improve global search performance

Session/Home/GlobalSearch/GlobalSearchViewController.swift

@@ -13,6 +13,7 @@ class GlobalSearchViewController: BaseVC, UITableViewDelegate, UITableViewDataSo
         }
     }
     var recentSearchResults: [String] = Array(Storage.shared.getRecentSearchResults().reversed())
+    var defaultSearchResults: HomeScreenSearchResultSet = HomeScreenSearchResultSet.noteToSelfOnly
     var searchResultSet: HomeScreenSearchResultSet = HomeScreenSearchResultSet.empty
     private var lastSearchText: String?
     var searcher: FullTextSearcher {
@@ -106,30 +107,10 @@ class GlobalSearchViewController: BaseVC, UITableViewDelegate, UITableViewDataSo
     var refreshTimer: Timer?
     
     private func refreshSearchResults() {
-
-        guard !searchResultSet.isEmpty else {
-            // To avoid incorrectly showing the "no results" state,
-            // always search immediately if the current result set is empty.
-            refreshTimer?.invalidate()
-            refreshTimer = nil
-
-            updateSearchResults(searchText: searchText)
-            return
-        }
-
-        if refreshTimer != nil {
-            // Don't start a new refresh timer if there's already one active.
-            return
-        }
-
         refreshTimer?.invalidate()
         refreshTimer = WeakTimer.scheduledTimer(timeInterval: 0.1, target: self, userInfo: nil, repeats: false) { [weak self] _ in
-            guard let self = self else {
-                return
-            }
-
+            guard let self = self else { return }
             self.updateSearchResults(searchText: self.searchText)
-            self.refreshTimer = nil
         }
     }
     
@@ -137,7 +118,7 @@ class GlobalSearchViewController: BaseVC, UITableViewDelegate, UITableViewDataSo
 
         let searchText = rawSearchText.stripped
         guard searchText.count > 0 else {
-            searchResultSet = HomeScreenSearchResultSet.noteToSelfOnly
+            searchResultSet = defaultSearchResults
             lastSearchText = nil
             reloadTableData()
             return
@@ -159,6 +140,7 @@ class GlobalSearchViewController: BaseVC, UITableViewDelegate, UITableViewDataSo
             self.searchResultSet = results
             self.isLoading = false
             self.reloadTableData()
+            self.refreshTimer = nil
         })
     }
     

SessionMessagingKit/Database/OWSPrimaryStorage.m

@@ -67,6 +67,7 @@ void VerifyRegistrationsForPrimaryStorage(OWSStorage *storage)
         [self loadDatabase];
 
         _dbReadPool = [[YapDatabaseConnectionPool alloc] initWithDatabase:self.database];
+        _dbReadPool.connectionLimit = 10; // Increase max read connection limit. Default is 3.
         _dbReadWriteConnection = [self newDatabaseConnection];
         _uiDatabaseConnection = [self newDatabaseConnection];
         

SessionMessagingKit/Utilities/FullTextSearchFinder.swift

@@ -30,6 +30,8 @@ public class FullTextSearchFinder: NSObject {
     private static var tsAccountManager: TSAccountManager {
         return TSAccountManager.sharedInstance()
     }
+    
+    public var newQueryTimestamp: UInt64 = 0
 
     // MARK: - Querying
 
@@ -89,6 +91,13 @@ public class FullTextSearchFinder: NSObject {
         guard let ext: YapDatabaseFullTextSearchTransaction = ext(transaction: transaction) else {
             return
         }
+        
+        // HACK: Full text search is too expensive even though we drop the max search results
+        // to a reasonable number. And the async read can sometimes block a thread and make
+        // other read threads wait for it to finish. The timestamp is a workaround to ensure
+        // only one thread can be running the full text search at one time.
+        let currentQueryTimestamp = NSDate.millisecondTimestamp()
+        newQueryTimestamp = currentQueryTimestamp
 
         let query = FullTextSearchFinder.query(searchText: searchText)
 
@@ -99,7 +108,7 @@ public class FullTextSearchFinder: NSObject {
         snippetOptions.endMatchText = ""
         snippetOptions.numberOfTokens = 5
         ext.enumerateKeysAndObjects(matching: query, with: snippetOptions) { (snippet: String, _: String, _: String, object: Any, stop: UnsafeMutablePointer<ObjCBool>) in
-            guard searchResultCount < maxSearchResults else {
+            guard searchResultCount < maxSearchResults && currentQueryTimestamp >= self.newQueryTimestamp else {
                 stop.pointee = true
                 return
             }

SignalUtilitiesKit/Profile Pictures/ProfilePictureView.swift

@@ -82,7 +82,6 @@ public final class ProfilePictureView : UIView {
             update()
         } else { // A one-to-one chat
             let thread = thread as! TSContactThread
-            hasTappableProfilePicture = OWSProfileManager.shared().profileAvatar(forRecipientId: thread.contactSessionID()) != nil
             update(for: thread.contactSessionID())
         }
     }
@@ -92,8 +91,10 @@ public final class ProfilePictureView : UIView {
         func getProfilePicture(of size: CGFloat, for publicKey: String) -> UIImage? {
             guard !publicKey.isEmpty else { return nil }
             if let profilePicture = OWSProfileManager.shared().profileAvatar(forRecipientId: publicKey) {
+                hasTappableProfilePicture = true
                 return profilePicture
             } else {
+                hasTappableProfilePicture = false
                 // TODO: Pass in context?
                 let displayName = Storage.shared.getContact(with: publicKey)?.name ?? publicKey
                 return Identicon.generatePlaceholderIcon(seed: publicKey, text: displayName, size: size)