diff options
author | redpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f> | 2010-10-18 23:24:01 +0000 |
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committer | redpony <redpony@ec762483-ff6d-05da-a07a-a48fb63a330f> | 2010-10-18 23:24:01 +0000 |
commit | e0ef743090038ee02d656cee11debd2246624ba0 (patch) | |
tree | e5e1d32402c8dcb490c574e24c087c56d4cc172e /klm/util/string_piece.hh | |
parent | 0c2514868f58bbfe422aa275e2905182cf2f57eb (diff) |
kenneth's LM preliminary integration
git-svn-id: https://ws10smt.googlecode.com/svn/trunk@681 ec762483-ff6d-05da-a07a-a48fb63a330f
Diffstat (limited to 'klm/util/string_piece.hh')
-rw-r--r-- | klm/util/string_piece.hh | 260 |
1 files changed, 260 insertions, 0 deletions
diff --git a/klm/util/string_piece.hh b/klm/util/string_piece.hh new file mode 100644 index 00000000..58008d13 --- /dev/null +++ b/klm/util/string_piece.hh @@ -0,0 +1,260 @@ +/* If you use ICU in your program, then compile with -DUSE_ICU -licui18n. If + * you don't use ICU, then this will use the Google implementation from Chrome. + * This has been modified from the original version to let you choose. + */ + +// Copyright 2008, Google Inc. +// All rights reserved. +// +// 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. +// Copied from strings/stringpiece.h with modifications +// +// A string-like object that points to a sized piece of memory. +// +// Functions or methods may use const StringPiece& parameters to accept either +// a "const char*" or a "string" value that will be implicitly converted to +// a StringPiece. The implicit conversion means that it is often appropriate +// to include this .h file in other files rather than forward-declaring +// StringPiece as would be appropriate for most other Google classes. +// +// Systematic usage of StringPiece is encouraged as it will reduce unnecessary +// conversions from "const char*" to "string" and back again. +// + +#ifndef BASE_STRING_PIECE_H__ +#define BASE_STRING_PIECE_H__ + +//Uncomment this line if you use ICU in your code. +//#define USE_ICU +//Uncomment this line if you want boost hashing for your StringPieces. +//#define USE_BOOST + +#include <cstring> +#include <iosfwd> + +#ifdef USE_ICU +#include <unicode/stringpiece.h> +U_NAMESPACE_BEGIN +#else + +#include <algorithm> +#include <ostream> +#include <string> +#include <string.h> + +class StringPiece { + public: + typedef size_t size_type; + + private: + const char* ptr_; + size_type length_; + + public: + // We provide non-explicit singleton constructors so users can pass + // in a "const char*" or a "string" wherever a "StringPiece" is + // expected. + StringPiece() : ptr_(NULL), length_(0) { } + StringPiece(const char* str) + : ptr_(str), length_((str == NULL) ? 0 : strlen(str)) { } + StringPiece(const std::string& str) + : ptr_(str.data()), length_(str.size()) { } + StringPiece(const char* offset, size_type len) + : ptr_(offset), length_(len) { } + + // data() may return a pointer to a buffer with embedded NULs, and the + // returned buffer may or may not be null terminated. Therefore it is + // typically a mistake to pass data() to a routine that expects a NUL + // terminated string. + const char* data() const { return ptr_; } + size_type size() const { return length_; } + size_type length() const { return length_; } + bool empty() const { return length_ == 0; } + + void clear() { ptr_ = NULL; length_ = 0; } + void set(const char* data, size_type len) { ptr_ = data; length_ = len; } + void set(const char* str) { + ptr_ = str; + length_ = str ? strlen(str) : 0; + } + void set(const void* data, size_type len) { + ptr_ = reinterpret_cast<const char*>(data); + length_ = len; + } + + char operator[](size_type i) const { return ptr_[i]; } + + void remove_prefix(size_type n) { + ptr_ += n; + length_ -= n; + } + + void remove_suffix(size_type n) { + length_ -= n; + } + + int compare(const StringPiece& x) const { + int r = wordmemcmp(ptr_, x.ptr_, std::min(length_, x.length_)); + if (r == 0) { + if (length_ < x.length_) r = -1; + else if (length_ > x.length_) r = +1; + } + return r; + } + + std::string as_string() const { + // std::string doesn't like to take a NULL pointer even with a 0 size. + return std::string(!empty() ? data() : "", size()); + } + + void CopyToString(std::string* target) const; + void AppendToString(std::string* target) const; + + // Does "this" start with "x" + bool starts_with(const StringPiece& x) const { + return ((length_ >= x.length_) && + (wordmemcmp(ptr_, x.ptr_, x.length_) == 0)); + } + + // Does "this" end with "x" + bool ends_with(const StringPiece& x) const { + return ((length_ >= x.length_) && + (wordmemcmp(ptr_ + (length_-x.length_), x.ptr_, x.length_) == 0)); + } + + // standard STL container boilerplate + typedef char value_type; + typedef const char* pointer; + typedef const char& reference; + typedef const char& const_reference; + typedef ptrdiff_t difference_type; + static const size_type npos; + typedef const char* const_iterator; + typedef const char* iterator; + typedef std::reverse_iterator<const_iterator> const_reverse_iterator; + typedef std::reverse_iterator<iterator> reverse_iterator; + iterator begin() const { return ptr_; } + iterator end() const { return ptr_ + length_; } + const_reverse_iterator rbegin() const { + return const_reverse_iterator(ptr_ + length_); + } + const_reverse_iterator rend() const { + return const_reverse_iterator(ptr_); + } + + size_type max_size() const { return length_; } + size_type capacity() const { return length_; } + + size_type copy(char* buf, size_type n, size_type pos = 0) const; + + size_type find(const StringPiece& s, size_type pos = 0) const; + size_type find(char c, size_type pos = 0) const; + size_type rfind(const StringPiece& s, size_type pos = npos) const; + size_type rfind(char c, size_type pos = npos) const; + + size_type find_first_of(const StringPiece& s, size_type pos = 0) const; + size_type find_first_of(char c, size_type pos = 0) const { + return find(c, pos); + } + size_type find_first_not_of(const StringPiece& s, size_type pos = 0) const; + size_type find_first_not_of(char c, size_type pos = 0) const; + size_type find_last_of(const StringPiece& s, size_type pos = npos) const; + size_type find_last_of(char c, size_type pos = npos) const { + return rfind(c, pos); + } + size_type find_last_not_of(const StringPiece& s, size_type pos = npos) const; + size_type find_last_not_of(char c, size_type pos = npos) const; + + StringPiece substr(size_type pos, size_type n = npos) const; + + static int wordmemcmp(const char* p, const char* p2, size_type N) { + return memcmp(p, p2, N); + } +}; + +inline bool operator==(const StringPiece& x, const StringPiece& y) { + if (x.size() != y.size()) + return false; + + return std::memcmp(x.data(), y.data(), x.size()) == 0; +} + +inline bool operator!=(const StringPiece& x, const StringPiece& y) { + return !(x == y); +} + +#endif + +inline bool operator<(const StringPiece& x, const StringPiece& y) { + const int r = std::memcmp(x.data(), y.data(), + std::min(x.size(), y.size())); + return ((r < 0) || ((r == 0) && (x.size() < y.size()))); +} + +inline bool operator>(const StringPiece& x, const StringPiece& y) { + return y < x; +} + +inline bool operator<=(const StringPiece& x, const StringPiece& y) { + return !(x > y); +} + +inline bool operator>=(const StringPiece& x, const StringPiece& y) { + return !(x < y); +} + +// allow StringPiece to be logged (needed for unit testing). +extern std::ostream& operator<<(std::ostream& o, const StringPiece& piece); + +#ifdef USE_BOOST +size_t hash_value(const StringPiece &str); + +/* Support for lookup of StringPiece in boost::unordered_map<std::string> */ +struct StringPieceCompatibleHash : public std::unary_function<const StringPiece &, size_t> { + size_t operator()(const StringPiece &str) const { + return hash_value(str); + } +}; + +struct StringPieceCompatibleEquals : public std::binary_function<const StringPiece &, const std::string &, bool> { + bool operator()(const StringPiece &first, const StringPiece &second) const { + return first == second; + } +}; +template <class T> typename T::const_iterator FindStringPiece(const T &t, const StringPiece &key) { + return t.find(key, StringPieceCompatibleHash(), StringPieceCompatibleEquals()); +} +template <class T> typename T::iterator FindStringPiece(T &t, const StringPiece &key) { + return t.find(key, StringPieceCompatibleHash(), StringPieceCompatibleEquals()); +} +#endif + +#ifdef USE_ICU +U_NAMESPACE_END +#endif + +#endif // BASE_STRING_PIECE_H__ |