Files
kage/clone/frontier.go
T
Duc-Tam Nguyen e6afa91e09 Add the clone engine, CLI, tests, CI, and docs
kage renders every page in headless Chrome, snapshots the final
DOM, strips all JavaScript, and localises CSS, images, and fonts
so a site can be browsed offline as a plain folder of files.

The engine is split into small packages:

  urlx      deterministic URL to local-path mapping and scope rules
  sanitize  remove scripts, on* handlers, and javascript: URLs
  asset     rewrite HTML and CSS references, download assets
  browser   headless Chrome pool over the DevTools protocol
  robots    robots.txt matcher
  clone     the orchestrator: a polite resumable breadth-first crawl

The cli package wires a cobra and fang command surface with two
commands, clone and serve. Every pure package has table tests; the
browser and clone packages add Chrome-driven end-to-end tests that
skip when no browser is present or under -short.

CI runs gofmt, vet, build, race tests, golangci-lint, govulncheck,
and a tidy check on Linux and macOS. A goreleaser config fans one
tag out to archives, deb/rpm/apk, a Chromium-bundled GHCR image,
and the package managers. A tago docs site builds to Pages and
Cloudflare.
2026-06-14 18:22:25 +07:00

107 lines
2.4 KiB
Go

package clone
import (
"encoding/json"
"os"
"path/filepath"
"sort"
"sync"
)
// frontier is the deduped set of page URLs kage has already seen. It is small,
// concurrency-safe, and persists to disk so --resume can skip work already done.
// The actual queueing is handled by the cloner's channels; the frontier only
// answers "is this URL new?" and remembers the answer.
type frontier struct {
mu sync.Mutex
seen map[string]bool // queued or visited
visited map[string]bool // fully written
}
func newFrontier() *frontier {
return &frontier{seen: map[string]bool{}, visited: map[string]bool{}}
}
// offer reports whether key is new (and records it as seen). A repeated key
// returns false so it is enqueued only once.
func (f *frontier) offer(key string) bool {
f.mu.Lock()
defer f.mu.Unlock()
if f.seen[key] {
return false
}
f.seen[key] = true
return true
}
// markVisited records that a page was written.
func (f *frontier) markVisited(key string) {
f.mu.Lock()
f.visited[key] = true
f.mu.Unlock()
}
// isVisited reports whether a page was already written in a previous run.
func (f *frontier) isVisited(key string) bool {
f.mu.Lock()
defer f.mu.Unlock()
return f.visited[key]
}
func (f *frontier) visitedCount() int {
f.mu.Lock()
defer f.mu.Unlock()
return len(f.visited)
}
// state is the JSON shape persisted for resume.
type state struct {
Visited []string `json:"visited"`
}
// load reads a previously saved visited set; a missing file is not an error.
func (f *frontier) load(path string) error {
data, err := os.ReadFile(path)
if err != nil {
if os.IsNotExist(err) {
return nil
}
return err
}
var s state
if err := json.Unmarshal(data, &s); err != nil {
return err
}
f.mu.Lock()
defer f.mu.Unlock()
for _, v := range s.Visited {
f.visited[v] = true
f.seen[v] = true
}
return nil
}
// save writes the visited set atomically (write temp, rename).
func (f *frontier) save(path string) error {
f.mu.Lock()
visited := make([]string, 0, len(f.visited))
for v := range f.visited {
visited = append(visited, v)
}
f.mu.Unlock()
sort.Strings(visited)
if err := os.MkdirAll(filepath.Dir(path), 0o755); err != nil {
return err
}
data, err := json.MarshalIndent(state{Visited: visited}, "", " ")
if err != nil {
return err
}
tmp := path + ".tmp"
if err := os.WriteFile(tmp, data, 0o644); err != nil {
return err
}
return os.Rename(tmp, path)
}