/**
* Determine the common suffix of two strings.
* @param text1 First string.
* @param text2 Second string.
* @return The number of characters common to the end of each string.
*/
CFIndex diff_commonSuffix(CFStringRef text1, CFStringRef text2) {
// Performance analysis: http://neil.fraser.name/news/2007/10/09/
CFIndex text1_length = CFStringGetLength(text1);
CFIndex text2_length = CFStringGetLength(text2);
CFStringInlineBuffer text1_inlineBuffer, text2_inlineBuffer;
CFStringInitInlineBuffer(text1, &text1_inlineBuffer, CFRangeMake(0, text1_length));
CFStringInitInlineBuffer(text2, &text2_inlineBuffer, CFRangeMake(0, text2_length));
UniChar char1, char2;
CFIndex n = MIN(text1_length, text2_length);
for (CFIndex i = 1; i <= n; i++) {
char1 = CFStringGetCharacterFromInlineBuffer(&text1_inlineBuffer, (text1_length - i));
char2 = CFStringGetCharacterFromInlineBuffer(&text2_inlineBuffer, (text2_length - i));
if (char1 != char2) {
return i - 1;
}
}
return n;
}
void stringGettingAtCharactersExample(void) {
CFStringRef str;
const UniChar *chars;
show(CFSTR("------------------Character Manipulations---------------"));
// Create some test CFString
str = CFStringCreateWithCString(NULL, "Hello World", kCFStringEncodingASCII);
show(CFSTR("Original String : %@"), str);
// The fastest way to get the contents; this might return NULL though
// depending on the system, the release, etc, so don't depend on it
// (unless you used CFStringCreateMutableWithExternalCharactersNoCopy())
chars = CFStringGetCharactersPtr(str);
// If that fails, you can try copying the UniChars out
// either into some stack buffer or some allocated piece of memory...
// Using the former is fine, but you need to know the size; the latter
// always works but requires allocating some memory; not too efficient.
if (chars == NULL) {
CFIndex length = CFStringGetLength(str);
UniChar *buffer = (UniChar*)malloc(length * sizeof(UniChar));
CFStringGetCharacters(str, CFRangeMake(0, length), buffer);
// Process the chars...
free(buffer);
}
else
show(CFSTR("Characters : %@"), str);
// You can use CFStringGetCharacterAtIndex() to get at the characters one at a time,
// but doing a lot of characters this way might get slow...
// An option is to use "inline buffer" functionality which mixes the convenience of
// one-at-a-time char access with efficiency of bulk access
{
CFStringInlineBuffer inlineBuffer;
CFIndex length = CFStringGetLength(str);
CFIndex cnt;
CFStringInitInlineBuffer(str, &inlineBuffer, CFRangeMake(0, length));
for (cnt = 0; cnt < length; cnt++) {
UniChar ch = CFStringGetCharacterFromInlineBuffer(&inlineBuffer, cnt);
// Process character...
(void)ch; // Dummy processing to prevent compiler warning...
}
}
}
static void printObjAsString(CFStringRef obj) {
CFStringInlineBuffer buf;
CFIndex len = CFStringGetLength(obj);
CFStringInitInlineBuffer(obj, &buf, CFRangeMake(0, len));
printf("\"");
for (CFIndex i = 0; i < len; ++ i) {
UniChar c = CFStringGetCharacterFromInlineBuffer(&buf, i);
if (c == '"' || c == '\\')
printf("\\%C", c);
else if (c >= ' ' && c <= '\x7F')
printf("%C", c);
else if (c == '\t')
printf("\\t");
else if (c == '\n')
printf("\\n");
else
printf("\\U%04x", c);
}
printf("\"");
}
__private_extern__ CFIndex CFPreferencesAppIntegerValue(CFStringRef key, CFStringRef appName, Boolean *keyExistsAndHasValidFormat) {
CFPropertyListRef value;
CFIndex result;
CFTypeID typeID = 0;
Boolean valid;
CFAssert1(appName != NULL, __kCFLogAssertion, "%s(): Cannot access application preferences with a NULL application name", __PRETTY_FUNCTION__);
CFAssert1(key != NULL, __kCFLogAssertion, "%s(): Cannot access preferences with a NULL key", __PRETTY_FUNCTION__);
value = CFPreferencesCopyAppValue(key, appName);
if (!keyExistsAndHasValidFormat) {
keyExistsAndHasValidFormat = &valid;
}
if (!value) {
*keyExistsAndHasValidFormat = false;
return 0;
}
typeID = CFGetTypeID(value);
if (typeID == CFStringGetTypeID()) {
SInt32 charIndex = 0;
SInt32 intVal;
CFStringInlineBuffer buf;
Boolean success;
CFStringInitInlineBuffer((CFStringRef)value, &buf, CFRangeMake(0, CFStringGetLength((CFStringRef)value)));
success = __CFStringScanInteger(&buf, NULL, &charIndex, false, &intVal);
*keyExistsAndHasValidFormat = (success && charIndex == CFStringGetLength((CFStringRef)value));
result = (*keyExistsAndHasValidFormat) ? intVal : 0;
} else if (typeID == CFNumberGetTypeID()) {
*keyExistsAndHasValidFormat = !CFNumberIsFloatType((CFNumberRef)value);
if (*keyExistsAndHasValidFormat) {
CFNumberGetValue((CFNumberRef)value, kCFNumberCFIndexType, &result);
} else {
result = 0;
}
} else {
// Unknown type
result = 0;
*keyExistsAndHasValidFormat = false;
}
CFRelease(value);
return result;
}
/* There has got to be an easier way to do this. For now we based this code
on CFNetwork/Connection/URLResponse.cpp. */
static CFStringRef copyParseMaxAge(CFStringRef cacheControlHeader) {
/* The format of the cache control header is a comma-separated list, but
each list element could be a key-value pair, with the value quoted and
possibly containing a comma. */
CFStringInlineBuffer inlineBuf;
CFRange componentRange;
CFIndex length = CFStringGetLength(cacheControlHeader);
bool done = false;
CFCharacterSetRef whitespaceSet = CFCharacterSetGetPredefined(kCFCharacterSetWhitespace);
CFStringRef maxAgeValue = NULL;
CFStringInitInlineBuffer(cacheControlHeader, &inlineBuf, CFRangeMake(0, length));
componentRange.location = 0;
while (!done) {
bool inQuotes = false;
bool foundComponentStart = false;
CFIndex charIndex = componentRange.location;
CFIndex componentEnd = -1;
CFRange maxAgeRg;
componentRange.length = 0;
while (charIndex < length) {
UniChar ch = CFStringGetCharacterFromInlineBuffer(&inlineBuf, charIndex);
if (!inQuotes && ch == ',') {
componentRange.length = charIndex - componentRange.location;
break;
}
if (!CFCharacterSetIsCharacterMember(whitespaceSet, ch)) {
if (!foundComponentStart) {
foundComponentStart = true;
componentRange.location = charIndex;
} else {
componentEnd = charIndex;
}
if (ch == '\"') {
inQuotes = (inQuotes == false);
}
}
charIndex ++;
}
if (componentEnd == -1) {
componentRange.length = charIndex - componentRange.location;
} else {
componentRange.length = componentEnd - componentRange.location + 1;
}
if (charIndex == length) {
/* Fell off the end; this is the last component. */
done = true;
}
/* componentRange should now contain the range of the current
component; trimmed of any whitespace. */
/* We want to look for a max-age value. */
if (!maxAgeValue && CFStringFindWithOptions(cacheControlHeader, CFSTR("max-age"), componentRange, kCFCompareCaseInsensitive | kCFCompareAnchored, &maxAgeRg)) {
CFIndex equalIdx;
CFIndex maxCompRg = componentRange.location + componentRange.length;
for (equalIdx = maxAgeRg.location + maxAgeRg.length; equalIdx < maxCompRg; equalIdx ++) {
UniChar equalCh = CFStringGetCharacterFromInlineBuffer(&inlineBuf, equalIdx);
if (equalCh == '=') {
// Parse out max-age value
equalIdx ++;
while (equalIdx < maxCompRg && CFCharacterSetIsCharacterMember(whitespaceSet, CFStringGetCharacterAtIndex(cacheControlHeader, equalIdx))) {
equalIdx ++;
}
if (equalIdx < maxCompRg) {
maxAgeValue = CFStringCreateWithSubstring(kCFAllocatorDefault, cacheControlHeader, CFRangeMake(equalIdx, maxCompRg-equalIdx));
}
} else if (!CFCharacterSetIsCharacterMember(whitespaceSet, equalCh)) {
// Not a valid max-age header; break out doing nothing
break;
}
}
}
if (!done && maxAgeValue) {
done = true;
}
if (!done) {
/* Advance to the next component; + 1 to get past the comma. */
componentRange.location = charIndex + 1;
}
}
return maxAgeValue;
}
