Core/grin
0
0
Fork 0
mirror of https://github.com/mimblewimble/grin.git synced 2025-01-21 03:21:08 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

Merkle doc: fix typos, clarify diagram

Browse source
This commit is contained in:
Ignotus Peverell 2017-07-24 21:37:14 +00:00
parent 3503ba7f66
commit 20e3382785
No known key found for this signature in database
GPG key ID: 99CD25F39F8F8211
1 changed files with 13 additions and 13 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

26
doc/merkle.md
View file

@ -179,16 +179,16 @@ insertion positions is also required.
The sum tree is split in chunks that are handled independently and stored in The sum tree is split in chunks that are handled independently and stored in
separate files. separate files.
G 3 G
/ \ / \
M \ 2 M \
/ \ \ ---- cutoff height H / \ \
X Y \ 1 X Y \ ---- cutoff height H=1
/ \ / \ \ / \ / \ \
A B C D E 0 A B C D E
[----] [----] [----] [----]
chunk1 chunk2 chunk1 chunk2
Each chunk is a full tree rooted at height H, lesser than R, the height of the Each chunk is a full tree rooted at height H, lesser than R, the height of the
tree root. Because our MMR is append-only, each chunk is guaranteed to never tree root. Because our MMR is append-only, each chunk is guaranteed to never
@ -197,7 +197,7 @@ contains the top nodes (above H) in the MMR as well as the leftover nodes on
its right side. its right side.
In the example above, we have 2 chunks X[A,B] and Y[C,D] and a root chunk In the example above, we have 2 chunks X[A,B] and Y[C,D] and a root chunk
G[M,E]. G[M,E]. The cutoff height H=1 and the root height R=3.
Note that each non-root chunk is a complete and fully valid MMR sum tree in Note that each non-root chunk is a complete and fully valid MMR sum tree in
itself. The the root chunk, with each chunk replaced with a single pruned itself. The the root chunk, with each chunk replaced with a single pruned
@ -209,16 +209,16 @@ size of the root chunk.
Assuming a cutoff height of H and a root height of R, the size (in nodes) of Assuming a cutoff height of H and a root height of R, the size (in nodes) of
each chunk is: each chunk is:
chunk_size = 2^(R+1)-1 chunk_size = 2^(H+1)-1
The maximum size of the root chunk is: The maximum size of the root chunk is:
root_size = 2^(R-H+1)-1 + 2^(R+1)-2 max_root_size = 2^(R-H)-1 + 2^(H+1)-2
If we set the cutoff height H=15 and assume a node size of 50 bytes, for a tree If we set the cutoff height H=15 and assume a node size of 50 bytes, for a tree
with a root at height 26 (capable of containing all Bitcoin UTXOs as this time) with a root at height 26 (capable of containing all Bitcoin UTXOs as this time)
we obtain a chunk size of about 3.3MB (without pruning) and a maximum root chunk we obtain a chunk size of about 3.3MB (without pruning) and a maximum root chunk
size of about 3.5MB. size of about 3.4MB.
### Tombstone Log ### Tombstone Log