Check in the pristine copy of ICU 4.6...

icu46/source/common/charstr.cpp

+/*
+*******************************************************************************
+*   Copyright (C) 2010, International Business Machines
+*   Corporation and others.  All Rights Reserved.
+*******************************************************************************
+*   file name:  charstr.cpp
+*   encoding:   US-ASCII
+*   tab size:   8 (not used)
+*   indentation:4
+*
+*   created on: 2010may19
+*   created by: Markus W. Scherer
+*/
+
+#include "unicode/utypes.h"
+#include "charstr.h"
+#include "cmemory.h"
+#include "cstring.h"
+
+U_NAMESPACE_BEGIN
+
+CharString &CharString::copyFrom(const CharString &s, UErrorCode &errorCode) {
+    if(U_SUCCESS(errorCode) && this!=&s && ensureCapacity(s.len+1, 0, errorCode)) {
+        len=s.len;
+        uprv_memcpy(buffer.getAlias(), s.buffer.getAlias(), len+1);
+    }
+    return *this;
+}
+
+CharString &CharString::truncate(int32_t newLength) {
+    if(newLength<0) {
+        newLength=0;
+    }
+    if(newLength<len) {
+        buffer[len=newLength]=0;
+    }
+    return *this;
+}
+
+CharString &CharString::append(char c, UErrorCode &errorCode) {
+    if(ensureCapacity(len+2, 0, errorCode)) {
+        buffer[len++]=c;
+        buffer[len]=0;
+    }
+    return *this;
+}
+
+CharString &CharString::append(const char *s, int32_t sLength, UErrorCode &errorCode) {
+    if(U_FAILURE(errorCode)) {
+        return *this;
+    }
+    if(sLength<-1 || (s==NULL && sLength!=0)) {
+        errorCode=U_ILLEGAL_ARGUMENT_ERROR;
+        return *this;
+    }
+    if(sLength<0) {
+        sLength=uprv_strlen(s);
+    }
+    if(sLength>0) {
+        if(s==(buffer.getAlias()+len)) {
+            // The caller wrote into the getAppendBuffer().
+            if(sLength>=(buffer.getCapacity()-len)) {
+                // The caller wrote too much.
+                errorCode=U_INTERNAL_PROGRAM_ERROR;
+            } else {
+                buffer[len+=sLength]=0;
+            }
+        } else if(buffer.getAlias()<=s && s<(buffer.getAlias()+len) &&
+                  sLength>=(buffer.getCapacity()-len)
+        ) {
+            // (Part of) this string is appended to itself which requires reallocation,
+            // so we have to make a copy of the substring and append that.
+            return append(CharString(s, sLength, errorCode), errorCode);
+        } else if(ensureCapacity(len+sLength+1, 0, errorCode)) {
+            uprv_memcpy(buffer.getAlias()+len, s, sLength);
+            buffer[len+=sLength]=0;
+        }
+    }
+    return *this;
+}
+
+char *CharString::getAppendBuffer(int32_t minCapacity,
+                                  int32_t desiredCapacityHint,
+                                  int32_t &resultCapacity,
+                                  UErrorCode &errorCode) {
+    if(U_FAILURE(errorCode)) {
+        resultCapacity=0;
+        return NULL;
+    }
+    int32_t appendCapacity=buffer.getCapacity()-len-1;  // -1 for NUL
+    if(appendCapacity>=minCapacity) {
+        resultCapacity=appendCapacity;
+        return buffer.getAlias()+len;
+    }
+    if(ensureCapacity(len+minCapacity+1, len+desiredCapacityHint+1, errorCode)) {
+        resultCapacity=buffer.getCapacity()-len-1;
+        return buffer.getAlias()+len;
+    }
+    resultCapacity=0;
+    return NULL;
+}
+
+CharString &CharString::appendInvariantChars(const UnicodeString &s, UErrorCode &errorCode) {
+    if(ensureCapacity(len+s.length()+1, 0, errorCode)) {
+        len+=s.extract(0, 0x7fffffff, buffer.getAlias()+len, buffer.getCapacity()-len, US_INV);
+    }
+    return *this;
+}
+
+UBool CharString::ensureCapacity(int32_t capacity,
+                                 int32_t desiredCapacityHint,
+                                 UErrorCode &errorCode) {
+    if(U_FAILURE(errorCode)) {
+        return FALSE;
+    }
+    if(capacity>buffer.getCapacity()) {
+        if(desiredCapacityHint==0) {
+            desiredCapacityHint=capacity+buffer.getCapacity();
+        }
+        if( (desiredCapacityHint<=capacity || buffer.resize(desiredCapacityHint, len+1)==NULL) &&
+            buffer.resize(capacity, len+1)==NULL
+        ) {
+            errorCode=U_MEMORY_ALLOCATION_ERROR;
+            return FALSE;
+        }
+    }
+    return TRUE;
+}
+
+U_NAMESPACE_END