[libvirt] [PATCHv2 03/13] virbuf: more detailed error reporting
The next patch wants to add some sanity checking, which would
be a different error than ENOMEM. Many existing callers blindly
report OOM failure if virBuf reports an error, and this will be
wrong in the (unlikely) case that they actually had a usage error
instead; but since the most common error really is ENOMEM, I'm
not going to fix all callers. Meanwhile, new discriminating
callers can react differently depending on what failure happened.
* src/util/buf.c (virBufferSetError): Add parameter.
(virBufferGrow, virBufferVasprintf, virBufferEscapeString)
(virBufferEscapeSexpr): Adjust callers.
---
src/util/buf.c | 26 +++++++++++++-------------
1 files changed, 13 insertions(+), 13 deletions(-)
diff --git a/src/util/buf.c b/src/util/buf.c
index c737696..98bb681 100644
--- a/src/util/buf.c
+++ b/src/util/buf.c
@@ -27,24 +27,24 @@
struct _virBuffer {
unsigned int size;
unsigned int use;
- unsigned int error;
+ unsigned int error; /* errno value, or -1 for usage error */
char *content;
};
/**
* virBufferFail
* @buf: the buffer
+ * @error: which error occurred (errno value, or -1 for usage)
*
- * Mark the buffer has having failed a memory allocation,
- * freeing the content and setting the error flag.
+ * Mark the buffer as failed, free the content and set the error flag.
*/
static void
-virBufferSetError(virBufferPtr buf)
+virBufferSetError(virBufferPtr buf, int error)
{
VIR_FREE(buf->content);
buf->size = 0;
buf->use = 0;
- buf->error = 1;
+ buf->error = error;
}
/**
@@ -70,7 +70,7 @@ virBufferGrow(virBufferPtr buf, unsigned int len)
size = buf->use + len + 1000;
if (VIR_REALLOC_N(buf->content, size) < 0) {
- virBufferSetError(buf);
+ virBufferSetError(buf, errno);
return -1;
}
buf->size = size;
@@ -184,15 +184,15 @@ void virBufferFreeAndReset(virBufferPtr buf)
* @buf: the buffer
*
* Check to see if the buffer is in an error state due
- * to failed memory allocation
+ * to failed memory allocation or usage error
*
- * Return true if in error, 0 if normal
+ * Return positive errno value or -1 on usage error, 0 if normal
*/
int
virBufferError(const virBufferPtr buf)
{
if (buf == NULL)
- return 1;
+ return -1;
return buf->error;
}
@@ -258,7 +258,7 @@ virBufferVasprintf(virBufferPtr buf, const char *format, va_list
argptr)
size = buf->size - buf->use;
if ((count = vsnprintf(&buf->content[buf->use],
size, format, copy)) < 0) {
- virBufferSetError(buf);
+ virBufferSetError(buf, errno);
va_end(copy);
return;
}
@@ -276,7 +276,7 @@ virBufferVasprintf(virBufferPtr buf, const char *format, va_list
argptr)
size = buf->size - buf->use;
if ((count = vsnprintf(&buf->content[buf->use],
size, format, argptr)) < 0) {
- virBufferSetError(buf);
+ virBufferSetError(buf, errno);
return;
}
}
@@ -313,7 +313,7 @@ virBufferEscapeString(virBufferPtr buf, const char *format, const char
*str)
if (xalloc_oversized(6, len) ||
VIR_ALLOC_N(escaped, 6 * len + 1) < 0) {
- virBufferSetError(buf);
+ virBufferSetError(buf, errno);
return;
}
@@ -401,7 +401,7 @@ virBufferEscapeSexpr(virBufferPtr buf,
if (xalloc_oversized(2, len) ||
VIR_ALLOC_N(escaped, 2 * len + 1) < 0) {
- virBufferSetError(buf);
+ virBufferSetError(buf, errno);
return;
}
--
1.7.4.4