[FileFormats.LP] I promised it was the last one but...

[matbesancon]

julia> instance = "/nfs/optimi/kombadon/MINLP/instances/qplib/lp/QPLIB_9008.lp.gz"

julia> o = MOI.Utilities.Model{Float64}()

julia> MOI.read_from_file(o, instance)
ERROR: zlib error: <no message> (code: -5)
Stacktrace:
  [1] changemode!(stream::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream}, newmode::Symbol)
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:732
  [2] callprocess(stream::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream}, inbuf::TranscodingStreams.Buffer, outbuf::TranscodingStreams.Buffer)
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:658
  [3] fillbuffer(stream::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream}; eager::Bool)
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:586
  [4] fillbuffer
    @ /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:573 [inlined]
  [5] eof(stream::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream})
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:191
  [6] eof(stream::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream})
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:189
  [7] _readline
    @ /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/LP/LP.jl:975 [inlined]
  [8] read!(io::TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, IOStream}, model::MathOptInterface.Utilities.GenericModel{Float64, MathOptInterface.Utilities.ObjectiveContainer{Float64}, MathOptInterface.Utilities.VariablesContainer{Float64}, MathOptInterface.FileFormats.LP.ModelFunctionConstraints{Float64}})
    @ MathOptInterface.FileFormats.LP /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/LP/LP.jl:952
  [9] #11
    @ /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/FileFormats.jl:121 [inlined]
 [10] open(::MathOptInterface.FileFormats.var"#11#12"{MathOptInterface.Utilities.GenericModel{Float64, MathOptInterface.Utilities.ObjectiveContainer{Float64}, MathOptInterface.Utilities.VariablesContainer{Float64}, MathOptInterface.FileFormats.LP.ModelFunctionConstraints{Float64}}}, ::Type{TranscodingStreams.TranscodingStream{CodecZlib.GzipDecompressor, S} where S<:IO}, ::String, ::String)
    @ TranscodingStreams /scratch/opt/mbesanco/.julia/packages/TranscodingStreams/DYpJd/src/stream.jl:164
 [11] compressed_open(f::Function, filename::String, mode::String, #unused#::MathOptInterface.FileFormats.Gzip)
    @ MathOptInterface.FileFormats /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/utils.jl:224
 [12] compressed_open(f::Function, filename::String, mode::String, #unused#::MathOptInterface.FileFormats.AutomaticCompression)
    @ MathOptInterface.FileFormats /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/utils.jl:251
 [13] read_from_file(model::MathOptInterface.Utilities.GenericModel{Float64, MathOptInterface.Utilities.ObjectiveContainer{Float64}, MathOptInterface.Utilities.VariablesContainer{Float64}, MathOptInterface.FileFormats.LP.ModelFunctionConstraints{Float64}}, filename::String)
    @ MathOptInterface.FileFormats /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/FileFormats/FileFormats.jl:120
 [14] read_from_file(model::MathOptInterface.Utilities.Model{Float64}, filename::String)
    @ MathOptInterface /scratch/opt/mbesanco/.julia/dev/MathOptInterface/src/MathOptInterface.jl:152
 [15] top-level scope
    @ REPL[14]:1

[matbesancon]

cc @odow

[odow]

Hmm. I remember coming across this one, and I had an answer. I think the problem is just really large and it hits some memory issue with zlib?

Potentially this? https://stackoverflow.com/questions/32367005/zlib-error-error-5-while-decompressing-data-incomplete-or-truncated-stream-in

[matbesancon]

ah fair enough, this is the largest instance in the QPLib by compressed size I think with 28M, although I see QPLIB_8547.lp.gz with 23M so seems to be a close call

[odow]

I wrote a proper parser in #2840 (and some follow on PRs). This is now fixed properly.

julia> function main()
           model = MOI.FileFormats.LP.Model{Float64}()
           MOI.read_from_file(model, "/Users/odow/Downloads/qplib/html/lp/QPLIB_9008.lp")
           return model
       end
main (generic function with 1 method)

julia> @time main();
 11.051303 seconds (403.91 M allocations: 14.411 GiB, 23.13% gc time, 0.04% compilation time)

julia> function main()
           model = MOI.FileFormats.LP.Model{Float64}()
           MOI.read_from_file(model, "/Users/odow/Downloads/qplib/html/lp/QPLIB_9008.lp.gz")
           return model
       end
main (generic function with 1 method)

julia> @time main();
  9.378364 seconds (403.91 M allocations: 14.395 GiB, 25.01% gc time)

julia> model = main()
MOI.FileFormats.LP.Model
├ ObjectiveSense: MIN_SENSE
├ ObjectiveFunctionType: MOI.ScalarQuadraticFunction{Float64}
├ NumberOfVariables: 1009306
└ NumberOfConstraints: 2998220
  ├ MOI.ScalarAffineFunction{Float64} in MOI.EqualTo{Float64}: 989604
  ├ MOI.VariableIndex in MOI.EqualTo{Float64}: 9996
  ├ MOI.VariableIndex in MOI.GreaterThan{Float64}: 999310
  └ MOI.VariableIndex in MOI.LessThan{Float64}: 999310