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[Qemu-devel] [PATCH v5 2/3] utils: provide size_to_str()
From: |
Peter Xu |
Subject: |
[Qemu-devel] [PATCH v5 2/3] utils: provide size_to_str() |
Date: |
Tue, 9 May 2017 19:25:04 +0800 |
I stole the algorithm from print_type_size(). I didn't generalize it
since that's using [KM...]iB while here we need [KM...]B to finally
be able to stands for page sizes (and even more general).
Signed-off-by: Peter Xu <address@hidden>
---
include/qemu-common.h | 1 +
util/cutils.c | 26 ++++++++++++++++++++++++++
2 files changed, 27 insertions(+)
diff --git a/include/qemu-common.h b/include/qemu-common.h
index d218821..d7d0448 100644
--- a/include/qemu-common.h
+++ b/include/qemu-common.h
@@ -145,6 +145,7 @@ void qemu_hexdump(const char *buf, FILE *fp, const char
*prefix, size_t size);
int parse_debug_env(const char *name, int max, int initial);
const char *qemu_ether_ntoa(const MACAddr *mac);
+char *size_to_str(double val);
void page_size_init(void);
/* returns non-zero if dump is in progress, otherwise zero is
diff --git a/util/cutils.c b/util/cutils.c
index 50ad179..5aaf370 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -619,3 +619,29 @@ const char *qemu_ether_ntoa(const MACAddr *mac)
return ret;
}
+
+/*
+ * Sample output:
+ *
+ * 1 -> "1 B"
+ * 528 -> "0.516 KB"
+ * 4096 -> "4 KB"
+ * 2402958 -> "2.29 MB"
+ * 1073741824 -> "1 GB"
+ *
+ * Please free the buffer after use.
+ */
+char *size_to_str(double val)
+{
+ static const char suffixes[] = { 'B', 'K', 'M', 'G', 'T', 'P', 'E' };
+ unsigned long div;
+ int i;
+
+ frexp(val, &i);
+ i /= 10;
+ assert(i < sizeof(suffixes));
+ div = 1ULL << (i * 10);
+
+ return g_strdup_printf("%0.3g %c%s", val / div,
+ suffixes[i], i ? "B" : "");
+}
--
2.7.4