I need to extract multiple variables to array from big string 0,5mb .This script is working when input string is smaller ~50kb and around 100 items to find. but target is around 7k items to extract from 0.5mb string. When there is less than 300 items it works. but finish after few sec. But if more im getting issue:
Communications error: <OS_xpc_error: <error: 0x321f9614> { count = 1, contents = "XPCErrorDescription" => <string: 0x321f986c> { length = 22, contents = "Connection interrupted" }
Code
NSUInteger count = 0, length = [dataString length];
NSRange range = NSMakeRange(0, length);
while(range.location != NSNotFound)
{
range = [dataString rangeOfString: #"userID_X" options:0 range:range];
if(range.location != NSNotFound)
{
range = NSMakeRange(range.location + range.length, length - (range.location + range.length));
count++;
}
}
NSLog(#"Count:%i",count);
realTokens = [NSMutableArray new];
realIds = [NSMutableArray new];
for (int gg=0; gg<count-1; gg++) {
NSArray *realidtemp;
NSArray *realtokentemp;
realidtemp = [[[dataString componentsSeparatedByString:#"userID_X"]objectAtIndex:1] componentsSeparatedByString:#"."];
realtokentemp = [[[dataString componentsSeparatedByString:#"userToken"]objectAtIndex:1] componentsSeparatedByString:#"."];
NSString *checkTkn = realtokentemp[0];
NSString *checkId = realidtemp[0];
if (![checkTkn containsString:#"EMPTY"] && ![checkId containsString:#"EMPTY"]) {
[realTokens addObject:checkTkn];
[realIds addObject:checkId];
NSString *fix1 = #"userToken";
NSString *fix2 = #"userID_X";
fix1 = [fix1 stringByAppendingString:checkTkn];
fix2 = [fix2 stringByAppendingString:checkId];
dataString = [dataString stringByReplacingOccurrencesOfString:fix1 withString:#"EMPTY"];
dataString = [dataString stringByReplacingOccurrencesOfString:fix2 withString:#"EMPTY"];
}
}
You perform many operations with a runtime proportional to the number of characters. That's something you need to avoid. You are also creating a huge number of huge autoreleased strings. Each time you call stringByReplacing... you create a new 0.5MB string. On an iPhone with 1GB RAM, 2,000 calls fill your RAM completely but you will crash earlier. componentsSeparatedByString is just as bad.
Create an NSMutableString for the result, and only add the pieces that you want to add. And please please please don't ask how to do that.
Related
I found a lot of examples how to find string between 2 strings, but none of which shows how to handle multiple occurrences of that string. I have for example string like this
"Hi, I am <id>User</id>. I am 20 <id>years old</id>, and live in <id>some country</id>."
The idea behind is that I want to hyperlink each occurrence of that string within UITextField, and remove tags from the string. I also have 2 types of the tag, one should display hyperlink, the other should popup alert view with some text description of the word or phrase clicked.
EDIT:
Found a perfectly good working solution to extend this logic with changing content of the text with attributed string between tags provided in the text. Link here.
#Aleksandar Try this.. it works for me..
NSString *serverOutput = #"Hi, I am <id>User</id>. I am 20 <id>years old</id>, and live in <id>some country</id>.";
if([serverOutput containsString:#"</id>"])
{
NSArray *arrSeparate = [serverOutput componentsSeparatedByString:#"</id>"];
NSString *output = #"";
for(int i=0; i<arrSeparate.count; i++)
{
if([[arrSeparate objectAtIndex:i] containsString:#"<id>"])
{
NSArray *arrTest = [[arrSeparate objectAtIndex:i] componentsSeparatedByString:#"<id>"];
if(output.length < 1)
output = [arrTest objectAtIndex:1];
else
output = [NSString stringWithFormat:#"%#\n%#",output,[arrTest objectAtIndex:1]];
}
}
serverOutput = output;
}
NSLog(#"%#", serverOutput);
Please look into this, and i hope this gets you all the range where the keyword exists
NSString *serverOutput = #"Hi, I am <id>User</id>. I am 20 <id>years old</id>, and live in <id>some country</id>";
NSUInteger count = 0, length = [serverOutput length];
NSRange startRange = NSMakeRange(0, length);
NSRange endRange = NSMakeRange(0, length);
while(startRange.location != NSNotFound)
{
startRange = [serverOutput rangeOfString: #"<id>" options:0 range:startRange];
if(startRange.location != NSNotFound)
{
endRange = [serverOutput rangeOfString: #"</id>" options:0 range:endRange];
startRange = NSMakeRange(startRange.location + startRange.length, length - (startRange.location + startRange.length));
endRange = NSMakeRange(endRange.location + endRange.length, length - (endRange.location + endRange.length));
count++;
}
}
startRange will be the range from where the tag starts and endRange is where starts
You can change the range, location, create attributed string and add hyperlink as the range of string is available to you.
Apples documentation says:
[...] current file systems such as HFS+ (used by Mac OS X) allow you to create filenames with a 255-character limit [...] symbols may actually take up to the equivalent of nine English characters to store [...] This should be considered when attempting to create longer names.
How do I limit the length of a NSString in a way that it is truly shorter than 255 characters, even when it includes symbols that might take more than one character to store?
I add my current implementation below. If i add e.g. emojis to the string, while length answers the resulting string would be by far smaller than 255, it is still too long to be accepted by a NSSavePanel as file name.
NSRange stringRange = {0, MIN([fileName length], 255)};
stringRange = [fileName rangeOfComposedCharacterSequencesForRange:stringRange];
fileName = [fileName substringWithRange:stringRange];
As suggested by #JoshCaswell, I did modify this answer to a similar question. It apparently does work (I wrote several tests), but it seems strange to me. Such an obvious task cannot be so complicated to achieve?
// filename contains the NSString that should be shortened
NSMutableString *truncatedString = [NSMutableString string];
NSUInteger bytesRead = 0;
NSUInteger charIdx = 0;
while (bytesRead < 250 && charIdx < [fileName length])
{
NSRange range = [fileName rangeOfComposedCharacterSequencesForRange:NSMakeRange(charIdx, 1)];
NSString *character = [fileName substringWithRange:NSMakeRange(charIdx, range.length)];
bytesRead += [character lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
charIdx = charIdx + range.length;
if (bytesRead <= 250)
[truncatedString appendString:character];
}
rangeOfComposedCharacterSequencesForRange: is basically doing the opposite of what you want: you give it a range that counts 255 composed characters, and it gives you the byte range that encompasses those, which might end up being much more than you want.
Unfortunately to do the reverse, you have to count the bytes manually. This isn't too hard, however, with enumerateSubstringsInRange:options:usingBlock:. Passing NSStringEnumerationByComposedCharacterSequences for the options gives you exactly what it says: each composed character in turn. You can then count the size of each with lengthOfBytesUsingEncoding:, passing the final encoding you'll be using (presumably UTF-8). Add up the bytes, keeping track of the character-based index, and stop when you've seen too many.
NSString * s = /* String containing multibyte characters */;
NSUInteger maxBytes = ...;
__block NSUInteger seenBytes = 0;
__block NSUInteger truncLength = 0;
NSRange fullLength = (NSRange){0, [s length]};
[s enumerateSubstringsInRange:fullLength
options:NSStringEnumerationByComposedCharacterSequences
usingBlock:
^(NSString *substring, NSRange substringRange,
NSRange _, BOOL *stop)
{
seenBytes += [substring lengthOfBytesUsingEncoding:NSUTF8StringEncoding];
if( seenBytes > maxBytes ){
*stop = YES;
return;
}
else {
truncLength += substringRange.length;
}
}];
NSString * truncS = [s substringToIndex:truncLength];
If I have a string like this.
NSString *string = #"😀1😀3😀5😀7😀"
To get a substring like #"3😀5" you have to account for the fact the smiley face character take two bytes.
NSString *substring = [string substringWithRange:NSMakeRange(5, 4)];
Is there a way to get the same substring by using the actual character index so NSMakeRange(3, 3) in this case?
Thanks to #Joe's link I was able to create a solution that works.
This still seems like a lot of work for just trying to create a substring at unicode character ranges for an NSString. Please post if you have a simpler solution.
#implementation NSString (UTF)
- (NSString *)substringWithRangeOfComposedCharacterSequences:(NSRange)range
{
NSUInteger codeUnit = 0;
NSRange result;
NSUInteger start = range.location;
NSUInteger i = 0;
while(i <= start)
{
result = [self rangeOfComposedCharacterSequenceAtIndex:codeUnit];
codeUnit += result.length;
i++;
}
NSRange substringRange;
substringRange.location = result.location;
NSUInteger end = range.location + range.length;
while(i <= end)
{
result = [self rangeOfComposedCharacterSequenceAtIndex:codeUnit];
codeUnit += result.length;
i++;
}
substringRange.length = result.location - substringRange.location;
return [self substringWithRange:substringRange];
}
#end
Example:
NSString *string = #"😀1😀3😀5😀7😀";
NSString *result = [string substringWithRangeOfComposedCharacterSequences:NSMakeRange(3, 3)];
NSLog(#"%#", result); // 3😀5
Make a swift extension of NSString and use new swift String struct. Has a beautifull String.Index that uses glyphs for counting characters and range selecting. Very usefull is cases like yours with emojis envolved
I am developing an iOS app using Xcode 4.6.2.
My app receives from the server lets say for example 1000 characters which is then stored in NSString.
What I want to do is: split the 1000 characters to multiple strings. Each string must be MAX 100 characters only.
The next question is how to check when the last word finished before the 100 characters so I don't perform the split in the middle of the word?
A regex-based solution:
NSString *string = // ... your 1000-character input
NSString *pattern = #"(?ws).{1,100}\\b";
NSError *error = NULL;
NSRegularExpression *regex = [NSRegularExpression regularExpressionWithPattern: pattern options: 0 error: &error];
NSArray *matches = [regex matchesInString:string options:0 range:NSMakeRange(0, [string length])];
NSMutableArray *result = [NSMutableArray array];
for (NSTextCheckingResult *match in matches) {
[result addObject: [string substringWithRange: match.range]];
}
The code for the regex and the matches part is taken directly from the docs, so the only difference is the pattern.
The pattern basically matches anything from 1 to 100 characters up to a word boundary. Being a greedy pattern, it will give the longest string possible while still ending with a whole word. This ensures that it won't split any words in the middle.
The (?ws) makes the word recognition work with Unicode's definition of word breaks (the w flag) and treat a line end as any other character (the s flag).
Notice that the algorithm doesn't handle "words" with more than 100 characters well - it will give you the last 100 characters and drop the first part, but that should be a corner case.
(assuming your words are separated by a single space, otherwise use rangeOfCharacterFromSet:options:range:)
Use NSString -- (NSRange)rangeOfString:(NSString *)aString options:(NSStringCompareOptions)mask range:(NSRange)aRange with:
aString as #" "
mask as NSBackwardsSearch
Then you need a loop, where you check that you haven't already got to the end of the string, then create a range (for use as aRange) so that you start 100 characters along the string and search backwards looking for the space. Once you find the space, the returned range will allow you to get the string with substringWithRange:.
(written freehand)
NSRange testRange = NSMakeRange(0, MIN(100, sourceString.length));
BOOL complete = NO;
NSMutableArray *lines = [NSMutableArray array];
while (!complete && (testRange.location + testRange.length) < sourceString.length) {
NSRange hitRange = [sourceString rangeOfString:#"" options:NSBackwardsSearch range:testRange];
if (hitRange.location != NSNotFound) {
[lines addObject:[sourceString substringWithRange:hitRange];
} else {
complete = YES;
}
NSInteger index = hitRange.location + hitRange.length;
testRange = NSMakeRange(index, MIN(100, sourceString.length - index));
}
This can help
- (NSArray *)chunksForString(NSString *)str {
NSMutableArray *chunks = [[NSMutableArray alloc] init];
double sizeChunk = 100.0; // or whatever you want
int length = 0;
int loopSize = ceil([str length]/sizeChunk);
for (int index = 0; index < loopSize; index++) {
NSInteger newRangeEndLimit = ([str length] - length) > sizeChunk ? sizeChunk : ([str length] - length);
[chunks addObject:[str substringWithRange:NSMakeRange(length, newRangeEndLimit)];
length += 99; // Minus 1 from the sizeChunk as indexing starts from 0
}
return chunks;
}
use NSArray *words = [stringFromServer componentsSeparatedBy:#" "];
this will give you words.
if you really need to make it nearest to 100 characters, start appending strings maintaining the total length of the appended strings and check that it should stay < 100.
I received an NSString from the server. Now I want to split it into the substring which I need.
How to split the string?
For example:
substring1:read from the second character to 5th character
substring2:read 10 characters from the 6th character.
You can also split a string by a substring, using NString's componentsSeparatedByString method.
Example from documentation:
NSString *list = #"Norman, Stanley, Fletcher";
NSArray *listItems = [list componentsSeparatedByString:#", "];
NSString has a few methods for this:
[myString substringToIndex:index];
[myString substringFromIndex:index];
[myString substringWithRange:range];
Check the documentation for NSString for more information.
I wrote a little method to split strings in a specified amount of parts.
Note that it only supports single separator characters. But I think it is an efficient way to split a NSString.
//split string into given number of parts
-(NSArray*)splitString:(NSString*)string withDelimiter:(NSString*)delimiter inParts:(int)parts{
NSMutableArray* array = [NSMutableArray array];
NSUInteger len = [string length];
unichar buffer[len+1];
//put separator in buffer
unichar separator[1];
[delimiter getCharacters:separator range:NSMakeRange(0, 1)];
[string getCharacters:buffer range:NSMakeRange(0, len)];
int startPosition = 0;
int length = 0;
for(int i = 0; i < len; i++) {
//if array is parts-1 and the character was found add it to array
if (buffer[i]==separator[0] && array.count < parts-1) {
if (length>0) {
[array addObject:[string substringWithRange:NSMakeRange(startPosition, length)]];
}
startPosition += length+1;
length = 0;
if (array.count >= parts-1) {
break;
}
}else{
length++;
}
}
//add the last part of the string to the array
[array addObject:[string substringFromIndex:startPosition]];
return array;
}