Add tx blob hash table

Cargo.lock

@@ -910,6 +910,7 @@ dependencies = [
  "monero-serai",
  "rayon",
  "serde",
+ "sha3",
  "tempfile",
  "thiserror",
  "tokio",

storage/txpool/Cargo.toml

@@ -29,6 +29,7 @@ bytemuck                 = { workspace = true, features = ["must_cast", "derive"
 bitflags                 = { workspace = true, features = ["std", "serde", "bytemuck"] }
 thiserror                = { workspace = true }
 hex                      = { workspace = true }
+sha3                     = { workspace = true, features = ["std"] }
 
 tower                    = { workspace = true, optional = true }
 rayon                    = { workspace = true, optional = true }

storage/txpool/src/free.rs

@@ -1,9 +1,11 @@
 //! General free functions (related to the tx-pool database).
 
 //---------------------------------------------------------------------------------------------------- Import
+use sha3::{Digest, Sha3_256};
+
 use cuprate_database::{ConcreteEnv, Env, EnvInner, InitError, RuntimeError, TxRw};
 
-use crate::{config::Config, tables::OpenTables};
+use crate::{config::Config, tables::OpenTables, types::TransactionBlobHash};
 
 //---------------------------------------------------------------------------------------------------- Free functions
 /// Open the txpool database using the passed [`Config`].
@@ -60,3 +62,15 @@ pub fn open(config: Config) -> Result<ConcreteEnv, InitError> {
 
     Ok(env)
 }
+
+/// Calculate the transaction blob hash.
+///
+/// This value is supposed to be quick to compute just based of the tx-blob without needing to parse the tx.
+///
+/// The exact way the hash is calculated is not stable and is subject to change, as such it should not be exposed
+/// as a way to interact with Cuprate externally.
+pub fn transaction_blob_hash(tx_blob: &[u8]) -> TransactionBlobHash {
+    let mut hasher = Sha3_256::new();
+    hasher.update(tx_blob);
+    hasher.finalize().into()
+}

storage/txpool/src/ops/tx_write.rs

@@ -8,6 +8,7 @@ use cuprate_database::{DatabaseRw, RuntimeError, StorableVec};
 use cuprate_types::TransactionVerificationData;
 
 use crate::{
+    free::transaction_blob_hash,
     ops::{
         key_images::{add_tx_key_images, remove_tx_key_images},
         TxPoolWriteError,
@@ -56,6 +57,10 @@ pub fn add_transaction(
     let kis_table = tables.spent_key_images_mut();
     add_tx_key_images(&tx.tx.prefix().inputs, &tx.tx_hash, kis_table)?;
 
+    // Add the blob hash to table 4.
+    let blob_hash = transaction_blob_hash(&tx.tx_blob);
+    tables.known_blob_hashes_mut().put(&blob_hash, &())?;
+
     Ok(())
 }
 
@@ -79,5 +84,9 @@ pub fn remove_transaction(
     let kis_table = tables.spent_key_images_mut();
     remove_tx_key_images(&tx.prefix().inputs, kis_table)?;
 
+    // Remove the blob hash from table 4.
+    let blob_hash = transaction_blob_hash(&tx_blob);
+    tables.known_blob_hashes_mut().delete(&blob_hash)?;
+
     Ok(())
 }

storage/txpool/src/service/interface.rs

@@ -26,10 +26,7 @@ pub enum TxpoolReadRequest {
 #[expect(clippy::large_enum_variant)]
 pub enum TxpoolReadResponse {
     /// A response containing the raw bytes of a transaction.
-    TxBlob {
-        tx_blob: Vec<u8>,
-        state_stem: bool,
-    },
+    TxBlob { tx_blob: Vec<u8>, state_stem: bool },
     /// A response of [`TransactionVerificationData`].
     TxVerificationData(TransactionVerificationData),
     /// The response for [`TxpoolReadRequest::FilterKnownTxBlobHashes`].

storage/txpool/src/tables.rs

@@ -16,7 +16,9 @@
 //! accessing _all_ tables defined here at once.
 use cuprate_database::{define_tables, StorableVec};
 
-use crate::types::{KeyImage, RawCachedVerificationState, TransactionHash, TransactionInfo};
+use crate::types::{
+    KeyImage, RawCachedVerificationState, TransactionBlobHash, TransactionHash, TransactionInfo,
+};
 
 define_tables! {
     /// Serialized transaction blobs.
@@ -41,5 +43,9 @@ define_tables! {
     ///
     /// This table contains the spent key images from all transactions in the pool.
     3 => SpentKeyImages,
-    KeyImage => TransactionHash
+    KeyImage => TransactionHash,
+
+    /// Transaction blob hashes that are in the pool.
+    4 => KnownBlobHashes,
+    TransactionBlobHash => (),
 }