![]() Comparing final file blocks after first blocks It’s a tempting feature, but the risks outweigh the benefits and the added complexity for corner cases, so I’m never planning to do this. The performance boost is usually not worth it, because at best, a few extra file comparisons may not happen. The straightforward “delete any duplicates as fast as possible” case is improved, but anything much more complex is impossible. Bash duplicate md5 finder full#It doesn’t necessarily speed things up very much and it guarantees that options which work on full file sets (such as the file ordering/sorting options) are not usable. This seems like a good idea on paper (and indeed, fdupes has implemented this as an option), but it’s not a good idea in practice for most cases. The file tree built in jdupes tends to balance out reasonably well on its own. fdupes tried to use red-black trees at one point, but discarded the implementation for similar reasons of insufficient gains. Bash duplicate md5 finder code#The use of a hash algorithm with minimally decent randomization would mostly balance things out from the start, though, so my concerns about excessive tree depth turned out to be unfounded, and tree rebalance code did nothing to improve overall performance, so it was ultimately scrapped. Tree balancingĪt one point, I wrote a spiffy bit of tree rebalancing code that would go down the file tree and change the parent-child relationships to more fairly balance out the tree depth for any given branch. This isn’t true in fdupes, where MD5 is still stubbornly used as the hash algorithm, but jdupes spends a ridiculous amount of time waiting on the operating system to complete disk reads and a very tiny amount of time waiting on hash calculations to complete. The problem is that the vast majority of the slowness in jdupes stems from waiting on I/O operations to complete, not from CPU usage. Even if they were, the hash algorithm won’t make enough of a difference to change anything in any real-world workloads. c/.h file pair, making it particularly easy to include with the program, but some replacement hash code bases are not so easily included. I chose xxHash64 in part due to its containment within a single. Candidates such as t1ha are certainly a little faster than xxHash64, but switching to them has no real value. Still, there are those who suggest changing the hash algorithm yet again to improve performance further. Since discovering that there were some potentially undesirable properties to jodyhash (though those properties had zero effect in practical testing on real-world data), the slightly faster xxHash64 fast hash algorithm has been used. MD5 is a CPU-intensive thing to calculate, but jodyhash was explicitly written to use primitive CPU operations that translate directly to simple, fast, and compact machine language instructions. This made a huge difference in program performance. One way I sped up jdupes after forking the original fdupes code was to swap out the MD5 secure hash algorithm for my own custom “jodyhash” fast hash algorithm. It’s time to swat some of these down more publicly, so here is a list of things that people suggest to speed up jdupes, but won’t really do that. I have received a lot of suggestions by both email and the jdupes issue tracker on GitHub, and while some of them have merit, there are quite a few that come up time and time again. Over the years, I’ve pretty much done everything possible that had a chance of significantly speeding up the program, but there are always novel ideas out there about what could be done to make things even better. It’s amazing how far it has spread over the past few years, especially considering it was originally just me working on speeding up fdupes because it was too slow and I didn’t really have any plans to release my changes. It would be helpful, for example, when two identical mp3 tracks or video files have different names.Some of you are probably aware that I’m the person behind the jdupes duplicate file finder. Bash duplicate md5 finder free#With Duplicate File Finder you can organize your media files and increase free disk space needed to enlarge your collection.ĭuplicate Files Deleter has the MD5 search engine which allows the program to search for duplicate files by content, regardless of other match criteria. If you have a music collection of several hundreds or even thousands mp3-files, you may want to sort them by deleting identical tracks. Media files collections, such as music, video, images and photos, often become the primary source of identical files. By deleting duplicate files you can reduce time needed to defragment your hard drives and minimize time used by antivirus to scan your computer. Identical files not only waste your hard disk space, but also may cause system slowdowns. Improve computer performance by deleting duplicate files ![]()
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