Removed support to change amount of storable nodes

3 files changed, 15 insertions, 14 deletions

diff --git a/README.md b/README.md
index 3225784..9795f2c 100644
--- a/README.md
+++ b/README.md
@@ -54,12 +54,18 @@ make
 
 Thanks to [jwalk][jwalk], all there was left to do is to write a command-line interface. As `jwalk` matures, **dua** should benefit instantly.
 
-### Tradeoffs
-
+### Limitations
+
+* In interactive mode, you will need about 60MB of memory for 1 million entries in the graph.
+* In interactive mode, the maximum amount of files is limited to 2^32 - 1 (`u32::max_value() - 1`) entries.
+  * One node is used as to 'virtual' root
+  * The actual amount of nodes stored might be lower, as there might be more edges than nodes, which are also limited by a `u32` (I guess)
+  * The limitation is imposed by the underlying [`petgraph`][petgraph] crate, which declares it as `unsafe` to use u64 for instance.
+  * It's possibly *UB* when that limit is reached, however, it was never observed either.
 * Dedication to `termion`
   * we use [`termion`][termion] exlusively, and even though [`tui`][tui] supports multiple backends, we only support its termion backend. _Reason_: `tui` is only used for parts of the program, and in all other parts `termion` is used for coloring the output. Thus we wouldn't support changing to a different backend anyway unless everything is done with TUI, which is really not what it is made for.
 
-
+[petgraph]: https://crates.io/crates/petgraph
 [rustup]: https://rustup.rs/
 [jwalk]: https://crates.io/crates/jwalk
 [termion]: https://crates.io/crates/termion
diff --git a/src/traverse.rs b/src/traverse.rs
index 9c2501c..3690c1e 100644
--- a/src/traverse.rs
+++ b/src/traverse.rs
@@ -4,9 +4,8 @@ use petgraph::graph::NodeIndex;
 use petgraph::{Directed, Direction, Graph};
 use std::{ffi::OsString, path::PathBuf, time::Duration, time::Instant};
 
-pub type TreeIndexType = u32;
-pub type TreeIndex = NodeIndex<TreeIndexType>;
-pub type Tree = Graph<EntryData, (), Directed, TreeIndexType>;
+pub type TreeIndex = NodeIndex;
+pub type Tree = Graph<EntryData, (), Directed>;
 
 #[derive(Eq, PartialEq, Debug, Default)]
 pub struct EntryData {
diff --git a/tests/interactive.rs b/tests/interactive.rs
index 6ade220..6ad4213 100644
--- a/tests/interactive.rs
+++ b/tests/interactive.rs
@@ -1,18 +1,15 @@
 mod app {
     use dua::{
         interactive::{widgets::SortMode, TerminalApp},
-        traverse::{EntryData, Tree, TreeIndex, TreeIndexType},
+        traverse::{EntryData, Tree, TreeIndex},
         ByteFormat, Color, TraversalSorting, WalkOptions,
     };
     use failure::Error;
     use petgraph::prelude::NodeIndex;
     use pretty_assertions::assert_eq;
-    use std::ffi::OsStr;
-    use std::path::PathBuf;
-    use std::{ffi::OsString, fmt, path::Path};
+    use std::{ffi::OsStr, ffi::OsString, fmt, path::Path, path::PathBuf};
     use termion::input::TermRead;
-    use tui::backend::TestBackend;
-    use tui::Terminal;
+    use tui::{backend::TestBackend, Terminal};
 
     const FIXTURE_PATH: &'static str = "tests/fixtures";
 
@@ -315,8 +312,7 @@ mod app {
 
     fn make_add_node<'a>(
         t: &'a mut Tree,
-    ) -> impl FnMut(&str, u64, Option<NodeIndex<TreeIndexType>>) -> NodeIndex<TreeIndexType> + 'a
-    {
+    ) -> impl FnMut(&str, u64, Option<NodeIndex>) -> NodeIndex + 'a {
         move |name, size, maybe_from_idx| {
             let n = t.add_node(EntryData {
                 name: OsString::from(name),