[bug] lot of bundle dependencies will surely fail

real sample and provement (It's obvious because factor 9176 has 2^3 multiplier so initial bits are pushed out of int(32) in just 11 iterations =)):

Code (CSharp):

1.             var deps = new[] {
2.                 "<WILL-BE-REPLACED>",
3.                 "startup-shared_assets_assets/fx_data/textures.bundle",
4.                 "shared_assets_assets/fx_data/materials.bundle",
5.                 "shaders_assets_all.bundle",
6.                 "music_assets_music/maptheme6final.bundle",
7.                 "fx_tex_assets_all.bundle",
8.                 "shared_assets_assets/textures/ui/campain_act02.bundle",
9.                 "shared_assets_assets/fx_data/meshes.bundle",
10.                 "startup-shared_assets_assets/textures/ui/campain_act02.bundle",
11.                 "startup-shared_assets_assets/textures/ui/campainart.bundle",
12.                 "startup-shared_assets_assets/fx_data/materials.bundle",
13.                 "shared_assets_assets/textures/ui/valleyoftreasures.bundle",
14.                 "startup-shared_assets_assets/fx_data/meshes.bundle",
15.                 "startup_UnityBuiltInShaders.bundle",
16.             };
17.             int ADDRESSABLES_CUSTOM_HASH(string[] deps1)
18.             {
19.                 //seed and and factor values taken from https://stackoverflow.com/question/1646807/quick-and-simple-hash-code-combinations
20.                 int hashCode = 1009;
21.                 foreach (var dep in deps1)
22.                     hashCode = hashCode * 9176 + dep.GetHashCode();
23.                 return hashCode;
24.             }
25.             deps[0] = "maps_assets_ref/valley1.bundle";
26.             var hashPart1 = deps[0].GetHashCode();
27.             var hashSum1 = ADDRESSABLES_CUSTOM_HASH(deps);          
28.             deps[0] = "maps_assets_ref/valley3.bundle";
29.             var hashPart2 = deps[0].GetHashCode();
30.             var hashSum2 = ADDRESSABLES_CUSTOM_HASH(deps);
31.             Debug.Log($"HASH: {hashPart1}=>{hashSum1} ??? {hashPart2}=>{hashSum2}");

workaround: code in ContentCatalogData.cs to replace with:

Code (CSharp):

1.  
2. //create extra entries for dependency sets
3. var hashSources = new Dictionary<int, string>(); ////>addressables: bugfix: try to detect incorrectly exported dependencies
4. ........
5.                 //**addressables - fix: better hash method for a lot of dependencies and additional checker for the same issue in the future
6.                 //    (9176 has 2^3 multiplier so inital bits are pushed out of int in just 11 iterations)
7.                
8.                 ////seed and and factor values taken from https://stackoverflow.com/questions/1646807/quick-and-simple-hash-code-combinations
9.                 //int hashCode = 1009;
10.                 //foreach (var dep in entry.Dependencies)
11.                 //    hashCode = hashCode * 9176 + dep.GetHashCode();
12.                
13.                 var hashSource = string.Join(null, entry.Dependencies);
14.                 var hashCode = hashSource.GetHashCode(); //NEW HASH METHOD: just for the sum of all dependencies
15.                 if (hashSources.TryGetValue(hashCode, out var previousHashSource)) {
16.                     if (hashSource != previousHashSource) {
17.                         throw new Exception($"INCORRECT HASH: the same hash ({hashCode}) for different dependency lists:\nsource 1: {previousHashSource}\nsource 2: {hashSource}");
18.                     }
19.                 } else {
20.                     hashSources.Add(hashCode, hashSource);
21.                 }
22.  

 

Oh, this fixed me a loot of issues. Thanks! EDIT: Maybe changing 9176 (like
5381) for some prime number would be sufficient.

 

You're right - some prime number can be sufficient, but checker's cost is nothing, comparing to passed/future debug time on the same. =)

 

it is the second time hash collision problem been posted, i hope unity will fix it soon

 

And still not fixed in 1.1.3 ...

 

So sad

I dare not update to latest Addressables right now cause I don't want to waste days working around new bugs in it like last time I updated.

 

@unity_bill

 

thanks

 

Thanks for workaround. I had problems with this function in Addressables 1.2.2 too.

 

When will this be fixed? It still happens in 1.2.4

 

Hi all,

While we wait for an official fix I made for our team a workaround with a new hash calculation function (working in all the builds we made):

Code (CSharp):

1. internal int CalculateCollectedHash(List<object> objects, Dictionary<int, object> hashSources)
2.         {
3.             //alphabetical hashing
4.             List<object> hashSource = objects.OrderBy(_x => _x.GetType().Name).ToList();
5.  
6.             //multiplicative hashing
7.             int seed = 487;
8.             int modifier = 31;
9.             int hashCode = hashSource.Aggregate(seed, (current, item) => (current * modifier) + item.GetHashCode());
10.          
11.             if (hashSources.TryGetValue(hashCode, out object previousHashSource))
12.             {
13.                 List<object> previousHash = previousHashSource as List<object>;
14.                 if ( hashSource.Count !=  previousHash.Count)
15.                 {
16.                     throw new Exception($"INCORRECT HASH: the same hash ({hashCode}) for different dependency lists:\nsource 1: {previousHashSource}\nsource 2: {hashSource}");
17.                 }
18.                 for (int i = 0; i < hashSource.Count; ++i)
19.                 {
20.                     if (hashSource[i].GetType().Name != previousHash[i].GetType().Name)
21.                     {
22.                         throw new Exception($"INCORRECT HASH: the same hash ({hashCode}) for different dependency lists:\nsource 1: {previousHashSource}\nsource 2: {hashSource}");
23.                     }
24.                 }
25.             }
26.             else
27.                 hashSources.Add(hashCode, hashSource);
28.  
29.             return hashCode;
30.         }

Hope this can help