Source Code of the client side program

gistfile1.go

	usr, err := user.Current() // Get the operating system user.
	if err != nil {
		log.Fatal( err )
	} else {
		monitorFolder := path.Join(usr.HomeDir, monitorFolderName) // A particular folder in the home directory.

		// Make sure the folder exists
		if ensureFolder(monitorFolder) {

			// fileStore is an object that caches the folder status in memory
			fileStore := common.NewFileRecordStore(monitorFolder)

			// Load previous state from a file, as users may shutdown the program, 
			// the program needs to restore to the previous state
			fileStore.LoadFromFile()

			// This is a concurrency channel. which is a bridge between file scan and the remote api call.
			changesChannel := make(chan common.FileRecord, 10)

			// This is a new thread, which read from the channel and call remote http api.
			go submitToRemote(changesChannel, fileStore)

			for {
				// This is the main thread, which scan the folder every 5 seconds, If any changes found, send it to the channel.
				fileStore.Scan(changesChannel)

				// scan interval.
				time.Sleep(folderScanInterval * time.Millisecond)
			}
		}
	}