| I think of PDAs as a hybrid between Accounts and UTXOs. They are account-like in some ways and UTXO-like in some ways. | |
| PDAs use the terminology of the account system. (account-like) | |
| PDAs are declared and mutated like storage items or storage maps. (account-like) | |
| Each PDA has its own id/address that is determined at creation time based on seed info like a signer or tx hash. (utxo-like) | |
| Transactions explicitly state which PDAs/UTXOs they access so the TPU knows which are parallelizable and which must be serialized without caring anything about the execution logic. (utxo-like) | |
| Transactions state which PDAs/UTXOs are read-only / peeks vs which ones they will mutate / consume (utxo-like) | |
| PDAs are mutable and reusable and keep the same storage address the whole time. (account-like) |
This document contains corrections to mistakes in the UTXO wallet assignmetn for PBA's Hong Kong cohort.
The doc comments on the transaction type incorrectly state that the output value should exceed the input value. This is exactly backwards. Luckily this is only a comment mistake, the tests are correct and this should not affect your programmin experience at all.
/// A Bonecoin Transaction
Joshy's reflections on the Blockchain and Smart Contracts hybrid module as delivered during week 2 of PBA3 in Berkeley 2023.
For the UCB cohort we largely re-wrote the smart contracts module, moving away from a narrow focus on ink! to a much broader perspective across the blockchain space and historically. We also integrated this content tightly with the existing blockchain module to create a week-long hybrid module. The motivation is that the idea of a smart contract predates blockchain and was a goal well before it was realized on blockchains.
I think this ordering makes a lot of sense and should be kept. However, I think the idea of one massive module can be improved upon. Thank you Nuke and Pauline for the opportunity to teach it as a monolith until the proper delineations became clear.
Grandpa is a Byzantine fault tolerant blockchain finality gadget (formal spec). This collaborative board game allows players to learn and practice the Grandpa protocol while also having fun together.
| // SPDX-License-Identifier: GPL-3.0-only | |
| pragma solidity >=0.8.0; | |
| contract Incrementor { | |
| uint private value; | |
| address private last_caller; | |
| function inc() public { | |
| value += 1; | |
| last_caller = msg.sender; |
| $ curl <endpoint> -H "Content-Type:application/json;charset=utf-8" -d '{ | |
| "jsonrpc":"2.0", | |
| "id":1, | |
| "method":"author_removeExtrinsic", | |
| "params": ["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 |
| $ ./target/release/polkadot --chain rococo-local-cfde-real-overseer.json --alice --tmp --discover-local | |
| 2020-11-18 10:09:03 Parity Polkadot | |
| 2020-11-18 10:09:03 ✌️ version 0.8.26-cfde0767-x86_64-linux-gnu | |
| 2020-11-18 10:09:03 ❤️ by Parity Technologies <admin@parity.io>, 2017-2020 | |
| 2020-11-18 10:09:03 📋 Chain specification: Rococo Local Testnet | |
| 2020-11-18 10:09:03 🏷 Node name: Alice | |
| 2020-11-18 10:09:03 👤 Role: AUTHORITY | |
| 2020-11-18 10:09:03 💾 Database: RocksDb at /tmp/substrateytfeEs/chains/rococo_local_testnet/db | |
| 2020-11-18 10:09:03 ⛓ Native runtime: rococo-10 (parity-rococo-v1-0.tx0.au0) | |
| 2020-11-18 10:09:05 🔨 Initializing Genesis block/state (state: 0x10aa…7cc8, header-hash: 0x7488…9bca) |
| joshy@pop-os:~/ProgrammingProjects/substrate-node-template$ ./target/release/node-template --chain local --alice --base-path /tmp/alice --force-authoring -ltxpool=trace | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner Substrate Node | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner ✌️ version 2.0.0-rc6-fcd577e-x86_64-linux-gnu | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner ❤️ by Substrate DevHub <https://github.com/substrate-developer-hub>, 2017-2020 | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner 📋 Chain specification: Local Testnet | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner 🏷 Node name: Alice | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner 👤 Role: AUTHORITY | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner 💾 Database: RocksDb at /tmp/alice/chains/local_testnet/db | |
| 2020-09-09 11:27:10.617 main INFO sc_cli::runner ⛓ Native runtime: node-template-1 (node-template-1.tx1.au1) | |
| 2020-09-09 11:27:10.718 main INFO sc_service::client::client 🔨 Initializing Genesis block/state (state: 0x6325…a0b3, h |
| $ cargo build --release -p rococo-collator | |
| Downloaded crypto-mac v0.8.0 | |
| Downloaded block-buffer v0.9.0 | |
| Downloaded opaque-debug v0.3.0 | |
| Downloaded aes v0.4.0 | |
| Downloaded generic-array v0.14.3 | |
| Downloaded ghash v0.3.0 | |
| Downloaded digest v0.9.0 | |
| Downloaded cpuid-bool v0.1.2 | |
| Downloaded stream-cipher v0.4.1 |
| $ cargo check | |
| Compiling utxo-workshop v2.0.0-alpha.5 (/home/joshy/ProgrammingProjects/utxo-workshop/node) | |
| Checking utxo-runtime v2.0.0-alpha.6 (/home/joshy/ProgrammingProjects/utxo-workshop/runtime) | |
| Checking sha3pow v2.0.0-alpha.6 (/home/joshy/ProgrammingProjects/utxo-workshop/node/sha3pow) | |
| error[E0599]: no method named `build` found for struct `sc_service::builder::ServiceBuilder<sp_runtime::generic::block::Block<sp_runtime::generic::header::Header<u32, sp_runtime::traits::BlakeTwo256>, sp_runtime::OpaqueExtrinsic>, utxo_runtime::RuntimeApi, sc_client::client::Client<sc_client_db::Backend<sp_runtime::generic::block::Block<sp_runtime::generic::header::Header<u32, sp_runtime::traits::BlakeTwo256>, sp_runtime::OpaqueExtrinsic>>, sc_client::call_executor::LocalCallExecutor<sc_client_db::Backend<sp_runtime::generic::block::Block<sp_runtime::generic::header::Header<u32, sp_runtime::traits::BlakeTwo256>, sp_runtime::OpaqueExtrinsic>>, sc_executor::native_executor::NativeExecutor<service::Executor>>, sp_ |