[libvirt] [PATCH 2/3] Routine to truncate virBuffer
Routine to truncate virBuffer
From: Bharata B Rao <bharata(a)linux.vnet.ibm.com>
Add a helper to truncate virBuffer.
/**
* virBufferTruncate:
* @buf: the buffer
* @len: number of bytes by which the buffer is truncated
*
* Truncate the buffer by @len bytes.
*
* Returns zero on success or -1 on error
*/
int virBufferTruncate(virBufferPtr buf, unsigned int len)
This doesn't reduce the buffer size, but instead reduces
the in-use buffer.
Signed-off-by: Bharata B Rao <bharata(a)linux.vnet.ibm.com>
---
src/libvirt_private.syms | 1 +
src/util/buf.c | 25 +++++++++++++++++++++++++
src/util/buf.h | 1 +
tests/virbuftest.c | 3 ++-
4 files changed, 29 insertions(+), 1 deletions(-)
diff --git a/src/libvirt_private.syms b/src/libvirt_private.syms
index 6a1562e..3a2ae86 100644
--- a/src/libvirt_private.syms
+++ b/src/libvirt_private.syms
@@ -33,6 +33,7 @@ virBufferEscapeString;
virBufferFreeAndReset;
virBufferGetIndent;
virBufferStrcat;
+virBufferTruncate;
virBufferURIEncodeString;
virBufferUse;
virBufferVasprintf;
diff --git a/src/util/buf.c b/src/util/buf.c
index 5043128..4bba350 100644
--- a/src/util/buf.c
+++ b/src/util/buf.c
@@ -123,6 +123,31 @@ virBufferGrow(virBufferPtr buf, unsigned int len)
}
/**
+ * virBufferTruncate:
+ * @buf: the buffer
+ * @len: number of bytes by which the buffer is truncated
+ *
+ * Truncate the buffer by @len bytes.
+ *
+ * Returns zero on success or -1 on error
+ */
+int
+virBufferTruncate(virBufferPtr buf, unsigned int len)
+{
+ if (buf->error)
+ return -1;
+
+ if ((signed)(buf->use - len) < 0) {
+ virBufferSetError(buf, -1);
+ return -1;
+ }
+
+ buf->use -= len;
+ buf->content[buf->use] = '\0';
+ return 0;
+}
+
+/**
* virBufferAdd:
* @buf: the buffer to append to
* @str: the string
diff --git a/src/util/buf.h b/src/util/buf.h
index 1a8ebfb..76f48e0 100644
--- a/src/util/buf.h
+++ b/src/util/buf.h
@@ -63,5 +63,6 @@ void virBufferURIEncodeString(virBufferPtr buf, const char *str);
void virBufferAdjustIndent(virBufferPtr buf, int indent);
int virBufferGetIndent(const virBufferPtr buf, bool dynamic);
+int virBufferTruncate(virBufferPtr buf, unsigned int len);
#endif /* __VIR_BUFFER_H__ */
diff --git a/tests/virbuftest.c b/tests/virbuftest.c
index 51a62fe..2230cb0 100644
--- a/tests/virbuftest.c
+++ b/tests/virbuftest.c
@@ -123,7 +123,8 @@ static int testBufAutoIndent(const void *data ATTRIBUTE_UNUSED)
virBufferAddChar(buf, '\n');
virBufferEscapeShell(buf, " 11");
virBufferAddChar(buf, '\n');
-
+ virBufferAsprintf(buf, "%d", 12);
+ virBufferTruncate(buf, 4);
result = virBufferContentAndReset(buf);
if (!result || STRNEQ(result, expected)) {
virtTestDifference(stderr, expected, result);