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v/cmd/tools/vwatch.v

481 lines
16 KiB
V

module main
import os
import time
import term
import flag
const scan_timeout_s = get_scan_timeout_seconds()
const max_v_cycles = 1000
const scan_frequency_hz = 4
const scan_period_ms = 1000 / scan_frequency_hz
const max_scan_cycles = scan_timeout_s * scan_frequency_hz
fn get_scan_timeout_seconds() int {
env_vw_timeout := os.getenv('VWATCH_TIMEOUT').int()
if env_vw_timeout == 0 {
$if gcboehm ? {
return 35000000 // over 1 year
} $else {
return 5 * 60
}
}
return env_vw_timeout
}
//
// Implements `v watch file.v` , `v watch run file.v` etc.
// With this command, V will collect all .v files that are needed for the
// compilation, then it will enter an infinite loop, monitoring them for
// changes.
//
// When a change is detected, it will stop the current process, if it is
// still running, then rerun/recompile/etc.
//
// In effect, this makes it easy to have an editor session and a separate
// terminal, running just `v watch run file.v`, and you will see your
// changes right after you save your .v file in your editor.
//
//
// Since -gc boehm is not available on all platforms yet,
// and this program leaks ~8MB/minute without it, the implementation here
// is done similarly to vfmt in 2 modes, in the same executable:
//
// a) A parent/manager process that only manages a single worker
// process. The parent process does mostly nothing except restarting
// workers, thus it does not leak much.
//
// b) A worker process, doing the actual monitoring/polling.
// Note: *workers are started with the --vwatchworker option*
//
// Worker processes will run for a limited number of iterations, then
// they will do exit(255), and then the parent will start a new worker.
// Exiting by any other code will cause the parent to also exit with the
// same error code. This limits the potential leak that a worker process
// can do, even without using the garbage collection mode.
//
struct VFileStat {
path string
mtime i64
}
[unsafe]
fn (mut vfs VFileStat) free() {
unsafe { vfs.path.free() }
}
enum RerunCommand {
restart
quit
}
struct Context {
mut:
pid int // the pid of the current process; useful while debugging manager/worker interactions
is_worker bool // true in the workers, false in the manager process
check_period_ms int = scan_period_ms
vexe string
affected_paths []string
vfiles []VFileStat
opts []string
rerun_channel chan RerunCommand
child_process &os.Process = unsafe { nil }
is_exiting bool // set by SIGINT/Ctrl-C
v_cycles int // how many times the worker has restarted the V compiler
scan_cycles int // how many times the worker has scanned for source file changes
clear_terminal bool // whether to clear the terminal before each re-run
keep_running bool // when true, re-run the program automatically if it exits on its own. Useful for gg apps.
silent bool // when true, watch will not print a timestamp line before each re-run
add_files []string // path to additional files that have to be watched for changes
ignore_exts []string // extensions of files that will be ignored, even if they change (useful for sqlite.db files for example)
cmd_before_run string // a command to run before each re-run
cmd_after_run string // a command to run after each re-run
only_watch []string // If not empty, *all* files that trigger updates, should match *at least one* of these s.match_glob() patterns. This is also triggered for vweb apps, to monitor for just *.v,*.js,*.css,*.html in vweb projects.
}
[if debug_vwatch ?]
fn (mut context Context) elog(msg string) {
eprintln('> vwatch ${context.pid}, ${msg}')
}
fn (context &Context) str() string {
return 'Context{ pid: ${context.pid}, is_worker: ${context.is_worker}, check_period_ms: ${context.check_period_ms}, vexe: ${context.vexe}, opts: ${context.opts}, is_exiting: ${context.is_exiting}, vfiles: ${context.vfiles}'
}
fn (mut context Context) is_ext_ignored(pf string, pf_ext string) bool {
for ipattern in context.ignore_exts {
if pf_ext.match_glob(ipattern) {
return true
}
}
if pf_ext in ['', '.so', '.a'] {
// on unix, the executables saved by compilers, usually do not have extensions at all, and shared libs are .so
return true
}
if pf_ext in ['.exe', '.dll', '.def'] {
// on windows, files with these extensions will be generated by the compiler
return true
}
// ignore common backup files saved by editors like emacs/jed/vim:
if pf_ext == '.bak' {
return true
}
if pf.starts_with('.#') {
return true
}
if pf.ends_with('~') {
return true
}
return false
}
fn (mut context Context) get_stats_for_affected_vfiles() []VFileStat {
if context.affected_paths.len == 0 {
mut apaths := map[string]bool{}
// The next command will make V parse the program, and print all .v files,
// needed for its compilation, without actually compiling it.
copts := context.opts.join(' ')
cmd := '"${context.vexe}" -silent -print-watched-files ${copts}'
// context.elog('> cmd: ${cmd}')
mut paths := []string{}
if context.add_files.len > 0 && context.add_files[0] != '' {
paths << context.add_files
}
vfiles := os.execute(cmd)
if vfiles.exit_code == 0 {
paths_trimmed := vfiles.output.trim_space()
reported_used_files := paths_trimmed.split_any('\n')
$if trace_reported_used_files ? {
context.elog('reported_used_files: ${reported_used_files}')
}
paths << reported_used_files
}
mut is_vweb_found := false
for vf in paths {
apaths[os.real_path(os.dir(vf))] = true
if vf.contains('vweb.v') {
is_vweb_found = true
}
}
if is_vweb_found {
if !os.args.any(it.starts_with('--only-watch')) {
// vweb is often used with SQLite .db or .sqlite3 files right next to the executable/source,
// that are updated by the vweb app, causing a restart of the app, which in turn causes the
// browser to reload the current page, that probably triggered the update in the first place.
// Note that the problem is not specific to SQLite, any database that stores its files in the
// current (project) folder, will also cause this.
println('`v watch` detected that you are compiling a vweb project.')
println(' Because of that, the `--only-watch=*.v,*.html,*.css,*.js` flag was also implied.')
println(' In result, `v watch` will ignore changes to other files.')
println(' Add your own --only-watch filter, if you wish to override that choice.')
println('')
context.only_watch = '*.v,*.html,*.css,*.js'.split_any(',')
}
}
context.affected_paths = apaths.keys()
// context.elog('vfiles paths to be scanned: $context.affected_paths')
}
// scan all files in the found folders:
mut newstats := []VFileStat{}
for path in context.affected_paths {
mut files := os.ls(path) or { []string{} }
next_file: for pf in files {
pf_path := os.join_path_single(path, pf)
if context.only_watch.len > 0 {
// in the whitelist mode, first only allow files, which match at least one of the patterns in context.only_watch:
mut matched_pattern_idx := -1
for ow_pattern_idx, ow_pattern in context.only_watch {
if pf_path.match_glob(ow_pattern) {
matched_pattern_idx = ow_pattern_idx
context.elog('> ${@METHOD} matched --only-watch pattern: ${ow_pattern}, for file: ${pf_path}')
break
}
}
if matched_pattern_idx == -1 {
context.elog('> ${@METHOD} --only-watch ignored file: ${pf_path}')
continue
}
}
// by default allow everything, except very specific extensions (backup files, executables etc):
pf_ext := os.file_ext(pf).to_lower()
if context.is_ext_ignored(pf, pf_ext) {
context.elog('> ${@METHOD} ignored extension: ${pf_ext}, for file: ${pf_path}')
continue
}
f := os.join_path(path, pf)
fullpath := os.real_path(f)
mtime := os.file_last_mod_unix(fullpath)
newstats << VFileStat{fullpath, mtime}
}
}
// always add the v compiler itself, so that if it is recompiled with `v self`
// the watcher will rerun the compilation too
newstats << VFileStat{context.vexe, os.file_last_mod_unix(context.vexe)}
return newstats
}
fn (mut context Context) get_changed_vfiles() int {
mut changed := 0
newfiles := context.get_stats_for_affected_vfiles()
for vfs in newfiles {
mut found := false
for existing_vfs in context.vfiles {
if existing_vfs.path == vfs.path {
found = true
if existing_vfs.mtime != vfs.mtime {
context.elog('> new updates for file: ${vfs}')
changed++
}
break
}
}
if !found {
changed++
continue
}
}
context.vfiles = newfiles
if changed > 0 {
context.elog('> get_changed_vfiles: ${changed}')
}
return changed
}
fn change_detection_loop(ocontext &Context) {
mut context := unsafe { ocontext }
for {
if context.v_cycles >= max_v_cycles || context.scan_cycles >= max_scan_cycles {
context.is_exiting = true
context.kill_pgroup()
time.sleep(50 * time.millisecond)
exit(255)
}
if context.is_exiting {
return
}
changes := context.get_changed_vfiles()
if changes > 0 {
context.rerun_channel <- RerunCommand.restart
}
time.sleep(context.check_period_ms * time.millisecond)
context.scan_cycles++
}
}
fn (mut context Context) kill_pgroup() {
if unsafe { context.child_process == 0 } {
return
}
if context.child_process.is_alive() {
context.child_process.signal_pgkill()
}
context.child_process.wait()
}
fn (mut context Context) run_before_cmd() {
if context.cmd_before_run != '' {
context.elog('> run_before_cmd: "${context.cmd_before_run}"')
os.system(context.cmd_before_run)
}
}
fn (mut context Context) run_after_cmd() {
if context.cmd_after_run != '' {
context.elog('> run_after_cmd: "${context.cmd_after_run}"')
os.system(context.cmd_after_run)
}
}
fn (mut context Context) compilation_runner_loop() {
cmd := '"${context.vexe}" ${context.opts.join(' ')}'
_ := <-context.rerun_channel
for {
context.elog('>> loop: v_cycles: ${context.v_cycles}')
if context.clear_terminal {
term.clear()
}
context.run_before_cmd()
timestamp := time.now().format_ss_milli()
context.child_process = os.new_process(context.vexe)
context.child_process.use_pgroup = true
context.child_process.set_args(context.opts)
context.child_process.run()
if !context.silent {
eprintln('${timestamp}: ${cmd} | pid: ${context.child_process.pid:7d} | reload cycle: ${context.v_cycles:5d}')
}
for {
mut notalive_count := 0
mut cmds := []RerunCommand{}
for {
if context.is_exiting {
return
}
if !context.child_process.is_alive() {
context.child_process.wait()
notalive_count++
if notalive_count == 1 {
// a short lived process finished, do cleanup:
context.run_after_cmd()
if context.keep_running {
break
}
}
}
select {
action := <-context.rerun_channel {
cmds << action
if action == .quit {
context.kill_pgroup()
return
}
}
100 * time.millisecond {
should_restart := RerunCommand.restart in cmds
cmds = []
if should_restart {
// context.elog('>>>>>>>> KILLING $context.child_process.pid')
context.kill_pgroup()
break
}
}
}
}
if !context.child_process.is_alive() {
context.elog('> child_process is no longer alive | notalive_count: ${notalive_count}')
context.child_process.wait()
context.child_process.close()
if notalive_count == 0 {
// a long running process was killed, do cleanup:
context.run_after_cmd()
}
break
}
}
context.v_cycles++
}
}
const ccontext = Context{
child_process: 0
}
fn main() {
mut context := unsafe { &Context(voidptr(&ccontext)) }
context.pid = os.getpid()
context.vexe = os.getenv('VEXE')
watch_pos := os.args.index('watch')
all_args_before_watch_cmd := os.args#[1..watch_pos]
all_args_after_watch_cmd := os.args#[watch_pos + 1..]
// dump(os.getpid())
// dump(all_args_before_watch_cmd)
// dump(all_args_after_watch_cmd)
// Options after `run` should be ignored, since they are intended for the user program, not for the watcher.
// For example, `v watch run x.v -a -b -k', should pass all of -a -b -k to the compiled and run program.
only_watch_options, has_run := all_before('run', all_args_after_watch_cmd)
mut fp := flag.new_flag_parser(only_watch_options)
fp.application('v watch')
fp.version('0.0.2')
fp.description('Collect all .v files needed for a compilation, then re-run the compilation when any of the source changes.')
fp.arguments_description('[--silent] [--clear] [--ignore .db] [--add /path/to/a/file.v] [run] program.v')
fp.allow_unknown_args()
context.is_worker = fp.bool('vwatchworker', 0, false, 'Internal flag. Used to distinguish vwatch manager and worker processes.')
context.silent = fp.bool('silent', `s`, false, 'Be more silent; do not print the watch timestamp before each re-run.')
context.clear_terminal = fp.bool('clear', `c`, false, 'Clears the terminal before each re-run.')
context.keep_running = fp.bool('keep', `k`, false, 'Keep the program running. Restart it automatically, if it exits by itself. Useful for gg/ui apps.')
context.add_files = fp.string('add', `a`, '', 'Add more files to be watched. Useful with `v watch --add=/tmp/feature.v run cmd/v /tmp/feature.v`, if you change *both* the compiler, and the feature.v file.').split_any(',')
context.ignore_exts = fp.string('ignore', `i`, '', 'Ignore files having these extensions. Useful with `v watch --ignore=.db run server.v`, if your server writes to an sqlite.db file in the same folder.').split_any(',')
context.only_watch = fp.string('only-watch', `o`, '', 'Watch only files matching these globe patterns. Example for a markdown renderer project: `v watch --only-watch=*.v,*.md run .`').split_any(',')
show_help := fp.bool('help', `h`, false, 'Show this help screen.')
context.cmd_before_run = fp.string('before', 0, '', 'A command to execute *before* each re-run.')
context.cmd_after_run = fp.string('after', 0, '', 'A command to execute *after* each re-run.')
if show_help {
println(fp.usage())
exit(0)
}
remaining_options := fp.finalize() or {
eprintln('Error: ${err}')
exit(1)
}
context.opts = []
context.opts << all_args_before_watch_cmd
context.opts << remaining_options
if has_run {
context.opts << 'run'
context.opts << all_after('run', all_args_after_watch_cmd)
}
context.elog('>>> context.pid: ${context.pid}')
context.elog('>>> context.vexe: ${context.vexe}')
context.elog('>>> context.opts: ${context.opts}')
context.elog('>>> context.is_worker: ${context.is_worker}')
context.elog('>>> context.clear_terminal: ${context.clear_terminal}')
context.elog('>>> context.add_files: ${context.add_files}')
context.elog('>>> context.ignore_exts: ${context.ignore_exts}')
context.elog('>>> context.only_watch: ${context.only_watch}')
if context.is_worker {
context.worker_main()
} else {
context.manager_main(all_args_before_watch_cmd, all_args_after_watch_cmd)
}
}
fn (mut context Context) manager_main(all_args_before_watch_cmd []string, all_args_after_watch_cmd []string) {
myexecutable := os.executable()
mut worker_opts := all_args_before_watch_cmd.clone()
worker_opts << ['watch', '--vwatchworker']
worker_opts << all_args_after_watch_cmd
for {
mut worker_process := os.new_process(myexecutable)
worker_process.set_args(worker_opts)
worker_process.run()
for {
if !worker_process.is_alive() {
worker_process.wait()
break
}
time.sleep(200 * time.millisecond)
}
if !(worker_process.code == 255 && worker_process.status == .exited) {
worker_process.close()
break
}
worker_process.close()
}
}
fn (mut context Context) worker_main() {
context.rerun_channel = chan RerunCommand{cap: 10}
os.signal_opt(.int, fn (_ os.Signal) {
mut context := unsafe { &Context(voidptr(&ccontext)) }
context.is_exiting = true
context.kill_pgroup()
}) or { panic(err) }
spawn context.compilation_runner_loop()
change_detection_loop(context)
}
fn all_before(needle string, all []string) ([]string, bool) {
needle_pos := all.index(needle)
if needle_pos == -1 {
return all, false
}
return all#[..needle_pos], true
}
fn all_after(needle string, all []string) []string {
needle_pos := all.index(needle)
if needle_pos == -1 {
return all
}
return all#[needle_pos + 1..]
}