move modules into their own files

3 files changed, 230 insertions, 0 deletions

diff --git a/src/interactive/app.rs b/src/interactive/app.rs
new file mode 100644
index 0000000..7021045
--- /dev/null
+++ b/src/interactive/app.rs
@@ -0,0 +1,197 @@
+use crate::{WalkOptions, WalkResult};
+use failure::Error;
+use petgraph::{prelude::NodeIndex, Directed, Direction, Graph};
+use std::time::{Duration, Instant};
+use std::{ffi::OsString, io, path::PathBuf};
+use termion::input::{Keys, TermReadEventsAndRaw};
+use tui::widgets::Widget;
+use tui::{backend::Backend, Terminal};
+
+pub type TreeIndexType = u32;
+pub type TreeIndex = NodeIndex<TreeIndexType>;
+pub type Tree = Graph<EntryData, (), Directed, TreeIndexType>;
+
+#[derive(Eq, PartialEq, Debug, Default)]
+pub struct EntryData {
+    pub name: OsString,
+    /// The entry's size in bytes. If it's a directory, the size is the aggregated file size of all children
+    pub size: u64,
+    /// If set, the item meta-data could not be obtained
+    pub metadata_io_error: bool,
+}
+
+/// State and methods representing the interactive disk usage analyser for the terminal
+#[derive(Default, Debug)]
+pub struct TerminalApp {
+    /// A tree representing the entire filestem traversal
+    pub tree: Tree,
+    /// The top-level node of the tree.
+    pub root_index: TreeIndex,
+    /// Amount of files or directories we have seen during the filesystem traversal
+    pub entries_traversed: u64,
+    /// Total amount of IO errors encountered when traversing the filesystem
+    pub io_errors: u64,
+}
+
+const GUI_REFRESH_RATE: Duration = Duration::from_millis(100);
+
+impl TerminalApp {
+    pub fn process_events<B, R>(
+        &mut self,
+        _terminal: &mut Terminal<B>,
+        _keys: Keys<R>,
+    ) -> Result<WalkResult, Error>
+    where
+        B: Backend,
+        R: io::Read + TermReadEventsAndRaw,
+    {
+        unimplemented!()
+    }
+
+    pub fn initialize<B>(
+        terminal: &mut Terminal<B>,
+        options: WalkOptions,
+        input: Vec<PathBuf>,
+    ) -> Result<TerminalApp, Error>
+    where
+        B: Backend,
+    {
+        fn set_size_or_panic(
+            tree: &mut Tree,
+            parent_node_idx: TreeIndex,
+            current_size_at_depth: u64,
+        ) {
+            tree.node_weight_mut(parent_node_idx)
+                .expect("node for parent index we just retrieved")
+                .size = current_size_at_depth;
+        }
+        fn parent_or_panic(tree: &mut Tree, parent_node_idx: TreeIndex) -> TreeIndex {
+            tree.neighbors_directed(parent_node_idx, Direction::Incoming)
+                .next()
+                .expect("every node in the iteration has a parent")
+        }
+        fn pop_or_panic(v: &mut Vec<u64>) -> u64 {
+            v.pop().expect("sizes per level to be in sync with graph")
+        }
+        let mut tree = Tree::new();
+        let mut io_errors = 0u64;
+        let mut entries_traversed = 0u64;
+
+        let root_index = tree.add_node(EntryData::default());
+        let (mut previous_node_idx, mut parent_node_idx) = (root_index, root_index);
+        let mut sizes_per_depth_level = Vec::new();
+        let mut current_size_at_depth = 0;
+        let mut previous_depth = 0;
+
+        let mut last_checked = Instant::now();
+
+        const INITIAL_CHECK_INTERVAL: usize = 500;
+        let mut check_instant_every = INITIAL_CHECK_INTERVAL;
+        let mut last_seen_eid;
+
+        for path in input.into_iter() {
+            last_seen_eid = 0;
+            for (eid, entry) in options
+                .iter_from_path(path.as_ref())
+                .into_iter()
+                .enumerate()
+            {
+                entries_traversed += 1;
+                let mut data = EntryData::default();
+                match entry {
+                    Ok(entry) => {
+                        data.name = entry.file_name;
+                        let file_size = match entry.metadata {
+                            Some(Ok(ref m)) if !m.is_dir() => m.len(),
+                            Some(Ok(_)) => 0,
+                            Some(Err(_)) => {
+                                io_errors += 1;
+                                data.metadata_io_error = true;
+                                0
+                            }
+                            None => unreachable!(
+                                "we ask for metadata, so we at least have Some(Err(..))). Issue in jwalk?"
+                            ),
+                        };
+
+                        match (entry.depth, previous_depth) {
+                            (n, p) if n > p => {
+                                sizes_per_depth_level.push(current_size_at_depth);
+                                current_size_at_depth = file_size;
+                                parent_node_idx = previous_node_idx;
+                            }
+                            (n, p) if n < p => {
+                                for _ in n..p {
+                                    set_size_or_panic(
+                                        &mut tree,
+                                        parent_node_idx,
+                                        current_size_at_depth,
+                                    );
+                                    current_size_at_depth +=
+                                        pop_or_panic(&mut sizes_per_depth_level);
+                                    parent_node_idx = parent_or_panic(&mut tree, parent_node_idx);
+                                }
+                                current_size_at_depth += file_size;
+                                set_size_or_panic(
+                                    &mut tree,
+                                    parent_node_idx,
+                                    current_size_at_depth,
+                                );
+                            }
+                            _ => {
+                                current_size_at_depth += file_size;
+                            }
+                        };
+
+                        data.size = file_size;
+                        let entry_index = tree.add_node(data);
+
+                        tree.add_edge(parent_node_idx, entry_index, ());
+                        previous_node_idx = entry_index;
+                        previous_depth = entry.depth;
+                    }
+                    Err(_) => io_errors += 1,
+                }
+
+                if eid != 0
+                    && eid % check_instant_every == 0
+                    && last_checked.elapsed() >= GUI_REFRESH_RATE
+                {
+                    let now = Instant::now();
+                    let elapsed = (now - last_checked).as_millis() as f64;
+                    check_instant_every = (INITIAL_CHECK_INTERVAL as f64
+                        * ((eid - last_seen_eid) as f64 / INITIAL_CHECK_INTERVAL as f64)
+                        * (GUI_REFRESH_RATE.as_millis() as f64 / elapsed))
+                        as usize;
+                    last_seen_eid = eid;
+                    last_checked = now;
+
+                    terminal.draw(|mut f| {
+                        let full_screen = f.size();
+                        super::widgets::Entries {
+                            tree: &tree,
+                            root: root_index,
+                        }
+                        .render(&mut f, full_screen)
+                    })?;
+                }
+            }
+        }
+
+        sizes_per_depth_level.push(current_size_at_depth);
+        current_size_at_depth = 0;
+        for _ in 0..previous_depth {
+            current_size_at_depth += pop_or_panic(&mut sizes_per_depth_level);
+            set_size_or_panic(&mut tree, parent_node_idx, current_size_at_depth);
+            parent_node_idx = parent_or_panic(&mut tree, parent_node_idx);
+        }
+        set_size_or_panic(&mut tree, root_index, current_size_at_depth);
+
+        Ok(TerminalApp {
+            tree,
+            root_index,
+            entries_traversed,
+            io_errors,
+        })
+    }
+}
diff --git a/src/interactive/mod.rs b/src/interactive/mod.rs
new file mode 100644
index 0000000..2268008
--- /dev/null
+++ b/src/interactive/mod.rs
@@ -0,0 +1,4 @@
+mod app;
+mod widgets;
+
+pub use self::app::*;
diff --git a/src/interactive/widgets.rs b/src/interactive/widgets.rs
new file mode 100644
index 0000000..61095ba
--- /dev/null
+++ b/src/interactive/widgets.rs
@@ -0,0 +1,29 @@
+use super::{Tree, TreeIndex};
+use petgraph::Direction;
+use tui::buffer::Buffer;
+use tui::layout::{Corner, Rect};
+use tui::widgets::{Block, Borders, List, Text, Widget};
+
+pub struct Entries<'a> {
+    pub tree: &'a Tree,
+    pub root: TreeIndex,
+}
+
+impl<'a> Widget for Entries<'a> {
+    fn draw(&mut self, area: Rect, buf: &mut Buffer) {
+        let Self { tree, root } = self;
+        List::new(
+            tree.neighbors_directed(*root, Direction::Outgoing)
+                .filter_map(|w| {
+                    tree.node_weight(w).map(|w| {
+                        Text::Raw(
+                            format!("{} | ----- | {}", w.size, w.name.to_string_lossy()).into(),
+                        )
+                    })
+                }),
+        )
+        .block(Block::default().borders(Borders::ALL).title("Entries"))
+        .start_corner(Corner::TopLeft)
+        .draw(area, buf);
+    }
+}