(Improvement/refactor) Using the keccak256 to compare if an address matches a new entry.

[Janther]

Before submitting a pull request, please provide the following information:

• What is it? (leave one option)

  • (Improvement) of existing functionality
  • (Refactor) of existing code (no functionality change)

• What was the root cause of the problem originally / what feature was missing? Instead of having a byte per byte comparison, addresses are hashed using keccak256 and that hash is being compared.

• How does this pull request solve it (in broad terms)? I stored the keccac256 hash in the PhysicalAddress struct in the registration and the lookup just checks if the keccak matches.

• Does it close any open issues? Closes #77

• Quick checklist

  • [x] docs were updated where necessary OR they don't need to be updated
  • [x] tests were updated where necessary OR they don't need to be updated

• Additional information

I performed a small refactor in the register_address function. Just cleaning up some duplicated code.

[coveralls]

Pull Request Test Coverage Report for Build 221

• 13 of 16 (81.25%) changed or added relevant lines in 1 file are covered.
• 14 unchanged lines in 1 file lost coverage.
• Overall coverage increased (+0.6%) to 68.468%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
blockchain/contracts/ProofOfPhysicalAddress.sol	13	16	81.25%
<!--	Total:	13	16	81.25%	-->

Files with Coverage Reduction	New Missed Lines	%
blockchain/contracts/ProofOfPhysicalAddress.sol	14	35.53%
<!--	Total:	14		-->

Totals
Change from base Build 218:	0.6%
Covered Lines:	764
Relevant Lines:	1067

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 222

• 14 of 18 (77.78%) changed or added relevant lines in 1 file are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage increased (+0.6%) to 68.421%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
blockchain/contracts/ProofOfPhysicalAddress.sol	14	18	77.78%
<!--	Total:	14	18	77.78%	-->

Files with Coverage Reduction	New Missed Lines	%
blockchain/contracts/ProofOfPhysicalAddress.sol	1	35.29%
<!--	Total:	1		-->

Totals
Change from base Build 218:	0.6%
Covered Lines:	764
Relevant Lines:	1068

---

💛 - Coveralls

[phahulin]

@Janther should we also get rid of comparisons with empty strings in favour of keccak256 or it's not worth it?

// now
require(!str_eq(name, ''));

// maybe?
bytes32 empty_hash = keccak256('');
require( keccak256(name) != empty_hash );

and remove function str_eq altogether?

[Janther]

That's the plan for the next PR, I have the commit ready but I like to keep PRs atomic. Once this PR is merged, I'll make the next one.

And it will be like this:

// before
require(!str_eq(name, ''));

// after
require(bytes(name).length > 0);