refactor database engine/options; add column descriptors

Signed-off-by: Jason Volk <jason@zemos.net>

src/database/engine/open.rs

@@ -0,0 +1,121 @@
+use std::{
+	collections::BTreeSet,
+	path::Path,
+	sync::{atomic::AtomicU32, Arc},
+};
+
+use conduwuit::{debug, debug_warn, implement, info, warn, Result};
+use rocksdb::{ColumnFamilyDescriptor, Options};
+
+use super::{
+	cf_opts::cf_options, db_opts::db_options, descriptor::Descriptor, repair::repair, Db, Engine,
+};
+use crate::{or_else, Context};
+
+#[implement(Engine)]
+#[tracing::instrument(skip_all)]
+pub(crate) async fn open(ctx: Arc<Context>, desc: &[Descriptor]) -> Result<Arc<Self>> {
+	let server = &ctx.server;
+	let config = &server.config;
+	let path = &config.database_path;
+
+	let db_opts = db_options(
+		config,
+		&ctx.env.lock().expect("environment locked"),
+		&ctx.row_cache.lock().expect("row cache locked"),
+	)?;
+
+	let cfds = Self::configure_cfds(&ctx, &db_opts, desc)?;
+	let num_cfds = cfds.len();
+	debug!("Configured {num_cfds} column descriptors...");
+
+	let load_time = std::time::Instant::now();
+	if config.rocksdb_repair {
+		repair(&db_opts, &config.database_path)?;
+	}
+
+	debug!("Opening database...");
+	let db = if config.rocksdb_read_only {
+		Db::open_cf_descriptors_read_only(&db_opts, path, cfds, false)
+	} else if config.rocksdb_secondary {
+		Db::open_cf_descriptors_as_secondary(&db_opts, path, path, cfds)
+	} else {
+		Db::open_cf_descriptors(&db_opts, path, cfds)
+	}
+	.or_else(or_else)?;
+
+	info!(
+		columns = num_cfds,
+		sequence = %db.latest_sequence_number(),
+		time = ?load_time.elapsed(),
+		"Opened database."
+	);
+
+	Ok(Arc::new(Self {
+		read_only: config.rocksdb_read_only,
+		secondary: config.rocksdb_secondary,
+		corks: AtomicU32::new(0),
+		pool: ctx.pool.clone(),
+		db,
+		ctx,
+	}))
+}
+
+#[implement(Engine)]
+#[tracing::instrument(name = "configure", skip_all)]
+fn configure_cfds(
+	ctx: &Arc<Context>,
+	db_opts: &Options,
+	desc: &[Descriptor],
+) -> Result<Vec<ColumnFamilyDescriptor>> {
+	let server = &ctx.server;
+	let config = &server.config;
+	let path = &config.database_path;
+	let existing = Self::discover_cfs(path, db_opts);
+	debug!(
+		"Found {} existing columns; have {} described columns",
+		existing.len(),
+		desc.len()
+	);
+
+	existing
+		.iter()
+		.filter(|&name| name != "default")
+		.filter(|&name| !desc.iter().any(|desc| desc.name == name))
+		.for_each(|name| {
+			debug_warn!("Found unknown column {name:?} in database which will not be opened.");
+		});
+
+	desc.iter()
+		.filter(|desc| !existing.contains(desc.name))
+		.for_each(|desc| {
+			debug!(
+				"Creating new column {:?} which was not found in the existing database.",
+				desc.name,
+			);
+		});
+
+	let cfopts: Vec<_> = desc
+		.iter()
+		.map(|desc| cf_options(ctx, db_opts.clone(), desc))
+		.collect::<Result<_>>()?;
+
+	let cfds: Vec<_> = desc
+		.iter()
+		.map(|desc| desc.name)
+		.map(ToOwned::to_owned)
+		.zip(cfopts.into_iter())
+		.map(|(name, opts)| ColumnFamilyDescriptor::new(name, opts))
+		.collect();
+
+	Ok(cfds)
+}
+
+#[implement(Engine)]
+#[tracing::instrument(name = "discover", skip_all)]
+fn discover_cfs(path: &Path, opts: &Options) -> BTreeSet<String> {
+	Db::list_cf(opts, path)
+		.unwrap_or_default()
+		.into_iter()
+		.collect::<BTreeSet<_>>()
+}