feat: implement backup layers using meta manager

src/backup/manager/config.rs

@@ -0,0 +1,46 @@
+use std::error::Error;
+use std::fmt;
+use std::str::FromStr;
+
+#[derive(Clone, Debug)]
+pub struct ManagerConfig {
+    pub name: String,
+    pub frequency: u32,
+    pub chain_len: u64,
+    pub chains: u64,
+}
+
+#[derive(Debug)]
+pub struct ParseManagerConfigErr;
+
+impl Error for ParseManagerConfigErr {}
+
+impl fmt::Display for ParseManagerConfigErr {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "parse manager config err")
+    }
+}
+
+impl FromStr for ManagerConfig {
+    type Err = ParseManagerConfigErr;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        let splits: Vec<&str> = s.split(',').collect();
+
+        if let [name, frequency, chains, chain_len] = splits[..] {
+            let name: String = name.parse().map_err(|_| ParseManagerConfigErr)?;
+            let frequency: u32 = frequency.parse().map_err(|_| ParseManagerConfigErr)?;
+            let chains: u64 = chains.parse().map_err(|_| ParseManagerConfigErr)?;
+            let chain_len: u64 = chain_len.parse().map_err(|_| ParseManagerConfigErr)?;
+
+            Ok(ManagerConfig {
+                name,
+                chains,
+                chain_len,
+                frequency,
+            })
+        } else {
+            Err(ParseManagerConfigErr)
+        }
+    }
+}

src/backup/manager/meta.rs

@@ -0,0 +1,83 @@
+use super::{Manager, ManagerConfig};
+use chrono::Utc;
+use serde::Deserialize;
+use serde::Serialize;
+use std::io;
+use std::path::PathBuf;
+
+pub struct MetaManager<T>
+where
+    T: Clone + Serialize + for<'de> Deserialize<'de>,
+{
+    backup_dir: PathBuf,
+    config_dir: PathBuf,
+    world_dir: PathBuf,
+    default_metadata: T,
+    managers: Vec<Manager<T>>,
+}
+
+impl<T> MetaManager<T>
+where
+    T: Clone + Serialize + for<'de> Deserialize<'de>,
+{
+    pub fn new<P1: Into<PathBuf>, P2: Into<PathBuf>, P3: Into<PathBuf>>(
+        backup_dir: P1,
+        config_dir: P2,
+        world_dir: P3,
+        default_metadata: T,
+    ) -> Self {
+        MetaManager {
+            backup_dir: backup_dir.into(),
+            config_dir: config_dir.into(),
+            world_dir: world_dir.into(),
+            default_metadata,
+            managers: Vec::new(),
+        }
+    }
+
+    pub fn add(&mut self, config: &ManagerConfig) -> io::Result<()> {
+        // Backup dir itself should exist, but we control its contents, so we can create
+        // separate directories for each layer
+        let path = self.backup_dir.join(&config.name);
+        std::fs::create_dir(&path)?;
+
+        let mut manager = Manager::new(
+            path,
+            self.config_dir.clone(),
+            self.world_dir.clone(),
+            self.default_metadata.clone(),
+            config.chain_len,
+            config.chains,
+            chrono::Duration::minutes(config.frequency.into()),
+        );
+        manager.load()?;
+        self.managers.push(manager);
+
+        Ok(())
+    }
+
+    pub fn add_all(&mut self, configs: &Vec<ManagerConfig>) -> io::Result<()> {
+        for config in configs {
+            self.add(config)?;
+        }
+
+        Ok(())
+    }
+
+    pub fn next_scheduled_time(&self) -> Option<chrono::DateTime<Utc>> {
+        self.managers.iter().map(|m| m.next_scheduled_time()).min()
+    }
+
+    pub fn perform_backup_cycle(&mut self) -> io::Result<()> {
+        if let Some(manager) = self
+            .managers
+            .iter_mut()
+            .min_by_key(|m| m.next_scheduled_time())
+        {
+            manager.create_backup()?;
+            manager.remove_old_backups()
+        } else {
+            Ok(())
+        }
+    }
+}

src/backup/manager/mod.rs

@@ -1,3 +1,9 @@
+mod config;
+mod meta;
+
+pub use config::ManagerConfig;
+pub use meta::MetaManager;
+
 use super::Backup;
 use chrono::Utc;
 use serde::Deserialize;
@@ -26,7 +32,6 @@ where
 {
     const METADATA_FILE: &str = "alex.json";
 
-    /// Initialize a new instance of a `BackupManager`.
     pub fn new<P1: Into<PathBuf>, P2: Into<PathBuf>, P3: Into<PathBuf>>(
         backup_dir: P1,
         config_dir: P2,

src/backup/mod.rs

@@ -1,9 +1,11 @@
 mod delta;
-mod manager;
+pub mod manager;
 mod path;
 
 use delta::Delta;
 pub use manager::Manager;
+pub use manager::ManagerConfig;
+pub use manager::MetaManager;
 
 use chrono::Utc;
 use flate2::write::GzEncoder;

src/cli.rs

@@ -1,52 +1,7 @@
+use crate::backup::ManagerConfig;
 use crate::server::ServerType;
 use clap::{Args, Parser, Subcommand};
-use std::error::Error;
-use std::fmt;
 use std::path::PathBuf;
-use std::str::FromStr;
-
-#[derive(Clone, Debug)]
-pub struct ManagerConfig {
-    name: String,
-    frequency: u32,
-    chain_len: u64,
-    chains: u64,
-}
-
-#[derive(Debug)]
-pub struct ParseManagerConfigErr;
-
-impl Error for ParseManagerConfigErr {}
-
-impl fmt::Display for ParseManagerConfigErr {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "parse manager config err")
-    }
-}
-
-impl FromStr for ManagerConfig {
-    type Err = ParseManagerConfigErr;
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
-        let splits: Vec<&str> = s.split(',').collect();
-
-        if let [name, frequency, chains, chain_len] = splits[..] {
-            let name: String = name.parse().map_err(|_| ParseManagerConfigErr)?;
-            let frequency: u32 = frequency.parse().map_err(|_| ParseManagerConfigErr)?;
-            let chains: u64 = chains.parse().map_err(|_| ParseManagerConfigErr)?;
-            let chain_len: u64 = chain_len.parse().map_err(|_| ParseManagerConfigErr)?;
-
-            Ok(ManagerConfig {
-                name,
-                chains,
-                chain_len,
-                frequency,
-            })
-        } else {
-            Err(ParseManagerConfigErr)
-        }
-    }
-}
 
 #[derive(Parser)]
 #[command(author, version, about, long_about = None)]
@@ -86,35 +41,6 @@ pub struct Cli {
     #[arg(long, env = "ALEX_LAYERS", global = true, value_delimiter = ';')]
     pub layers: Vec<ManagerConfig>,
 
-    /// Length of a backup chain
-    #[arg(
-        short = 'l',
-        long,
-        default_value_t = 4,
-        env = "ALEX_CHAIN_LEN",
-        global = true
-    )]
-    pub chain_len: u64,
-    /// How many backup chains to keep
-    #[arg(
-        short = 'n',
-        long,
-        default_value_t = 7,
-        env = "ALEX_CHAINS",
-        global = true
-    )]
-    pub chains: u64,
-
-    /// How frequently to perform a backup, in minutes; 0 to disable.
-    #[arg(
-        short = 't',
-        long,
-        default_value_t = 0,
-        env = "ALEX_FREQUENCY",
-        global = true
-    )]
-    pub frequency: u32,
-
     /// Type of server
     #[arg(long, default_value = "unknown", env = "ALEX_SERVER", global = true)]
     pub server: ServerType,

src/main.rs

@@ -5,7 +5,7 @@ mod signals;
 mod stdin;
 
 use clap::Parser;
-use cli::{BackupArgs, Cli, Commands, RunArgs};
+use cli::{Cli, Commands, RunArgs};
 use std::io;
 use std::sync::{Arc, Mutex};
 
@@ -13,7 +13,7 @@ fn backups_thread(counter: Arc<Mutex<server::ServerProcess>>) {
     loop {
         let next_scheduled_time = {
             let server = counter.lock().unwrap();
-            server.backups.next_scheduled_time()
+            server.backups.next_scheduled_time().unwrap()
         };
 
         let now = chrono::offset::Utc::now();
@@ -39,11 +39,9 @@ fn command_run(cli: &Cli, args: &RunArgs) -> io::Result<()> {
         .config(cli.config.clone())
         .world(cli.world.clone())
         .backup(cli.backup.clone())
+        .managers(cli.layers.clone())
         .xms(args.xms)
-        .xmx(args.xmx)
-        .chain_len(cli.chain_len)
-        .chains_to_keep(cli.chains)
-        .frequency(cli.frequency);
+        .xmx(args.xmx);
     cmd.canonicalize()?;
 
     if args.dry {
@@ -54,7 +52,7 @@ fn command_run(cli: &Cli, args: &RunArgs) -> io::Result<()> {
 
     let counter = Arc::new(Mutex::new(cmd.spawn()?));
 
-    if cli.frequency > 0 {
+    if !cli.layers.is_empty() {
         let clone = Arc::clone(&counter);
         std::thread::spawn(move || backups_thread(clone));
     }
@@ -67,32 +65,23 @@ fn command_run(cli: &Cli, args: &RunArgs) -> io::Result<()> {
     signals::handle_signals(&mut signals, counter)
 }
 
-fn commands_backup(cli: &Cli, _args: &BackupArgs) -> io::Result<()> {
-    let metadata = server::Metadata {
-        server_type: cli.server,
-        server_version: cli.server_version.clone(),
-    };
+// fn commands_backup(cli: &Cli, _args: &BackupArgs) -> io::Result<()> {
+//     let metadata = server::Metadata {
+//         server_type: cli.server,
+//         server_version: cli.server_version.clone(),
+//     };
+//     let mut meta = MetaManager::new(cli.backup, cli.config, cli.world, metadata);
+//     meta.add_all(&cli.layers)?;
 
-    let mut manager = backup::Manager::new(
-        cli.backup.clone(),
-        cli.config.clone(),
-        cli.world.clone(),
-        metadata,
-        cli.chain_len,
-        cli.chains,
-        chrono::Duration::minutes(cli.frequency.into()),
-    );
-    manager.load()?;
-
-    manager.create_backup()?;
-    manager.remove_old_backups()
-}
+//     manager.create_backup()?;
+//     manager.remove_old_backups()
+// }
 
 fn main() -> io::Result<()> {
     let cli = Cli::parse();
 
     match &cli.command {
         Commands::Run(args) => command_run(&cli, args),
-        Commands::Backup(args) => commands_backup(&cli, args),
+        Commands::Backup(_) => Ok(()),
     }
 }

src/server/command.rs

@@ -1,40 +1,12 @@
-use crate::backup::Manager as BackupManager;
-use crate::server::ServerProcess;
-use clap::ValueEnum;
-use serde::{Deserialize, Serialize};
+use crate::backup::ManagerConfig;
+use crate::backup::MetaManager;
+use crate::server::{Metadata, ServerProcess, ServerType};
 use std::fmt;
 use std::fs::File;
 use std::io::Write;
 use std::path::{Path, PathBuf};
 use std::process::{Command, Stdio};
 
-#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ValueEnum, Serialize, Deserialize)]
-pub enum ServerType {
-    Unknown,
-    Paper,
-    Forge,
-    Vanilla,
-}
-
-impl fmt::Display for ServerType {
-    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let s = match self {
-            ServerType::Unknown => "Unknown",
-            ServerType::Paper => "PaperMC",
-            ServerType::Forge => "Forge",
-            ServerType::Vanilla => "Vanilla",
-        };
-
-        write!(f, "{}", s)
-    }
-}
-
-#[derive(Clone, Serialize, Deserialize)]
-pub struct Metadata {
-    pub server_type: ServerType,
-    pub server_version: String,
-}
-
 pub struct ServerCommand {
     type_: ServerType,
     version: String,
@@ -45,9 +17,7 @@ pub struct ServerCommand {
     backup_dir: PathBuf,
     xms: u64,
     xmx: u64,
-    chain_len: u64,
-    chains_to_keep: u64,
-    frequency: u32,
+    managers: Vec<ManagerConfig>,
 }
 
 impl ServerCommand {
@@ -62,9 +32,7 @@ impl ServerCommand {
             backup_dir: PathBuf::from("backups"),
             xms: 1024,
             xmx: 2048,
-            chain_len: 4,
-            chains_to_keep: 7,
-            frequency: 0,
+            managers: Vec::new(),
         }
     }
 
@@ -105,18 +73,9 @@ impl ServerCommand {
         self
     }
 
-    pub fn chain_len(mut self, v: u64) -> Self {
-        self.chain_len = v;
-        self
-    }
+    pub fn managers(mut self, configs: Vec<ManagerConfig>) -> Self {
+        self.managers = configs;
 
-    pub fn chains_to_keep(mut self, v: u64) -> Self {
-        self.chains_to_keep = v;
-        self
-    }
-
-    pub fn frequency(mut self, v: u32) -> Self {
-        self.frequency = v;
         self
     }
 
@@ -207,22 +166,19 @@ impl ServerCommand {
             server_type: self.type_,
             server_version: self.version.clone(),
         };
-        let mut manager = BackupManager::new(
+        let mut meta = MetaManager::new(
             self.backup_dir.clone(),
             self.config_dir.clone(),
             self.world_dir.clone(),
             metadata,
-            self.chain_len,
-            self.chains_to_keep,
-            chrono::Duration::minutes(self.frequency.into()),
         );
-        manager.load()?;
+        meta.add_all(&self.managers)?;
 
         let mut cmd = self.create_cmd();
         self.accept_eula()?;
         let child = cmd.spawn()?;
 
-        Ok(ServerProcess::new(manager, child))
+        Ok(ServerProcess::new(meta, child))
     }
 }
 

src/server/mod.rs

@@ -1,5 +1,36 @@
 mod command;
 mod process;
 
-pub use command::{Metadata, ServerCommand, ServerType};
+pub use command::ServerCommand;
 pub use process::ServerProcess;
+
+use clap::ValueEnum;
+use serde::{Deserialize, Serialize};
+use std::fmt;
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ValueEnum, Serialize, Deserialize)]
+pub enum ServerType {
+    Unknown,
+    Paper,
+    Forge,
+    Vanilla,
+}
+
+impl fmt::Display for ServerType {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let s = match self {
+            ServerType::Unknown => "Unknown",
+            ServerType::Paper => "PaperMC",
+            ServerType::Forge => "Forge",
+            ServerType::Vanilla => "Vanilla",
+        };
+
+        write!(f, "{}", s)
+    }
+}
+
+#[derive(Clone, Serialize, Deserialize)]
+pub struct Metadata {
+    pub server_type: ServerType,
+    pub server_version: String,
+}

src/server/process.rs

@@ -1,15 +1,15 @@
-use crate::backup::Manager as BackupManager;
+use crate::backup::MetaManager;
 use crate::server::Metadata;
 use std::io::Write;
 use std::process::Child;
 
 pub struct ServerProcess {
     child: Child,
-    pub backups: BackupManager<Metadata>,
+    pub backups: MetaManager<Metadata>,
 }
 
 impl ServerProcess {
-    pub fn new(manager: BackupManager<Metadata>, child: Child) -> ServerProcess {
+    pub fn new(manager: MetaManager<Metadata>, child: Child) -> ServerProcess {
         ServerProcess {
             child,
             backups: manager,
@@ -59,16 +59,12 @@ impl ServerProcess {
         std::thread::sleep(std::time::Duration::from_secs(10));
 
         let start_time = chrono::offset::Utc::now();
-        let res = self.backups.create_backup();
+        let res = self.backups.perform_backup_cycle();
 
         // The server's save feature needs to be enabled again even if the archive failed to create
         self.custom("save-on")?;
         self.custom("save-all")?;
 
-        if res.is_ok() {
-            self.backups.remove_old_backups()?;
-        }
-
         let duration = chrono::offset::Utc::now() - start_time;
         let duration_str = format!(
             "{}m{}s",