zecfoundation
/
zebra
mirror of https://github.com/ZcashFoundation/zebra.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

fix(doc): Fix bugs in the lightwalletd database design (#3964) 

* Re-order column families in design in dependency order

* Minor RFC design tweaks and fixes

Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
This commit is contained in:
teor 2022-03-28 08:59:43 +10:00 committed by GitHub
parent dcade546c0
commit 7d4c92f7d6
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
1 changed files with 9 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

16
book/src/dev/rfcs/0005-state-updates.md
View File

@ -611,10 +611,10 @@ We use the following rocksdb column families:
| `hash_by_tx_loc` | `TransactionLocation` | `transaction::Hash` | Never |
| `tx_loc_by_hash` | `transaction::Hash` | `TransactionLocation` | Never |
| *Transparent* | | | |
| `utxo_by_out_loc` | `OutputLocation` | `Output \|\| AddressLocation` | Delete |
| `balance_by_transparent_addr` | `transparent::Address` | `Amount \|\| AddressLocation` | Update |
| `utxo_by_transparent_addr_loc` | `AddressLocation` | `AtLeastOne<OutputLocation>` | Up/Del |
| `tx_by_transparent_addr_loc` | `AddressLocation` | `AtLeastOne<TransactionLocation>` | Append |
| `utxo_by_out_loc` | `OutputLocation` | `Output \|\| AddressLocation` | Delete |
| `utxo_by_transparent_addr_loc` | `AddressLocation` | `Vec<OutputLocation>` | Up/Del |
| *Sprout* | | | |
| `sprout_nullifiers` | `sprout::Nullifier` | `()` | Never |
| `sprout_anchors` | `sprout::tree::Root` | `sprout::tree::NoteCommitmentTree` | Never |
@ -645,7 +645,7 @@ Block and Transaction Data:
- `AddressLocation`: the first `OutputLocation` used by a `transparent::Address`.
Always has the same value for each address, even if the first output is spent.
- `Utxo`: `Output`, derives extra fields from the `OutputLocation` key
- `AtLeastOne<T>`: `[T; AtLeastOne::len()]` (for known-size `T`)
- `AtLeastOne<T>` and `Vec<T>`: `[T; len()]` (for known-size `T`)
We use big-endian encoding for keys, to allow database index prefix searches.
@ -746,8 +746,9 @@ So they should not be used for consensus-critical checks.
Blocks can be re-created on request using the following process:
- Look up `height` in `height_by_hash`
- Get the block header for `height` from `block_header_by_height`
- Use a [`prefix_iterator`](https://docs.rs/rocksdb/0.17.0/rocksdb/struct.DBWithThreadMode.html#method.prefix_iterator)
to get each transaction with `height` from `tx_by_loc`
- Iterate from `TransactionIndex` 0,
to get each transaction with `height` from `tx_by_loc`,
stopping when there are no more transactions in the block
- Block headers are stored by height, not by hash. This has the downside that looking
up a block by hash requires an extra level of indirection. The upside is
@ -784,15 +785,16 @@ So they should not be used for consensus-critical checks.
- `utxo_by_transparent_addr_loc` stores unspent transparent output locations
by address. UTXO locations are appended by each block.
This list includes the `AddressLocation`, if it has not been spent.
(This duplicate data is small, and helps simplify the code.)
- When a block write deletes a UTXO from `utxo_by_out_loc`,
that UTXO location should be deleted from `utxo_by_transparent_addr_loc`.
The `OutputLocations` are in order, so the deleted UTXO can be found using a
[binary search](https://doc.rust-lang.org/std/vec/struct.Vec.html#method.binary_search).
This is an index optimisation, which does not affect query results.
- `tx_by_transparent_addr_loc` stores transaction locations by address.
This list includes transactions containing spent UTXOs.
It also includes the `TransactionLocation` from the `AddressLocation`.
It also includes the `TransactionLocation` of the transaction for the `AddressLocation`.
(This duplicate data is small, and helps simplify the code.)
- The `sprout_note_commitment_tree` stores the note commitment tree state