community: spaces, an owner-signed roster with epochs, a bounded window of signed lines, bodies sealed to a rotating key when private

crates/space-contract/src/lib.rs

@@ -0,0 +1,118 @@
+//! The SoulStream Space contract. Multi-writer: the owner offers
+//! checkpoints, members offer messages; `persona_state::space::merge_space`
+//! is the bouncer (owner signature, roster, dedup, per-author fairness,
+//! the window). Deterministic by construction, so every delivery order
+//! converges; a state that does not merge to itself is refused.
+//!
+//! Build: `cargo build --release --target wasm32-unknown-unknown` in this
+//! directory; copy `target/wasm32-unknown-unknown/release/
+//! soulstream_space_contract.wasm` to `src-tauri/assets/space_contract.wasm`
+//! and re-pin the code hash in `src-tauri/src/spaces.rs`.
+
+use freenet_stdlib::prelude::*;
+use persona_state::space as t;
+
+pub struct Contract;
+
+fn parts(parameters: &Parameters<'static>) -> Result<([u8; 32], [u8; 16]), ContractError> {
+    t::params_parts(parameters.as_ref())
+        .ok_or_else(|| ContractError::Other("params are not family+owner+space".into()))
+}
+
+fn collect<'a>(state: &'a State<'static>, data: &'a [UpdateData<'static>]) -> (Vec<&'a [u8]>, bool) {
+    let mut candidates: Vec<&[u8]> = Vec::new();
+    if !state.as_ref().is_empty() {
+        candidates.push(state.as_ref());
+    }
+    let mut any_parse = false;
+    let mut push = |b: &'a [u8]| {
+        if !b.is_empty() {
+            any_parse |= bincode::deserialize::<t::SpaceState>(b).is_ok();
+            candidates.push(b);
+        }
+    };
+    for ud in data {
+        match ud {
+            UpdateData::State(s) => push(s.as_ref()),
+            UpdateData::Delta(d) => push(d.as_ref()),
+            UpdateData::StateAndDelta { state, delta } => {
+                push(state.as_ref());
+                push(delta.as_ref());
+            }
+            _ => {}
+        }
+    }
+    (candidates, any_parse)
+}
+
+#[contract]
+impl ContractInterface for Contract {
+    fn validate_state(
+        parameters: Parameters<'static>,
+        state: State<'static>,
+        _related: RelatedContracts<'static>,
+    ) -> Result<ValidateResult, ContractError> {
+        let (owner, space_id) = parts(&parameters)?;
+        let bytes = state.as_ref();
+        if bytes.is_empty() {
+            return Ok(ValidateResult::Valid);
+        }
+        if bytes.len() > t::MAX_STATE_BYTES {
+            return Err(ContractError::Other(format!(
+                "space state {} bytes over cap {}",
+                bytes.len(),
+                t::MAX_STATE_BYTES
+            )));
+        }
+        let merged = t::merge_space(&owner, &space_id, &[bytes]);
+        let canon = bincode::serialize(&merged).map_err(|e| ContractError::Deser(e.to_string()))?;
+        if canon != bytes {
+            return Err(ContractError::Other(
+                "state is not canonical (unsigned, off-roster, or over the window)".into(),
+            ));
+        }
+        Ok(ValidateResult::Valid)
+    }
+
+    fn update_state(
+        parameters: Parameters<'static>,
+        state: State<'static>,
+        data: Vec<UpdateData<'static>>,
+    ) -> Result<UpdateModification<'static>, ContractError> {
+        let (owner, space_id) = parts(&parameters)?;
+        let (candidates, any_parse) = collect(&state, &data);
+        if !any_parse && !data.is_empty() {
+            return Err(ContractError::InvalidUpdate);
+        }
+        let merged = t::merge_space(&owner, &space_id, &candidates);
+        let bytes = bincode::serialize(&merged).map_err(|e| ContractError::Deser(e.to_string()))?;
+        Ok(UpdateModification::valid(State::from(bytes)))
+    }
+
+    fn summarize_state(
+        parameters: Parameters<'static>,
+        state: State<'static>,
+    ) -> Result<StateSummary<'static>, ContractError> {
+        let _ = parts(&parameters)?;
+        if state.as_ref().is_empty() {
+            return Ok(StateSummary::from(Vec::new()));
+        }
+        Ok(StateSummary::from(blake3::hash(state.as_ref()).as_bytes().to_vec()))
+    }
+
+    fn get_state_delta(
+        parameters: Parameters<'static>,
+        state: State<'static>,
+        summary: StateSummary<'static>,
+    ) -> Result<StateDelta<'static>, ContractError> {
+        let _ = parts(&parameters)?;
+        if state.as_ref().is_empty() {
+            return Ok(StateDelta::from(Vec::new()));
+        }
+        if summary.as_ref() == blake3::hash(state.as_ref()).as_bytes() {
+            Ok(StateDelta::from(Vec::new()))
+        } else {
+            Ok(StateDelta::from(state.as_ref().to_vec()))
+        }
+    }
+}