remove extra advanced config and make db_cache_capacity_mb total

DEPLOY.md

@@ -111,26 +111,8 @@ trusted_servers = ["matrix.org"]
 
 address = "127.0.0.1" # This makes sure Conduit can only be reached using the reverse proxy
 
-## sqlite
-
-# The amount of memory that the database will use, with the following formula;
-# (db_cache_capacity * (sqlite_read_pool_size + 1)), in bytes
-#db_cache_capacity = 1073741824 # in bytes, 1024 * 1024 * 1024
-
-# How many permanent read connections will be open to the database,
-# increase this if you see "creating spillover reader" in your logs.
-#sqlite_read_pool_size = 2 # default: max(cpu core count, 1)
-
-# If the database WAL (conduit.db-wal file) should be cleaned on a timer.
-#sqlite_wal_clean_timer = false
-
-# How many seconds should pass before the WAL clean task should fire.
-# Note: Is dependant on sqlite_wal_clean_timer being true.
-#sqlite_wal_clean_second_interval = 60
-
-# How long the WAL clean task should (in seconds) try to wait while
-# getting exclusive access to the database (before giving up).
-#sqlite_wal_clean_second_timeout = 2
+# The total amount of memory that the database will use.
+#db_cache_capacity_mb = 10
 ```
 
 ## Setting the correct file permissions

conduit-example.toml

@@ -43,23 +43,5 @@ address = "127.0.0.1" # This makes sure Conduit can only be reached using the re
 
 proxy = "none" # more examples can be found at src/database/proxy.rs:6
 
-## sqlite
-
-# The amount of memory that the database will use, with the following formula;
-# (db_cache_capacity * (sqlite_read_pool_size + 1)), in bytes
-#db_cache_capacity = 1073741824 # in bytes, 1024 * 1024 * 1024
-
-# How many permanent read connections will be open to the database,
-# increase this if you see "creating spillover reader" in your logs.
-#sqlite_read_pool_size = 2 # default: max(cpu core count, 1)
-
-# If the database WAL (conduit.db-wal file) should be cleaned on a timer.
-#sqlite_wal_clean_timer = false
-
-# How many seconds should pass before the WAL clean task should fire.
-# Note: Is dependant on sqlite_wal_clean_timer being true.
-#sqlite_wal_clean_second_interval = 60
-
-# How long the WAL clean task should (in seconds) try to wait while
-# getting exclusive access to the database (before giving up).
-#sqlite_wal_clean_second_timeout = 2
+# The total amount of memory that the database will use.
+#db_cache_capacity_mb = 10

debian/postinst

@@ -77,26 +77,8 @@ max_request_size = 20_000_000 # in bytes
 #log = "info,state_res=warn,rocket=off,_=off,sled=off"
 #workers = 4 # default: cpu core count * 2
 
-## sqlite
-
-# The amount of memory that the database will use, with the following formula;
-# (db_cache_capacity * (sqlite_read_pool_size + 1)), in bytes
-#db_cache_capacity = 1073741824 # in bytes, 1024 * 1024 * 1024
-
-# How many permanent read connections will be open to the database,
-# increase this if you see "creating spillover reader" in your logs.
-#sqlite_read_pool_size = 2 # default: max(cpu core count, 1)
-
-# If the database WAL (conduit.db-wal file) should be cleaned on a timer.
-#sqlite_wal_clean_timer = false
-
-# How many seconds should pass before the WAL clean task should fire.
-# Note: Is dependant on sqlite_wal_clean_timer being true.
-#sqlite_wal_clean_second_interval = 60
-
-# How long the WAL clean task should (in seconds) try to wait while
-# getting exclusive access to the database (before giving up).
-#sqlite_wal_clean_second_timeout = 2
+# The total amount of memory that the database will use.
+#db_cache_capacity_mb = 10
 EOF
     fi
     ;;

src/database.rs

@@ -43,8 +43,8 @@ use self::proxy::ProxyConfig;
 pub struct Config {
     server_name: Box<ServerName>,
     database_path: String,
-    #[serde(default = "default_db_cache_capacity")]
-    db_cache_capacity: u32,
+    #[serde(default = "default_db_cache_capacity_mb")]
+    db_cache_capacity_mb: f64,
     #[serde(default = "default_sqlite_read_pool_size")]
     sqlite_read_pool_size: usize,
     #[serde(default = "false_fn")]
@@ -105,8 +105,8 @@ fn true_fn() -> bool {
     true
 }
 
-fn default_db_cache_capacity() -> u32 {
-    1024 * 1024 * 1024
+fn default_db_cache_capacity_mb() -> f64 {
+    10.0
 }
 
 fn default_sqlite_read_pool_size() -> usize {

src/database/abstraction/sled.rs

@@ -14,7 +14,7 @@ impl DatabaseEngine for Engine {
         Ok(Arc::new(Engine(
             sled::Config::default()
                 .path(&config.database_path)
-                .cache_capacity(config.db_cache_capacity as u64)
+                .cache_capacity((config.db_cache_capacity_mb * 1024 * 1024) as u64)
                 .use_compression(true)
                 .open()?,
         )))

src/database/abstraction/sqlite.rs

@@ -58,7 +58,13 @@ impl<'a> Deref for HoldingConn<'a> {
 }
 
 impl Pool {
-    fn new<P: AsRef<Path>>(path: P, num_readers: usize, cache_size: u32) -> Result<Self> {
+    fn new<P: AsRef<Path>>(path: P, num_readers: usize, total_cache_size_mb: f64) -> Result<Self> {
+        // calculates cache-size per permanent connection
+        // 1. convert MB to KiB
+        // 2. divide by permanent connections
+        // 3. round down to nearest integer
+        let cache_size: u32 = ((total_cache_size_mb * 1024.0) / (num_readers + 1) as f64) as u32;
+
         let writer = Mutex::new(Self::prepare_conn(&path, Some(cache_size))?);
 
         let mut readers = Vec::new();
@@ -128,7 +134,7 @@ impl DatabaseEngine for Engine {
         let pool = Pool::new(
             Path::new(&config.database_path).join("conduit.db"),
             config.sqlite_read_pool_size,
-            config.db_cache_capacity / 1024, // bytes -> kb
+            config.db_cache_capacity_mb,
         )?;
 
         pool.write_lock()