refactor database engine/options; add column descriptors

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

src/database/engine/db_opts.rs

@@ -0,0 +1,133 @@
+use std::{cmp, convert::TryFrom};
+
+use conduwuit::{utils, Config, Result};
+use rocksdb::{statistics::StatsLevel, Cache, DBRecoveryMode, Env, LogLevel, Options};
+
+use super::{cf_opts::cache_size, logger::handle as handle_log};
+
+/// Create database-wide options suitable for opening the database. This also
+/// sets our default column options in case of opening a column with the same
+/// resulting value. Note that we require special per-column options on some
+/// columns, therefor columns should only be opened after passing this result
+/// through cf_options().
+pub(crate) fn db_options(config: &Config, env: &Env, row_cache: &Cache) -> Result<Options> {
+	const DEFAULT_STATS_LEVEL: StatsLevel = if cfg!(debug_assertions) {
+		StatsLevel::ExceptDetailedTimers
+	} else {
+		StatsLevel::DisableAll
+	};
+
+	let mut opts = Options::default();
+
+	// Logging
+	set_logging_defaults(&mut opts, config);
+
+	// Processing
+	opts.set_max_background_jobs(num_threads::<i32>(config)?);
+	opts.set_max_subcompactions(num_threads::<u32>(config)?);
+	opts.set_avoid_unnecessary_blocking_io(true);
+	opts.set_max_file_opening_threads(0);
+
+	// IO
+	opts.set_atomic_flush(true);
+	opts.set_manual_wal_flush(true);
+	opts.set_enable_pipelined_write(false);
+	if config.rocksdb_direct_io {
+		opts.set_use_direct_reads(true);
+		opts.set_use_direct_io_for_flush_and_compaction(true);
+	}
+	if config.rocksdb_optimize_for_spinning_disks {
+		// speeds up opening DB on hard drives
+		opts.set_skip_checking_sst_file_sizes_on_db_open(true);
+		opts.set_skip_stats_update_on_db_open(true);
+		//opts.set_max_file_opening_threads(threads.try_into().unwrap());
+	}
+
+	// Blocks
+	opts.set_row_cache(row_cache);
+
+	// Files
+	opts.set_table_cache_num_shard_bits(7);
+	opts.set_wal_size_limit_mb(1024 * 1024 * 1024);
+	opts.set_max_total_wal_size(1024 * 1024 * 512);
+	opts.set_db_write_buffer_size(cache_size(config, 1024 * 1024 * 32, 1));
+
+	// Misc
+	opts.set_disable_auto_compactions(!config.rocksdb_compaction);
+	opts.create_missing_column_families(true);
+	opts.create_if_missing(true);
+
+	opts.set_statistics_level(match config.rocksdb_stats_level {
+		| 0 => StatsLevel::DisableAll,
+		| 1 => DEFAULT_STATS_LEVEL,
+		| 2 => StatsLevel::ExceptHistogramOrTimers,
+		| 3 => StatsLevel::ExceptTimers,
+		| 4 => StatsLevel::ExceptDetailedTimers,
+		| 5 => StatsLevel::ExceptTimeForMutex,
+		| 6_u8..=u8::MAX => StatsLevel::All,
+	});
+
+	opts.set_report_bg_io_stats(match config.rocksdb_stats_level {
+		| 0..=1 => false,
+		| 2_u8..=u8::MAX => true,
+	});
+
+	// Default: https://github.com/facebook/rocksdb/wiki/WAL-Recovery-Modes#ktoleratecorruptedtailrecords
+	//
+	// Unclean shutdowns of a Matrix homeserver are likely to be fine when
+	// recovered in this manner as it's likely any lost information will be
+	// restored via federation.
+	opts.set_wal_recovery_mode(match config.rocksdb_recovery_mode {
+		| 0 => DBRecoveryMode::AbsoluteConsistency,
+		| 1 => DBRecoveryMode::TolerateCorruptedTailRecords,
+		| 2 => DBRecoveryMode::PointInTime,
+		| 3 => DBRecoveryMode::SkipAnyCorruptedRecord,
+		| 4_u8..=u8::MAX => unimplemented!(),
+	});
+
+	// <https://github.com/facebook/rocksdb/wiki/Track-WAL-in-MANIFEST>
+	// "We recommend to set track_and_verify_wals_in_manifest to true for
+	// production, it has been enabled in production for the entire database cluster
+	// serving the social graph for all Meta apps."
+	opts.set_track_and_verify_wals_in_manifest(true);
+
+	opts.set_paranoid_checks(config.rocksdb_paranoid_file_checks);
+
+	opts.set_env(env);
+
+	Ok(opts)
+}
+
+fn set_logging_defaults(opts: &mut Options, config: &Config) {
+	let rocksdb_log_level = match config.rocksdb_log_level.as_ref() {
+		| "debug" => LogLevel::Debug,
+		| "info" => LogLevel::Info,
+		| "warn" => LogLevel::Warn,
+		| "fatal" => LogLevel::Fatal,
+		| _ => LogLevel::Error,
+	};
+
+	opts.set_log_level(rocksdb_log_level);
+	opts.set_max_log_file_size(config.rocksdb_max_log_file_size);
+	opts.set_log_file_time_to_roll(config.rocksdb_log_time_to_roll);
+	opts.set_keep_log_file_num(config.rocksdb_max_log_files);
+	opts.set_stats_dump_period_sec(0);
+
+	if config.rocksdb_log_stderr {
+		opts.set_stderr_logger(rocksdb_log_level, "rocksdb");
+	} else {
+		opts.set_callback_logger(rocksdb_log_level, &handle_log);
+	}
+}
+
+fn num_threads<T: TryFrom<usize>>(config: &Config) -> Result<T> {
+	const MIN_PARALLELISM: usize = 2;
+
+	let requested = if config.rocksdb_parallelism_threads != 0 {
+		config.rocksdb_parallelism_threads
+	} else {
+		utils::available_parallelism()
+	};
+
+	utils::math::try_into::<T, usize>(cmp::max(MIN_PARALLELISM, requested))
+}