@CDProjekt: Let's go over the scenarios you have left for your customers (Customers of a mature game you developed for a mature consumer to play) to take advantage of shall we?
Scenario 1: Redownload the entire game.
I dunno about you but I have 450KB/s internet and it takes 17 minutes to download a single 300MB segment of the installation files. Downloading the entire game patch takes hours to do and there is no way to guarentee it will succeed, on top of this you have to run the installer and wait for it to either succeed or error before you can determine if you need to proceed to repeat the download process, further wasting time. If the installer fails, prepare to waste several more hours/spend several more hours browsing the internet with really slow internet with the download going in the background.
Scenario 2: Download random segments and hope that it works, potentially reducing the down time from several hours, to half an hour.
1) Download entire patch via downloader
2) Run the installer and find out that it won't install fully, instead reporting a file is corrupt.
3) Seeing as there are no files by the name reported, the user is left to randomly guess which TW2EE_Patch-#.bin file is to blame.
4) User randomly selects a TW2EE_Patch-#.bin file from http://en.thewitcher.com/ee_manual/ and prays it is the right one
5) User finishes downloading the TW2EE_Patch-#.bin file without knowing if it downloaded properly or not.
6) They locate the copy of the TW2EE_Patch-#.bin file that they previously downloaded, now without knowing if the original copy they downloaded was correctly downloaded or not, they replace it with the copy they just then downloaded and also don't know if it was downloaded correctly or not.
7) User has either replaced a correct/functional copy of a randomly selected TW2EE_Patch-#.bin file with a incomplete/corrupt copy of the randomly selected TW2EE_Patch-#.bin file or been incredibly lucky and no harm was done, the 2nd copy they downloaded ended up being correctly downloaded. Still no way for the user to know if that part was the one that was corrupt to begin with though so a good chance the consumer has wasted time even if the file downloaded properly.
8.) The only way to verify this? Run the installer and wait another numerous amount of minutes and hope it completes without fail.
9) What? You thought after all that that it would work? HELL NO! Chances of that are so slim it isn't even funny. More likely then not you're gonna have to begin again at step 2. Say good bye to trying to be smart and save time.
Scenario 3: Using checksums the user can determine which parts are faulty and target just those files when determining which files to redownload. (Your customers were working together to make this sceneraio possible, but then you guys,
for no good reason at all (That you have given so far),
decided to try and nullify any previous attempts at making this sceneraio possible. Good job guys, bravo.)
1) Download entire patch via downloader
2) Verify the integrity of the download
3) Determine which files are corrupt (If any)
4) Redownload corrupt files
5) Verify integrity of files
6) If all files pass, proceed to step 7. Otherwise return to step 3.
7) Install patch
8.) Done. Enjoy the game!
Edit: Tremendous THANK YOU goes to this guy http://en.thewitcher.com/forum/index.php?/topic/29103-md5-and-sha1-checksums-for-tw2ee/page__view__findpost__p__806503 for keeping Scenario 3 alive!
