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);
>
--
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