1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/intl/icu/source/common/unicode/stringpiece.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,224 @@
1.4 +// Copyright (C) 2009-2013, International Business Machines
1.5 +// Corporation and others. All Rights Reserved.
1.6 +//
1.7 +// Copyright 2001 and onwards Google Inc.
1.8 +// Author: Sanjay Ghemawat
1.9 +
1.10 +// This code is a contribution of Google code, and the style used here is
1.11 +// a compromise between the original Google code and the ICU coding guidelines.
1.12 +// For example, data types are ICU-ified (size_t,int->int32_t),
1.13 +// and API comments doxygen-ified, but function names and behavior are
1.14 +// as in the original, if possible.
1.15 +// Assertion-style error handling, not available in ICU, was changed to
1.16 +// parameter "pinning" similar to UnicodeString.
1.17 +//
1.18 +// In addition, this is only a partial port of the original Google code,
1.19 +// limited to what was needed so far. The (nearly) complete original code
1.20 +// is in the ICU svn repository at icuhtml/trunk/design/strings/contrib
1.21 +// (see ICU ticket 6765, r25517).
1.22 +
1.23 +#ifndef __STRINGPIECE_H__
1.24 +#define __STRINGPIECE_H__
1.25 +
1.26 +/**
1.27 + * \file
1.28 + * \brief C++ API: StringPiece: Read-only byte string wrapper class.
1.29 + */
1.30 +
1.31 +#include "unicode/utypes.h"
1.32 +#include "unicode/uobject.h"
1.33 +#include "unicode/std_string.h"
1.34 +
1.35 +// Arghh! I wish C++ literals were "string".
1.36 +
1.37 +U_NAMESPACE_BEGIN
1.38 +
1.39 +/**
1.40 + * A string-like object that points to a sized piece of memory.
1.41 + *
1.42 + * We provide non-explicit singleton constructors so users can pass
1.43 + * in a "const char*" or a "string" wherever a "StringPiece" is
1.44 + * expected.
1.45 + *
1.46 + * Functions or methods may use const StringPiece& parameters to accept either
1.47 + * a "const char*" or a "string" value that will be implicitly converted to
1.48 + * a StringPiece.
1.49 + *
1.50 + * Systematic usage of StringPiece is encouraged as it will reduce unnecessary
1.51 + * conversions from "const char*" to "string" and back again.
1.52 + *
1.53 + * @stable ICU 4.2
1.54 + */
1.55 +class U_COMMON_API StringPiece : public UMemory {
1.56 + private:
1.57 + const char* ptr_;
1.58 + int32_t length_;
1.59 +
1.60 + public:
1.61 + /**
1.62 + * Default constructor, creates an empty StringPiece.
1.63 + * @stable ICU 4.2
1.64 + */
1.65 + StringPiece() : ptr_(NULL), length_(0) { }
1.66 + /**
1.67 + * Constructs from a NUL-terminated const char * pointer.
1.68 + * @param str a NUL-terminated const char * pointer
1.69 + * @stable ICU 4.2
1.70 + */
1.71 + StringPiece(const char* str);
1.72 +#if U_HAVE_STD_STRING
1.73 + /**
1.74 + * Constructs from a std::string.
1.75 + * @stable ICU 4.2
1.76 + */
1.77 + StringPiece(const std::string& str)
1.78 + : ptr_(str.data()), length_(static_cast<int32_t>(str.size())) { }
1.79 +#endif
1.80 + /**
1.81 + * Constructs from a const char * pointer and a specified length.
1.82 + * @param offset a const char * pointer (need not be terminated)
1.83 + * @param len the length of the string; must be non-negative
1.84 + * @stable ICU 4.2
1.85 + */
1.86 + StringPiece(const char* offset, int32_t len) : ptr_(offset), length_(len) { }
1.87 + /**
1.88 + * Substring of another StringPiece.
1.89 + * @param x the other StringPiece
1.90 + * @param pos start position in x; must be non-negative and <= x.length().
1.91 + * @stable ICU 4.2
1.92 + */
1.93 + StringPiece(const StringPiece& x, int32_t pos);
1.94 + /**
1.95 + * Substring of another StringPiece.
1.96 + * @param x the other StringPiece
1.97 + * @param pos start position in x; must be non-negative and <= x.length().
1.98 + * @param len length of the substring;
1.99 + * must be non-negative and will be pinned to at most x.length() - pos.
1.100 + * @stable ICU 4.2
1.101 + */
1.102 + StringPiece(const StringPiece& x, int32_t pos, int32_t len);
1.103 +
1.104 + /**
1.105 + * Returns the string pointer. May be NULL if it is empty.
1.106 + *
1.107 + * data() may return a pointer to a buffer with embedded NULs, and the
1.108 + * returned buffer may or may not be null terminated. Therefore it is
1.109 + * typically a mistake to pass data() to a routine that expects a NUL
1.110 + * terminated string.
1.111 + * @return the string pointer
1.112 + * @stable ICU 4.2
1.113 + */
1.114 + const char* data() const { return ptr_; }
1.115 + /**
1.116 + * Returns the string length. Same as length().
1.117 + * @return the string length
1.118 + * @stable ICU 4.2
1.119 + */
1.120 + int32_t size() const { return length_; }
1.121 + /**
1.122 + * Returns the string length. Same as size().
1.123 + * @return the string length
1.124 + * @stable ICU 4.2
1.125 + */
1.126 + int32_t length() const { return length_; }
1.127 + /**
1.128 + * Returns whether the string is empty.
1.129 + * @return TRUE if the string is empty
1.130 + * @stable ICU 4.2
1.131 + */
1.132 + UBool empty() const { return length_ == 0; }
1.133 +
1.134 + /**
1.135 + * Sets to an empty string.
1.136 + * @stable ICU 4.2
1.137 + */
1.138 + void clear() { ptr_ = NULL; length_ = 0; }
1.139 +
1.140 + /**
1.141 + * Reset the stringpiece to refer to new data.
1.142 + * @param xdata pointer the new string data. Need not be nul terminated.
1.143 + * @param len the length of the new data
1.144 + * @stable ICU 4.8
1.145 + */
1.146 + void set(const char* xdata, int32_t len) { ptr_ = xdata; length_ = len; }
1.147 +
1.148 + /**
1.149 + * Reset the stringpiece to refer to new data.
1.150 + * @param str a pointer to a NUL-terminated string.
1.151 + * @stable ICU 4.8
1.152 + */
1.153 + void set(const char* str);
1.154 +
1.155 + /**
1.156 + * Removes the first n string units.
1.157 + * @param n prefix length, must be non-negative and <=length()
1.158 + * @stable ICU 4.2
1.159 + */
1.160 + void remove_prefix(int32_t n) {
1.161 + if (n >= 0) {
1.162 + if (n > length_) {
1.163 + n = length_;
1.164 + }
1.165 + ptr_ += n;
1.166 + length_ -= n;
1.167 + }
1.168 + }
1.169 +
1.170 + /**
1.171 + * Removes the last n string units.
1.172 + * @param n suffix length, must be non-negative and <=length()
1.173 + * @stable ICU 4.2
1.174 + */
1.175 + void remove_suffix(int32_t n) {
1.176 + if (n >= 0) {
1.177 + if (n <= length_) {
1.178 + length_ -= n;
1.179 + } else {
1.180 + length_ = 0;
1.181 + }
1.182 + }
1.183 + }
1.184 +
1.185 + /**
1.186 + * Maximum integer, used as a default value for substring methods.
1.187 + * @stable ICU 4.2
1.188 + */
1.189 + static const int32_t npos; // = 0x7fffffff;
1.190 +
1.191 + /**
1.192 + * Returns a substring of this StringPiece.
1.193 + * @param pos start position; must be non-negative and <= length().
1.194 + * @param len length of the substring;
1.195 + * must be non-negative and will be pinned to at most length() - pos.
1.196 + * @return the substring StringPiece
1.197 + * @stable ICU 4.2
1.198 + */
1.199 + StringPiece substr(int32_t pos, int32_t len = npos) const {
1.200 + return StringPiece(*this, pos, len);
1.201 + }
1.202 +};
1.203 +
1.204 +/**
1.205 + * Global operator == for StringPiece
1.206 + * @param x The first StringPiece to compare.
1.207 + * @param y The second StringPiece to compare.
1.208 + * @return TRUE if the string data is equal
1.209 + * @stable ICU 4.8
1.210 + */
1.211 +U_EXPORT UBool U_EXPORT2
1.212 +operator==(const StringPiece& x, const StringPiece& y);
1.213 +
1.214 +/**
1.215 + * Global operator != for StringPiece
1.216 + * @param x The first StringPiece to compare.
1.217 + * @param y The second StringPiece to compare.
1.218 + * @return TRUE if the string data is not equal
1.219 + * @stable ICU 4.8
1.220 + */
1.221 +inline UBool operator!=(const StringPiece& x, const StringPiece& y) {
1.222 + return !(x == y);
1.223 +}
1.224 +
1.225 +U_NAMESPACE_END
1.226 +
1.227 +#endif // __STRINGPIECE_H__
