chore: improve performance of nvm version command

[maksimr]

fix #1694

This pull request reduces CPU time from 50ms to 15ms.

What was done:

1. I have changed command printf on echo because printf is slower than echo
   (printf - 2ms, echo - 0.09ms)
   chore: improve performance of nvm version command #1695 (comment)
2. Replace while cycle from nvm_tree_contains_path on string comparison
   (while - 14ms, str comparison - 0.06ms)
3. Changed getting node version in nvm_ls_current from node --version to getting it from NVM_LS_CURRENT_NODE_PATH.
   (node --version - 13ms, from string - 0.09ms)

Before:

v6.8.0
num  calls                time                       self            name
-----------------------------------------------------------------------------------
 1)    2          28.13    14.07   51.58%     28.13    14.07   51.58%  nvm_tree_contains_path
 2)    1          45.82    45.82   84.01%     15.08    15.08   27.65%  nvm_ls_current
 3)    2          54.51    27.26   99.96%      8.61     4.31   15.79%  nvm
 4)    1           2.61     2.61    4.79%      2.61     2.61    4.79%  nvm_echo
 5)    1          45.90    45.90   84.17%      0.08     0.08    0.15%  nvm_version
 6)    1          54.54    54.54  100.00%      0.02     0.02    0.04%  run-test

-----------------------------------------------------------------------------------

 6)    1          54.54    54.54  100.00%      0.02     0.02    0.04%  run-test
       1/2        54.51    54.51   99.96%      4.50     4.50             nvm [3]

-----------------------------------------------------------------------------------

       1/2        54.51    54.51   99.96%      4.50     4.50             run-test [6]
       1/2        50.01    50.01   91.70%      4.11     4.11             nvm [3]
 3)    2          54.51    27.26   99.96%      8.61     4.31   15.79%  nvm
       1/1        45.90    45.90   84.17%      0.08     0.08             nvm_version [5]
       1/2        50.01    50.01   91.70%      4.11     4.11             nvm [3]

-----------------------------------------------------------------------------------

       1/1        45.90    45.90   84.17%      0.08     0.08             nvm [3]
 5)    1          45.90    45.90   84.17%      0.08     0.08    0.15%  nvm_version
       1/1        45.82    45.82   84.01%     15.08    15.08             nvm_ls_current [2]

-----------------------------------------------------------------------------------

       1/1        45.82    45.82   84.01%     15.08    15.08             nvm_version [5]
 2)    1          45.82    45.82   84.01%     15.08    15.08   27.65%  nvm_ls_current
       1/1         2.61     2.61    4.79%      2.61     2.61             nvm_echo [4]
       2/2        28.13    14.07   51.58%     28.13    14.07             nvm_tree_contains_path [1]

-----------------------------------------------------------------------------------

       2/2        28.13    14.07   51.58%     28.13    14.07             nvm_ls_current [2]
 1)    2          28.13    14.07   51.58%     28.13    14.07   51.58%  nvm_tree_contains_path

-----------------------------------------------------------------------------------

       1/1         2.61     2.61    4.79%      2.61     2.61             nvm_ls_current [2]
 4)    1           2.61     2.61    4.79%      2.61     2.61    4.79%  nvm_echo

After:

v6.8.0
num  calls                time                       self            name
-----------------------------------------------------------------------------------
 1)    2          11.88     5.94   99.83%      8.06     4.03   67.76%  nvm
 2)    1           3.75     3.75   31.51%      3.55     3.55   29.82%  nvm_ls_current
 3)    2           0.11     0.06    0.93%      0.11     0.06    0.93%  nvm_tree_contains_path
 4)    1           0.09     0.09    0.76%      0.09     0.09    0.76%  nvm_echo
 5)    1           3.82     3.82   32.06%      0.07     0.07    0.55%  nvm_version
 6)    1          11.90    11.90  100.00%      0.02     0.02    0.17%  run-test

-----------------------------------------------------------------------------------

 6)    1          11.90    11.90  100.00%      0.02     0.02    0.17%  run-test
       1/2        11.88    11.88   99.83%      4.06     4.06             nvm [1]

-----------------------------------------------------------------------------------

       1/2        11.88    11.88   99.83%      4.06     4.06             run-test [6]
       1/2         7.82     7.82   65.74%      4.01     4.01             nvm [1]
 1)    2          11.88     5.94   99.83%      8.06     4.03   67.76%  nvm
       1/1         3.82     3.82   32.06%      0.07     0.07             nvm_version [5]
       1/2         7.82     7.82   65.74%      4.01     4.01             nvm [1]

-----------------------------------------------------------------------------------

       1/1         3.82     3.82   32.06%      0.07     0.07             nvm [1]
 5)    1           3.82     3.82   32.06%      0.07     0.07    0.55%  nvm_version
       1/1         3.75     3.75   31.51%      3.55     3.55             nvm_ls_current [2]

-----------------------------------------------------------------------------------

       1/1         3.75     3.75   31.51%      3.55     3.55             nvm_version [5]
 2)    1           3.75     3.75   31.51%      3.55     3.55   29.82%  nvm_ls_current
       1/1         0.09     0.09    0.76%      0.09     0.09             nvm_echo [4]
       2/2         0.11     0.06    0.93%      0.11     0.06             nvm_tree_contains_path [3]

-----------------------------------------------------------------------------------

       2/2         0.11     0.06    0.93%      0.11     0.06             nvm_ls_current [2]
 3)    2           0.11     0.06    0.93%      0.11     0.06    0.93%  nvm_tree_contains_path

-----------------------------------------------------------------------------------

       1/1         0.09     0.09    0.76%      0.09     0.09             nvm_ls_current [2]
 4)    1           0.09     0.09    0.76%      0.09     0.09    0.76%  nvm_echo

[ljharb]

There's a few legit tests failing.

In particular, some of the substitutions you're using seem to not be working.

[ljharb]

Why this change? This is problematic; the command is necessary to bypass any user aliases or functions, and the printf is more reliable than echo across shells.

[maksimr]

@ljharb

I have described it in the description.

I have changed command printf on echo because printf is slower than echo
(printf - 2ms, echo - 0.09ms)

What do you think about command echo?

Thanks

[ljharb]

We can certainly try it; I think i added automated tests around this one. Specifically the issue was about multiline input on specific shells, I think dash and sh.

[maksimr]

🤔 I have checked and I was wrong.

command printf majorized by command so if we could not remove command I just revert this change

Thanks

[ljharb]

Sounds good; some slowdowns are inevitable for correctness, sadly, but we can still try to shave off time wherever we can :-)

[ljharb]

This is reporting "bad substitution" - https://travis-ci.org/creationix/nvm/jobs/320732790#L1029

[ljharb]

Still seeing test failures :-/

[maksimr]

@ljharb yup, tests fail because they rely on some externals commands for example that code will call node --version

[maksimr]

I will try to figure out how fix tests

[ljharb]

@maksimr hi! it's been awhile, but i've rebased this and it's failing some tests. any chance you're still interested in finishing this PR?

[maksimr]

@ljharb I have checked changes again with node@14.17.6 on M1 and don't see too much profit from it. So let's close it.

Thanks!

[ljharb]

Ok, that’s unfortunate - any speed improvement helps. If you ever change your mind, please reopen this PR in the future.

[maksimr]

@ljharb sure, we use nvm heavily but I guess that main pitfall from the issue was fixed by node itself or by Moore law :)
If we face a problem or find a way to improve nvm somehow I definitely make a PR