Thank you all for your answers and suggestions. My use case is to create CFStrings from Unicode - which in the majority of cases are "short" strings - say, less than 100 characters. In this case, I create an immutable CFString directly in one go.
Less frequently in the typical use case of the application, I have to deal with larger strings, say base64 encoded images, or something like this. Yet, I need to create a CFString. Since the content will be received over the net, I naturally get content in chunks anyway (namely NSData objects received from a connection). So, in order to avoid a large temporary buffer which holds the complete string, I use a smaller buffer, e.g. 4 KByte and then append this small buffer to the resulting CFString, until it is complete. As Greg suggested, I'll try my solution first and test whether it will work efficiently: CFStringRef tmp = CFStringCreateWithBytesNoCopy(kCFAllocatorDefault, bytes, numBytes, encoding, NO, kCFAllocatorNull); CFStringAppend(myMutableString, tmp); CFRelease(tmp); Nonetheless, if there is a chance that a possible implementation void CFStringAppendBytes ( CFMutableStringRef theString, const void* bytes, CFIndex numBytes, CFStringEncoding encoding ); will be faster, or uses less memory, I'll also file an enhancement request. Thanks All! Regards Andreas On Mar 28, 2012, at 9:24 PM, Greg Parker wrote: > On Mar 28, 2012, at 11:00 AM, Charles Srstka <[email protected]> wrote: >> Unicode NULL is the least of your problems. In UTF16, each character in the >> normal ASCII range is going to contain a zero as one of its two bytes (which >> one, of course, depending on whether the encoding is big- or little-endian). >> CFStringAppendCString(), along with the other functions that take C strings, >> stops at the first zero byte it hits, which means that unless your entire >> file is in a non-Western script, it’s going to get cut short. >> >> CFStringAppendCString() is not what you want if you might be using UTF16. > > That's right. The first thing CFStringAppendCString() does is call strlen(). > > CoreFoundation does have a function internally that would do what you want. > You could file a bug report asking for a new API to match. However, it > requires almost as much work as using a temporary CFString object anyway, > except in some ASCII and UTF-16 cases. I would not expect your > CFStringCreateWithBytesNoCopy() solution to be much slower unless you're > performing a large number of short appends with one of CFString's preferred > encodings. > > > -- > Greg Parker [email protected] Runtime Wrangler _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
