Indexer

The indexer program can be used to index Solana addresses into serial lists for fast and efficient off-chain lookups.

Get Started

```yaml

Cargo.toml

[dependencies] cronos-indexer = { version = "0.0.1" } ```

Instructions

create_list

• Initializes a new List account.
• Errors if:
  • The list already exists for the given owner and namespace.

delete_list

• Closes an List account.
• Returns rent to owner.

push_element

• Initializes a new Element account.
• Appends the element to the index's data structure.
• Errors if:
  • The list is already at max capacity.

pop_element

• Closes an Element account.
• Removes the element from the index's data structure.
• Returns rent to owner.

State

List

• Metadata for managing a list of addresses.
• PDA is a hash of the owner's address and a custom namespace address.

Element

• An address value with a position in a list.
• PDA is a hash of the list's address and the pointer's position.

Examples

These examples are for Solana programs that need to create and manage their own on-chain lists. These examples show an Anchor program that has a singleton "authority account" for signing instructions on behalf of the program.

Create a list

Here is an example instruction create_my_list that creates an list owned by the program.

```rs // createmylist.rs

use { crate::state::, anchor_lang::{prelude::, solanaprogram::systemprogram}, std::mem::size_of, };

[derive(Accounts)]

[instruction(bump: u8)]

pub struct CreateMyList<'info> { #[account( mut, seeds = [SEED_AUTHORITY], bump = authority.bump, owner = crate::ID )] pub authority: Account<'info, Authority>,

#[account(mut)]
pub list: AccountInfo<'info>,

#[account(address = list_program::ID)]
pub list_program: Program<'info, list_program::program::ListProgram>,

#[account(
    init,
    payer = signer,
    space = 8 + size_of<Namespace>()
)]
pub namespace: Account<'info, Namespace>

#[account(mut)]
pub signer: Signer<'info>,

#[account(address = system_program::ID)]
pub system_program: Program<'info, System>,

}

pub fn handler(ctx: Context, bump: u8) -> ProgramResult { // Get accounts. let authority = &ctx.accounts.authority; let list = &ctx.accounts.list; let listprogram = &ctx.accounts.listprogram; let namespace = &ctx.accounts.namespace; let signer = &ctx.accounts.signer; let systemprogram = &ctx.accounts.systemprogram;

// Create a list owned by the program authority.
list_program::cpi::create_index(
    CpiContext::new_with_signer(
        list_program.to_account_info(),
        list_program::cpi::accounts::CreateList {
            index: index.to_account_info(),
            namespace: namespace.to_account_info(),
            owner: authority.to_account_info(),
            payer: signer.to_account_info(),
            system_program: system_program.to_account_info(),
        },
        &[&[SEED_AUTHORITY, &[authority.bump]]],
    ),
    bump,
)

} ```

Push an element

Here is an example instruction push_my_element that adds an element to a list owned by the program.

```rs // createmypointer.rs

use { crate::state::, anchor_lang::{prelude::, solanaprogram::systemprogram}, std::mem::size_of, };

[derive(Accounts)]

[instruction(reference: Pubkey, bump: u8)]

pub struct CreateMyPointer<'info> { #[account( mut, seeds = [SEED_AUTHORITY], bump = authority.bump, owner = crate::ID )] pub authority: Account<'info, Authority>,

#[account()]
pub element: AccountInfo<'info>,

#[account(
  mut,
  constraint = list.owner == authority.key(),
  constraint = list.namespace == namespace.key(),
  owner = list_program.key()
)]
pub list: AccountInfo<'info>,

#[account(address = list_program::ID)]
pub list_program: Program<'info, list_program::program::IndexProgram>,

#[account()]
pub namespace: Account<'info, Namespace>

#[account(mut)]
pub signer: Signer<'info>,

#[account(address = system_program::ID)]
pub system_program: Program<'info, System>,

}

pub fn handler( ctx: Context, reference: Pubkey, bump: u8, ) -> ProgramResult { // Get accounts. let authority = &ctx.accounts.authority; let element = &ctx.accounts.element; let list = &ctx.accounts.list; let listprogram = &ctx.accounts.listprogram; let signer = &ctx.accounts.signer; let systemprogram = &ctx.accounts.systemprogram;

// Add the reference address into the list.
list_program::cpi::push_element(
    CpiContext::new_with_signer(
        list_program.to_account_info(),
        list_program::cpi::accounts::PushElement {
            element: element.to_account_info(),
            list: list.to_account_info(),
            owner: authority.to_account_info(),
            payer: signer.to_account_info(),
            system_program: system_program.to_account_info(),
        },
        &[&[SEED_AUTHORITY, &[authority.bump]]],
    ),
    reference,
    bump,
)

} ```