diff options
author | Kenneth Heafield <github@kheafield.com> | 2012-10-15 16:58:33 +0400 |
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committer | Kenneth Heafield <github@kheafield.com> | 2012-10-15 16:58:33 +0400 |
commit | 0eb98df0fe32a8e31188fa107f789afd73d81ccf (patch) | |
tree | 6b2f5bb5a21e132f419da1fa7064f94eb74428e6 /util/string_piece.cc | |
parent | ed00315c8cf4c0b0f8ebc535cf676139b25ab087 (diff) |
Submodules are evil. Undo it.
Diffstat (limited to 'util/string_piece.cc')
-rw-r--r-- | util/string_piece.cc | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/util/string_piece.cc b/util/string_piece.cc new file mode 100644 index 000000000..b422cefc9 --- /dev/null +++ b/util/string_piece.cc @@ -0,0 +1,192 @@ +// Copyright 2004 The RE2 Authors. All Rights Reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in string_piece.hh. + +#include "util/string_piece.hh" + +#include <algorithm> + +#include <limits.h> + +#ifndef HAVE_ICU + +typedef StringPiece::size_type size_type; + +void StringPiece::CopyToString(std::string* target) const { + target->assign(ptr_, length_); +} + +size_type StringPiece::find(const StringPiece& s, size_type pos) const { + if (length_ < 0 || pos > static_cast<size_type>(length_)) + return npos; + + const char* result = std::search(ptr_ + pos, ptr_ + length_, + s.ptr_, s.ptr_ + s.length_); + const size_type xpos = result - ptr_; + return xpos + s.length_ <= length_ ? xpos : npos; +} + +size_type StringPiece::find(char c, size_type pos) const { + if (length_ <= 0 || pos >= static_cast<size_type>(length_)) { + return npos; + } + const char* result = std::find(ptr_ + pos, ptr_ + length_, c); + return result != ptr_ + length_ ? result - ptr_ : npos; +} + +size_type StringPiece::rfind(const 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; +} + +size_type StringPiece::rfind(char c, size_type pos) const { + if (length_ <= 0) return npos; + for (int 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(const StringPiece& characters_wanted, + bool* table) { + const size_type length = characters_wanted.length(); + const char* const data = characters_wanted.data(); + for (size_type i = 0; i < length; ++i) { + table[static_cast<unsigned char>(data[i])] = true; + } +} + +size_type StringPiece::find_first_of(const 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 (size_type i = pos; i < length_; ++i) { + if (lookup[static_cast<unsigned char>(ptr_[i])]) { + return i; + } + } + return npos; +} + +size_type StringPiece::find_first_not_of(const 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 (size_type i = pos; i < length_; ++i) { + if (!lookup[static_cast<unsigned char>(ptr_[i])]) { + return i; + } + } + return npos; +} + +size_type StringPiece::find_first_not_of(char c, size_type pos) const { + if (length_ == 0) + return npos; + + for (; pos < length_; ++pos) { + if (ptr_[pos] != c) { + return pos; + } + } + return npos; +} + +size_type StringPiece::find_last_of(const 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 (size_type i = std::min(pos, length_ - 1); ; --i) { + if (lookup[static_cast<unsigned char>(ptr_[i])]) + return i; + if (i == 0) + break; + } + return npos; +} + +size_type StringPiece::find_last_not_of(const StringPiece& s, + size_type pos) const { + if (length_ == 0) + return npos; + + size_type i = std::min(pos, 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) { + if (!lookup[static_cast<unsigned char>(ptr_[i])]) + return i; + if (i == 0) + break; + } + return npos; +} + +size_type StringPiece::find_last_not_of(char c, size_type pos) const { + if (length_ == 0) + return npos; + + for (size_type i = std::min(pos, length_ - 1); ; --i) { + if (ptr_[i] != c) + return i; + if (i == 0) + break; + } + 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 size_type StringPiece::npos = size_type(-1); + +#endif // !HAVE_ICU |