From a30e0f4a8cddafcc3f028378c89d492618a49fb7 Mon Sep 17 00:00:00 2001
From: timeshifter <timeshifter@sumatrae>
Date: Wed, 6 May 2026 19:14:50 +0200
Subject: [PATCH] add stuff

---
 config.toml    |  2 ++
 src/config.rs  |  1 +
 src/lib.rs     |  1 +
 src/main.rs    | 12 +++++++++--
 src/pathbuf.rs | 58 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/todo.rs    | 14 +++++++++++-
 src/zfs.rs     |  4 ++--
 7 files changed, 87 insertions(+), 5 deletions(-)
 create mode 100644 src/pathbuf.rs

diff --git a/config.toml b/config.toml
index 505baa1..f72ce0f 100644
--- a/config.toml
+++ b/config.toml
@@ -3,6 +3,8 @@ snapshot_interval = "monthly"
 
 local_pool_name = "tank"
 
+do_not_backup_datasets = ["docker", "cache"]
+
 [backup_pools]
 backup1 = 'a235c116-764f-4082-97fc-47ca31e11e53'
 backup2 = '200ced55-894c-4f70-b089-b140e60193fc'
diff --git a/src/config.rs b/src/config.rs
index 2c5fad3..99f3c66 100644
--- a/src/config.rs
+++ b/src/config.rs
@@ -8,6 +8,7 @@ pub struct Config {
     pub snapshot_tag: String,
     pub snapshot_interval: String,
     pub local_pool_name: String,
+    pub do_not_backup_datasets: Vec<String>,
     pub backup_pools: BackupPools,
 }
 
diff --git a/src/lib.rs b/src/lib.rs
index f4dd8a2..46a603e 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,5 +1,6 @@
 pub mod cmd;
 pub mod config;
 pub mod encryption;
+pub mod pathbuf;
 pub mod todo;
 pub mod zfs;
diff --git a/src/main.rs b/src/main.rs
index bc97d41..b534054 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -26,6 +26,7 @@ fn main() -> Result<()> {
         &backup_pool,
         config.snapshot_tag,
         config.snapshot_interval,
+        config.do_not_backup_datasets,
     )?;
 
     if something_was_done {
@@ -56,9 +57,16 @@ fn do_backup(
     backup_pool: &ZPool,
     snapshot_tag: String,
     snapshot_interval: String,
+    datasets: Vec<String>,
 ) -> Result<bool> {
-    let todos = todo::Todo::plan(local_pool, backup_pool, snapshot_tag, snapshot_interval)
-        .context("planning todos")?;
+    let todos = todo::Todo::plan(
+        local_pool,
+        backup_pool,
+        datasets,
+        snapshot_tag,
+        snapshot_interval,
+    )
+    .context("planning todos")?;
 
     if todos.is_empty() {
         println!("nothing to do");
diff --git a/src/pathbuf.rs b/src/pathbuf.rs
new file mode 100644
index 0000000..6b35196
--- /dev/null
+++ b/src/pathbuf.rs
@@ -0,0 +1,58 @@
+use crate::zfs::Dataset;
+
+pub trait Relative {
+    fn is_child_of(&self, other: &Dataset) -> bool;
+}
+
+impl Relative for Dataset {
+    fn is_child_of(&self, other: &Dataset) -> bool {
+        let self_components: Vec<_> = self.0.components().collect();
+        let other_components: Vec<_> = other.0.components().collect();
+
+        if self_components.len() < other_components.len() {
+            return false;
+        }
+
+        other
+            .0
+            .iter()
+            .zip(self.0.iter())
+            .map(|(left, right)| left == right)
+            .reduce(|left, right| left && right)
+            .unwrap()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::path::PathBuf;
+
+    use super::*;
+
+    #[test]
+    fn base() {
+        let mut pb1 = PathBuf::new();
+        pb1.push("/a/b/c");
+        let ds1 = Dataset::new(pb1);
+
+        let mut pb2 = PathBuf::new();
+        pb2.push("/a/b/c/d");
+        let ds2 = Dataset::new(pb2);
+
+        assert!(ds2.is_child_of(&ds1));
+        assert!(!ds1.is_child_of(&ds2));
+    }
+
+    #[test]
+    fn not_related() {
+        let mut pb1 = PathBuf::new();
+        pb1.push("/a/z/c");
+        let ds1 = Dataset::new(pb1);
+
+        let mut pb2 = PathBuf::new();
+        pb2.push("/a/b/c");
+        let ds2 = Dataset::new(pb2);
+
+        assert!(!ds2.is_child_of(&ds1));
+    }
+}
diff --git a/src/todo.rs b/src/todo.rs
index 1b429a8..5839bc3 100644
--- a/src/todo.rs
+++ b/src/todo.rs
@@ -1,8 +1,12 @@
+use std::path::PathBuf;
+
 use anyhow::Result;
 
 use crate::zfs::Snapshot;
 use crate::zfs::ZPool;
 
+use crate::pathbuf::Relative;
+
 use crate::zfs::Dataset;
 
 pub enum Todo {
@@ -29,12 +33,20 @@ impl Todo {
     pub fn plan(
         local: &ZPool,
         remote: &ZPool,
+        do_not_backup_datasets: Vec<String>,
         snapshot_tag: String,
         snapshot_interval: String,
     ) -> Result<Vec<Self>> {
         let mut result = vec![];
 
-        for local_dataset in &local.datasets {
+        'outer: for local_dataset in &local.datasets {
+            for do_not_backup in &do_not_backup_datasets {
+                let ds = Dataset::new(PathBuf::from(do_not_backup));
+                if local_dataset.is_child_of(&ds) {
+                    continue 'outer;
+                }
+            }
+
             let last_snapshot_with_tag =
                 local_dataset.find_last_snapshot_with_tag(&snapshot_tag, &snapshot_interval)?;
 
diff --git a/src/zfs.rs b/src/zfs.rs
index e6e9e9c..29b2aa2 100644
--- a/src/zfs.rs
+++ b/src/zfs.rs
@@ -120,10 +120,10 @@ impl ZPool {
 /// E.g. if the name of the pool is `tank`, with the elements `ROOT` and `default` below it, this
 /// struct would contain `tank/ROOT/default`.
 #[derive(Debug, PartialEq, Clone)]
-pub struct Dataset(PathBuf);
+pub struct Dataset(pub(crate) PathBuf);
 
 impl Dataset {
-    fn new(path: PathBuf) -> Self {
+    pub fn new(path: PathBuf) -> Self {
         Self(path)
     }