From 79cba2e500b29f77cacfe0fcc68402d221f2330d Mon Sep 17 00:00:00 2001
From: NikVolf <nikvolf@gmail.com>
Date: Tue, 10 Sep 2019 12:51:23 +0300
Subject: [PATCH] run against long examples

---
 examples/long.rs | 73 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 73 insertions(+)
 create mode 100644 examples/long.rs

diff --git a/examples/long.rs b/examples/long.rs
new file mode 100644
index 000000000..bb2f2d481
--- /dev/null
+++ b/examples/long.rs
@@ -0,0 +1,73 @@
+use zcash_mmr::{Entry, EntryLink, NodeData, Tree};
+
+#[path= "lib/shared.rs"]
+mod share;
+
+fn prepare_tree(vec: &Vec<NodeData>) -> Tree {
+
+    assert!(vec.len() > 0);
+
+    // integer log2 of (vec.len()+1), -1
+    let mut h = (32 - ((vec.len()+1) as u32).leading_zeros() - 1)-1;
+    let mut peak_pos = (1 << (h+1)) - 1;
+    let mut nodes = Vec::new();
+
+    loop {
+
+        if peak_pos > vec.len() {
+            // left child, -2^h
+            peak_pos = peak_pos - (1<<h);
+            h = h - 1;
+        }
+
+        if peak_pos <= vec.len() {
+            let mut peak: Entry = vec[peak_pos-1].clone().into();
+            let left_idx = (peak_pos - (1<<h) - 1) as u32;
+            let right_idx = (peak_pos - 2) as u32;
+            if h != 0 {
+                peak.update_siblings(
+                    EntryLink::Stored(left_idx),
+                    EntryLink::Stored(right_idx),
+                );
+            }
+            nodes.push(((peak_pos-1) as u32, peak));
+
+            println!("Peak #{}: ({}, {})", nodes.len(), left_idx, right_idx);
+
+            // right sibling
+            peak_pos = peak_pos + (1 << (h+1)) - 1;
+        }
+
+        if h == 0 {
+            break;
+        }
+    }
+
+    Tree::new(vec.len() as u32, nodes, vec![])
+}
+
+fn main() {
+    let number= match std::env::args().skip(1).next() {
+        None => { eprintln!("writer <number of nodes> [<out_file>]"); std::process::exit(1); },
+        Some(number) => {
+            number.parse::<usize>().expect("invalid number")
+        }
+    };
+
+    let long_vec = share::NodeDataIterator::new().take(number)
+        .collect::<Vec<NodeData>>();
+
+    let now = std::time::Instant::now();
+
+    let tree = prepare_tree(&long_vec);
+
+    println!("Tree final root: {}-{}",
+        tree.root_node().expect("root").data().start_height,
+        tree.root_node().expect("root").data().end_height,
+    );
+
+    println!("Prepare tree of {} length: {} ns / {} mcs / {} ms",
+        number,
+        now.elapsed().as_nanos(), now.elapsed().as_micros(), now.elapsed().as_millis()
+    );
+}