worker: reuse session reference for compaction reads

.yoi/tickets/00001KXS81AMT/item.md

@@ -0,0 +1,39 @@
+---
+title: 'Compactionのsession探索toolsをSessionReferenceViewへ移行する'
+state: 'closed'
+created_at: '2026-07-17T23:54:22Z'
+updated_at: '2026-07-18T00:02:34Z'
+assignee: null
+---
+
+## 背景
+
+`SessionReferenceView` は extract / compact の共通基盤として導入されたが、直後の実装では compaction の `search_session_log` のみが view を使い、`read_session_items` は旧 compact 専用 formatter / direct item traversal のままだった。
+
+既存 compact も explore tool 群を利用するものに寄せるため、この Ticket では compaction の session read/search tools を `SessionReferenceView` へ統合する。
+
+## 実装要件
+
+- compaction の `search_session_log` は `SessionReferenceView::search` を使う。
+- compaction の `read_session_items` は `SessionReferenceView::read` を使う。
+- `read_session_items` の existing `mode = compact | full` semantics は維持する。
+  - compact: tool arguments / tool result content を omitted にする。
+  - full: bounded に tool arguments / tool result content を読める。
+- 旧 compact 専用の session search / format helper を削除する。
+- `SessionReferenceView` 側に read detail mode を追加し、compact / full を表現できるようにする。
+- 既存 compact tests を維持または更新する。
+
+## 非目標
+
+- compaction prompt を大きく変えない。
+- compact worker の tool 名を変更しない。
+- extract の `session-explore` feature 本体はこの Ticket では実装しない。
+
+## 受け入れ条件
+
+- `search_session_log` と `read_session_items` がどちらも `SessionReferenceView` を経由する。
+- compact mode で raw tool content が出ない。
+- full mode で bounded tool content が読める。
+- `cargo test -p worker compact::worker` が通る。
+- `cargo test -p worker` が通る。
+- code 変更として `nix build .#yoi` が通る。

.yoi/tickets/00001KXS81AMT/resolution.md

@@ -0,0 +1,11 @@
+Compaction session exploration now uses `SessionReferenceView` for both search and read paths.
+
+`read_session_items` delegates to `SessionReferenceView::read`, preserving compact/full behavior through a new read detail mode. Old compact-specific search/format helpers were removed.
+
+Validation passed:
+- `cargo fmt --check`
+- `cargo test -p worker compact::worker`
+- `cargo test -p worker session_reference`
+- `cargo test -p worker`
+- `cargo test -p memory`
+- `nix build .#yoi`

.yoi/tickets/00001KXS81AMT/thread.md

@@ -0,0 +1,68 @@
+<!-- event: create author: "yoi ticket" at: 2026-07-17T23:54:22Z -->
+
+## 作成
+
+LocalTicketBackend によって作成されました。
+
+---
+
+<!-- event: implementation_report author: hare at: 2026-07-18T00:02:34Z -->
+
+## Implementation report
+
+Migrated compaction session exploration to `SessionReferenceView`.
+
+Changes:
+- Added `ReadDetail` to `SessionReferenceView` so reads can preserve compact/full semantics.
+- Updated `read_session_items` to use `SessionReferenceView::read` with `ReadSelector::EntryRange`.
+- Kept compact mode omitting tool arguments / tool result content and full mode bounded.
+- Removed old compact-specific session search/format helpers.
+- `search_session_log` already used `SessionReferenceView::search` and remains on that path.
+
+Validation:
+- `cargo fmt --check`
+- `cargo test -p worker compact::worker`
+- `cargo test -p worker session_reference`
+- `cargo test -p worker`
+- `cargo test -p memory`
+- `nix build .#yoi`
+
+
+---
+
+<!-- event: state_changed author: "yoi ticket" at: 2026-07-18T00:02:34Z from: inprogress to: done reason: cli_state field: state -->
+
+## State changed
+
+State changed to `done`.
+
+
+---
+
+<!-- event: state_changed author: hare at: 2026-07-18T00:02:34Z from: done to: closed reason: closed field: state -->
+
+## State changed
+
+Ticket を closed にしました。
+
+
+---
+
+<!-- event: close author: hare at: 2026-07-18T00:02:34Z status: closed -->
+
+## 完了
+
+Compaction session exploration now uses `SessionReferenceView` for both search and read paths.
+
+`read_session_items` delegates to `SessionReferenceView::read`, preserving compact/full behavior through a new read detail mode. Old compact-specific search/format helpers were removed.
+
+Validation passed:
+- `cargo fmt --check`
+- `cargo test -p worker compact::worker`
+- `cargo test -p worker session_reference`
+- `cargo test -p worker`
+- `cargo test -p memory`
+- `nix build .#yoi`
+
+
+---

crates/worker/src/compact/worker.rs

@@ -30,7 +30,10 @@ use tools::ScopedFs;
 
 use crate::compact::usage_tracker::UsageTracker;
 use crate::fs_view::{ReadRequirement, slice_lines};
-use crate::session_reference::{ReferenceKind, SearchOptions, SessionReferenceView};
+use crate::session_reference::{
+    ReadDetail, ReadOptions, ReadSelector, ReferenceKind, SearchOptions, SessionReferenceView,
+    ToolPart,
+};
 
 /// Aggregated output of a compact worker run.
 #[derive(Debug, Default, Clone)]
@@ -241,17 +244,36 @@ impl Tool for ReadSessionItemsTool {
         let offset = params.offset.min(self.state.items.len());
         let limit = params.limit.clamp(1, SESSION_READ_MAX_ITEMS);
         let end = offset.saturating_add(limit).min(self.state.items.len());
-        let mut blocks = Vec::new();
-        for idx in offset..end {
-            blocks.push(format_session_item(
-                idx,
-                &self.state.items[idx],
-                mode,
-                4_000,
-            ));
+        let detail = match mode {
+            SessionReadMode::Compact => ReadDetail::Compact,
+            SessionReadMode::Full => ReadDetail::Full,
+        };
+        let read = if offset >= end {
+            crate::session_reference::ReadResult {
+                entries: Vec::new(),
+                truncated: false,
             }
-        let mut content = blocks.join("\n\n");
-        let truncated = truncate_to_token_budget(&mut content, SESSION_TOOL_MAX_OUTPUT_TOKENS);
+        } else {
+            self.state.view.read(
+                ReadSelector::EntryRange([offset as u64, end.saturating_sub(1) as u64]),
+                ReadOptions {
+                    include_tools: true,
+                    tool_part: ToolPart::Both,
+                    detail,
+                    max_items: limit,
+                    max_bytes: 48 * 1024,
+                },
+            )
+        };
+        let mut content = read
+            .entries
+            .iter()
+            .map(|entry| entry.text.clone())
+            .collect::<Vec<_>>()
+            .join("\n\n");
+        let token_truncated =
+            truncate_to_token_budget(&mut content, SESSION_TOOL_MAX_OUTPUT_TOKENS);
+        let truncated = read.truncated || token_truncated;
         let summary = if truncated {
             format!(
                 "Read session items {offset}..{end} in {mode:?} mode; output truncated. Narrow the range."
@@ -284,93 +306,6 @@ impl SessionReadMode {
     }
 }
 
-fn session_item_search_text(item: &Item) -> String {
-    match item {
-        Item::Message { role, content, .. } => format!(
-            "{:?} {}",
-            role,
-            content
-                .iter()
-                .map(|p| p.as_text())
-                .collect::<Vec<_>>()
-                .join("")
-        ),
-        Item::ToolCall {
-            name, arguments, ..
-        } => format!("tool_call {name} {arguments}"),
-        Item::ToolResult {
-            summary, content, ..
-        } => format!(
-            "tool_result {summary} {}",
-            content.as_deref().unwrap_or_default()
-        ),
-        Item::Reasoning { text, summary, .. } => format!("reasoning {text} {}", summary.join(" ")),
-    }
-}
-
-fn format_session_item(idx: usize, item: &Item, mode: SessionReadMode, max_chars: usize) -> String {
-    match item {
-        Item::Message { role, content, .. } => {
-            let text = content
-                .iter()
-                .map(|p| p.as_text())
-                .collect::<Vec<_>>()
-                .join("");
-            format!(
-                "[{idx} Message {:?}] {}",
-                role,
-                truncate_chars(&text, max_chars)
-            )
-        }
-        Item::ToolCall {
-            name, arguments, ..
-        } => match mode {
-            SessionReadMode::Compact => format!("[{idx} ToolCall] {name} (arguments omitted)"),
-            SessionReadMode::Full => format!(
-                "[{idx} ToolCall] {name}\narguments: {}",
-                truncate_chars(arguments, max_chars)
-            ),
-        },
-        Item::ToolResult {
-            summary,
-            content,
-            is_error,
-            ..
-        } => match mode {
-            SessionReadMode::Compact => format!(
-                "[{idx} ToolResult{}] {} (content omitted)",
-                if *is_error { " error" } else { "" },
-                truncate_chars(summary, 800)
-            ),
-            SessionReadMode::Full => format!(
-                "[{idx} ToolResult{}] {}\ncontent: {}",
-                if *is_error { " error" } else { "" },
-                truncate_chars(summary, 800),
-                truncate_chars(content.as_deref().unwrap_or(""), max_chars)
-            ),
-        },
-        Item::Reasoning { summary, .. } => match mode {
-            SessionReadMode::Compact => format!(
-                "[{idx} Reasoning] {} (body omitted)",
-                truncate_chars(&summary.join(" "), 800)
-            ),
-            SessionReadMode::Full => format!(
-                "[{idx} Reasoning] {} (body omitted)",
-                truncate_chars(&summary.join(" "), 800)
-            ),
-        },
-    }
-}
-
-fn truncate_chars(text: &str, max_chars: usize) -> String {
-    if text.chars().count() <= max_chars {
-        return text.to_string();
-    }
-    let mut out = text.chars().take(max_chars).collect::<String>();
-    out.push_str("… [truncated]");
-    out
-}
-
 fn truncate_to_token_budget(text: &mut String, max_tokens: u64) -> bool {
     let max_bytes = max_tokens.saturating_mul(4) as usize;
     if text.len() <= max_bytes {

crates/worker/src/session_reference.rs

@@ -121,10 +121,17 @@ pub(crate) enum ReadSelector<'a> {
     EntryRange([u64; 2]),
 }
 
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+pub(crate) enum ReadDetail {
+    Compact,
+    Full,
+}
+
 #[derive(Debug, Clone)]
 pub(crate) struct ReadOptions {
     pub include_tools: bool,
     pub tool_part: ToolPart,
+    pub detail: ReadDetail,
     pub max_items: usize,
     pub max_bytes: usize,
 }
@@ -134,6 +141,7 @@ impl Default for ReadOptions {
         Self {
             include_tools: true,
             tool_part: ToolPart::Both,
+            detail: ReadDetail::Compact,
             max_items: DEFAULT_READ_MAX_ITEMS,
             max_bytes: DEFAULT_READ_MAX_BYTES,
         }
@@ -344,7 +352,7 @@ impl SessionReferenceView {
             let Some(item) = self.items.get(entry.entry_range[0] as usize) else {
                 continue;
             };
-            let text = render_item(item, entry, max_bytes.saturating_sub(bytes));
+            let text = render_item(item, entry, options.detail, max_bytes.saturating_sub(bytes));
             bytes = bytes.saturating_add(text.len());
             entries.push(ReadEntry {
                 id: entry.id.clone(),
@@ -378,7 +386,12 @@ impl SessionReferenceView {
     }
 }
 
-fn render_item(item: &Item, entry: &ReferenceEntry, max_bytes: usize) -> String {
+fn render_item(
+    item: &Item,
+    entry: &ReferenceEntry,
+    detail: ReadDetail,
+    max_bytes: usize,
+) -> String {
     let text = match item {
         Item::Message { role, content, .. } => {
             let text = content
@@ -390,14 +403,28 @@ fn render_item(item: &Item, entry: &ReferenceEntry, max_bytes: usize) -> String
         }
         Item::ToolCall {
             name, arguments, ..
-        } => format!("[{} ToolInput {name}]\narguments: {arguments}", entry.id),
+        } => match detail {
+            ReadDetail::Compact => format!("[{} ToolInput {name}] (arguments omitted)", entry.id),
+            ReadDetail::Full => format!("[{} ToolInput {name}]\narguments: {arguments}", entry.id),
+        },
         Item::ToolResult {
-            summary, content, ..
-        } => format!(
-            "[{} ToolOutput]\nsummary: {summary}\ncontent: {}",
+            summary,
+            content,
+            is_error,
+            ..
+        } => match detail {
+            ReadDetail::Compact => format!(
+                "[{} ToolOutput{}]\nsummary: {summary}\ncontent: (omitted)",
                 entry.id,
+                if *is_error { " error" } else { "" }
+            ),
+            ReadDetail::Full => format!(
+                "[{} ToolOutput{}]\nsummary: {summary}\ncontent: {}",
+                entry.id,
+                if *is_error { " error" } else { "" },
                 content.as_deref().unwrap_or_default()
             ),
+        },
         Item::Reasoning { .. } => format!("[{} Reasoning omitted]", entry.id),
     };
     truncate_chars(&text, max_bytes)
@@ -488,6 +515,7 @@ mod tests {
             ReadSelector::EntryRange([0, 3]),
             ReadOptions {
                 include_tools: false,
+                detail: ReadDetail::Compact,
                 max_items: 10,
                 max_bytes: 1_000,
                 ..ReadOptions::default()