Wallet logic

src/wallet/utils.rs

@@ -0,0 +1,48 @@
+// De-facto standard "dust limit" (even though it should change based on the output type)
+const DUST_LIMIT_SATOSHI: u64 = 546;
+
+// we implement this trait to make sure we don't mess up the comparison with off-by-one like a <
+// instead of a <= etc. The constant value for the dust limit is not public on purpose, to
+// encourage the usage of this trait.
+pub trait IsDust {
+    fn is_dust(&self) -> bool;
+}
+
+impl IsDust for u64 {
+    fn is_dust(&self) -> bool {
+        *self <= DUST_LIMIT_SATOSHI
+    }
+}
+
+pub struct ChunksIterator<I: Iterator> {
+    iter: I,
+    size: usize,
+}
+
+impl<I: Iterator> ChunksIterator<I> {
+    pub fn new(iter: I, size: usize) -> Self {
+        ChunksIterator { iter, size }
+    }
+}
+
+impl<I: Iterator> Iterator for ChunksIterator<I> {
+    type Item = Vec<<I as std::iter::Iterator>::Item>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        let mut v = Vec::new();
+        for _ in 0..self.size {
+            let e = self.iter.next();
+
+            match e {
+                None => break,
+                Some(val) => v.push(val),
+            }
+        }
+
+        if v.is_empty() {
+            return None;
+        }
+
+        Some(v)
+    }
+}