Implement TotalDownload functionality

With the recent 'multibar' interface changes TotalDownload has been disabled.
Now we have a new UI and we need to find another way to display this
information.

When 'TotalDownload' config option is enabled we are going to have an extra
progress bar at the bottom of the screen that shows how much of the entire
download has been completed.

Closes FS#68202

Signed-off-by: Anatol Pomozov <anatol.pomozov@gmail.com>
Signed-off-by: Allan McRae <allan@archlinux.org>

3 files changed, 106 insertions, 51 deletions

diff --git a/doc/pacman.conf.5.asciidoc b/doc/pacman.conf.5.asciidoc
index 3c2f1fea..9bd31916 100644
--- a/doc/pacman.conf.5.asciidoc
+++ b/doc/pacman.conf.5.asciidoc
@@ -191,10 +191,8 @@ Options
 	not support escape characters.
 
 *TotalDownload*::
-	When downloading, display the amount downloaded, download rate, ETA,
-	and completed percentage of the entire download list rather
-	than the percent of each individual download target. The progress
-	bar is still based solely on the current file download.
+	When downloading, display an extra progress bar with the amount downloaded,
+	download rate, ETA, and completed percentage of the entire download list.
 	This option won't work if XferCommand is used.
 
 *CheckSpace*::
diff --git a/lib/libalpm/sync.c b/lib/libalpm/sync.c
index 5d8652a5..e25e56d4 100644
--- a/lib/libalpm/sync.c
+++ b/lib/libalpm/sync.c
@@ -846,11 +846,6 @@ finish:
 		pkg->download_size = 0;
 	}
 
-	/* clear out value to let callback know we are done */
-	if(handle->totaldlcb) {
-		handle->totaldlcb(0);
-	}
-
 	return ret;
 }
 
diff --git a/src/pacman/callback.c b/src/pacman/callback.c
index 12ab952f..9cc7541d 100644
--- a/src/pacman/callback.c
+++ b/src/pacman/callback.c
@@ -40,8 +40,9 @@
 #include "conf.h"
 
 /* download progress bar */
-static off_t list_xfered = 0.0;
+static int total_enabled = 0;
 static off_t list_total = 0.0;
+static struct pacman_progress_bar *totalbar;
 
 /* delayed output during progress bar */
 static int on_progress = 0;
@@ -56,10 +57,12 @@ static alpm_list_t *output = NULL;
 
 struct pacman_progress_bar {
 	const char *filename;
-	off_t xfered;
+	off_t xfered; /* Current amount of transferred data */
 	off_t total_size;
 	uint64_t init_time; /* Time when this download started doing any progress */
 	uint64_t sync_time; /* Last time we updated the bar info */
+	off_t sync_xfered; /* Amount of transferred data at the `sync_time` timestamp. It can be
+	                      smaller than `xfered` if we did not update bar UI for a while. */
 	double rate;
 	unsigned int eta; /* ETA in seconds */
 	bool completed; /* transfer is completed */
@@ -92,6 +95,11 @@ struct pacman_multibar_ui {
 
 struct pacman_multibar_ui multibar_ui = {0};
 
+static int dload_progressbar_enabled(void);
+static void init_total_progressbar(void);
+static void update_bar_finalstats(struct pacman_progress_bar *bar);
+static void draw_pacman_progress_bar(struct pacman_progress_bar *bar);
+
 void multibar_move_completed_up(bool value) {
 	multibar_ui.move_completed_up = value;
 }
@@ -327,6 +335,10 @@ void cb_event(alpm_event_t *event)
 		case ALPM_EVENT_PKG_RETRIEVE_START:
 			colon_printf(_("Retrieving packages...\n"));
 			on_progress = 1;
+			total_enabled = config->totaldownload && list_total;
+			if(total_enabled) {
+				init_total_progressbar();
+			}
 			break;
 		case ALPM_EVENT_DISKSPACE_START:
 			if(config->noprogressbar) {
@@ -388,6 +400,12 @@ void cb_event(alpm_event_t *event)
 		case ALPM_EVENT_PKG_RETRIEVE_DONE:
 		case ALPM_EVENT_PKG_RETRIEVE_FAILED:
 			console_cursor_move_end();
+			if(total_enabled && dload_progressbar_enabled()) {
+				update_bar_finalstats(totalbar);
+				draw_pacman_progress_bar(totalbar);
+				printf("\n");
+			}
+			total_enabled = 0;
 			flush_output_list();
 			on_progress = 0;
 			break;
@@ -679,11 +697,6 @@ void cb_progress(alpm_progress_t event, const char *pkgname, int percent,
 void cb_dl_total(off_t total)
 {
 	list_total = total;
-	/* if we get a 0 value, it means this list has finished downloading,
-	 * so clear out our list_xfered as well */
-	if(total == 0) {
-		list_xfered = 0;
-	}
 }
 
 static int dload_progressbar_enabled(void)
@@ -726,6 +739,16 @@ static bool find_bar_for_filename(const char *filename, int *index, struct pacma
 	return false;
 }
 
+static void init_total_progressbar(void)
+{
+	totalbar = calloc(1, sizeof(struct pacman_progress_bar));
+	assert(totalbar);
+	totalbar->filename = _("Total:");
+	totalbar->init_time = get_time_ms();
+	totalbar->total_size = list_total;
+	totalbar->rate = 0.0;
+}
+
 static void draw_pacman_progress_bar(struct pacman_progress_bar *bar)
 {
 	int infolen;
@@ -742,7 +765,7 @@ static void draw_pacman_progress_bar(struct pacman_progress_bar *bar)
 	const unsigned short cols = getcols();
 
 	if(bar->total_size) {
-		file_percent = (bar->xfered * 100) / bar->total_size;
+		file_percent = (bar->sync_xfered * 100) / bar->total_size;
 	} else {
 		file_percent = 100;
 	}
@@ -802,7 +825,7 @@ static void draw_pacman_progress_bar(struct pacman_progress_bar *bar)
 	}
 
 	rate_human = humanize_size((off_t)bar->rate, '\0', -1, &rate_label);
-	xfered_human = humanize_size(bar->xfered, '\0', -1, &xfered_label);
+	xfered_human = humanize_size(bar->sync_xfered, '\0', -1, &xfered_label);
 
 	printf(" %ls%-*s ", wcfname, padwid, "");
 	/* We will show 1.62 MiB/s, 11.6 MiB/s, but 116 KiB/s and 1116 KiB/s */
@@ -851,49 +874,100 @@ static void dload_init_event(const char *filename, alpm_download_event_init_t *d
 	printf(_(" %s downloading...\n"), filename);
 	multibar_ui.cursor_lineno++;
 	multibar_ui.active_downloads_num++;
+
+	if(total_enabled) {
+		/* redraw the total download progress bar */
+		draw_pacman_progress_bar(totalbar);
+		printf("\n");
+		multibar_ui.cursor_lineno++;
+	}
 }
 
-/* Draws download progress */
-static void dload_progress_event(const char *filename, alpm_download_event_progress_t *data)
+/* Update progress bar rate/eta stats.
+ * Returns true if the bar redraw is required, false otherwise
+ */
+static bool update_bar_stats(struct pacman_progress_bar *bar)
 {
-	int index;
-	struct pacman_progress_bar *bar;
-	int64_t curr_time = get_time_ms();
-	double last_chunk_rate;
 	int64_t timediff;
-	bool ok;
-
-	if(!dload_progressbar_enabled()) {
-		return;
-	}
-
-	ok = find_bar_for_filename(filename, &index, &bar);
-	assert(ok);
+	off_t last_chunk_amount;
+	double last_chunk_rate;
+	int64_t curr_time = get_time_ms();
 
 	/* compute current average values */
 	timediff = curr_time - bar->sync_time;
 
 	if(timediff < UPDATE_SPEED_MS) {
 		/* return if the calling interval was too short */
-		return;
+		return false;
 	}
+	last_chunk_amount = bar->xfered - bar->sync_xfered;
+	bar->sync_xfered = bar->xfered;
 	bar->sync_time = curr_time;
 
-	last_chunk_rate = (double)(data->downloaded - bar->xfered) / (timediff / 1000.0);
+	last_chunk_rate = (double)last_chunk_amount * 1000 / timediff;
 	/* average rate to reduce jumpiness */
 	bar->rate = (last_chunk_rate + 2 * bar->rate) / 3;
 	if(bar->rate > 0.0) {
-		bar->eta = (data->total - data->downloaded) / bar->rate;
+		bar->eta = (bar->total_size - bar->sync_xfered) / bar->rate;
 	} else {
 		bar->eta = UINT_MAX;
 	}
 
+	return true;
+}
+
+static void update_bar_finalstats(struct pacman_progress_bar *bar)
+{
+	int64_t timediff;
+
+	/* compute final values */
+	bar->xfered = bar->total_size;
+	bar->sync_xfered = bar->total_size;
+	timediff = get_time_ms() - bar->init_time;
+
+	/* if transfer was too fast, treat it as a 1ms transfer, for the sake
+	* of the rate calculation */
+	if(timediff < 1)
+		timediff = 1;
+
+	bar->rate = (double)bar->total_size * 1000 / timediff;
+	/* round elapsed time (in ms) to the nearest second */
+	bar->eta = (unsigned int)(timediff + 500) / 1000;
+}
+
+/* Handles download progress event */
+static void dload_progress_event(const char *filename, alpm_download_event_progress_t *data)
+{
+	int index;
+	struct pacman_progress_bar *bar;
+	bool ok;
+	off_t last_chunk_amount;
+
+	if(!dload_progressbar_enabled()) {
+		return;
+	}
+
+	ok = find_bar_for_filename(filename, &index, &bar);
+	assert(ok);
+
 	/* Total size is received after the download starts. */
-	bar->total_size = data->total;
+	last_chunk_amount = data->downloaded - bar->xfered;
 	bar->xfered = data->downloaded;
+	bar->total_size = data->total;
+
+	if(update_bar_stats(bar)) {
+		console_cursor_goto_bar(index);
+		draw_pacman_progress_bar(bar);
+	}
+
+	if(total_enabled) {
+		totalbar->xfered += last_chunk_amount;
+		if(update_bar_stats(totalbar)) {
+			console_cursor_move_end();
+			draw_pacman_progress_bar(totalbar);
+		}
+	}
 
-	console_cursor_goto_bar(index);
-	draw_pacman_progress_bar(bar);
 	fflush(stdout);
 }
 
@@ -902,7 +976,6 @@ static void dload_complete_event(const char *filename, alpm_download_event_compl
 {
 	int index;
 	struct pacman_progress_bar *bar;
-	int64_t timediff;
 	bool ok;
 
 	if(!dload_progressbar_enabled()) {
@@ -923,18 +996,7 @@ static void dload_complete_event(const char *filename, alpm_download_event_compl
 		/* The line contains text from previous status. Erase these leftovers. */
 		console_erase_line();
 	} else if(data->result == 0) {
-		/* compute final values */
-		bar->xfered = bar->total_size;
-		timediff = get_time_ms() - bar->init_time;
-
-		/* if transfer was too fast, treat it as a 1ms transfer, for the sake
-		 * of the rate calculation */
-		if(timediff < 1)
-			timediff = 1;
-
-		bar->rate = (double)bar->xfered / (timediff / 1000.0);
-		/* round elapsed time (in ms) to the nearest second */
-		bar->eta = (unsigned int)(timediff + 500) / 1000;
+		update_bar_finalstats(bar);
 
 		if(multibar_ui.move_completed_up && index != 0) {
 			/* If this item completed then move it to the top.