merged manually

lib/src/lightclient/checkpoints.rs

@@ -0,0 +1,90 @@
+pub fn get_closest_checkpoint(chain_name: &str, height: u64) ->  Option<(u64, &'static str, &'static str)> {
+    match chain_name {
+        "test" => get_test_checkpoint(height),
+        "main" => get_main_checkpoint(height),
+        _      => None
+    }
+}
+
+fn get_test_checkpoint(height: u64) ->  Option<(u64, &'static str, &'static str)> {
+    let checkpoints: Vec<(u64, &str, &str)> = vec![
+        (105942, "",
+                 ""
+        ),
+        (105943, "",
+                 ""
+        )
+    ];
+
+    find_checkpoint(height, checkpoints)
+}
+
+
+fn get_main_checkpoint(height: u64) ->  Option<(u64, &'static str, &'static str)> {
+    let checkpoints: Vec<(u64, &str, &str)> = vec![
+        (105942, "00000001c0199f329ee03379bf1387856dbab23765da508bf9b9d8d544f212c0",
+                 ""
+        )
+    ];
+
+    find_checkpoint(height, checkpoints)
+}
+
+fn find_checkpoint(height: u64, chkpts: Vec<(u64, &'static str, &'static str)>) -> Option<(u64, &'static str, &'static str)> {
+    // Find the closest checkpoint
+    let mut heights = chkpts.iter().map(|(h, _, _)| *h as u64).collect::<Vec<_>>();
+    heights.sort();
+
+    match get_first_lower_than(height, heights) {
+        Some(closest_height) => {
+            chkpts.iter().find(|(h, _, _)| *h ==  closest_height).map(|t| *t)
+        },
+        None    => None
+    }
+}
+
+fn get_first_lower_than(height: u64, heights: Vec<u64>) -> Option<u64> {
+    // If it's before the first checkpoint, return None. 
+    if heights.len() == 0 || height < heights[0] {
+        return None;
+    }
+
+    for (i, h) in heights.iter().enumerate() {
+        if height < *h {
+            return Some(heights[i-1]);
+        }
+    }
+
+    return Some(*heights.last().unwrap());
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    #[test]
+    fn test_lower_than() {
+        assert_eq!(get_first_lower_than( 9, vec![10, 30, 40]), None);
+        assert_eq!(get_first_lower_than(10, vec![10, 30, 40]).unwrap(), 10);
+        assert_eq!(get_first_lower_than(11, vec![10, 30, 40]).unwrap(), 10);
+        assert_eq!(get_first_lower_than(29, vec![10, 30, 40]).unwrap(), 10);
+        assert_eq!(get_first_lower_than(30, vec![10, 30, 40]).unwrap(), 30);
+        assert_eq!(get_first_lower_than(40, vec![10, 30, 40]).unwrap(), 40);
+        assert_eq!(get_first_lower_than(41, vec![10, 30, 40]).unwrap(), 40);
+        assert_eq!(get_first_lower_than(99, vec![10, 30, 40]).unwrap(), 40);
+    }
+
+    #[test]
+    fn test_checkpoints() {
+        assert_eq!(get_test_checkpoint(990000), None);
+        assert_eq!(get_test_checkpoint(100000).unwrap().0, 100000);
+        assert_eq!(get_test_checkpoint(110000).unwrap().0, 100000);
+        assert_eq!(get_test_checkpoint(111000).unwrap().0, 1100000);
+        assert_eq!(get_test_checkpoint(112000).unwrap().0, 1100000);
+
+        assert_eq!(get_main_checkpoint(990000), None);
+        assert_eq!(get_main_checkpoint(110000).unwrap().0, 110000);
+        assert_eq!(get_main_checkpoint(111000).unwrap().0, 110000);
+    }
+
+}