indexer-database

main.rs

fn main()

returns -> Result which can be - empty result, programming successful exit of the program - error

Description - THe main function is the starting point of the indexer. It takes no parameters and is responsible for initializing the indexer data environment and calling other functions.

Initializing Data Environment - Before calling the functions which actually indexes the transactions we need to set some data which are required for these functions to work properly.

List of required data -

1. contract_metadata

The contract_metadata is a struct of type ContractMetaData which contains the basic data fetched from our Mongodb collection contracts.

The ContractMetaData type:

pub struct ContractMetaData {
    pub contract_address: String,
    pub read_abi_from: String,
    pub chain_id: String,
    pub function_of_interest: String,
    pub contract_name: String,
    pub contract_description: String,
    pub contract_slug: String,
    pub method_of_interest:std::collections::HashSet<String>,
    pub methods:Document,
}

Key points

• contract_address: Address of the contract that we will index
• read_abi_from: Address of the contract from where we get the Application Binary Interface (ABI) of the project smart contract. This is usually required if the above contract_address is a proxy contract, then we cannot use that ABI, instead we get it from read_abi_from, which will be given by the user.
• chain_id: Id of the chain where the contract is deployed
• function_of_interest: A list of functions which will be indexed if a transaction happens on anyone of them

2. contract_result

This is tuple of contract_metadata, contract_fetched_abi, and contract_abi. The function that returns the data for this comes from utils.rs -> utils_contract_data(contract_slug)????.

3. contract_abi

This contains the ABI of the contract that is on the second index position of contract_result. At first the smart contract ABI is a String type, stored in contract_fetched_abi variable. We convert the String type to

utils.rs