Opaque robj: add get/set methods and remove all robj->ptr refs

[SoftlyRaining]

I wanted to know if I could do this by quickly writing some scripts. It probably took twice as long as I thought, but only 4-5 hours so not terrible, and now I know. 🤷🏻‍♀️ All but the necessary references in object.c have been replaced using objectGetVal and objectSetVal.

I know we want to make robj opaque so it's easier to refactor it or change its internal structure. I thought there was an issue for this but I can't find it offhand.

[codecov]

Codecov Report

Attention: Patch coverage is 84.02226% with 201 lines in your changes missing coverage. Please review.

Project coverage is 71.01%. Comparing base (78bcc0a) to head (5b5de16).
Report is 5 commits behind head on unstable.

Files with missing lines	Patch %	Lines
src/sentinel.c	0.00%	73 Missing ⚠️
src/module.c	1.88%	52 Missing ⚠️
src/debug.c	78.26%	20 Missing ⚠️
src/object.c	84.52%	13 Missing ⚠️
src/rdb.c	94.44%	5 Missing ⚠️
src/t_list.c	91.22%	5 Missing ⚠️
src/cluster_legacy.c	88.23%	4 Missing ⚠️
src/replication.c	89.74%	4 Missing ⚠️
src/t_stream.c	94.44%	4 Missing ⚠️
src/db.c	95.89%	3 Missing ⚠️
... and 12 more

Additional details and impacted files

@@             Coverage Diff              @@
##           unstable    #1658      +/-   ##
============================================
- Coverage     71.02%   71.01%   -0.02%     
============================================
  Files           121      121              
  Lines         65176    65218      +42     
============================================
+ Hits          46290    46313      +23     
- Misses        18886    18905      +19     

Files with missing lines	Coverage Δ
src/bitops.c	93.77% <100.00%> (+0.30%)	⬆️
src/cluster_slot_stats.c	94.35% <100.00%> (ø)
src/commandlog.c	96.58% <100.00%> (ø)
src/config.c	78.40% <100.00%> (+0.01%)	⬆️
src/eval.c	57.06% <100.00%> (ø)
src/expire.c	96.59% <100.00%> (ø)
src/functions.c	94.50% <100.00%> (ø)
src/geo.c	93.58% <100.00%> (ø)
src/latency.c	81.21% <100.00%> (+0.29%)	⬆️
src/lazyfree.c	86.11% <100.00%> (ø)
... and 32 more

... and 7 files with indirect coverage changes

[zuiderkwast]

Awesome! Tbh, I'd prefer the complete change in one PR so we can get the benefit in memory usage. A separate commit within the same PR for the assignments and then a final commit to actually save memory in the object struct.

Feel free to write down you regexes so we can review those instead of alongside the actual diff. :D

[SoftlyRaining]

Ok, I added objectSetVal.

I could post the python scripts I used, but they're pretty bad. I only worked on them to the extent that it'd save me time - They mangle a few instances but did the bulk of the editing for me. Here's the one I used for the last objectSetVal commit. The json I load is derived from VS Code's "find all references" feature.

import json

with open('ptrrefs.json') as f:
    refs = json.load(f)

for file in list(refs.keys()):
    with open(file, 'r') as src:
        lines = src.readlines()
    print('====', file, '====')
    for (lineno, char) in refs[file]:
        lineno -= 1 # line number is 1-based
        char -= 1 # char number also 1-based

        line = lines[lineno]
        count = line.count('->ptr = ')
        if count == 0:
            continue
        assert(count == 1)
        (robj, val_ptr) = line.strip()[:-1].split('->ptr = ')
        whitespace = line[:len(line) - len(line.lstrip())]
        print(lineno, line[:-1])
        lines[lineno] =  f'{whitespace}objectSetVal({robj}, {val_ptr});\n'

    with open(file, 'w') as src:
        src.writelines(lines)