[libvirt] [PATCH] util: add support for parsing roman numerals
In loving memory of the glorious Roman Empire, add support
for parsing roman numerals to all the positive virStrToLong
variants (those that reject negative numbers).
Now you can finally do:
<memory unit='MiB'>CCLVI</memory>
---
src/util/virstring.c | 78 ++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 78 insertions(+)
diff --git a/src/util/virstring.c b/src/util/virstring.c
index 69abc26..81c2052 100644
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -313,6 +313,69 @@ virStringListGetFirstWithPrefix(char **strings,
return NULL;
}
+const char *digits = "IVXLCDM";
+const unsigned values[] = { 1, 5, 10, 50, 100, 500, 1000 };
+
+static int
+virRomanStrToLong_ul(char const *s, unsigned long *result)
+{
+ unsigned long ret = 0;
+ char const *cur;
+
+ if (*s == '\0')
+ return -1;
+
+ for (cur = s; *cur != '\0'; cur++) {
+ size_t pos;
+ char const *lookup;
+
+ lookup = strchr(digits, *cur);
+ if (!lookup)
+ return -1;
+ pos = lookup - digits;
+
+ if (*(cur + 1) != '\0' && strchr(digits + pos + 1, *(cur + 1)))
{
+ ret -= values[pos];
+ } else {
+ if (ret > ULONG_MAX - values[pos])
+ return -1;
+ ret += values[pos];
+ }
+ }
+ *result = ret;
+ return 0;
+}
+
+static int
+virRomanStrToLong_ull(char const *s, unsigned long long *result)
+{
+ unsigned long long ret = 0;
+ char const *cur;
+
+ if (*s == '\0')
+ return -1;
+
+ for (cur = s; *cur != '\0'; cur++) {
+ size_t pos;
+ char const *lookup;
+
+ lookup = strchr(digits, *cur);
+ if (!lookup)
+ return -1;
+ pos = lookup - digits;
+
+ if (*(cur + 1) != '\0' && strchr(digits + pos + 1, *(cur + 1)))
{
+ ret -= values[pos];
+ } else {
+ if (ret > ULLONG_MAX - values[pos])
+ return -1;
+ ret += values[pos];
+ }
+ }
+ *result = ret;
+ return 0;
+}
+
/* Like strtol, but produce an "int" result, and check more carefully.
Return 0 upon success; return -1 to indicate failure.
When END_PTR is NULL, the byte after the final valid digit must be NUL.
@@ -379,6 +442,11 @@ virStrToLong_uip(char const *s, char **end_ptr, int base, unsigned
int *result)
char *p;
bool err = false;
+ if (virRomanStrToLong_ul(s, &val) == 0) {
+ *result = val;
+ return 0;
+ }
+
errno = 0;
val = strtoul(s, &p, base); /* exempt from syntax-check */
err = (memchr(s, '-', p - s) ||
@@ -441,6 +509,11 @@ virStrToLong_ulp(char const *s, char **end_ptr, int base,
char *p;
int err;
+ if (virRomanStrToLong_ul(s, &val) == 0) {
+ *result = val;
+ return 0;
+ }
+
errno = 0;
val = strtoul(s, &p, base); /* exempt from syntax-check */
err = (memchr(s, '-', p - s) ||
@@ -504,6 +577,11 @@ virStrToLong_ullp(char const *s, char **end_ptr, int base,
char *p;
int err;
+ if (virRomanStrToLong_ull(s, &val) == 0) {
+ *result = val;
+ return 0;
+ }
+
errno = 0;
val = strtoull(s, &p, base); /* exempt from syntax-check */
err = (memchr(s, '-', p - s) ||
--
2.10.2