobs() returns a vector of string_view objects,
  // which refer to the original input (|encoded_blobs|), and therefore may
  // not outlive it.
  //
  // Note that the returned std::string might have been reserved for significantly
  // more memory than it ends up using. If the caller to EncodeBlobs() intends
  // to store the result long-term, he should consider shrink_to_fit()-ing it.
  std::string EncodeBlobs(const std::vector<std::string>& blobs);
  std::vector<absl::string_view> DecodeBlobs(absl::string_view encoded_blobs,
                                             size_t num_of_blobs);
  
  }  // namespace webrtc
  
  #endif  // LOGGING_RTC_EVENT_LOG_ENCODER_BLOB_ENCODING_H_
  