boatramp_node/

handlers.rs

//! WebAssembly handler-runtime assembly (moved from the binary — node-library N2b).
//!
//! Builds `boatramp_server::HandlerRuntime` from `[handlers]` config: the wasmtime
//! engine plus the libsql `sql` binding (single-node file per site, a cluster sqld
//! namespace, or an external Postgres/MySQL). Handlers-gated; a lean node gets a
//! disabled runtime. Lives here (not the backend-agnostic `boatramp-server`)
//! because it drives the concrete `boatramp-storage` SQL backends.

#[cfg(feature = "handlers")]
use crate::error::Error;
use crate::error::Result;
use boatramp_core::kv::KvStore;
use std::path::Path;
use std::sync::Arc;

/// Build the WebAssembly handler runtime. With the `handlers` feature it wraps a
/// wasmtime engine serving the kv/blob bindings from the server's own backends;
/// otherwise it is an empty placeholder (handler routes fall through to static).
#[cfg(feature = "handlers")]
pub fn build_handler_runtime(
    kv: Arc<dyn KvStore>,
    storage: Arc<dyn boatramp_core::Storage>,
    data_dir: &Path,
    handlers_cfg: Option<&crate::config::HandlersConfig>,
    messaging_override: Option<Arc<dyn boatramp_core::messaging::Messaging>>,
    max_blob_bytes: u64,
    max_component_bytes: u64,
) -> Result<boatramp_server::HandlerRuntime> {
    // Opt-in pooling allocator: faster instantiation, large
    // up-front virtual reservation — benchmark before enabling.
    let limits = boatramp_handlers::Limits::default();
    let engine = if handlers_cfg.is_some_and(|h| h.pooling) {
        boatramp_handlers::HandlerEngine::with_pooling(limits, 64)?
    } else {
        boatramp_handlers::HandlerEngine::new(limits, 64)?
    };
    let sql = build_sql_backends(handlers_cfg.and_then(|h| h.bindings.sql.as_ref()), data_dir)?;
    // The `wasi:messaging` substrate: single-node `LogMessaging` over the same
    // blob/KV backends by default, or the cluster coordinator when one is given.
    let messaging: Arc<dyn boatramp_core::messaging::Messaging> = messaging_override
        .unwrap_or_else(|| {
            Arc::new(boatramp_core::messaging::LogMessaging::new(
                storage.clone(),
                kv.clone(),
            ))
        });
    let runtime =
        boatramp_server::HandlerRuntime::new(engine, kv, storage, Some(sql), Some(messaging));
    // Apply the posture's host-side blob cap + component-size cap.
    runtime.set_max_blob_bytes(max_blob_bytes);
    runtime.set_max_component_bytes(max_component_bytes);
    Ok(runtime)
}

/// Resolve the `[handlers.bindings.sql]` config to the libsql SQL backend.
/// Single-node by default (an embedded file per site under `<data-dir>`); set
/// `url` to bind a shared sqld cluster (a namespace per site). Either way sites
/// get a real database boundary — see `boatramp_core::sql`.
#[cfg(feature = "handlers")]
fn build_sql_backends(
    cfg: Option<&crate::config::SqlBindingConfig>,
    data_dir: &Path,
) -> Result<Arc<dyn boatramp_core::sql::SqlBackends>> {
    let resolve_env = |var: &Option<String>| -> Result<Option<String>> {
        match var {
            Some(var) => Ok(Some(
                std::env::var(var).map_err(|_| Error::SqlEnvUnset(var.clone()))?,
            )),
            None => Ok(None),
        }
    };

    let backend = match cfg.and_then(|c| c.url.as_ref()) {
        // Cluster: a sqld namespace per site. Auth tokens come from the
        // environment, never the config file.
        Some(url) => {
            let cfg = cfg.expect("url implies cfg");
            let admin_url = cfg.admin_url.as_ref().ok_or(Error::SqlAdminUrlRequired)?;
            let token = resolve_env(&cfg.token_env)?.unwrap_or_default();
            let admin_token = resolve_env(&cfg.admin_token_env)?;
            let backends = boatramp_storage::LibsqlSqlBackends::remote(
                url.clone(),
                admin_url.clone(),
                token,
                admin_token,
            );
            // Optional read-replica routing: reads → replica, writes → primary.
            match &cfg.replica_url {
                Some(replica_url) => backends.with_read_replica(replica_url.clone()),
                None => backends,
            }
        }
        // Single-node: an embedded file per site.
        None => {
            let dir = cfg
                .and_then(|c| c.dir.clone())
                .unwrap_or_else(|| data_dir.join("handlers-sql"));
            boatramp_storage::LibsqlSqlBackends::local(dir)
        }
    };
    // Preview SQL policy (how preview deployments relate to live data).
    let preview_mode = match cfg.and_then(|c| c.preview_mode.as_deref()) {
        None | Some("empty") => boatramp_core::sql::PreviewSqlMode::Empty,
        Some("branch") => boatramp_core::sql::PreviewSqlMode::Branch,
        Some("shared") => boatramp_core::sql::PreviewSqlMode::Shared,
        Some(other) => return Err(Error::UnknownPreviewMode(other.to_string())),
    };
    let preview_init = match cfg.and_then(|c| c.preview_init.as_ref()) {
        Some(path) => {
            Some(
                std::fs::read_to_string(path).map_err(|err| Error::PreviewInitRead {
                    path: path.clone(),
                    source: err,
                })?,
            )
        }
        None => None,
    };
    let default: Arc<dyn boatramp_core::sql::SqlBackends> =
        Arc::new(backend.with_preview_policy(preview_mode, preview_init));

    // Overlay any external (bring-your-own) databases on the managed default.
    // With none configured the default is returned unchanged (and a build
    // without an external SQL engine never has to link the sqlx path).
    let databases = cfg.map(|c| &c.databases);
    if databases.is_none_or(std::collections::BTreeMap::is_empty) {
        return Ok(default);
    }
    let databases = databases.expect("checked non-empty above");

    #[cfg(any(feature = "sql-postgres", feature = "sql-mysql"))]
    {
        use boatramp_storage::sql_sqlx::{
            connect, CompositeSqlBackends, ExternalSqlKind, ExternalSqlOptions,
        };
        let mut composite = CompositeSqlBackends::new(default);
        for (name, db) in databases {
            let kind = ExternalSqlKind::parse(&db.kind).ok_or_else(|| Error::SqlExternalKind {
                name: name.clone(),
                kind: db.kind.clone(),
            })?;
            if db.url_env.trim().is_empty() {
                return Err(Error::SqlExternalUrlEnvMissing(name.clone()));
            }
            // The connection URL(s) are secrets, resolved from the environment.
            let url =
                std::env::var(&db.url_env).map_err(|_| Error::SqlEnvUnset(db.url_env.clone()))?;
            let read_url = match &db.read_url_env {
                Some(var) => Some(std::env::var(var).map_err(|_| Error::SqlEnvUnset(var.clone()))?),
                None => None,
            };
            let opts = ExternalSqlOptions::new(url)
                .with_read_url(read_url)
                .with_max_connections(db.pool_max)
                .read_only(db.read_only)
                .with_connect_timeout(db.connect_timeout_secs.map(std::time::Duration::from_secs));
            let external = connect(kind, &opts).map_err(|source| Error::SqlExternalConnect {
                name: name.clone(),
                source,
            })?;
            composite = composite.with_external(name.clone(), external, db.allow_preview);
        }
        Ok(Arc::new(composite))
    }
    #[cfg(not(any(feature = "sql-postgres", feature = "sql-mysql")))]
    {
        let name = databases.keys().next().cloned().unwrap_or_default();
        Err(Error::SqlExternalUnavailable(name))
    }
}

#[cfg(not(feature = "handlers"))]
pub fn build_handler_runtime(
    _kv: Arc<dyn KvStore>,
    _storage: Arc<dyn boatramp_core::Storage>,
    _data_dir: &Path,
    _handlers_cfg: Option<&crate::config::HandlersConfig>,
    _messaging_override: Option<Arc<dyn boatramp_core::messaging::Messaging>>,
    _max_blob_bytes: u64,
    _max_component_bytes: u64,
) -> Result<boatramp_server::HandlerRuntime> {
    Ok(boatramp_server::HandlerRuntime::disabled())
}