update generalized-state-compression.md

content/courses/state-compression/generalized-state-compression.md

@@ -14,7 +14,7 @@ description:
 - State Compression on Solana is most commonly used for compressed NFTs, but
  it's possible to use it for arbitrary data
 - State Compression lowers the amount of data you have to store onchain by
- leveraging Merkle trees.
+ leveraging [Merkle trees](https://en.wikipedia.org/wiki/Merkle_tree).
 - Merkle trees store a single hash that represents an entire binary tree of
  hashes. Each leaf on a Merkle tree is a hash of that leaf's data.
 - Concurrent Merkle trees are a specialized version of Merkle trees that allow
@@ -263,18 +263,48 @@ a simple messaging program, your `Message` struct might look as follows:
 ```rust
 #[derive(AnchorSerialize)]
 pub struct MessageLog {
- leaf_node: [u8; 32], // The leaf node hash
- from: Pubkey, // Pubkey of the message sender
- to: Pubkey,  // Pubkey of the message recipient
- message: String, // The message to send
+ pub leaf_node: [u8; 32], // leaf node hash
+ pub from: Pubkey,
+  pub to: Pubkey,
+ pub message: String, // message to send
 }
 
 impl MessageLog {
  // Constructs a new message log from given leaf node and message
  pub fn new(leaf_node: [u8; 32], from: Pubkey, to: Pubkey, message: String) -> Self {
- Self { leaf_node, from, to, message }
+ Self {
+ leaf_node,
+ from,
+ to,
+ message,
+ }
  }
 }
+
+#[derive(Accounts)]
+pub struct MessageAccounts<'info> {
+ // The payer for the transaction
+ #[account(mut)]
+ pub owner: Signer<'info>,
+
+ // The pda authority for the merkle tree, only used for signing
+ #[account(
+ seeds = [merkle_tree.key().as_ref()],
+ bump,
+ )]
+ pub tree_authority: SystemAccount<'info>,
+
+ // The merkle tree account
+ /// CHECK: This account is validated by the spl account compression program
+ #[account(mut)]
+ pub merkle_tree: UncheckedAccount<'info>,
+
+ // The noop program to log data
+ pub log_wrapper: Program<'info, Noop>,
+
+ // The spl account compression program
+ pub compression_program: Program<'info, SplAccountCompression>,
+}
 ```
 
 To be abundantly clear, **this is not an account that you will be able to read
@@ -311,18 +341,19 @@ pub fn create_messages_tree(
 ) -> Result<()> {
  // Get the address for the Merkle tree account
  let merkle_tree = ctx.accounts.merkle_tree.key();
+
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[
  &[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+ &[ctx.bumps.tree_authority], // The bump seed for the pda
  ],
  ];
 
  // Create cpi context for init_empty_merkle_tree instruction.
  let cpi_ctx = CpiContext::new_with_signer(
  ctx.accounts.compression_program.to_account_info(), // The spl account compression program
- Initialize {
+ spl_account_compression::cpi::accounts::Initialize {
  authority: ctx.accounts.tree_authority.to_account_info(), // The authority for the Merkle tree, using a PDA
  merkle_tree: ctx.accounts.merkle_tree.to_account_info(), // The Merkle tree account to be initialized
  noop: ctx.accounts.log_wrapper.to_account_info(), // The noop program to log data
@@ -331,7 +362,7 @@ pub fn create_messages_tree(
  );
 
  // CPI to initialize an empty Merkle tree with given max depth and buffer size
- init_empty_merkle_tree(cpi_ctx, max_depth, max_buffer_size)?;
+ spl_account_compression::cpi::init_empty_merkle_tree(cpi_ctx, max_depth, max_buffer_size)?;
 
  Ok(())
 }
@@ -367,19 +398,29 @@ like this:
 pub fn append_message(ctx: Context<MessageAccounts>, message: String) -> Result<()> {
  // Hash the message + whatever key should have update authority
  let leaf_node = keccak::hashv(&[message.as_bytes(), ctx.accounts.sender.key().as_ref()]).to_bytes();
- // Create a new "message log" using the leaf node hash, sender, receipient, and message
- let message_log = MessageLog::new(leaf_node.clone(), ctx.accounts.sender.key().clone(), ctx.accounts.receipient.key().clone(), message);
+
+ // Create a new "message log" using the leaf node hash, sender, recipient, and message
+ let message_log = MessageLog::new(
+ leaf_node.clone(),
+ ctx.accounts.sender.key().clone(),
+ ctx.accounts.recipient.key().clone(),
+ message
+ );
+
  // Log the "message log" data using noop program
  wrap_application_data_v1(message_log.try_to_vec()?, &ctx.accounts.log_wrapper)?;
+
  // Get the address for the Merkle tree account
  let merkle_tree = ctx.accounts.merkle_tree.key();
+
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[
  &[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+ &[ctx.bumps.tree_authority], // The bump seed for the pda
  ],
  ];
+
  // Create a new cpi context and append the leaf node to the Merkle tree.
  let cpi_ctx = CpiContext::new_with_signer(
  ctx.accounts.compression_program.to_account_info(), // The spl account compression program
@@ -390,8 +431,10 @@ pub fn append_message(ctx: Context<MessageAccounts>, message: String) -> Result<
  },
  signer_seeds // The seeds for pda signing
  );
+
  // CPI to append the leaf node to the Merkle tree
  append(cpi_ctx, leaf_node)?;
+
  Ok(())
 }
 ```
@@ -442,17 +485,14 @@ pub fn update_message(
  old_message: String,
  new_message: String
 ) -> Result<()> {
- let old_leaf = keccak
- ::hashv(&[old_message.as_bytes(), ctx.accounts.sender.key().as_ref()])
- .to_bytes();
-
+ let old_leaf = keccak::hashv(&[old_message.as_bytes(), ctx.accounts.sender.key().as_ref()]).to_bytes();
  let merkle_tree = ctx.accounts.merkle_tree.key();
 
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[
  &[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+ &[ctx.bumps.tree_authority], // The bump seed for the pda
  ],
  ];
 
@@ -462,7 +502,6 @@ pub fn update_message(
  msg!("Messages are the same!");
  return Ok(());
  }
-
  let cpi_ctx = CpiContext::new_with_signer(
  ctx.accounts.compression_program.to_account_info(), // The spl account compression program
  VerifyLeaf {
@@ -474,12 +513,16 @@ pub fn update_message(
  verify_leaf(cpi_ctx, root, old_leaf, index)?;
  }
 
- let new_leaf = keccak
- ::hashv(&[new_message.as_bytes(), ctx.accounts.sender.key().as_ref()])
- .to_bytes();
+ let new_leaf = keccak::hashv(&[new_message.as_bytes(), ctx.accounts.sender.key().as_ref()]).to_bytes();
 
  // Log out for indexers
- let message_log = MessageLog::new(new_leaf.clone(), ctx.accounts.sender.key().clone(), ctx.accounts.recipient.key().clone(), new_message);
+ let message_log = MessageLog::new(
+ new_leaf.clone(),
+ ctx.accounts.sender.key().clone(),
+ ctx.accounts.recipient.key().clone(),
+ new_message
+ );
+
  // Log the "message log" data using noop program
  wrap_application_data_v1(message_log.try_to_vec()?, &ctx.accounts.log_wrapper)?;
 
@@ -494,7 +537,7 @@ pub fn update_message(
  },
  signer_seeds // The seeds for pda signing
  );
- // CPI to append the leaf node to the Merkle tree
+ // CPI to replace the leaf node in the Merkle tree
  replace_leaf(cpi_ctx, root, old_leaf, new_leaf, index)?;
  }
 
@@ -628,7 +671,7 @@ app.
 Start by initializing an Anchor program:
 
 ```bash
-anchor init compressed-notes
+anchor init compressed-notes --template=multiple
 ```
 
 We’ll be using the `spl-account-compression` crate with the `cpi` feature
@@ -638,7 +681,7 @@ enabled. Let’s add it as a dependency in `programs/compressed-notes/Cargo.toml
 [dependencies]
 anchor-lang = "0.28.0"
 spl-account-compression = { version="0.2.0", features = ["cpi"] }
-solana-program = "1.16.0"
+solana-program = ">=1.18.11,<=2"
 ```
 
 We’ll be testing locally but we need both the Compression program and the Noop
@@ -806,7 +849,7 @@ pub mod compressed_notes {
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[&[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+  &[ctx.bumps.tree_authority], // The bump seed for the pda
  ]];
 
  // Create cpi context for init_empty_merkle_tree instruction.
@@ -878,7 +921,7 @@ pub mod compressed_notes {
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[&[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+  &[ctx.bumps.tree_authority], // The bump seed for the pda
  ]];
  // Create a new cpi context and append the leaf node to the Merkle tree.
  let cpi_ctx = CpiContext::new_with_signer(
@@ -958,7 +1001,7 @@ pub mod compressed_notes {
  // Define the seeds for pda signing
  let signer_seeds: &[&[&[u8]]] = &[&[
  merkle_tree.as_ref(), // The address of the Merkle tree account as a seed
- &[*ctx.bumps.get("tree_authority").unwrap()], // The bump seed for the pda
+  &[ctx.bumps.tree_authority], // The bump seed for the pda
  ]];
 
  // Verify Leaf
@@ -1019,6 +1062,12 @@ install it:
 yarn add @solana/spl-account-compression
 ```
 
+or
+
+```bash
+npm install @solana/spl-account-compression
+```
+
 Next, we’re going to give you the contents of a utility file we’ve created to
 make testing easier. Create a `utils.ts` file in the `tests` directory, add in
 the below, then we’ll explain it.