Re: [libvirt] [PATCH 08/11] util: Add util to pad string
On 06/07/2013 01:03 PM, Osier Yang wrote:
The string can be padded either on the left (@from_right=false) or
right
(@from_right=true).
---
src/libvirt_private.syms | 1 +
src/util/virstring.c | 38 ++++++++++++++++++++++++++++++++++++++
src/util/virstring.h | 6 ++++++
tests/utiltest.c | 28 ++++++++++++++++++++++++++++
4 files changed, 73 insertions(+)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index ce39cc6..27fb0b5 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -1822,6 +1822,7 @@ virStringArrayHasString;
virStringFreeList;
virStringJoin;
virStringListLength;
+virStringPad;
virStringSplit;
virStrncpy;
virStrndup;
diff --git a/src/util/virstring.c b/src/util/virstring.c
index 1937f82..498daab 100644
--- a/src/util/virstring.c
+++ b/src/util/virstring.c
@@ -608,3 +608,41 @@ size_t virStringListLength(char **strings)
return i;
}
+
This needs a description, params, returns, etc. section. To me padding
usually denotes adding something to the end of a string
I would like to understand the value of "length" (which I believe is a
size_t rather than a unsigned int, right?
I think most importantly - caller is expected to free the returned
buffer, right?
+char *
+virStringPad(const char *src,
+ char padchar,
+ unsigned int length,
+ bool from_right)
+{
+ virBuffer buf = VIR_BUFFER_INITIALIZER;
+ int len;
+ int i;
It seems you're trying to create a virBufferPrependChar() to go along
with the existing virBufferAddChar() or virBufferAddLit().
Essentially you're creating a string buffer of "length - len" filled
with 'padchar' and then prepending or appending it onto the existing
string.
I guess I'm somewhat surprised this hasn't already been done.
In any case, I would have expected something as follows (error
conditions aside):
if APPPEND (eg, change 1234 into 12340000)
virBufferAdd(&buf, src);
for (i = len; i < length; i++)
virBufferAddChar(&buf, padchar);
else (PREPEND)
for (i = len; i < length; i++)
virBufferAddChar(&buf, padchar);
virBufferAdd(&buf, src)
John
+
+ len = strlen(src);
+
+ if (len > length)
+ return NULL;
+
+ if (!from_right) {
+ for (i = 0; i < length - len; i++) {
+ virBufferAsprintf(&buf, "%c", padchar);
+ }
+
+ virBufferAsprintf(&buf, "%s", src);
+ } else {
+ virBufferAsprintf(&buf, "%s", src);
+
+ for (i = 0; i < length - len; i++) {
+ virBufferAsprintf(&buf, "%c", padchar);
+ }
+ }
+
+ if (virBufferError(&buf)) {
+ virBufferFreeAndReset(&buf);
+ virReportOOMError();
+ return NULL;
+ }
+
+ return virBufferContentAndReset(&buf);
+}
diff --git a/src/util/virstring.h b/src/util/virstring.h
index 34ffae1..5809167 100644
--- a/src/util/virstring.h
+++ b/src/util/virstring.h
@@ -166,4 +166,10 @@ int virStrndup(char **dest, const char *src, ssize_t n, bool report,
int domcode
size_t virStringListLength(char **strings);
+char *virStringPad(const char *src,
+ char padchar,
+ unsigned int length,
+ bool from_right)
+ ATTRIBUTE_NONNULL(1);
+
#endif /* __VIR_STRING_H__ */
diff --git a/tests/utiltest.c b/tests/utiltest.c
index 41fdd7e..d567ecc 100644
--- a/tests/utiltest.c
+++ b/tests/utiltest.c
@@ -226,6 +226,33 @@ cleanup:
}
static int
+testStringPad(const void *data ATTRIBUTE_UNUSED)
+{
+ const char *str = "1ff2";
+ char *lpadstr = NULL;
+ char *rpadstr = NULL;
+ int ret = -1;
+
+ if (!(lpadstr = virStringPad(str, '0', 7, false)))
+ return -1;
+
+ if (STRNEQ(lpadstr, "0001ff2"))
+ goto cleanup;
+
+ if (!(rpadstr = virStringPad(str, '0', 7, true)))
+ goto cleanup;
+
+ if (STRNEQ(rpadstr, "1ff2000"))
+ goto cleanup;
+
+ ret = 0;
+cleanup:
+ VIR_FREE(lpadstr);
+ VIR_FREE(rpadstr);
+ return ret;
+}
+
+static int
mymain(void)
{
int result = 0;
@@ -251,6 +278,7 @@ mymain(void)
DO_TEST(ParseVersionString);
DO_TEST(FindPCIDeviceByVPD);
DO_TEST(ParseStableScsiHostAddress);
+ DO_TEST(StringPad);
cleanup:
VIR_FREE(test_sysfs);