CODEWITHSUNDEEP
iossortingsearch
Rahul
Rahul

Reputation: 5834

How to minimise the search time in Objective-C

I am Implementing a search in a JSON data which contains data in HTML format.

Problem is that the Data is very big.

And I have to show the matched Searches in Color as shown In Image:

For example I searched for How:

enter image description here

My Searching Flow is Like that:

Step 1: - Check for presence of Data

Step 2: - Strip Html Tags from Searching Content

Step 3: - Perform Search In Content using NSRange rangeOfString options

Step 4: - If Match Found. Break Content in Sentence By using componentSeparatedByString (as I have to show the sentence in which i have found the search)

Step 5: - Pass the Sentence in Function which is returning me the
Attributed String

Step 6: - Add Results In array and reload the table

I am performing the search result in TextField Delegate method shouldChangeCharactersInRange

The problem is I am getting my table in delay of 1 to 2 sec.

And if type to fast then Suppose I search for Animal then I get search for ani anim and at last animal.

How Can I enhance my searching.

Upvotes: 1

Views: 80

Answers (1)

Sulthan
Sulthan

Reputation: 130102

My advice is the following:

Preparation

Steps 1 and 2. Don't repeat them for every search, do them once before starting to search or during only the first search.

Additional Step: Split the text into sentences. You will have a NSArray of sentences as your input.

Search

Use the search text to build a NSPredicate (e.g. contains[cd]). Filter the input array using that predicate. That should be very fast.

Reload the table to display results. Don't bother with attributed strings here.

Highlighting

Highlight using the current search text when displaying the cell (generate an attributed string). You will highlight only what is actually displayed so this should be very fast.

Possible improvements

Debouncing - Don't start searching immediately after search text changes. Start a timer which will search in 0.1-0.5 seconds. If there is a new search text update sooner, cancel the previous timer and start a new one. This will merge several updates into one updates.

Use previous search result - if the previous search text is a substring of the new search text, you can search only the previous results, that is, less data to search.

If the search is still too slow (if you really have an enormous amount of text), perform the search in a different dispatch queue and show an activity indicator until the results are done.

Upvotes: 1

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