Remove allocations in AmplNLReader.jl

[tmigot]

I ran the following script:

using Pkg
Pkg.activate(".")
using NLPModelsTest, AmplNLReader

problems = ["BROWNDEN", "HS5", "HS6", "HS10", "HS11", "HS13", "HS14"]
map(
    nlp -> print_nlp_allocations(nlp, test_allocs_nlpmodels(nlp)),
    (AmplModel(joinpath("test/problems", lowercase(problem) * ".nl"), safe = true) for problem in problems)
)

and it returns the following allocations:

  Problem name: test/problems/brownden.nl
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: ███████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_structure!: ████████████████████ 192.0 
                         hprod!: ██████████████⋅⋅⋅⋅⋅⋅ 128.0 
                  hess_op_prod!: ██████████████⋅⋅⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs5.nl
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: ████████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_structure!: ████████████████████ 160.0 
                         hprod!: ████████████████⋅⋅⋅⋅ 128.0 
                  hess_op_prod!: ████████████████⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs6.nl
                     hprod_lag!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                        jtprod!: ████████████████████ 1504.0
                         jprod!: ████████████████████ 1488.0
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
         jac_op_transpose_prod!: ████████████████████ 1504.0
                          cons!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                   jac_op_prod!: ████████████████████ 1488.0
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_lag_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
              hess_lag_op_prod!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                     jac_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                hess_structure!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                         hprod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                 jac_structure!: ████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 256.0 
                  hess_op_prod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs10.nl
                     hprod_lag!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                        jtprod!: ████████████████████ 1504.0
                         jprod!: ████████████████████ 1488.0
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
         jac_op_transpose_prod!: ████████████████████ 1504.0
                          cons!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                   jac_op_prod!: ████████████████████ 1488.0
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_lag_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
              hess_lag_op_prod!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                     jac_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                hess_structure!: ███⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 160.0 
                         hprod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                 jac_structure!: ████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 256.0 
                  hess_op_prod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs11.nl
                     hprod_lag!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                        jtprod!: ████████████████████ 1504.0
                         jprod!: ████████████████████ 1488.0
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
         jac_op_transpose_prod!: ████████████████████ 1504.0
                          cons!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                   jac_op_prod!: ████████████████████ 1488.0
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_lag_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
              hess_lag_op_prod!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                     jac_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                hess_structure!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                         hprod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                 jac_structure!: ████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 256.0 
                  hess_op_prod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs13.nl
                     hprod_lag!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                        jtprod!: ████████████████████ 1504.0
                         jprod!: ████████████████████ 1488.0
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
         jac_op_transpose_prod!: ████████████████████ 1504.0
                          cons!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                   jac_op_prod!: ████████████████████ 1488.0
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_lag_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
              hess_lag_op_prod!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                     jac_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 64.0  
                hess_structure!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                         hprod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                 jac_structure!: ████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 256.0 
                  hess_op_prod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 

  Problem name: test/problems/hs14.nl
                     hprod_lag!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 80.0  
                        jtprod!: ████████████████████ 1664.0
                         jprod!: ████████████████████ 1664.0
                            obj: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
         jac_op_transpose_prod!: ████████████████████ 1664.0
                          cons!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                    hess_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 80.0  
                   jac_op_prod!: ████████████████████ 1664.0
                          grad!: ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 0.0   
                hess_lag_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 80.0  
              hess_lag_op_prod!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 80.0  
                     jac_coord!: █⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 80.0  
                hess_structure!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 128.0 
                         hprod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 160.0 
                 jac_structure!: ████⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 320.0 
                  hess_op_prod!: ██⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅ 160.0 

A list (to be updated) of the things that allocate:

• [ ] there is no objective-only hprod!
• [ ] hprod! and hess_coord! allocate because of the cons call here https://github.com/JuliaSmoothOptimizers/AmplNLReader.jl/blob/f47a2f7564c21da7e6c14bc89c244d61fdd387a4/src/ampl_model.jl#L483 and there https://github.com/JuliaSmoothOptimizers/AmplNLReader.jl/blob/f47a2f7564c21da7e6c14bc89c244d61fdd387a4/src/ampl_model.jl#L649
• [ ] Same for jac_coord! https://github.com/JuliaSmoothOptimizers/AmplNLReader.jl/blob/f47a2f7564c21da7e6c14bc89c244d61fdd387a4/src/ampl_model.jl#L418
• [x] I think hess_structure! and jac_structure! allocate in this test only because the input vectors are not Cint
• [ ] jprod and jtprod evaluate the jacobian matrix

[dpo]

Also, each call to jac_coord evaluates the constraints and allocates a vector. That would be easy to preallocate.