Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Clean up SSZ multiproofs spec: unused function #2715

Closed
wants to merge 1 commit into from
Closed

Clean up SSZ multiproofs spec: unused function #2715

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
31 changes: 0 additions & 31 deletions ssz/merkle-proofs.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -11,7 +11,6 @@
- [Generalized Merkle tree index](#generalized-merkle-tree-index)
- [SSZ object to index](#ssz-object-to-index)
- [Helpers for generalized indices](#helpers-for-generalized-indices)
- [`concat_generalized_indices`](#concat_generalized_indices)
- [`get_generalized_index_length`](#get_generalized_index_length)
- [`get_generalized_index_bit`](#get_generalized_index_bit)
- [`generalized_index_sibling`](#generalized_index_sibling)
Expand Down Expand Up @@ -39,22 +38,6 @@ def get_power_of_two_ceil(x: int) -> int:
return 2 * get_power_of_two_ceil((x + 1) // 2)
```

```python
def get_power_of_two_floor(x: int) -> int:
"""
Get the power of 2 for given input, or the closest lower power of 2 if the input is not a power of 2.
The zero case is a placeholder and not used for math with generalized indices.
Commonly used for "what power of two makes up the root bit of the generalized index?"
Example: 0->1, 1->1, 2->2, 3->2, 4->4, 5->4, 6->4, 7->4, 8->8, 9->8
"""
if x <= 1:
return 1
if x == 2:
return x
else:
return 2 * get_power_of_two_floor(x // 2)
```

## Generalized Merkle tree index

In a binary Merkle tree, we define a "generalized index" of a node as `2**depth + index`. Visually, this looks as follows:
Expand Down Expand Up @@ -191,20 +174,6 @@ def get_generalized_index(typ: SSZType, path: Sequence[Union[int, SSZVariableNam

_Usage note: functions outside this section should manipulate generalized indices using only functions inside this section. This is to make it easier for developers to implement generalized indices with underlying representations other than bigints._

#### `concat_generalized_indices`

```python
def concat_generalized_indices(*indices: GeneralizedIndex) -> GeneralizedIndex:
"""
Given generalized indices i1 for A -> B, i2 for B -> C .... i_n for Y -> Z, returns
the generalized index for A -> Z.
"""
o = GeneralizedIndex(1)
for i in indices:
o = GeneralizedIndex(o * get_power_of_two_floor(i) + (i - get_power_of_two_floor(i)))
return o
```

#### `get_generalized_index_length`

```python
Expand Down