lib/printbuf: Unit specifiers

This adds options to printbuf for specifying whether units should be
printed raw (default) or with human readable units, and for controlling
whether human-readable units should be base 2 (default), or base 10.

This also adds new helpers that obey these options:

 - pr_human_readable_u64
 - pr_human_readable_s64
These obey printbuf->si_units

 - pr_units_u64
 - pr_units_s64
These obey both printbuf-human_readable_units and printbuf->si_units

Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>

1 files changed, 57 insertions, 0 deletions

diff --git a/lib/printbuf.c b/lib/printbuf.c
index 395c681e3acb..047470025748 100644
--- a/lib/printbuf.c
+++ b/lib/printbuf.c
@@ -10,6 +10,7 @@
 
 #include <linux/err.h>
 #include <linux/slab.h>
+#include <linux/string_helpers.h>
 #include <linux/printbuf.h>
 
 static inline size_t printbuf_linelen(struct printbuf *buf)
@@ -199,3 +200,59 @@ void prt_tab_rjust(struct printbuf *buf)
 	buf->tabstop++;
 }
 EXPORT_SYMBOL(prt_tab_rjust);
+
+/**
+ * prt_human_readable_u64 - Print out a u64 in human readable units
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units
+ */
+void prt_human_readable_u64(struct printbuf *buf, u64 v)
+{
+	printbuf_make_room(buf, 10);
+	buf->pos += string_get_size(v, 1, !buf->si_units,
+				    buf->buf + buf->pos,
+				    printbuf_remaining_size(buf));
+}
+EXPORT_SYMBOL(prt_human_readable_u64);
+
+/**
+ * prt_human_readable_s64 - Print out a s64 in human readable units
+ *
+ * Units of 2^10 (default) or 10^3 are controlled via @buf->si_units
+ */
+void prt_human_readable_s64(struct printbuf *buf, s64 v)
+{
+	if (v < 0)
+		prt_char(buf, '-');
+	prt_human_readable_u64(buf, abs(v));
+}
+EXPORT_SYMBOL(prt_human_readable_s64);
+
+/**
+ * prt_units_u64 - Print out a u64 according to printbuf unit options
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void prt_units_u64(struct printbuf *out, u64 v)
+{
+	if (out->human_readable_units)
+		prt_human_readable_u64(out, v);
+	else
+		prt_printf(out, "%llu", v);
+}
+EXPORT_SYMBOL(prt_units_u64);
+
+/**
+ * prt_units_s64 - Print out a s64 according to printbuf unit options
+ *
+ * Units are either raw (default), or human reabable units (controlled via
+ * @buf->human_readable_units)
+ */
+void prt_units_s64(struct printbuf *out, s64 v)
+{
+	if (v < 0)
+		prt_char(out, '-');
+	prt_units_u64(out, abs(v));
+}
+EXPORT_SYMBOL(prt_units_s64);