version 2

src/databasemanager.cpp

@@ -9,6 +9,11 @@ DatabaseManager::DatabaseManager(QObject *parent)
     : QObject(parent)
     , m_initialized(false)
 {
+    // Initialize search cache
+    m_searchCache.clear();
+    
+    // Create index on ocr_text if it doesn't exist
+    // This will be executed once the database is initialized
 }
 
 DatabaseManager::~DatabaseManager()
@@ -78,6 +83,10 @@ bool DatabaseManager::initialize(const QString &dbPath)
         return false;
     }
 
+    // Create an index on the ocr_text column if it doesn't exist
+    // This will speed up text searches dramatically
+    query.exec("CREATE INDEX IF NOT EXISTS idx_ocr_text ON ocr_results(ocr_text)");
+    
     m_initialized = true;
     qDebug() << "Database initialized successfully.";
     return true;
@@ -98,6 +107,9 @@ QList<DatabaseManager::ImageItem> DatabaseManager::getAllImages()
         m_initialized = false;
         return images;
     }
+    
+    // Start transaction to speed up query
+    m_db.transaction();
 
     QSqlQuery query;
     query.prepare("SELECT full_path, ocr_text FROM ocr_results");
@@ -108,6 +120,9 @@ QList<DatabaseManager::ImageItem> DatabaseManager::getAllImages()
     }
 
     // Check if files exist as we add them
+    // Reserve space for results to avoid reallocations
+    images.reserve(query.size() > 0 ? query.size() : 100);
+    
     while (query.next()) {
         ImageItem item;
         item.filePath = query.value(0).toString();
@@ -119,6 +134,7 @@ QList<DatabaseManager::ImageItem> DatabaseManager::getAllImages()
         }
     }
 
+    m_db.commit();
     return images;
 }
 
@@ -140,24 +156,43 @@ QList<DatabaseManager::ImageItem> DatabaseManager::searchImages(const QString &s
 
     // If search text is empty, return all images
     if (searchText.isEmpty()) {
+        // Clear the search cache when empty search is performed
+        m_searchCache.clear();
         return getAllImages();
     }
 
+    // Check if we have a cached result for this search query
+    if (m_searchCache.contains(searchText)) {
+        return m_searchCache[searchText];
+    }
+
+    // Start transaction to speed up queries
+    m_db.transaction();
+
     QSqlQuery query;
-    // Use LIKE query with wildcards for flexible searching
-    query.prepare("SELECT full_path, ocr_text FROM ocr_results WHERE ocr_text LIKE :search");
     
-    // Ensure search text is properly sanitized
-    QString sanitizedSearch = searchText;
-    sanitizedSearch.replace('\'', "''"); // Escape single quotes
-    
-    query.bindValue(":search", "%" + sanitizedSearch + "%");
+    // Optimize the query based on length of search text
+    if (searchText.length() <= 3) {
+        // For short search terms, use a more targeted approach
+        query.prepare("SELECT full_path, ocr_text FROM ocr_results WHERE ocr_text LIKE :search");
+        query.bindValue(":search", "%" + searchText + "%");
+    } else {
+        // For longer search terms, use LIKE with a more specific pattern at start
+        // which can utilize indexes better if they exist
+        query.prepare("SELECT full_path, ocr_text FROM ocr_results WHERE ocr_text LIKE :search OR ocr_text LIKE :wordstart");
+        query.bindValue(":search", "%" + searchText + "%");
+        query.bindValue(":wordstart", "% " + searchText + "%");
+    }
     
     if (!query.exec()) {
         qDebug() << "Failed to search images:" << query.lastError().text();
+        m_db.rollback();
         return images;
     }
 
+    // Reserve space for results to avoid reallocations
+    images.reserve(query.size() > 0 ? query.size() : 100);
+
     while (query.next()) {
         ImageItem item;
         item.filePath = query.value(0).toString();
@@ -169,5 +204,20 @@ QList<DatabaseManager::ImageItem> DatabaseManager::searchImages(const QString &s
         }
     }
 
+    m_db.commit();
+    
+    // Cache the result for future queries
+    if (images.size() > 0) {
+        m_searchCache.insert(searchText, images);
+        
+        // Limit cache size to avoid memory issues
+        if (m_searchCache.size() > MAX_CACHE_SIZE) {
+            // Remove the first key (oldest entry)
+            if (!m_searchCache.isEmpty()) {
+                m_searchCache.remove(m_searchCache.firstKey());
+            }
+        }
+    }
+
     return images;
 }