Skip to content

⚡ Bolt: Hoist os.Executable() from loop in generateCronContent #91

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
minibota wants to merge 1 commit into
base: main
Choose a base branch
from
Open

⚡ Bolt: Hoist os.Executable() from loop in generateCronContent #91

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
2 changes: 2 additions & 0 deletions .jules/bolt.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,3 +5,5 @@
## 2025-12-18 - [JSON Unmarshalling] **Learning:** Polymorphic JSON messages (flat structure) often lead to double parsing (once for type, once for content). **Action:** Use a "Unified" struct containing all possible fields to allow single-pass unmarshalling when fields do not collide.

## 2024-05-22 - [Buffer String Construction] **Learning:** Using `strings.Builder` with `Grow` is significantly faster than `bytes.Buffer` for constructing strings from parts, as `strings.Builder.String()` avoids the final allocation. **Action:** Prefer `strings.Builder` over `bytes.Buffer` when the final goal is a `string`.

## 2026-01-29 - [System Call Hoisting] **Learning:** `os.Executable()` on Linux performs a `readlink` syscall which is not cached by the Go runtime. In a loop, this syscall overhead dominates execution time (e.g., ~2.8µs vs ~0.35µs per op). **Action:** Hoist `os.Executable()` and similar system calls (like `os.Getwd`) out of hot loops.
12 changes: 6 additions & 6 deletions cmd/daemon.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -417,6 +417,12 @@ func generateCronContent(jobs []protocol.JobDefinition, systemMode bool) []byte
buf.WriteString("SHELL=/bin/bash\n")
buf.WriteString("PATH=/usr/local/bin:/usr/bin:/bin\n\n")

// Self-executable path
execPath, err := os.Executable()
if err != nil {
execPath = "/usr/local/bin/cc-agent"
}

for _, job := range jobs {
if containsNewline(job.CronExpression) || containsNewline(job.JobID) || containsNewline(job.Command) {
log.Printf("Skipping job %q: contains invalid characters", job.JobID)
Expand All @@ -434,12 +440,6 @@ func generateCronContent(jobs []protocol.JobDefinition, systemMode bool) []byte
buf.WriteString("root ")
}

// Self-executable path
execPath, err := os.Executable()
if err != nil {
execPath = "/usr/local/bin/cc-agent"
}

buf.WriteString(execPath)
buf.WriteString(" exec --job-id ")
writeShellQuote(&buf, job.JobID)
Expand Down