Hi, I wanted to open a ROOT File from GitLab repo. I tried:
TFile* file = TFile::Open(“url/filename”);
and
TFile* file = TFile::Open(“url/filename”, “WEB”);
But It didn’t find the file.
How can I do it?
Imanol
Please read tips for efficient and successful posting and posting code
ROOT Version: Not Provided
Platform: Not Provided
Compiler: Not Provided
Try:
root -l -q -b -e 'TFile *f = TFile::Open("http://root.cern.ch/files/atlas.root"); f->ls();'
root -l -q -b -e 'TFile *f = TFile::Open("https://root.cern.ch/files/atlas.root"); f->ls();'
It works, but I don’t understand the difference between this and my code. Maybe the GitLab server is spoiling something?
Imanol
You may need something like: "http://myusername:mypasswd@my.server/my/file.root"
Make sure that “wget” works, e.g.: wget http://myusername:mypasswd@my.server/my/file.root
Here’s a simple GitHub test (note: the “View raw” link is used):
root -l -q -b -e 'TFile *f = TFile::Open("https://github.com/root-project/root/blob/master/tutorials/gallery.root?raw=true"); f->ls();'
That GitHub test works, I guess that the difference is the permission, my repository is private. How can I add this?
Make sure you can retrieve your file with the “wget” and/or “curl”. Then ROOT should be able to retrieve it, too.
I can retrieve it with “wget” but ROOT is giving me the error:
Error in : can not open file “path/file” with davix: Result HTTP 404 : File not found after 3 attempts (18)
Have you added the “token”, e.g.:
"https://my.git.lab/api/v4/projects/MyRepositoryID/repository/files/MyFile.root/raw?private_token=MyReadApiOrReadRepositoryToken"
@Axel We need someone who could have a look at it.
What do you mean? Where should I add this?
How exactly do you get your file with “wget”?
wget https://gitlab.cern.ch/ path /filename
Do I understand it right that when you:
wget https://gitlab.cern.ch/path/filename.root
you really get the raw “filename.root” (which you can then open in ROOT)?
@Axel … ROOT 6.26/10 on a Ubuntu 22.04 / x86_64 / GCC 11.3.0 fails in a simple test:
gitlab.cern.ch → HepMC/HepMC3 → python/test/inputIO4.root
This is a public repository, so “wget” doesn’t need any tokens:
wget "https://gitlab.cern.ch/api/v4/projects/hepmc%2FHepMC3/repository/files/python%2Ftest%2FinputIO4.root/raw" -O inputIO4.root
wget "https://gitlab.cern.ch/api/v4/projects/6751/repository/files/python%2Ftest%2FinputIO4.root/raw" -O inputIO4.root
Unfortunately, ROOT fails:
root -l -q -b -e 'TFile *f = TFile::Open("https://gitlab.cern.ch/api/v4/projects/hepmc%2FHepMC3/repository/files/python%2Ftest%2FinputIO4.root/raw");'
root -l -q -b -e 'TFile *f = TFile::Open("https://gitlab.cern.ch/api/v4/projects/6751/repository/files/python%2Ftest%2FinputIO4.root/raw");'
Even if I try to use a “Personal Access Token” (a “read_repository” or “read_api” one):
root -l -q -b -e 'TFile *f = TFile::Open("https://gitlab.cern.ch/api/v4/projects/hepmc%2FHepMC3/repository/files/python%2Ftest%2FinputIO4.root/raw?private_token=AReadRepositoryOrReadApiToken");'
root -l -q -b -e 'TFile *f = TFile::Open("https://gitlab.cern.ch/api/v4/projects/6751/repository/files/python%2Ftest%2FinputIO4.root/raw?private_token=AReadRepositoryOrReadApiToken");'
In all cases, I get the following:
Error in <TDavixFile::Init>: file https://gitlab.cern.ch/api/v4/projects/.../repository/files/python%2Ftest%2FinputIO4.root/raw is truncated at 0 bytes: should be 2127856, trying to recover
Warning in <TDavixFile::Init>: no keys recovered, file has been made a Zombie
root -l -q -b -e 'TFile *f = TFile::Open("https://gitlab.cern.ch/hepmc/HepMC3/-/raw/master/python/test/inputIO4.root?inline=false");' works more or less well 
@Axel Could you please post the relevant link to GitLab documentation?
The one I know is:
GitLab → API Docs → REST API resources → Repository files API → Get raw file from repository
I just went here
Then there’s the “Download” button on the right, I took its URL. Note that GitLab is no full featured web server - this isn’t as fast / efficient as a regular Apache / nginx etc.
@Axel Could you please try “your method” with some “private GitLab repository” (which requires a “private_token” to retrieve files)?
Sorry, I just decided to use another strategy, so this is no longer necessary. Thank you for your help