From f1619f896caa5e021c92e5c57fcea8f96326a474 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@z.cash>
Date: Thu, 5 Dec 2019 14:29:08 +0000
Subject: [PATCH] Clearer variable names in MMR tests

---
 librustzcash/src/tests/mmr.rs | 41 ++++++++++++++++-------------------
 1 file changed, 19 insertions(+), 22 deletions(-)

diff --git a/librustzcash/src/tests/mmr.rs b/librustzcash/src/tests/mmr.rs
index aca4766..4107a75 100644
--- a/librustzcash/src/tests/mmr.rs
+++ b/librustzcash/src/tests/mmr.rs
@@ -10,8 +10,8 @@ struct TreeView {
     extra: Vec<(u32, Entry)>,
 }
 
-fn draft(into: &mut Vec<(u32, Entry)>, vec: &[NodeData], peak_pos: usize, h: u32) {
-    let node_data = vec[peak_pos - 1].clone();
+fn draft(into: &mut Vec<(u32, Entry)>, nodes: &[NodeData], peak_pos: usize, h: u32) {
+    let node_data = nodes[peak_pos - 1].clone();
     let peak: Entry = match h {
         0 => node_data.into(),
         _ => Entry::new(
@@ -24,27 +24,27 @@ fn draft(into: &mut Vec<(u32, Entry)>, vec: &[NodeData], peak_pos: usize, h: u32
     into.push(((peak_pos - 1) as u32, peak));
 }
 
-fn prepare_tree(vec: &[NodeData]) -> TreeView {
-    assert!(!vec.is_empty());
+fn prepare_tree(nodes: &[NodeData]) -> TreeView {
+    assert!(!nodes.is_empty());
 
-    // integer log2 of (vec.len()+1), -1
-    let mut h = (32 - ((vec.len() + 1) as u32).leading_zeros() - 1) - 1;
+    // integer log2 of (nodes.len()+1), -1
+    let mut h = (32 - ((nodes.len() + 1) as u32).leading_zeros() - 1) - 1;
     let mut peak_pos = (1 << (h + 1)) - 1;
-    let mut nodes = Vec::new();
+    let mut peaks = Vec::new();
 
     // used later
     let mut last_peak_pos = 0;
     let mut last_peak_h = 0;
 
     loop {
-        if peak_pos > vec.len() {
+        if peak_pos > nodes.len() {
             // left child, -2^h
             peak_pos -= 1 << h;
             h -= 1;
         }
 
-        if peak_pos <= vec.len() {
-            draft(&mut nodes, vec, peak_pos, h);
+        if peak_pos <= nodes.len() {
+            draft(&mut peaks, nodes, peak_pos, h);
 
             // save to be used in next loop
             last_peak_pos = peak_pos;
@@ -70,25 +70,22 @@ fn prepare_tree(vec: &[NodeData]) -> TreeView {
         h -= 1;
 
         // drafting left child
-        draft(&mut extra, vec, left_pos, h);
+        draft(&mut extra, nodes, left_pos, h);
 
         // drafting right child
-        draft(&mut extra, vec, right_pos, h);
+        draft(&mut extra, nodes, right_pos, h);
 
         // continuing on right slope
         peak_pos = right_pos;
     }
 
-    TreeView {
-        peaks: nodes,
-        extra,
-    }
+    TreeView { peaks, extra }
 }
 
-fn preload_tree_append(vec: &[NodeData]) -> (Vec<u32>, Vec<[u8; zcash_mmr::MAX_ENTRY_SIZE]>) {
-    assert!(!vec.is_empty());
+fn preload_tree_append(nodes: &[NodeData]) -> (Vec<u32>, Vec<[u8; zcash_mmr::MAX_ENTRY_SIZE]>) {
+    assert!(!nodes.is_empty());
 
-    let tree_view = prepare_tree(vec);
+    let tree_view = prepare_tree(nodes);
 
     let mut indices = Vec::new();
     let mut bytes = Vec::new();
@@ -107,11 +104,11 @@ fn preload_tree_append(vec: &[NodeData]) -> (Vec<u32>, Vec<[u8; zcash_mmr::MAX_E
 
 // also returns number of peaks
 fn preload_tree_delete(
-    vec: &[NodeData],
+    nodes: &[NodeData],
 ) -> (Vec<u32>, Vec<[u8; zcash_mmr::MAX_ENTRY_SIZE]>, usize) {
-    assert!(!vec.is_empty());
+    assert!(!nodes.is_empty());
 
-    let tree_view = prepare_tree(vec);
+    let tree_view = prepare_tree(nodes);
 
     let mut indices = Vec::new();
     let mut bytes = Vec::new();