// Copyright 2015 The Chromium Authors

//

// Licensed under the Apache License, Version 2.0 (the "License");

// you may not use this file except in compliance with the License.

// You may obtain a copy of the License at

//

//     https://www.apache.org/licenses/LICENSE-2.0

//

// Unless required by applicable law or agreed to in writing, software

// distributed under the License is distributed on an "AS IS" BASIS,

// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

// See the License for the specific language governing permissions and

// limitations under the License.

#include "input.h"

BSSL_NAMESPACE_BEGIN

namespace der {

bool operator==(Input lhs, Input rhs) { return Span(lhs) == Span(rhs); }

bool operator!=(Input lhs, Input rhs) { return !(lhs == rhs); }

ByteReader::ByteReader(Input in) : data_(in) {}

bool ByteReader::ReadByte(uint8_t *byte_p) {

  if (!HasMore()) {

    return false;

  }

  *byte_p = data_[0];

  Advance(1);

  return true;

}

bool ByteReader::ReadBytes(size_t len, Input *out) {

  if (len > data_.size()) {

    return false;

  }

  *out = Input(data_.first(len));

  Advance(len);

  return true;

}

// Returns whether there is any more data to be read.

bool ByteReader::HasMore() { return !data_.empty(); }

void ByteReader::Advance(size_t len) {

  BSSL_CHECK(len <= data_.size());

  data_ = data_.subspan(len);

}

}  // namespace der

BSSL_NAMESPACE_END