gracefully ignore unknown columns; add dropped flag in descriptor

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

src/database/engine/cf_opts.rs

@@ -72,7 +72,7 @@ fn descriptor_cf_options(
 }
 
 fn set_table_options(opts: &mut Options, desc: &Descriptor, cache: Option<&Cache>) -> Result {
-	let mut table = table_options(desc);
+	let mut table = table_options(desc, cache.is_some());
 	if let Some(cache) = cache {
 		table.set_block_cache(cache);
 	} else {
@@ -119,13 +119,13 @@ fn uc_options(desc: &Descriptor) -> UniversalCompactOptions {
 	opts
 }
 
-fn table_options(desc: &Descriptor) -> BlockBasedOptions {
+fn table_options(desc: &Descriptor, has_cache: bool) -> BlockBasedOptions {
 	let mut opts = BlockBasedOptions::default();
 
 	opts.set_block_size(desc.block_size);
 	opts.set_metadata_block_size(desc.index_size);
 
-	opts.set_cache_index_and_filter_blocks(true);
+	opts.set_cache_index_and_filter_blocks(has_cache);
 	opts.set_pin_top_level_index_and_filter(false);
 	opts.set_pin_l0_filter_and_index_blocks_in_cache(false);
 	opts.set_partition_pinning_tier(BlockBasedPinningTier::None);
@@ -144,10 +144,13 @@ fn table_options(desc: &Descriptor) -> BlockBasedOptions {
 }
 
 fn get_cache(ctx: &Context, desc: &Descriptor) -> Option<Cache> {
-	let config = &ctx.server.config;
+	if desc.dropped {
+		return None;
+	}
 
 	// Some cache capacities are overriden by server config in a strange but
 	// legacy-compat way
+	let config = &ctx.server.config;
 	let cap = match desc.name {
 		| "eventid_pduid" => Some(config.eventid_pdu_cache_capacity),
 		| "eventid_shorteventid" => Some(config.eventidshort_cache_capacity),

src/database/engine/descriptor.rs

@@ -14,6 +14,7 @@ pub(crate) enum CacheDisp {
 #[derive(Debug, Clone)]
 pub(crate) struct Descriptor {
 	pub(crate) name: &'static str,
+	pub(crate) dropped: bool,
 	pub(crate) cache_disp: CacheDisp,
 	pub(crate) key_size_hint: Option<usize>,
 	pub(crate) val_size_hint: Option<usize>,
@@ -39,6 +40,7 @@ pub(crate) struct Descriptor {
 
 pub(crate) static BASE: Descriptor = Descriptor {
 	name: EMPTY,
+	dropped: false,
 	cache_disp: CacheDisp::Shared,
 	key_size_hint: None,
 	val_size_hint: None,

src/database/engine/open.rs

@@ -4,11 +4,15 @@ use std::{
 	sync::{atomic::AtomicU32, Arc},
 };
 
-use conduwuit::{debug, debug_warn, implement, info, warn, Result};
+use conduwuit::{debug, implement, info, warn, Result};
 use rocksdb::{ColumnFamilyDescriptor, Options};
 
 use super::{
-	cf_opts::cf_options, db_opts::db_options, descriptor::Descriptor, repair::repair, Db, Engine,
+	cf_opts::cf_options,
+	db_opts::db_options,
+	descriptor::{self, Descriptor},
+	repair::repair,
+	Db, Engine,
 };
 use crate::{or_else, Context};
 
@@ -72,38 +76,46 @@ fn configure_cfds(
 	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
+	let creating = desc.iter().filter(|desc| !existing.contains(desc.name));
+
+	let missing = 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.");
-		});
+		.filter(|&name| !desc.iter().any(|desc| desc.name == name));
 
-	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,
-			);
-		});
+	debug!(
+		existing = existing.len(),
+		described = desc.len(),
+		missing = missing.clone().count(),
+		creating = creating.clone().count(),
+		"Discovered database columns"
+	);
+
+	missing.clone().for_each(|name| {
+		debug!("Found unrecognized column {name:?} in existing database.");
+	});
+
+	creating.map(|desc| desc.name).for_each(|name| {
+		debug!("Creating new column {name:?} not previously found in existing database.");
+	});
+
+	let missing_descriptors = missing
+		.clone()
+		.map(|_| Descriptor { dropped: true, ..descriptor::BASE });
 
 	let cfopts: Vec<_> = desc
 		.iter()
-		.map(|desc| cf_options(ctx, db_opts.clone(), desc))
+		.cloned()
+		.chain(missing_descriptors)
+		.map(|ref desc| cf_options(ctx, db_opts.clone(), desc))
 		.collect::<Result<_>>()?;
 
 	let cfds: Vec<_> = desc
 		.iter()
 		.map(|desc| desc.name)
 		.map(ToOwned::to_owned)
+		.chain(missing.cloned())
 		.zip(cfopts.into_iter())
 		.map(|(name, opts)| ColumnFamilyDescriptor::new(name, opts))
 		.collect();