Enable bgsave config to be read from the cfg file

Now, the `bgsave` key can be read and parsed from the config file

examples/config-files/badcfg2.toml

@@ -0,0 +1,8 @@
+# This is a bad toml file since it contains an invalid value of `every` in BGSAVE
+[server]
+host = "127.0.0.1"
+port = 2003
+
+[bgsave]
+every = 0.5 # Not possible!
+enabled = true

examples/config-files/template.toml

@@ -12,8 +12,9 @@ port = 2003 # The port to which you want TDB to bind to
 # Set `noart` to true if you want to disable terminal artwork
 noart = false
 
-# This key is *REQUIRED*
+# This key is *OPTIONAL*, but will be required post 0.5.0
 [bgsave]
 # Run `BGSAVE` `every` seconds. For example, setting this to 60 will cause BGSAVE to run
 # every 1 minute
+enabled = true
 every = 120

server/src/config/mod.rs

@@ -35,6 +35,26 @@ use toml;
 pub struct Config {
     /// The `server` key
     server: ServerConfig,
+    /// The `bgsave` key
+    bgsave: Option<BGSave>,
+}
+
+/// This struct represents the `bgsave` key in the TOML file
+///
+/* TODO(@ohsayan): As of now, we will keep this optional, but post 0.5.0,
+ * we will make it compulsory (so that we don't break semver)
+ * See the link below for more details:
+ * https://github.com/terrabasedb/terrabasedb/issues/21#issuecomment-693217709
+ */
+#[derive(Deserialize, Debug, PartialEq)]
+pub struct BGSave {
+    /// Whether BGSAVE is enabled or not
+    ///
+    /// If `enabled` is set to true, and an `every` field is also present, we will
+    /// display a warning, that the `every` key is unused
+    enabled: bool,
+    /// Every 'n' seconds
+    every: u64,
 }
 
 /// This struct represents the `server` key in the TOML file
@@ -60,6 +80,10 @@ pub struct ParsedConfig {
     port: u16,
     /// If `noart` is set to true, no terminal artwork should be displayed
     noart: bool,
+    /// Whether BGSAVE is enabled or not
+    bgsave_enabled: bool,
+    /// Run `BGSAVE` every _n_ seconds
+    bgsave_duration: u64,
 }
 
 impl ParsedConfig {
@@ -77,6 +101,11 @@ impl ParsedConfig {
     /// Create a `ParsedConfig` instance from a `Config` object, which is a parsed
     /// TOML file (represented as an object)
     const fn from_config(cfg: Config) -> Self {
+        let (bgsave_enabled, bgsave_duration) = if let Some(bgsave) = cfg.bgsave {
+            (bgsave.enabled, bgsave.every)
+        } else {
+            (true, 120)
+        };
         ParsedConfig {
             host: cfg.server.host,
             port: cfg.server.port,
@@ -85,6 +114,8 @@ impl ParsedConfig {
             } else {
                 false
             },
+            bgsave_enabled,
+            bgsave_duration,
         }
     }
     /// Create a new file
@@ -98,26 +129,44 @@ impl ParsedConfig {
             host: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             port,
             noart: false,
+            bgsave_enabled: true,
+            bgsave_duration: 120,
         }
     }
     /// Create a new `ParsedConfig` with the default `port` and `noart` settngs
     /// and a supplied `host`
     pub const fn default_with_host(host: IpAddr) -> Self {
-        ParsedConfig::new(host, 2003, false)
+        ParsedConfig::new(host, 2003, false, true, 120)
     }
     /// Create a new `ParsedConfig` with all the fields
-    pub const fn new(host: IpAddr, port: u16, noart: bool) -> Self {
-        ParsedConfig { host, port, noart }
+    pub const fn new(
+        host: IpAddr,
+        port: u16,
+        noart: bool,
+        bgsave_enabled: bool,
+        bgsave_duration: u64,
+    ) -> Self {
+        ParsedConfig {
+            host,
+            port,
+            noart,
+            bgsave_enabled,
+            bgsave_duration,
+        }
     }
-    /// Create a default `ParsedConfig` with:
+    /// Create a default `ParsedConfig` with the following setup defaults:
     /// - `host`: 127.0.0.1
     /// - `port` : 2003
     /// - `noart` : false
+    /// - `bgsave_enabled` : true
+    /// - `bgsave_duration` : 120
     pub const fn default() -> Self {
         ParsedConfig {
             host: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             port: 2003,
             noart: false,
+            bgsave_enabled: true,
+            bgsave_duration: 120,
         }
     }
     /// Return a (host, port) tuple which can be bound to with `TcpListener`
@@ -140,14 +189,7 @@ fn test_config_toml_okayport() {
     "#
     .to_owned();
     let cfg = ParsedConfig::new_from_toml_str(file).unwrap();
-    assert_eq!(
-        cfg,
-        ParsedConfig {
-            port: 2003,
-            host: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
-            noart: false,
-        }
-    );
+    assert_eq!(cfg, ParsedConfig::default(),);
 }
 /// Gets a `toml` file from `WORKSPACEROOT/examples/config-files`
 #[cfg(test)]
@@ -258,6 +300,8 @@ fn test_config_file_noart() {
             port: 2003,
             host: IpAddr::V4(Ipv4Addr::new(127, 0, 0, 1)),
             noart: true,
+            bgsave_enabled: true,
+            bgsave_duration: 120,
         }
     );
 }
@@ -273,6 +317,24 @@ fn test_config_file_ipv6() {
             port: 2003,
             host: IpAddr::V6(Ipv6Addr::new(0, 0, 0, 0, 0, 0, 0, 0x1)),
             noart: false,
+            bgsave_enabled: true,
+            bgsave_duration: 120,
         }
     );
 }
+
+#[test]
+#[cfg(test)]
+fn test_config_file_template() {
+    let file = get_toml_from_examples_dir("template.toml".to_owned()).unwrap();
+    let cfg = ParsedConfig::new_from_toml_str(file).unwrap();
+    assert_eq!(cfg, ParsedConfig::default());
+}
+
+#[test]
+#[cfg(test)]
+fn test_config_file_bad_bgsave_section() {
+    let file = get_toml_from_examples_dir("badcfg2.toml".to_owned()).unwrap();
+    let cfg = ParsedConfig::new_from_toml_str(file);
+    assert!(cfg.is_err());
+}