Add a utility function to humanize sizes

Converts the given size in bytes in two possible ways:
1) target_unit is specified (!= 0): size is converted to target unit.
2) target_unit is not specified (== '\0'): size is converted to the first
   unit which will bring size to below 2048.

If specified, label will point to the long label ('MB') if long_labels is
set or the short label ('M') if it is not.

Dan: use '\0' rather than 0 for the special value as a matter of coding
style for char variables.

Signed-off-by: Jakob Gruber <jakob.gruber@gmail.com>
Signed-off-by: Dan McGee <dan@archlinux.org>

4 files changed, 68 insertions, 50 deletions

diff --git a/src/pacman/callback.c b/src/pacman/callback.c
index 08c1cf3f..7fb52129 100644
--- a/src/pacman/callback.c
+++ b/src/pacman/callback.c
@@ -492,10 +492,11 @@ void cb_dl_progress(const char *filename, off_t file_xfered, off_t file_total)
 
 	int totaldownload = 0;
 	off_t xfered, total;
-	double rate = 0.0, timediff = 0.0, f_xfered = 0.0;
+	double rate = 0.0, timediff = 0.0;
 	unsigned int eta_h = 0, eta_m = 0, eta_s = 0;
+	double rate_human, xfered_human;
+	const char *rate_label, *xfered_label;
 	int file_percent = 0, total_percent = 0;
-	char rate_size = 'K', xfered_size = 'K';
 
 	if(config->noprogressbar || file_total == -1) {
 		if(file_xfered == 0) {
@@ -557,7 +558,7 @@ void cb_dl_progress(const char *filename, off_t file_xfered, off_t file_total)
 		diff_sec = current_time.tv_sec - initial_time.tv_sec;
 		diff_usec = current_time.tv_usec - initial_time.tv_usec;
 		timediff = diff_sec + (diff_usec / 1000000.0);
-		rate = xfered / (timediff * 1024.0);
+		rate = xfered / timediff;
 
 		/* round elapsed time to the nearest second */
 		eta_s = (int)(timediff + 0.5);
@@ -569,10 +570,10 @@ void cb_dl_progress(const char *filename, off_t file_xfered, off_t file_total)
 			/* return if the calling interval was too short */
 			return;
 		}
-		rate = (xfered - xfered_last) / (timediff * 1024.0);
+		rate = (xfered - xfered_last) / timediff;
 		/* average rate to reduce jumpiness */
 		rate = (rate + 2 * rate_last) / 3;
-		eta_s = (total - xfered) / (rate * 1024.0);
+		eta_s = (total - xfered) / rate;
 		rate_last = rate;
 		xfered_last = xfered;
 	}
@@ -626,37 +627,13 @@ void cb_dl_progress(const char *filename, off_t file_xfered, off_t file_total)
 
 	}
 
-	/* Awesome formatting for progress bar.  We need a mess of Kb->Mb->Gb stuff
-	 * here. We'll use limit of 2048 for each until we get some empirical */
-	/* rate_size = 'K'; was set above */
-	if(rate > 2048.0) {
-		rate /= 1024.0;
-		rate_size = 'M';
-		if(rate > 2048.0) {
-			rate /= 1024.0;
-			rate_size = 'G';
-			/* we should not go higher than this for a few years (9999.9 Gb/s?)*/
-		}
-	}
-
-	f_xfered = xfered / 1024.0; /* convert to K by default */
-	/* xfered_size = 'K'; was set above */
-	if(f_xfered > 2048.0) {
-		f_xfered /= 1024.0;
-		xfered_size = 'M';
-		if(f_xfered > 2048.0) {
-			f_xfered /= 1024.0;
-			xfered_size = 'G';
-			/* I should seriously hope that archlinux packages never break
-			 * the 9999.9GB mark... we'd have more serious problems than the progress
-			 * bar in pacman */
-		}
-	}
+	rate_human = humanize_size((off_t)rate, '\0', 0, &rate_label);
+	xfered_human = humanize_size(xfered, '\0', 0, &xfered_label);
 
 	/* 1 space + filenamelen + 1 space + 7 for size + 1 + 7 for rate + 2 for /s + 1 space + 8 for eta */
-	printf(" %ls%-*s %6.1f%c %#6.1f%c/s %02u:%02u:%02u", wcfname,
-			padwid, "", f_xfered, xfered_size,
-			rate, rate_size, eta_h, eta_m, eta_s);
+	printf(" %ls%-*s %6.1f%s %#6.1f%s/s %02u:%02u:%02u", wcfname,
+			padwid, "", xfered_human, xfered_label, rate_human, rate_label,
+			eta_h, eta_m, eta_s);
 
 	free(fname);
 	free(wcfname);
diff --git a/src/pacman/package.c b/src/pacman/package.c
index d8dde695..e3a4614a 100644
--- a/src/pacman/package.c
+++ b/src/pacman/package.c
@@ -51,6 +51,8 @@ void dump_pkg_full(pmpkg_t *pkg, int level)
 	const char *reason;
 	time_t bdate, idate;
 	char bdatestr[50] = "", idatestr[50] = "";
+	const char *label;
+	double size;
 	const alpm_list_t *i;
 	alpm_list_t *requiredby = NULL, *depstrings = NULL;
 
@@ -105,17 +107,17 @@ void dump_pkg_full(pmpkg_t *pkg, int level)
 	}
 	list_display(_("Conflicts With :"), alpm_pkg_get_conflicts(pkg));
 	list_display(_("Replaces       :"), alpm_pkg_get_replaces(pkg));
+
+	size = humanize_size(alpm_pkg_get_size(pkg), 'K', 1, &label);
 	if(level < 0) {
-		printf(_("Download Size  : %6.2f K\n"),
-			(double)alpm_pkg_get_size(pkg) / 1024.0);
-	}
-	if(level == 0) {
-		printf(_("Compressed Size: %6.2f K\n"),
-			(double)alpm_pkg_get_size(pkg) / 1024.0);
+		printf(_("Download Size  : %6.2f %s\n"), size, label);
+	} else if(level == 0) {
+		printf(_("Compressed Size: %6.2f %s\n"), size, label);
 	}
 
-	printf(_("Installed Size : %6.2f K\n"),
-			(double)alpm_pkg_get_isize(pkg) / 1024.0);
+	size = humanize_size(alpm_pkg_get_isize(pkg), 'K', 1, &label);
+	printf(_("Installed Size : %6.2f %s\n"), size, label);
+
 	string_display(_("Packager       :"), alpm_pkg_get_packager(pkg));
 	string_display(_("Architecture   :"), alpm_pkg_get_arch(pkg));
 	string_display(_("Build Date     :"), bdatestr);
diff --git a/src/pacman/util.c b/src/pacman/util.c
index cf33dabf..7080b2b7 100644
--- a/src/pacman/util.c
+++ b/src/pacman/util.c
@@ -522,9 +522,10 @@ void list_display_linebreak(const char *title, const alpm_list_t *list)
 void display_targets(const alpm_list_t *pkgs, int install)
 {
 	char *str;
+	const char *label;
+	double size;
 	const alpm_list_t *i;
 	off_t isize = 0, dlsize = 0;
-	double mbisize = 0.0, mbdlsize = 0.0;
 	alpm_list_t *targets = NULL;
 
 	if(!pkgs) {
@@ -545,19 +546,17 @@ void display_targets(const alpm_list_t *pkgs, int install)
 		targets = alpm_list_add(targets, str);
 	}
 
-	/* Convert byte sizes to MB */
-	mbdlsize = (double)dlsize / (1024.0 * 1024.0);
-	mbisize = (double)isize / (1024.0 * 1024.0);
-
 	if(install) {
 		pm_asprintf(&str, _("Targets (%d):"), alpm_list_count(targets));
 		list_display(str, targets);
 		free(str);
 		printf("\n");
 
-		printf(_("Total Download Size:    %.2f MB\n"), mbdlsize);
+		size = humanize_size(dlsize, 'M', 1, &label);
+		printf(_("Total Download Size:    %.2f %s\n"), size, label);
 		if(!(config->flags & PM_TRANS_FLAG_DOWNLOADONLY)) {
-			printf(_("Total Installed Size:   %.2f MB\n"), mbisize);
+			size = humanize_size(isize, 'M', 1, &label);
+			printf(_("Total Installed Size:   %.2f %s\n"), size, label);
 		}
 	} else {
 		pm_asprintf(&str, _("Remove (%d):"), alpm_list_count(targets));
@@ -565,7 +564,8 @@ void display_targets(const alpm_list_t *pkgs, int install)
 		free(str);
 		printf("\n");
 
-		printf(_("Total Removed Size:   %.2f MB\n"), mbisize);
+		size = humanize_size(isize, 'M', 1, &label);
+		printf(_("Total Removed Size:   %.2f %s\n"), size, label);
 	}
 
 	FREELIST(targets);
@@ -606,6 +606,44 @@ static char *pkg_get_location(pmpkg_t *pkg)
 	}
 }
 
+/** Converts sizes in bytes into human readable units.
+ *
+ * @param bytes the size in bytes
+ * @param target_unit '\0' or a short label. If equal to one of the short unit
+ * labels ('B', 'K', ...) bytes is converted to target_unit; if '\0', the first
+ * unit which will bring the value to below a threshold of 2048 will be chosen.
+ * @param long_labels whether to use short ("K") or long ("KB") unit labels
+ * @param label will be set to the appropriate unit label
+ *
+ * @return the size in the appropriate unit
+ */
+double humanize_size(off_t bytes, const char target_unit, int long_labels,
+		const char **label)
+{
+	static const char *shortlabels[] = {"B", "K", "M", "G", "T", "P"};
+	static const char *longlabels[] = {"B", "KB", "MB", "GB", "TB", "PB"};
+	static const int unitcount = sizeof(shortlabels) / sizeof(shortlabels[0]);
+
+	const char **labels = long_labels ? longlabels : shortlabels;
+	double val = (double)bytes;
+	int index;
+
+	for(index = 0; index < unitcount - 1; index++) {
+		if(target_unit != '\0' && shortlabels[index][0] == target_unit) {
+			break;
+		} else if(target_unit == '\0' && val <= 2048.0) {
+			break;
+		}
+		val /= 1024.0;
+	}
+
+	if(label) {
+		*label = labels[index];
+	}
+
+	return(val);
+}
+
 void print_packages(const alpm_list_t *packages)
 {
 	const alpm_list_t *i;
diff --git a/src/pacman/util.h b/src/pacman/util.h
index 234a631d..6a20ba4f 100644
--- a/src/pacman/util.h
+++ b/src/pacman/util.h
@@ -52,6 +52,7 @@ char *strtrim(char *str);
 char *strreplace(const char *str, const char *needle, const char *replace);
 alpm_list_t *strsplit(const char *str, const char splitchar);
 void string_display(const char *title, const char *string);
+double humanize_size(off_t bytes, const char target_unit, int long_labels, const char **label);
 void list_display(const char *title, const alpm_list_t *list);
 void list_display_linebreak(const char *title, const alpm_list_t *list);
 void display_targets(const alpm_list_t *pkgs, int install);