Address Lookup Table decoder

carbon-address-lookup-table-decoder decodes the instructions and accounts of the Address Lookup Table program (AddressLookupTab1e1111111111111111111111111): 5 instructions, 1 account type. It is generated with Codama from the program's IDL; see decoders for how decoders plug into a pipeline.

Other core and SPL decoders: Associated Token Account, SPL Memo, SPL Name Service, SPL Token, Stake Program, System Program, Token-2022. To decode several in one pipeline, see core and SPL program decoders.

The serde feature derives Serialize/Deserialize on every type, postgres adds tables and processors for Postgres, and graphql adds a schema for the GraphQL server.

Usage#

This program crawls recent Address Lookup Table transactions from the public RPC and prints every decoded ExtendLookupTable instruction. Add the dependencies:

cargo add carbon-core@2.0.0 carbon-address-lookup-table-decoder@2.0.0 carbon-rpc-transaction-crawler-datasource@2.0.0 carbon-log-metrics@2.0.0 env_logger tokio --features tokio/full

use {
    carbon_core::{
        error::CarbonResult, instruction::InstructionProcessorInputType, pipeline::Pipeline,
        processor::Processor,
    },
    carbon_log_metrics::LogMetrics,
    carbon_address_lookup_table_decoder::{
        instructions::AddressLookupTableInstruction, AddressLookupTableDecoder, PROGRAM_ID,
    },
    carbon_rpc_transaction_crawler_datasource::{ConnectionConfig, Filters, RpcTransactionCrawler},
    std::sync::Arc,
};

#[tokio::main]
async fn main() -> CarbonResult<()> {
    env_logger::init();

    // Fetches the program's recent transactions over JSON-RPC, newest first.
    let datasource = RpcTransactionCrawler::new(
        "https://api.mainnet-beta.solana.com".to_string(),
        PROGRAM_ID,
        ConnectionConfig::default(),
        Filters::new(None, None, None),
        None,
    );

    Pipeline::builder()
        .datasource(datasource)
        .metrics(Arc::new(LogMetrics::new()))
        .instruction(AddressLookupTableDecoder, InstructionLogger)
        .build()?
        .run()
        .await
}

struct InstructionLogger;

impl Processor<InstructionProcessorInputType<'_, AddressLookupTableInstruction>> for InstructionLogger {
    async fn process(
        &mut self,
        input: &InstructionProcessorInputType<'_, AddressLookupTableInstruction>,
    ) -> CarbonResult<()> {
        let signature = input.metadata.transaction_metadata.signature;
        if let AddressLookupTableInstruction::ExtendLookupTable { data, accounts, .. } = input.decoded_instruction {
            println!("extend_lookup_table {signature}: {data:?} address={}", accounts.address);
        }
        Ok(())
    }
}

RUST_LOG=info cargo run

Each ExtendLookupTable instruction prints one line with the transaction signature and the decoded ExtendLookupTable data. The public endpoint rate-limits requests, so the first lines can take a while; use your own RPC URL for anything beyond a test. See stream with RPC for the crawler options.

Decode accounts#

The transaction crawler emits transactions only. To decode accounts, use a datasource that emits account updates. This program subscribes to the program's accounts with programSubscribe on the public WebSocket endpoint and prints every decoded AddressLookupTable account as it changes. Add the datasource and the Solana RPC types it takes:

cargo add carbon-rpc-program-subscribe-datasource@2.0.0 solana-client@4.2.2

use {
    carbon_core::{
        account::AccountProcessorInputType, error::CarbonResult, pipeline::Pipeline,
        processor::Processor,
    },
    carbon_log_metrics::LogMetrics,
    carbon_address_lookup_table_decoder::{
        accounts::AddressLookupTableAccount, AddressLookupTableDecoder, PROGRAM_ID,
    },
    carbon_rpc_program_subscribe_datasource::{Filters, RpcProgramSubscribe},
    solana_client::rpc_config::{RpcAccountInfoConfig, RpcProgramAccountsConfig, UiAccountEncoding},
    std::sync::Arc,
};

#[tokio::main]
async fn main() -> CarbonResult<()> {
    env_logger::init();

    // Streams every change to an account owned by the program (programSubscribe).
    let config = RpcProgramAccountsConfig {
        account_config: RpcAccountInfoConfig {
            encoding: Some(UiAccountEncoding::Base64),
            ..Default::default()
        },
        ..Default::default()
    };
    let datasource = RpcProgramSubscribe::new(
        "wss://api.mainnet-beta.solana.com".to_string(),
        Filters::new(PROGRAM_ID, Some(config)),
    );

    Pipeline::builder()
        .datasource(datasource)
        .metrics(Arc::new(LogMetrics::new()))
        .account(AddressLookupTableDecoder, AccountLogger)
        .build()?
        .run()
        .await
}

struct AccountLogger;

impl Processor<AccountProcessorInputType<'_, AddressLookupTableAccount>> for AccountLogger {
    async fn process(
        &mut self,
        input: &AccountProcessorInputType<'_, AddressLookupTableAccount>,
    ) -> CarbonResult<()> {
        let AddressLookupTableAccount::AddressLookupTable(address_lookup_table) = &input.decoded_account.data;
        println!("address_lookup_table {}: {address_lookup_table:?}", input.metadata.pubkey);
        Ok(())
    }
}

RUST_LOG=info cargo run

Each update to a AddressLookupTable account prints its address and decoded fields; the program runs until you stop it. Cargo resolves solana-client to 4.2.2, the exact version the datasource pins, so both use the same RpcProgramAccountsConfig type. To load every existing account once instead of streaming changes, see load account state.

Instructions#

Variants of AddressLookupTableInstruction. Each is AddressLookupTableInstruction::<Variant> { program_id, data, accounts }, where data and accounts are the types listed under the variant, exported from carbon_address_lookup_table_decoder::instructions. Discriminators are the leading bytes of the instruction data, in hex.

How an instruction decodes. The decoder returns a variant only when all of these hold; otherwise the instruction is skipped and no processor is called:

1. The instruction's program ID is AddressLookupTab1e1111111111111111111111111.
2. The data starts with the variant's discriminator, and the rest deserializes into its data type.
3. The instruction has at least as many accounts as the variant requires (the "Required accounts" count under each variant).

Accounts. They are matched by position, in the order listed. An account marked optional is None only when the instruction ends before it; Anchor programs pass the program ID as a placeholder for an omitted optional account, so check for Some(PROGRAM_ID) too. Accounts after the listed ones are in accounts.remaining as AccountMetas. The decoder doesn't record whether an account signed or was writable: read that from input.raw_instruction.accounts[i].is_signer and .is_writable, which follow the same order. It doesn't check signer, writable, owner or PDA constraints either; the program enforced those when the transaction executed, so a decoded instruction from a successful transaction already satisfied them.

CloseLookupTable#

Discriminator 04000000 · data CloseLookupTable · accounts CloseLookupTableInstructionAccounts.

No data fields.

Required accounts: 3; extras go to remaining.

Fields of CloseLookupTableInstructionAccounts, in account order:

CreateLookupTable#

Discriminator 00000000 · data CreateLookupTable · accounts CreateLookupTableInstructionAccounts.

Required accounts: 4; extras go to remaining.

Fields of CreateLookupTableInstructionAccounts, in account order:

DeactivateLookupTable#

Discriminator 03000000 · data DeactivateLookupTable · accounts DeactivateLookupTableInstructionAccounts.

No data fields.

Required accounts: 2; extras go to remaining.

Fields of DeactivateLookupTableInstructionAccounts, in account order:

ExtendLookupTable#

Discriminator 02000000 · data ExtendLookupTable · accounts ExtendLookupTableInstructionAccounts.

Required accounts: 4; extras go to remaining.

Fields of ExtendLookupTableInstructionAccounts, in account order:

FreezeLookupTable#

Discriminator 01000000 · data FreezeLookupTable · accounts FreezeLookupTableInstructionAccounts.

No data fields.

Required accounts: 2; extras go to remaining.

Fields of FreezeLookupTableInstructionAccounts, in account order:

Accounts#

Variants of AddressLookupTableAccount. Each wraps a boxed struct from carbon_address_lookup_table_decoder::accounts::<module>. decode_account only considers accounts owned by PROGRAM_ID and returns the first variant that matches.

AddressLookupTable#

Discriminator 01000000 · accounts::address_lookup_table::AddressLookupTable.