Incremental indexing: HEAD 변경 시 delta만 재인덱싱

AGENTS.md

@@ -73,7 +73,7 @@ Pick ──Enter──→ View ──Tab──→ Diff
 
 Semantic-search threading: indexing and engine-load each run on their own thread, talk via `mpsc::channel` (`IndexMessage`, `EngineMessage`). `EngineMessage::Ready(Box<SearchEngine>)` hands the heap-allocated engine to the main thread. `with_silenced_stdio()` redirects stderr during model load to keep hf-hub progress bars out of the alternate screen — **Unix-only** (`libc::dup2`).
 
-Index dir `.glc-index/` has `meta.toml` with `INDEX_VERSION` (currently 3), `head_oid`, per-component metadata. Mismatched version or oid forces rebuild.
+Index dir `.glc-index/` has `meta.toml` with `INDEX_VERSION` (currently 5), `head_oid`, per-component metadata. Mismatched version forces full rebuild. Mismatched `head_oid` triggers incremental update (BM25 `delete_term` + turbovec `remove` for stale docs, embed only the delta) when the old `head_oid` is still reachable; otherwise falls back to full rebuild.
 
 ## Architecture gotchas
 

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "gluck"
-version = "0.8.2"
+version = "0.9.0"
 edition = "2021"
 
 [[bin]]

src/search/bm25.rs

@@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
 use tantivy::collector::TopDocs;
 use tantivy::query::QueryParser;
 use tantivy::schema::{
-    Field, IndexRecordOption, Schema, TextFieldIndexing, TextOptions, FAST, STORED, STRING,
+    Field, IndexRecordOption, Schema, TextFieldIndexing, TextOptions, FAST, INDEXED, STORED, STRING,
 };
 use tantivy::tokenizer::{LowerCaser, NgramTokenizer, TextAnalyzer};
 use tantivy::{Index, IndexReader, IndexWriter, ReloadPolicy, TantivyError};
@@ -47,7 +47,7 @@ fn make_schema() -> (Schema, Bm25Fields) {
             .set_index_option(IndexRecordOption::WithFreqs),
     );
 
-    let id = builder.add_u64_field("id", FAST | STORED);
+    let id = builder.add_u64_field("id", FAST | STORED | INDEXED);
     let kind = builder.add_text_field("kind", STRING | STORED);
     let title = builder.add_text_field("title", text_opts);
     let body = builder.add_text_field("body", body_opts);
@@ -139,6 +139,11 @@ impl Bm25Index {
         Ok(())
     }
 
+    pub fn delete_doc(&self, writer: &mut IndexWriter, doc_id: u64) {
+        let term = tantivy::Term::from_field_u64(self.fields.id, doc_id);
+        writer.delete_term(term);
+    }
+
     pub fn commit(&self, mut writer: IndexWriter) -> Result<(), TantivyError> {
         writer.commit()?;
         self.reader.reload()?;
@@ -387,6 +392,25 @@ mod tests {
         assert_eq!(got.line_end, Some(20));
     }
 
+    #[test]
+    fn test_delete_doc_removes_from_search() {
+        let (_dir, idx) = tmp_index();
+        let mut w = idx.writer().unwrap();
+        idx.add_doc(&mut w, &commit_meta(1, "hello world"), "greeting")
+            .unwrap();
+        idx.add_doc(&mut w, &commit_meta(2, "hello again"), "second")
+            .unwrap();
+        idx.commit(w).unwrap();
+        assert_eq!(idx.search("he", 10).unwrap().len(), 2);
+
+        let mut w = idx.writer().unwrap();
+        idx.delete_doc(&mut w, 1);
+        idx.commit(w).unwrap();
+        let r = idx.search("he", 10).unwrap();
+        assert_eq!(r.len(), 1);
+        assert_eq!(r[0].0, 2);
+    }
+
     #[test]
     fn test_path_field_exact_match_query() {
         let (_dir, idx) = tmp_index();

src/search/diff.rs

@@ -0,0 +1,147 @@
+use std::path::Path;
+
+use git2::{DiffOptions, Oid};
+
+use crate::git::commit::CommitInfo;
+use crate::git::repo::GitRepo;
+use crate::search::SearchError;
+
+#[derive(Debug, Default, PartialEq, Eq)]
+pub struct FileChanges {
+    pub added: Vec<String>,
+    pub modified: Vec<String>,
+    pub deleted: Vec<String>,
+}
+
+pub fn compute_file_changes(
+    repo: &GitRepo,
+    old_oid: &str,
+    new_oid: &str,
+) -> Result<FileChanges, SearchError> {
+    let r = repo.repository();
+    let old = Oid::from_str(old_oid).map_err(|e| SearchError::Git(e.to_string()))?;
+    let new = Oid::from_str(new_oid).map_err(|e| SearchError::Git(e.to_string()))?;
+    let old_tree = r
+        .find_commit(old)
+        .and_then(|c| c.tree())
+        .map_err(|e| SearchError::Git(e.to_string()))?;
+    let new_tree = r
+        .find_commit(new)
+        .and_then(|c| c.tree())
+        .map_err(|e| SearchError::Git(e.to_string()))?;
+
+    let mut opts = DiffOptions::new();
+    let diff = r
+        .diff_tree_to_tree(Some(&old_tree), Some(&new_tree), Some(&mut opts))
+        .map_err(|e| SearchError::Git(e.to_string()))?;
+
+    let mut out = FileChanges::default();
+    for delta in diff.deltas() {
+        match delta.status() {
+            git2::Delta::Added | git2::Delta::Copied => {
+                if let Some(p) = delta.new_file().path().and_then(Path::to_str) {
+                    out.added.push(p.to_string());
+                }
+            }
+            git2::Delta::Modified => {
+                if let Some(p) = delta.new_file().path().and_then(Path::to_str) {
+                    out.modified.push(p.to_string());
+                }
+            }
+            git2::Delta::Deleted => {
+                if let Some(p) = delta.old_file().path().and_then(Path::to_str) {
+                    out.deleted.push(p.to_string());
+                }
+            }
+            git2::Delta::Renamed => {
+                if let Some(p) = delta.old_file().path().and_then(Path::to_str) {
+                    out.deleted.push(p.to_string());
+                }
+                if let Some(p) = delta.new_file().path().and_then(Path::to_str) {
+                    out.added.push(p.to_string());
+                }
+            }
+            _ => {}
+        }
+    }
+    Ok(out)
+}
+
+pub fn commits_since(
+    repo: &GitRepo,
+    old_oid: &str,
+    new_oid: &str,
+) -> Result<Vec<CommitInfo>, SearchError> {
+    let r = repo.repository();
+    let new = Oid::from_str(new_oid).map_err(|e| SearchError::Git(e.to_string()))?;
+    let old = Oid::from_str(old_oid).map_err(|e| SearchError::Git(e.to_string()))?;
+    let mut revwalk = r.revwalk().map_err(|e| SearchError::Git(e.to_string()))?;
+    revwalk
+        .push(new)
+        .map_err(|e| SearchError::Git(e.to_string()))?;
+    // hide old_oid — old_oid에 도달 가능한 커밋은 결과에서 제외
+    revwalk
+        .hide(old)
+        .map_err(|e| SearchError::Git(e.to_string()))?;
+    let mut out = Vec::new();
+    for oid in revwalk.flatten() {
+        if let Ok(c) = r.find_commit(oid) {
+            out.push(CommitInfo::from_git_commit(&c));
+        }
+    }
+    Ok(out)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::git::repo::tests::{add_file_commit, init_test_repo};
+
+    #[test]
+    fn test_commits_since_excludes_old_and_includes_new() {
+        let (_dir, repo) = init_test_repo();
+        let c1 = add_file_commit(&repo, "a.txt", b"1", "first");
+        let c2 = add_file_commit(&repo, "b.txt", b"2", "second");
+        let c3 = add_file_commit(&repo, "c.txt", b"3", "third");
+
+        let gr = crate::git::repo::GitRepo::open(_dir.path()).unwrap();
+        let commits = commits_since(&gr, &c1.to_string(), &c3.to_string()).unwrap();
+        // old_oid(c1) 자체는 제외, c2/c3만 포함
+        let oids: Vec<String> = commits.iter().map(|c| c.id.to_string()).collect();
+        assert!(oids.contains(&c2.to_string()));
+        assert!(oids.contains(&c3.to_string()));
+        assert!(!oids.contains(&c1.to_string()));
+    }
+
+    #[test]
+    fn test_added_modified_deleted_classified() {
+        let (_dir, repo) = init_test_repo();
+        let _c1 = add_file_commit(&repo, "keep.txt", b"v1", "Add keep");
+        let c2 = add_file_commit(&repo, "drop.txt", b"x", "Add drop");
+        let c3_oid = {
+            // c3: modify keep.txt, delete drop.txt, add new.txt
+            std::fs::write(_dir.path().join("keep.txt"), b"v2").unwrap();
+            std::fs::remove_file(_dir.path().join("drop.txt")).unwrap();
+            std::fs::write(_dir.path().join("new.txt"), b"hi").unwrap();
+            let mut idx = repo.index().unwrap();
+            idx.add_path(std::path::Path::new("keep.txt")).unwrap();
+            idx.add_path(std::path::Path::new("new.txt")).unwrap();
+            idx.remove_path(std::path::Path::new("drop.txt")).unwrap();
+            idx.write().unwrap();
+            let tree_oid = idx.write_tree().unwrap();
+            let tree = repo.find_tree(tree_oid).unwrap();
+            let sig = git2::Signature::now("t", "t@e").unwrap();
+            let head = repo.head().unwrap().peel_to_commit().unwrap();
+            repo.commit(Some("HEAD"), &sig, &sig, "c3", &tree, &[&head])
+                .unwrap()
+                .to_string()
+        };
+
+        let gr = crate::git::repo::GitRepo::open(_dir.path()).unwrap();
+        // c2를 baseline으로 사용 — c1 tree에는 drop.txt가 없어 c1→c3 diff로는 Deleted 감지 불가
+        let changes = compute_file_changes(&gr, &c2.to_string(), &c3_oid).unwrap();
+        assert!(changes.added.iter().any(|p| p == "new.txt"));
+        assert!(changes.modified.iter().any(|p| p == "keep.txt"));
+        assert!(changes.deleted.iter().any(|p| p == "drop.txt"));
+    }
+}