winx_code_agent/tools/
multi_file_edit.rs

1//! Implementation of the `MultiFileEdit` tool.
2//!
3//! Applies edits across several files all-or-nothing at the COMPUTE stage: every
4//! file is validated and its new content computed in memory first (reusing
5//! `file_write_or_edit::plan_edit`), and only if ALL succeed is anything written.
6//! So a SEARCH block that fails to match in the last file leaves the earlier
7//! files untouched, instead of the half-edited tree N separate `FileWriteOrEdit`
8//! calls would leave.
9//!
10//! The write stage is a sequence of individually-atomic single-file renames
11//! (`commit_edit` -> `write_no_follow`). It stops at the first I/O failure and
12//! reports which files were already written; it does NOT roll them back (each is
13//! already crash-safe on its own, and a second write pass could fail and corrupt
14//! more state).
15
16use std::collections::HashSet;
17use std::sync::Arc;
18
19use tokio::sync::Mutex;
20use tracing::instrument;
21
22use crate::errors::{Result, WinxError};
23use crate::state::bash_state::BashState;
24use crate::tools::file_write_or_edit::{commit_edit, plan_edit};
25use crate::types::{normalize_thread_id, FileEditEntry, MultiFileEdit};
26
27/// Upper bound on files per batch. The whole batch holds the `bash_state` lock
28/// across its (synchronous) file IO, so a huge batch would block the executor
29/// and other sessions for a long time. A real multi-file refactor is well under
30/// this; the cap is a guard against a pathological request.
31const MAX_FILES_PER_BATCH: usize = 100;
32
33#[instrument(level = "info", skip(bash_state_arc, multi))]
34pub async fn handle_tool_call(
35    bash_state_arc: &Arc<Mutex<Option<BashState>>>,
36    multi: MultiFileEdit,
37) -> Result<String> {
38    let mut bash_state_guard = bash_state_arc.lock().await;
39
40    // Cheap validation up front (needs only the current thread id).
41    {
42        let bash_state = bash_state_guard.as_ref().ok_or(WinxError::BashStateNotInitialized)?;
43        let thread_id = normalize_thread_id(&multi.thread_id);
44        if thread_id != bash_state.current_thread_id {
45            return Err(WinxError::ThreadIdMismatch(thread_id));
46        }
47    }
48    if multi.files.len() < 2 {
49        return Err(WinxError::ArgumentParseError(
50            "MultiFileEdit needs at least 2 files; use FileWriteOrEdit for a single file."
51                .to_string(),
52        ));
53    }
54    if multi.files.len() > MAX_FILES_PER_BATCH {
55        return Err(WinxError::ArgumentParseError(format!(
56            "MultiFileEdit is limited to {MAX_FILES_PER_BATCH} files per batch (got {}); split the \
57             change into smaller batches.",
58            multi.files.len()
59        )));
60    }
61
62    // Move the state onto the blocking pool for the synchronous plan+commit IO
63    // (reading every file, then writing every file). The guard is held throughout,
64    // so the slot stays locked — mutual exclusion is preserved; `take` just lets us
65    // own the value across spawn_blocking. This frees the tokio worker instead of
66    // pinning it on up to MAX_FILES_PER_BATCH file reads/writes.
67    let mut state = bash_state_guard.take().ok_or(WinxError::BashStateNotInitialized)?;
68    let recovery_state = state.clone();
69    let files = multi.files;
70    let joined = tokio::task::spawn_blocking(move || {
71        let result = std::panic::catch_unwind(std::panic::AssertUnwindSafe(|| {
72            apply_batch(&mut state, &files)
73        }))
74        .unwrap_or_else(|_| {
75            Err(WinxError::CommandExecutionError(
76                "MultiFileEdit panicked on the blocking worker".to_string(),
77            ))
78        });
79        (state, result)
80    })
81    .await;
82
83    match joined {
84        Ok((state, result)) => {
85            *bash_state_guard = Some(state);
86            result
87        }
88        Err(error) => {
89            *bash_state_guard = Some(recovery_state);
90            Err(WinxError::CommandExecutionError(format!(
91                "MultiFileEdit blocking task failed: {error}"
92            )))
93        }
94    }
95}
96
97/// Plan every file (all-or-nothing at the compute stage), reject duplicate
98/// targets, then commit sequentially. Synchronous (file IO) — runs on the
99/// blocking pool, never on a tokio worker.
100fn apply_batch(bash_state: &mut BashState, files: &[FileEditEntry]) -> Result<String> {
101    // PHASE 1: plan every file (validate + compute new content) with NO writes.
102    // Any failure aborts the whole batch having touched nothing on disk.
103    let mut planned = Vec::with_capacity(files.len());
104    for (index, entry) in files.iter().enumerate() {
105        let edit = plan_edit(
106            bash_state,
107            &entry.file_path,
108            entry.percentage_to_change,
109            &entry.text_or_search_replace_blocks,
110        )
111        .map_err(|e| {
112            // Plan failures (bad path, mode gate, stale/unread file, SEARCH miss)
113            // are all caused by the agent's input, so keep them client-classified
114            // (invalid_request) rather than wrapping in a server-error variant.
115            WinxError::ArgumentParseError(format!(
116                "MultiFileEdit aborted before writing anything - file {} ({}) failed validation: {e}",
117                index + 1,
118                entry.file_path
119            ))
120        })?;
121        planned.push(edit);
122    }
123
124    // Reject duplicate targets, checked on the RESOLVED path (so `a.txt` and its
125    // absolute form can't both slip through and clobber each other): two entries
126    // for the same file don't compose - the second is computed from the original,
127    // not the first's result, so it would silently overwrite the first.
128    let mut seen = HashSet::with_capacity(planned.len());
129    for edit in &planned {
130        if !seen.insert(edit.target()) {
131            return Err(WinxError::ArgumentParseError(format!(
132                "MultiFileEdit targets '{}' more than once; edits to the same file don't compose - \
133                 combine them into a single entry.",
134                edit.target()
135            )));
136        }
137    }
138
139    // PHASE 2: commit sequentially. Each write is individually atomic (temp +
140    // rename). On the first failure, stop and report honestly without rolling
141    // back already-written files.
142    let total = planned.len();
143    let mut summaries = Vec::with_capacity(total);
144    for (committed, edit) in planned.into_iter().enumerate() {
145        let target = edit.target().to_string();
146        match commit_edit(bash_state, edit) {
147            Ok(summary) => summaries.push(format!("[{target}]\n{summary}")),
148            Err(e) => {
149                return Err(WinxError::CommandExecutionError(format!(
150                    "MultiFileEdit: committed {committed} of {total} files, then failed writing \
151                     {target}: {e}\nThe {committed} already-written file(s) were NOT rolled back. \
152                     Re-read the affected files and retry the rest."
153                )));
154            }
155        }
156    }
157
158    Ok(format!("MultiFileEdit applied all {total} edits:\n\n{}", summaries.join("\n\n")))
159}
winx_code_agent/tools/multi_file_edit.rs

winx_code_agent/tools/
multi_file_edit.rs
