From 7e689438aece239620e18e8e8e5e565797a2caab Mon Sep 17 00:00:00 2001
From: "Alexander \"Arav\" Andreev" <me@arav.top>
Date: Wed, 25 May 2022 18:51:01 +0400
Subject: [PATCH] Added comments for inotify watcher.

---
 pkg/watcher/linux.go | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/pkg/watcher/linux.go b/pkg/watcher/linux.go
index 7951476..972a2fa 100644
--- a/pkg/watcher/linux.go
+++ b/pkg/watcher/linux.go
@@ -7,8 +7,12 @@ import (
 	"github.com/pkg/errors"
 )
 
+// CrDelMask predefined constant with create and delete events.
 const CrDelMask uint32 = syscall.IN_CREATE | syscall.IN_DELETE
 
+// inotifyCount is amount of InotifyEvent structures
+// we read in WatchForMask(). 16 was chosen experimentally,
+// with lesser amount events are often missing.
 const inotifyCount = 16
 
 type InotifyWatcher struct {
@@ -17,6 +21,8 @@ type InotifyWatcher struct {
 	closed bool
 }
 
+// NewInotifyWatcher initialises inotify mechanism and returns
+// an instance of InotifyWatcher.
 func NewInotifyWatcher() (w *InotifyWatcher, err error) {
 	w = &InotifyWatcher{closed: false}
 
@@ -30,6 +36,8 @@ func NewInotifyWatcher() (w *InotifyWatcher, err error) {
 	return w, nil
 }
 
+// AddWatch sets on watch file or directory specified in `path`
+// for syscall.IN_XXXX events specified in `mask`.
 func (w *InotifyWatcher) AddWatch(path string, mask uint32) error {
 	wd, err := syscall.InotifyAddWatch(w.fd, path, mask)
 	if err != nil {
@@ -41,7 +49,8 @@ func (w *InotifyWatcher) AddWatch(path string, mask uint32) error {
 	return nil
 }
 
-// WatchForMask checking for events from mask and returns inotify mask to channel.
+// WatchForMask checks for events specified in `mask` and sends them
+// to channel `fired`. See `man inotify` for events.
 func (w *InotifyWatcher) WatchForMask(fired chan uint32, mask uint32) {
 	go func() {
 		for !w.closed {
@@ -65,6 +74,8 @@ func (w *InotifyWatcher) WatchForMask(fired chan uint32, mask uint32) {
 	}()
 }
 
+// Close removes all watchers, closes inotify descriptor and stops all
+// WatchForMask() event loops.
 func (w *InotifyWatcher) Close() error {
 	for _, wd := range w.wds {
 		if _, err := syscall.InotifyRmWatch(w.fd, uint32(wd)); err != nil {