Add --max-count option

README.md

@@ -69,6 +69,7 @@ Serie - A rich git commit graph in your terminal, like magic 📚
 Usage: serie [OPTIONS]
 
 Options:
+  -n, --max-count <NUMBER>        Maximum number of commits to render
   -p, --protocol <TYPE>           Image protocol to render graph [default: auto] [possible values: auto, iterm, kitty]
   -o, --order <TYPE>              Commit ordering algorithm [default: chrono] [possible values: chrono, topo]
   -g, --graph-width <TYPE>        Commit graph image cell width [default: auto] [possible values: auto, double, single]

docs/src/getting-started/command-line-options.md

@@ -1,5 +1,12 @@
 # Command Line Options
 
+## -n, --max-count \<NUMBER\>
+
+Maximum number of commits to render.
+
+If not specified, all commits will be rendered.
+It behaves similarly to the `--max-count` option of `git log`.
+
 ## -p, --protocol \<TYPE\>
 
 A protocol type for rendering images of commit graphs.

src/git.rs

@@ -124,11 +124,11 @@ pub struct Repository {
 }
 
 impl Repository {
-    pub fn load(path: &Path, sort: SortCommit) -> Result<Self> {
+    pub fn load(path: &Path, sort: SortCommit, max_count: Option<usize>) -> Result<Self> {
         check_git_repository(path)?;
 
         let stashes = load_all_stashes(path);
-        let commits = load_all_commits(path, sort, &stashes);
+        let commits = load_all_commits(path, sort, &stashes, max_count);
 
         let commits = merge_stashes_to_commits(commits, stashes);
         let commit_hashes = commits.iter().map(|c| c.commit_hash.clone()).collect();
@@ -250,7 +250,12 @@ fn is_bare_repository(path: &Path) -> bool {
     output.status.success() && output.stdout == b"true\n"
 }
 
-fn load_all_commits(path: &Path, sort: SortCommit, stashes: &[Commit]) -> Vec<Commit> {
+fn load_all_commits(
+    path: &Path,
+    sort: SortCommit,
+    stashes: &[Commit],
+    max_count: Option<usize>,
+) -> Vec<Commit> {
     let mut cmd = Command::new("git");
     cmd.arg("log");
 
@@ -271,6 +276,10 @@ fn load_all_commits(path: &Path, sort: SortCommit, stashes: &[Commit]) -> Vec<Co
     });
     cmd.arg("HEAD");
 
+    if let Some(n) = max_count {
+        cmd.arg("--max-count").arg(n.to_string());
+    }
+
     cmd.current_dir(path).stdout(Stdio::piped());
 
     let mut process = cmd.spawn().unwrap();

src/graph/calc.rs

@@ -257,6 +257,16 @@ fn calc_edges(
         if max_pos_x < pos_x {
             max_pos_x = pos_x;
         }
+
+        // draw down edge if has parent but parent not in the graph (when max_count is set)
+        if !commit.parent_commit_hashes.is_empty()
+            && repository.commit(&commit.parent_commit_hashes[0]).is_none()
+        {
+            edges[pos_y].push(WrappedEdge::new(EdgeType::Down, pos_x, pos_x, hash));
+            ((pos_y + 1)..commits.len()).for_each(|y| {
+                edges[y].push(WrappedEdge::new(EdgeType::Vertical, pos_x, pos_x, hash));
+            });
+        }
     }
 
     for commit in commits {

src/lib.rs

@@ -23,6 +23,10 @@ use serde::Deserialize;
 #[derive(Parser)]
 #[command(version)]
 struct Args {
+    /// Maximum number of commits to render
+    #[arg(short = 'n', long, value_name = "NUMBER")]
+    max_count: Option<usize>,
+
     /// Image protocol to render graph [default: auto]
     #[arg(short, long, value_name = "TYPE")]
     protocol: Option<ImageProtocolType>,
@@ -133,6 +137,7 @@ pub fn run() -> Result<()> {
     let (core_config, ui_config, graph_config, color_theme, key_bind_patch) = config::load()?;
     let key_bind = keybind::KeyBind::new(key_bind_patch);
 
+    let max_count = args.max_count;
     let image_protocol = args.protocol.or(core_config.option.protocol).into();
     let order = args.order.or(core_config.option.order).into();
     let graph_width = args.graph_width.or(core_config.option.graph_width);
@@ -144,7 +149,7 @@ pub fn run() -> Result<()> {
 
     let graph_color_set = color::GraphColorSet::new(&graph_config.color);
 
-    let repository = git::Repository::load(Path::new("."), order)?;
+    let repository = git::Repository::load(Path::new("."), order, max_count)?;
 
     let graph = graph::calc_graph(&repository);
 

src/widget/commit_list.rs

@@ -9,7 +9,7 @@ use ratatui::{
     text::{Line, Span},
     widgets::{List, ListItem, StatefulWidget, Widget},
 };
-use rustc_hash::FxHashMap;
+use rustc_hash::{FxHashMap, FxHashSet};
 use tui_input::{backend::crossterm::EventHandler, Input};
 
 use crate::{
@@ -180,6 +180,7 @@ impl SearchMatcher {
 #[derive(Debug)]
 pub struct CommitListState<'a> {
     commits: Vec<CommitInfo<'a>>,
+    commit_hash_set: FxHashSet<&'a CommitHash>,
     graph_image_manager: GraphImageManager<'a>,
     graph_cell_width: u16,
     head: &'a Head,
@@ -210,8 +211,10 @@ impl<'a> CommitListState<'a> {
         default_fuzzy: bool,
     ) -> CommitListState<'a> {
         let total = commits.len();
+        let commit_hash_set = commits.iter().map(|c| &c.commit.commit_hash).collect();
         CommitListState {
             commits,
+            commit_hash_set,
             graph_image_manager,
             graph_cell_width,
             head,
@@ -242,8 +245,10 @@ impl<'a> CommitListState<'a> {
 
     pub fn select_parent(&mut self) {
         if let Some(target_commit) = self.selected_commit_parent_hash().cloned() {
-            while target_commit.as_str() != self.selected_commit_hash().as_str() {
-                self.select_next();
+            if self.commit_hash_set.contains(&target_commit) {
+                while target_commit.as_str() != self.selected_commit_hash().as_str() {
+                    self.select_next();
+                }
             }
         }
     }

tests/graph.rs

@@ -114,6 +114,12 @@ fn branch_001() -> TestResult {
             git::SortCommit::Chronological,
             graph::GraphStyle::Angular,
         ),
+        GenerateGraphOption::new(
+            "branch_001_max_count",
+            git::SortCommit::Chronological,
+            graph::GraphStyle::Rounded,
+        )
+        .with_max_count(10),
     ];
 
     copy_git_dir(repo_path, "branch_001");
@@ -195,6 +201,12 @@ fn branch_002() -> TestResult {
             git::SortCommit::Chronological,
             graph::GraphStyle::Angular,
         ),
+        GenerateGraphOption::new(
+            "branch_002_max_count",
+            git::SortCommit::Chronological,
+            graph::GraphStyle::Rounded,
+        )
+        .with_max_count(5),
     ];
 
     copy_git_dir(repo_path, "branch_002");
@@ -1340,24 +1352,31 @@ fn parse_date(date: &str) -> DateTime<Utc> {
     Utc.from_utc_datetime(&dt)
 }
 
-struct GenerateGraphOption<'a> {
-    output_name: &'a str,
+struct GenerateGraphOption {
+    output_name: &'static str,
     sort: git::SortCommit,
     style: graph::GraphStyle,
+    max_count: Option<usize>,
 }
 
-impl GenerateGraphOption<'_> {
+impl GenerateGraphOption {
     fn new(
-        output_name: &str,
+        output_name: &'static str,
         sort: git::SortCommit,
         style: graph::GraphStyle,
-    ) -> GenerateGraphOption<'_> {
+    ) -> GenerateGraphOption {
         GenerateGraphOption {
             output_name,
             sort,
             style,
+            max_count: None,
         }
     }
+
+    fn with_max_count(mut self, max_count: usize) -> GenerateGraphOption {
+        self.max_count = Some(max_count);
+        self
+    }
 }
 
 fn generate_and_output_graph_images(repo_path: &Path, options: &[GenerateGraphOption]) {
@@ -1368,10 +1387,11 @@ fn generate_and_output_graph_images(repo_path: &Path, options: &[GenerateGraphOp
 
 fn generate_and_output_graph_image<P: AsRef<Path>>(path: P, option: &GenerateGraphOption) {
     // Build graphs in the same way as application
+    let max_count = option.max_count;
     let graph_color_config = config::GraphColorConfig::default();
     let graph_color_set = color::GraphColorSet::new(&graph_color_config);
     let cell_width_type = graph::CellWidthType::Double;
-    let repository = git::Repository::load(path.as_ref(), option.sort).unwrap();
+    let repository = git::Repository::load(path.as_ref(), option.sort, max_count).unwrap();
     let graph = graph::calc_graph(&repository);
     let image_params = graph::ImageParams::new(&graph_color_set, cell_width_type);
     let drawing_pixels = graph::DrawingPixels::new(&image_params);