// Protocol Buffers - Google's data interchange format

// Copyright 2008 Google Inc.  All rights reserved.

// https://developers.google.com/protocol-buffers/

//

// Redistribution and use in source and binary forms, with or without

// modification, are permitted provided that the following conditions are

// met:

//

//     * Redistributions of source code must retain the above copyright

// notice, this list of conditions and the following disclaimer.

//     * Redistributions in binary form must reproduce the above

// copyright notice, this list of conditions and the following disclaimer

// in the documentation and/or other materials provided with the

// distribution.

//     * Neither the name of Google Inc. nor the names of its

// contributors may be used to endorse or promote products derived from

// this software without specific prior written permission.

//

// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

#include <google/protobuf/stubs/stringpiece.h>

#include <string.h>

#include <algorithm>

#include <climits>

#include <string>

#include <ostream>

#include <google/protobuf/stubs/logging.h>

namespace google {

namespace protobuf {

std::ostream& operator<<(std::ostream& o, StringPiece piece) {

  o.write(piece.data(), piece.size());

  return o;

}

// Out-of-line error path.

void StringPiece::LogFatalSizeTooBig(size_t size, const char* details) {

  GOOGLE_LOG(FATAL) << "size too big: " << size << " details: " << details;

}

StringPiece::StringPiece(StringPiece x, stringpiece_ssize_type pos)

    : ptr_(x.ptr_ + pos), length_(x.length_ - pos) {

  GOOGLE_DCHECK_LE(0, pos);

  GOOGLE_DCHECK_LE(pos, x.length_);

}

StringPiece::StringPiece(StringPiece x,

                         stringpiece_ssize_type pos,

                         stringpiece_ssize_type len)

    : ptr_(x.ptr_ + pos), length_(std::min(len, x.length_ - pos)) {

  GOOGLE_DCHECK_LE(0, pos);

  GOOGLE_DCHECK_LE(pos, x.length_);

  GOOGLE_DCHECK_GE(len, 0);

}

void StringPiece::CopyToString(std::string* target) const {

  target->assign(ptr_, length_);

}

void StringPiece::AppendToString(std::string* target) const {

  target->append(ptr_, length_);

}

bool StringPiece::Consume(StringPiece x) {

  if (starts_with(x)) {

    ptr_ += x.length_;

    length_ -= x.length_;

    return true;

  }

  return false;

}

bool StringPiece::ConsumeFromEnd(StringPiece x) {

  if (ends_with(x)) {

    length_ -= x.length_;

    return true;

  }

  return false;

}

stringpiece_ssize_type StringPiece::copy(char* buf,

                                         size_type n,

                                         size_type pos) const {

  stringpiece_ssize_type ret = std::min(length_ - pos, n);

  memcpy(buf, ptr_ + pos, ret);

  return ret;

}

bool StringPiece::contains(StringPiece s) const {

  return find(s, 0) != npos;

}

stringpiece_ssize_type StringPiece::find(StringPiece s, size_type pos) const {

  if (length_ <= 0 || pos > static_cast<size_type>(length_)) {

    if (length_ == 0 && pos == 0 && s.length_ == 0) return 0;

    return npos;

  }

  const char *result = std::search(ptr_ + pos, ptr_ + length_,

                                   s.ptr_, s.ptr_ + s.length_);

  return result == ptr_ + length_ ? npos : result - ptr_;

}

stringpiece_ssize_type StringPiece::find(char c, size_type pos) const {

  if (length_ <= 0 || pos >= static_cast<size_type>(length_)) {

    return npos;

  }

  const char* result = static_cast<const char*>(

      memchr(ptr_ + pos, c, length_ - pos));

  return result != nullptr ? result - ptr_ : npos;

}

stringpiece_ssize_type StringPiece::rfind(StringPiece s, size_type pos) const {

  if (length_ < s.length_) return npos;

  const size_t ulen = length_;

  if (s.length_ == 0) return std::min(ulen, pos);

  const char* last = ptr_ + std::min(ulen - s.length_, pos) + s.length_;

  const char* result = std::find_end(ptr_, last, s.ptr_, s.ptr_ + s.length_);

  return result != last ? result - ptr_ : npos;

}

// Search range is [0..pos] inclusive.  If pos == npos, search everything.

stringpiece_ssize_type StringPiece::rfind(char c, size_type pos) const {

  // Note: memrchr() is not available on Windows.

  if (length_ <= 0) return npos;

  for (stringpiece_ssize_type i =

      std::min(pos, static_cast<size_type>(length_ - 1));

       i >= 0; --i) {

    if (ptr_[i] == c) {

      return i;

    }

  }

  return npos;

}

// For each character in characters_wanted, sets the index corresponding

// to the ASCII code of that character to 1 in table.  This is used by

// the find_.*_of methods below to tell whether or not a character is in

// the lookup table in constant time.

// The argument `table' must be an array that is large enough to hold all

// the possible values of an unsigned char.  Thus it should be be declared

// as follows:

//   bool table[UCHAR_MAX + 1]

static inline void BuildLookupTable(StringPiece characters_wanted,

                                    bool* table) {

  const stringpiece_ssize_type length = characters_wanted.length();

  const char* const data = characters_wanted.data();

  for (stringpiece_ssize_type i = 0; i < length; ++i) {

    table[static_cast<unsigned char>(data[i])] = true;

  }

}

stringpiece_ssize_type StringPiece::find_first_of(StringPiece s,

                                                  size_type pos) const {

  if (length_ <= 0 || s.length_ <= 0) {

    return npos;

  }

  // Avoid the cost of BuildLookupTable() for a single-character search.

  if (s.length_ == 1) return find_first_of(s.ptr_[0], pos);

  bool lookup[UCHAR_MAX + 1] = { false };

  BuildLookupTable(s, lookup);

  for (stringpiece_ssize_type i = pos; i < length_; ++i) {

    if (lookup[static_cast<unsigned char>(ptr_[i])]) {

      return i;

    }

  }

  return npos;

}

stringpiece_ssize_type StringPiece::find_first_not_of(StringPiece s,

                                                      size_type pos) const {

  if (length_ <= 0) return npos;

  if (s.length_ <= 0) return 0;

  // Avoid the cost of BuildLookupTable() for a single-character search.

  if (s.length_ == 1) return find_first_not_of(s.ptr_[0], pos);

  bool lookup[UCHAR_MAX + 1] = { false };

  BuildLookupTable(s, lookup);

  for (stringpiece_ssize_type i = pos; i < length_; ++i) {

    if (!lookup[static_cast<unsigned char>(ptr_[i])]) {

      return i;

    }

  }

  return npos;

}

stringpiece_ssize_type StringPiece::find_first_not_of(char c,

                                                      size_type pos) const {

  if (length_ <= 0) return npos;

  for (; pos < static_cast<size_type>(length_); ++pos) {

    if (ptr_[pos] != c) {

      return pos;

    }

  }

  return npos;

}

stringpiece_ssize_type StringPiece::find_last_of(StringPiece s,

                                                 size_type pos) const {

  if (length_ <= 0 || s.length_ <= 0) return npos;

  // Avoid the cost of BuildLookupTable() for a single-character search.

  if (s.length_ == 1) return find_last_of(s.ptr_[0], pos);

  bool lookup[UCHAR_MAX + 1] = { false };

  BuildLookupTable(s, lookup);

  for (stringpiece_ssize_type i =

       std::min(pos, static_cast<size_type>(length_ - 1)); i >= 0; --i) {

    if (lookup[static_cast<unsigned char>(ptr_[i])]) {

      return i;

    }

  }

  return npos;

}

stringpiece_ssize_type StringPiece::find_last_not_of(StringPiece s,

                                                     size_type pos) const {

  if (length_ <= 0) return npos;

  stringpiece_ssize_type i = std::min(pos, static_cast<size_type>(length_ - 1));

  if (s.length_ <= 0) return i;

  // Avoid the cost of BuildLookupTable() for a single-character search.

  if (s.length_ == 1) return find_last_not_of(s.ptr_[0], pos);

  bool lookup[UCHAR_MAX + 1] = { false };

  BuildLookupTable(s, lookup);

  for (; i >= 0; --i) {

    if (!lookup[static_cast<unsigned char>(ptr_[i])]) {

      return i;

    }

  }

  return npos;

}

stringpiece_ssize_type StringPiece::find_last_not_of(char c,

                                                     size_type pos) const {

  if (length_ <= 0) return npos;

  for (stringpiece_ssize_type i =

       std::min(pos, static_cast<size_type>(length_ - 1)); i >= 0; --i) {

    if (ptr_[i] != c) {

      return i;

    }

  }

  return npos;

}

StringPiece StringPiece::substr(size_type pos, size_type n) const {

  if (pos > length_) pos = length_;

  if (n > length_ - pos) n = length_ - pos;

  return StringPiece(ptr_ + pos, n);

}

const StringPiece::size_type StringPiece::npos = size_type(-1);

}  // namespace protobuf

}  // namespace google