Undo Functionality for Attribute Renames / Deletion + New Implementation of Committing Changing to Disk

[lapp0]

fixes #72

fixes #57

• implement undo via Updates
• parser.persist_updates: iterate over Updates and apply their changes
  • Possible better alternative: update configuration files by calculating changes to OptionTree
• ensure DiffWidget works with the changes
• update architecture.org to reflect how Updates and persisting now work in Nix-Gui
• handle all TODOs
• (referenced / created separate issues below)
• update version to nix-gui to 0.2.0, as this fixes the last remaining issue in milestone 1 (moved to New v0.2.0 Screenshot #240)

New issues to address shortcomings of this PR

During creation of this PR, new (non-urgent) requirements for Nix-Gui have been discovered / created, but are out of scope for this already-oversized PR.

• Write Changes to Correct Module #243
• Store OptionTree.configured_change_cache as a CachedHashDict(), use in __hash__ and __eq__ functions #244
• Full integration tests for all state_model mutation functions. #245
• Restructure parser.py #246
• Clean up SyntaxTree hashing. #247
• Sanitize Terminology #75

Immediate follow up PR

Code injection is messy and doesn't work properly at all for lists.

• Fix code placement #248

[lapp0]

Attempting to cache OptionTree functions based on changes to in_memory_cache. This is more expensive to calculate than changing then checking the change_marker. However, it gives us the ability to reuse old cached results if the in_memory_cache is reverted. Additionally, it is a more coherent model.

Testing results for ``tests/test_option_tree.py::test_lru_cache_fast` below.

        1    0.010    0.010 3892.400 3892.400 test_option_tree.py:57(test_lru_cache_fast)
    14394    2.877    0.000 3862.389    0.268 option_tree.py:81(__hash__)
  14355/1    0.104    0.000 3852.905 3852.905 option_tree.py:298(count_leaves)
   2501/1    0.232    0.000 3852.905 3852.905 {built-in method builtins.sum}
    14454   89.177    0.006 3307.828    0.229 {built-in method builtins.sorted}
 32817590  238.372    0.000 3141.048    0.000 attribute.py:51(__lt__)
 65646319  215.903    0.000 2711.201    0.000 attribute.py:55(__str__)
 65646319  537.903    0.000 2435.324    0.000 attribute.py:61(<listcomp>)
328708610  573.728    0.000 1897.424    0.000 re.py:188(match)
328708917  566.456    0.000  852.991    0.000 re.py:289(_compile)
44009963/312612   60.418    0.000  552.338    0.002 {built-in method builtins.hash}
 14565720   68.506    0.000  481.796    0.000 option_definition.py:162(__hash__)
328715305  470.825    0.000  470.825    0.000 {method 'match' of 're.Pattern' objects}
 14565720   47.334    0.000  392.160    0.000 hash_by_json.py:13(hash_object)
 14565723   96.365    0.000  337.442    0.000 __init__.py:183(dumps)
358057957/358057948  303.642    0.000  303.692    0.000 {built-in method builtins.isinstance}
 14565723   74.518    0.000  204.265    0.000 encoder.py:182(encode)
131286801/65650743  126.217    0.000  191.885    0.000 {built-in method builtins.len}
 14565723  106.192    0.000  106.192    0.000 encoder.py:204(iterencode)
 65635332   65.667    0.000   96.244    0.000 attribute.py:48(__len__)
80235306/80234700   66.496    0.000   66.506    0.000 {method 'join' of 'str' objects}
 14565724   36.812    0.000   36.812    0.000 encoder.py:104(__init__)
 14860492   25.557    0.000   33.428    0.000 attribute.py:71(__hash__)
     11/1    0.013    0.001   28.592   28.592 cache.py:62(wrapper)
        1    0.000    0.000   28.586   28.586 api.py:10(get_option_tree)
        8    0.001    0.000   22.377    2.797 nix_eval.py:44(nix_instantiate_eval)

Observations:

• __hash__ takes a quarter second on average, not good
• This test was done with many Undefined, which are quick and easy to hash, so the cost of option_definition.py:162(__hash__) may be underreported
• Attribute.__lt__ for sorting is an expensive operation because it calls a re.match many times on an uncompiled regexp.

Solution: compile regexp, lru_cache regexp result.

[lapp0]

Improved result

        1    0.010    0.010 1652.020 1652.020 test_option_tree.py:57(test_lru_cache_fast)
    14465    2.824    0.000 1623.365    0.112 option_tree.py:81(__hash__)
  14355/1    0.101    0.000 1614.034 1614.034 option_tree.py:298(count_leaves)
   2501/1    0.213    0.000 1614.034 1614.034 {built-in method builtins.sum}
    14525   76.293    0.005 1066.960    0.073 {built-in method builtins.sorted}
 32979279  188.776    0.000  917.820    0.000 attribute.py:53(__lt__)
 65969696  197.845    0.000  571.359    0.000 attribute.py:57(__str__)
44225657/312750   59.890    0.000  553.942    0.002 {built-in method builtins.hash}
 14637572   69.997    0.000  484.900    0.000 option_definition.py:162(__hash__)
 14637572   46.429    0.000  393.826    0.000 hash_by_json.py:13(hash_object)
 14637575   97.900    0.000  339.659    0.000 __init__.py:183(dumps)
 65969696  329.374    0.000  329.398    0.000 attribute.py:58(<listcomp>)
 14637575   76.085    0.000  205.499    0.000 encoder.py:182(encode)
131933486/65974050  100.314    0.000  157.819    0.000 {built-in method builtins.len}
 14637575  105.933    0.000  105.933    0.000 encoder.py:204(iterencode)
 65958710   57.504    0.000   80.979    0.000 attribute.py:50(__len__)
80630182/80629576   50.198    0.000   50.207    0.000 {method 'join' of 'str' objects}
 14637576   36.260    0.000   36.260    0.000 encoder.py:104(__init__)
 14932415   24.803    0.000   32.550    0.000 attribute.py:68(__hash__)
     11/1    0.009    0.001   27.314   27.314 cache.py:62(wrapper)
        1    0.000    0.000   27.309   27.309 api.py:10(get_option_tree)
        8    0.001    0.000   21.572    2.697 nix_eval.py:44(nix_instantiate_eval)
        8    0.001    0.000   21.434    2.679 nix_eval.py:33(nix_instantiate)
        8    0.001    0.000   21.419    2.677 subprocess.py:464(run)
        8    0.000    0.000   21.341    2.668 subprocess.py:1090(communicate)
        8    0.020    0.003   21.341    2.668 subprocess.py:1926(_communicate)

Seems sorting is taking a while, I'll try SortedDict

[lapp0]

Substantially improved by implementing CachedHashDict

        1    2.647    2.647   66.963   66.963 test_option_tree.py:57(test_lru_cache_fast)
     1012    0.005    0.000   37.886    0.037 cached_hash_dict.py:20(__setitem__)
     1013    0.055    0.000   37.879    0.037 cached_hash_dict.py:37(_recalculate_hash)
     1000    0.009    0.000   37.050    0.037 option_tree.py:197(insert_attribute)
     1073    1.722    0.002   25.465    0.024 {built-in method builtins.sorted}
  1127360    3.998    0.000   20.060    0.000 attribute.py:53(__lt__)
     11/1    0.007    0.001   17.908   17.908 cache.py:62(wrapper)
        1    0.000    0.000   17.904   17.904 api.py:10(get_option_tree)
        8    0.001    0.000   14.329    1.791 nix_eval.py:44(nix_instantiate_eval)
        8    0.001    0.000   14.246    1.781 nix_eval.py:33(nix_instantiate)
        8    0.001    0.000   14.234    1.779 subprocess.py:464(run)
        8    0.000    0.000   14.165    1.771 subprocess.py:1090(communicate)
        8    0.015    0.002   14.165    1.771 subprocess.py:1926(_communicate)
      794    0.012    0.000   14.126    0.018 selectors.py:403(select)
      794   14.112    0.018   14.112    0.018 {method 'poll' of 'select.poll' objects}
3309238/1771301    2.424    0.000   13.803    0.000 {built-in method builtins.hash}
  2265859    4.330    0.000   12.692    0.000 attribute.py:57(__str__)
   512582    1.625    0.000   10.919    0.000 option_definition.py:162(__hash__)
   512582    1.100    0.000    8.773    0.000 hash_by_json.py:13(hash_object)
        1    0.001    0.001    8.130    8.130 nix_eval.py:82(get_all_nixos_options)
   512585    2.120    0.000    7.514    0.000 __init__.py:183(dumps)
  2265859    7.396    0.000    7.418    0.000 attribute.py:58(<listcomp>)
   546293    2.085    0.000    4.898    0.000 attribute.py:12(__init__)
   512585    1.719    0.000    4.580    0.000 encoder.py:182(encode)
      3/1    0.001    0.000    4.452    4.452 parser.py:59(get_all_option_values)
4525553/2269234    2.163    0.000    3.462    0.000 {built-in method builtins.len}

[lapp0]

Massively improved with improvements to CachedHashDict:

584459 0.454 0.000 1.638 0.000 option_tree.py:81(__hash__)

[lapp0]

A few changes, still need architecture.org updated as well