icuSources/common/charstr.h

   1 // © 2016 and later: Unicode, Inc. and others.
   2 // License & terms of use: http://www.unicode.org/copyright.html
   3 /*
   4 **********************************************************************
   5 *   Copyright (c) 2001-2015, International Business Machines
   6 *   Corporation and others.  All Rights Reserved.
   7 **********************************************************************
   8 *   Date        Name        Description
   9 *   11/19/2001  aliu        Creation.
  10 *   05/19/2010  markus      Rewritten from scratch
  11 **********************************************************************
  12 */
  13
  14 #ifndef CHARSTRING_H
  15 #define CHARSTRING_H
  16
  17 #include "unicode/utypes.h"
  18 #include "unicode/unistr.h"
  19 #include "unicode/uobject.h"
  20 #include "cmemory.h"
  21
  22 U_NAMESPACE_BEGIN
  23
  24 // Windows needs us to DLL-export the MaybeStackArray template specialization,
  25 // but MacOS X cannot handle it. Same as in digitlst.h.
  26 #if !U_PLATFORM_IS_DARWIN_BASED
  27 template class U_COMMON_API MaybeStackArray<char, 40>;
  28 #endif
  29
  30 /**
  31  * ICU-internal char * string class.
  32  * This class does not assume or enforce any particular character encoding.
  33  * Raw bytes can be stored. The string object owns its characters.
  34  * A terminating NUL is stored, but the class does not prevent embedded NUL characters.
  35  *
  36  * This class wants to be convenient but is also deliberately minimalist.
  37  * Please do not add methods if they only add minor convenience.
  38  * For example:
  39  *   cs.data()[5]='a';  // no need for setCharAt(5, 'a')
  40  */
  41 class U_COMMON_API CharString : public UMemory {
  42 public:
  43     CharString() : len(0) { buffer[0]=0; }
  44     CharString(StringPiece s, UErrorCode &errorCode) : len(0) {
  45         buffer[0]=0;
  46         append(s, errorCode);
  47     }
  48     CharString(const CharString &s, UErrorCode &errorCode) : len(0) {
  49         buffer[0]=0;
  50         append(s, errorCode);
  51     }
  52     CharString(const char *s, int32_t sLength, UErrorCode &errorCode) : len(0) {
  53         buffer[0]=0;
  54         append(s, sLength, errorCode);
  55     }
  56     ~CharString() {}
  57
  58     /**
  59      * Replaces this string's contents with the other string's contents.
  60      * CharString does not support the standard copy constructor nor
  61      * the assignment operator, to make copies explicit and to
  62      * use a UErrorCode where memory allocations might be needed.
  63      */
  64     CharString &copyFrom(const CharString &other, UErrorCode &errorCode);
  65
  66     UBool isEmpty() const { return len==0; }
  67     int32_t length() const { return len; }
  68     char operator[](int32_t index) const { return buffer[index]; }
  69     StringPiece toStringPiece() const { return StringPiece(buffer.getAlias(), len); }
  70
  71     const char *data() const { return buffer.getAlias(); }
  72     char *data() { return buffer.getAlias(); }
  73
  74     /** @return last index of c, or -1 if c is not in this string */
  75     int32_t lastIndexOf(char c) const;
  76
  77     CharString &clear() { len=0; buffer[0]=0; return *this; }
  78     CharString &truncate(int32_t newLength);
  79
  80     CharString &append(char c, UErrorCode &errorCode);
  81     CharString &append(StringPiece s, UErrorCode &errorCode) {
  82         return append(s.data(), s.length(), errorCode);
  83     }
  84     CharString &append(const CharString &s, UErrorCode &errorCode) {
  85         return append(s.data(), s.length(), errorCode);
  86     }
  87     CharString &append(const char *s, int32_t sLength, UErrorCode &status);
  88     /**
  89      * Returns a writable buffer for appending and writes the buffer's capacity to
  90      * resultCapacity. Guarantees resultCapacity>=minCapacity if U_SUCCESS().
  91      * There will additionally be space for a terminating NUL right at resultCapacity.
  92      * (This function is similar to ByteSink.GetAppendBuffer().)
  93      *
  94      * The returned buffer is only valid until the next write operation
  95      * on this string.
  96      *
  97      * After writing at most resultCapacity bytes, call append() with the
  98      * pointer returned from this function and the number of bytes written.
  99      *
 100      * @param minCapacity required minimum capacity of the returned buffer;
 101      *                    must be non-negative
 102      * @param desiredCapacityHint desired capacity of the returned buffer;
 103      *                            must be non-negative
 104      * @param resultCapacity will be set to the capacity of the returned buffer
 105      * @param errorCode in/out error code
 106      * @return a buffer with resultCapacity>=min_capacity
 107      */
 108     char *getAppendBuffer(int32_t minCapacity,
 109                           int32_t desiredCapacityHint,
 110                           int32_t &resultCapacity,
 111                           UErrorCode &errorCode);
 112
 113     CharString &appendInvariantChars(const UnicodeString &s, UErrorCode &errorCode);
 114
 115     /**
 116      * Appends a filename/path part, e.g., a directory name.
 117      * First appends a U_FILE_SEP_CHAR if necessary.
 118      * Does nothing if s is empty.
 119      */
 120     CharString &appendPathPart(StringPiece s, UErrorCode &errorCode);
 121
 122     /**
 123      * Appends a U_FILE_SEP_CHAR if this string is not empty
 124      * and does not already end with a U_FILE_SEP_CHAR or U_FILE_ALT_SEP_CHAR.
 125      */
 126     CharString &ensureEndsWithFileSeparator(UErrorCode &errorCode);
 127
 128 private:
 129     MaybeStackArray<char, 40> buffer;
 130     int32_t len;
 131
 132     UBool ensureCapacity(int32_t capacity, int32_t desiredCapacityHint, UErrorCode &errorCode);
 133
 134     CharString(const CharString &other); // forbid copying of this class
 135     CharString &operator=(const CharString &other); // forbid copying of this class
 136 };
 137
 138 U_NAMESPACE_END
 139
 140 #endif
 141 //eof