Make the attribute access Read method a bit easier to implement.

[bzbarsky-apple]

Consumers should not have to worry about what the right TLV tag is for
the attribute value, or exactly how to put their data into the TLV
writer. We can use a partially applied version of the Encode generic
for this.

Fixes: #9938

Also fixes an issue around the handling of null TLVWriter and the
apDataExists outparam in ReadSingleClusterData.

Problem

See above.

Change overview

See above.

Testing

No behavior changes apart from fixing the (not exercised by anything so far) null TLVWriter and non-null apDataExists bits. Passes existing tests.

[todo]

Add DataVersion support

connectedhomeip/src/app/util/ember-compatibility-functions.cpp

Lines 221 to 227 in 2782de5

	// TODO: Add DataVersion support
	ReturnErrorOnFailure(
	apWriter->Put(chip::TLV::ContextTag(AttributeDataElement::kCsTag_DataVersion), kTemporaryDataVersion));
	}
	return CHIP_NO_ERROR;
	}
	}

---

This comment was generated by todo based on a TODO comment in 2782de5 in #9976. cc @bzbarsky-apple.

[github-actions]

Size increase report for "gn_qpg-example-build" from 45c7a41

File	Section	File	VM
chip-qpg6100-lighting-example.out	.text	192	192

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-qpg6100-lighting-example.out.map and ./pull_artifact/chip-qpg6100-lighting-example.out.map:

BLOAT EXECUTION FAILED WITH CODE 1:
bloaty: unknown file type for file './pull_artifact/chip-qpg6100-lighting-example.out.map'

Comparing ./master_artifact/chip-qpg6100-lighting-example.out and ./pull_artifact/chip-qpg6100-lighting-example.out:

sections,vmsize,filesize
.debug_line,0,7359
.debug_info,0,6184
.debug_str,0,1783
.strtab,0,488
.text,192,192
.debug_abbrev,0,190
.symtab,0,176
.debug_frame,0,148
.debug_aranges,0,40
[Unmapped],0,-192
.debug_ranges,0,-888
.debug_loc,0,-1808

[github-actions]

Size increase report for "esp32-example-build" from 45c7a41

File	Section	File	VM
chip-all-clusters-app.elf	.flash.text	60	60

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-all-clusters-app.elf and ./pull_artifact/chip-all-clusters-app.elf:

sections,vmsize,filesize
.debug_info,0,11766
.debug_line,0,8733
.debug_str,0,1274
.debug_abbrev,0,940
.debug_loc,0,494
.debug_ranges,0,200
.strtab,0,69
.flash.text,60,60
.shstrtab,0,3
.riscv.attributes,0,-3
.debug_frame,0,-8
[Unmapped],0,-60

[github-actions]

Size increase report for "nrfconnect-example-build" from 45c7a41

File	Section	File	VM
chip-lock.elf	text	192	192

Full report output

BLOAT REPORT

Files found only in the build output:
    report.csv

Comparing ./master_artifact/chip-shell.elf and ./pull_artifact/chip-shell.elf:

sections,vmsize,filesize
.debug_line,0,4535
.debug_info,0,2535
.debug_str,0,1702
.debug_frame,0,148
.debug_abbrev,0,58
.debug_aranges,0,40
.shstrtab,0,1
.symtab,0,-16
.strtab,0,-29
.debug_ranges,0,-1016
.debug_loc,0,-2234

Comparing ./master_artifact/chip-lock.elf and ./pull_artifact/chip-lock.elf:

sections,vmsize,filesize
.debug_info,0,6559
.debug_line,0,5823
.debug_str,0,1771
.strtab,0,488
text,192,192
.debug_abbrev,0,186
.symtab,0,176
.debug_frame,0,148
.debug_aranges,0,40
.debug_ranges,0,-888
.debug_loc,0,-1759