Batch deletion of duplicate lines & list sorting tool | ZeroTools

The core of this duplicate row removal tool is the characteristics of the Set object, which directly uses the hash table implementation inside the JavaScript engine.

The huge text data that is input is expanded into a one-dimensional array using line feed characters as delimiters.

When inserting this array element into the Set object sequentially, the engine calculates the hash value of the string and maps it to a memory address.

Since the Set structure has the property of ignoring insertions when the same hash value and the same character string already exist, batch detection and removal of duplicate rows can be completed with O(N) time complexity for the number of array elements N.

Extremely high performance when processing millions of rows of data compared to traditional nested loop square comparison algorithms

Furthermore, in order to reduce the load on the V8 engine's garbage collection, references to intermediate arrays that are no longer needed are immediately discarded to prevent memory leaks.

A multi-stage preprocessing model is implemented to absorb fluctuations that cannot be captured by a simple exact match search when determining text duplication.

The first step is a trimming process that uses regular expressions to quickly remove half-width spaces, tab characters, Unicode-specific zero-width spaces, etc. that exist before and after the string.

Subsequently, if the blank line removal option is enabled, lines consisting only of newlines or lines containing only white space characters will be excluded from the array by the filtering function.

Additionally, in scenarios where the disable case sensitivity setting is selected, all string elements are normalized to a single case using the String prototype's toLowerCase method.

These preprocessings are applied in-place or stream processing before moving to the main deduplication algorithm, and serve to maximize the accuracy of hash calculations by subsequent Set structures.

Unique deduplicated text lines are provided with sorting operations based on user requirements.

This tool uses a natural sorting algorithm to solve the problem that numbers in strings are not evaluated as expected with simple lexicographical sorting.

By using the Collator constructor belonging to the JavaScript Intl object and enabling the numeric option, the numbers contained in the string are compared as logical values ​​and the file names, log sequence numbers, etc.

are arranged in an order that matches human intuition.

This natural order sorting is passed to the sort method of the Array prototype as a comparison function and is executed with the worst case complexity O(NlogN).

Also, if a reverse sort is requested, the order of elements in the array can be completely reversed while minimizing additional memory allocation by applying the reverse method to the array after sorting or by inverting the sign of the return value of the comparison function.

Immediate processing of input text within the browser's local environment without any data being sent to an external server is extremely important from the perspective of privacy protection and latency reduction.

However, when processing several megabytes of text data synchronously on the main thread, there is a risk that DOM rendering will be blocked and the user interface will freeze.

To avoid this, large text parsing is offloaded to a background thread using WebWorker.

A structured clone algorithm is used to pass data between the main thread and worker threads, and processing progress and completion notifications are asynchronously transmitted through the postMessage interface.

This design allows users to enjoy the benefits of secure text processing that maximizes client-side computational resources while maintaining a seamless experience in the browser.

To visualize data processing meta information, the difference in the number of text lines and data reduction rate before and after duplicate line deletion is dynamically calculated.

A formula is applied that maintains the array length when the initial input text is divided into lines and the array length after being made unique by the Set structure, and calculates the reduction rate based on these values.

The calculation result is immediately bound to the DOM element and rendered on the screen as an indicator to quantitatively check the effectiveness of the process.

Furthermore, the Clipboard API integrated into the Navigator interface is utilized to quickly pass the final processing results to other applications.

By calling the asynchronous method writeText, users can safely copy tens of thousands of lines of clean text data to the clipboard with a single click, instantly completing the data transfer from system memory to the clipboard buffer.

This tool's high-speed string processing ability provides practical value as a database batch preprocessing guide for system management and marketing operations.

For example, when analyzing access logs merged from multiple servers, by using this tool to eliminate duplicate entries whose timestamps and IP addresses perfectly match, it is possible to significantly reduce storage consumption and query execution time in subsequent analysis platforms.

In addition, when examining email lists for marketing campaigns, we use a multi-stage preprocessing model to normalize duplicate email addresses that include fluctuations in uppercase and lowercase letters and unintentional spaces, and extract a unique list.

This cleaned data functions as a sanitization process before being input to a relational database or cloud storage as an SQL bulk insert statement or CSV payload, directly contributing to improving data quality and optimizing the processing efficiency of the entire system.