On 09/29/2011 06:22 PM, Eric Blake wrote:
Rather than having to adjust all callers in a chain to deal with
indentation, it is nicer to have virBuffer do auto-indentation.
* src/util/buf.h (_virBuffer): Increase size.
(virBufferAdjustIndent, virBufferGetIndent): New prototypes.
* src/libvirt_private.syms (buf.h): Export new functions.
* src/util/buf.c (virBufferAdjustIndent, virBufferGetIndent): New
functions.
(virBufferSetError, virBufferAdd, virBufferAddChar)
(virBufferVasprintf, virBufferStrcat, virBufferURIEncodeString):
Implement auto-indentation.
* tests/virbuftest.c (testBufAutoIndent): Test it.
(testBufInfiniteLoop): Don't rely on internals.
Idea by Daniel P. Berrange.
---
src/libvirt_private.syms | 2 +
src/util/buf.c | 138 ++++++++++++++++++++++++++++-----------------
src/util/buf.h | 12 +++-
tests/virbuftest.c | 85 +++++++++++++++++++++++++---
4 files changed, 172 insertions(+), 65 deletions(-)
@@ -79,35 +124,39 @@ virBufferGrow(virBufferPtr buf, unsigned int len)
/**
* virBufferAdd:
- * @buf: the buffer to add to
- * @str: the string
- * @len: the number of bytes to add
+ * @buf: the buffer to append to
+ * @str: the string
+ * @len: the number of bytes to add, or -1
*
- * Add a string range to an XML buffer. if len == -1, the length of
- * str is recomputed to the full string.
+ * Add a string range to an XML buffer. If @len == -1, the length of
+ * str is recomputed to the full string. Auto indentation may be applied.
*
*/
void
virBufferAdd(const virBufferPtr buf, const char *str, int len)
{
unsigned int needSize;
+ int indent;
/* context for a later comment */
- if ((str == NULL) || (buf == NULL) || (len == 0))
+ if (!str || !buf || (len == 0&& buf->indent == 0))
return;
if (buf->error)
return;
+ indent = virBufferGetIndent(buf, true);
+
if (len< 0)
len = strlen(str);
- needSize = buf->use + len + 2;
+ needSize = buf->use + indent + len + 2;
if (needSize> buf->size&&
virBufferGrow(buf, needSize - buf->use)< 0)
return;
- memcpy (&buf->content[buf->use], str, len);
- buf->use += len;
+ memset(&buf->content[buf->use], ' ', indent);
+ memcpy(&buf->content[buf->use + indent], str, len);
+ buf->use += indent + len;
buf->content[buf->use] = '\0';
}
@@ -116,27 +165,13 @@ virBufferAdd(const virBufferPtr buf, const char *str, int len)
* @buf: the buffer to append to
* @c: the character to add
*
- * Add a single character 'c' to a buffer.
+ * Add a single character 'c' to a buffer. Auto indentation may be applied.
*
*/
void
-virBufferAddChar (virBufferPtr buf, char c)
+virBufferAddChar(virBufferPtr buf, char c)
{
- unsigned int needSize;
-
- if (buf == NULL)
- return;
-
- if (buf->error)
- return;
-
- needSize = buf->use + 2;
- if (needSize> buf->size&&
- virBufferGrow (buf, needSize - buf->use)< 0)
- return;
-
- buf->content[buf->use++] = c;
- buf->content[buf->use] = '\0';
+ virBufferAdd(buf,&c, 1);
}
This has slightly more overhead than the previous version, but I don't
think adding a char is such a common operation that it would impact
performance. This also simplifies mantenance. I like it.
/**
@@ -218,7 +253,7 @@ virBufferUse(const virBufferPtr buf)
* @format: the format
* @...: the variable list of arguments
*
- * Do a formatted print to an XML buffer.
+ * Do a formatted print to an XML buffer. Auto indentation may be applied.
*/
void
virBufferAsprintf(virBufferPtr buf, const char *format, ...)
@@ -231,11 +266,11 @@ virBufferAsprintf(virBufferPtr buf, const char *format, ...)
/**
* virBufferVasprintf:
- * @buf: the buffer to dump
+ * @buf: the buffer to append to
* @format: the format
* @argptr: the variable list of arguments
*
- * Do a formatted print to an XML buffer.
+ * Do a formatted print to an XML buffer. Auto indentation may be applied.
*/
void
virBufferVasprintf(virBufferPtr buf, const char *format, va_list argptr)
@@ -249,6 +284,9 @@ virBufferVasprintf(virBufferPtr buf, const char *format, va_list argptr)
if (buf->error)
return;
+ if (buf->indent)
+ virBufferAdd(buf, "", -1);
+
virBufferAdd is a no-op, if this expression is true (see context above):
" if (!str || !buf || (len == 0 && buf->indent == 0))". You could save a
call to strlen and the if clause if you call virBufferAdd(buf, "", 0)
The len=0 will be automaticaly used (as the only way to accept len==0 as
a correct value is if indentation is requested). You can also save a
line with the if clause and call it directly. ( Looks like you've
prepared it for this to happen :D)
if (buf->size == 0&&
virBufferGrow(buf, 100)< 0)
return;
@@ -431,7 +472,7 @@ virBufferEscapeSexpr(virBufferPtr buf,
*
* Append the string to the buffer. The string will be URI-encoded
* during the append (ie any non alpha-numeric characters are replaced
- * with '%xx' hex sequences).
+ * with '%xx' hex sequences). Auto indentation may be applied.
*/
void
virBufferURIEncodeString(virBufferPtr buf, const char *str)
@@ -447,6 +488,9 @@ virBufferURIEncodeString(virBufferPtr buf, const char *str)
if (buf->error)
return;
+ if (buf->indent)
+ virBufferAdd(buf, "", -1);
Same as above ...
@@ -476,7 +520,8 @@ virBufferURIEncodeString(virBufferPtr buf, const char *str)
* @buf: the buffer to append to
* @...: the variable list of strings, the last argument must be NULL
*
- * Concatenate strings to an XML buffer.
+ * Concatenate strings to an XML buffer. Auto indentation may be applied
+ * after each string argument.
*/
void
virBufferStrcat(virBufferPtr buf, ...)
@@ -488,18 +533,7 @@ virBufferStrcat(virBufferPtr buf, ...)
return;
va_start(ap, buf);
-
- while ((str = va_arg(ap, char *)) != NULL) {
- unsigned int len = strlen(str);
- unsigned int needSize = buf->use + len + 2;
-
- if (needSize> buf->size) {
- if (virBufferGrow(buf, needSize - buf->use)< 0)
- break;
- }
- memcpy(&buf->content[buf->use], str, len);
- buf->use += len;
- buf->content[buf->use] = 0;
- }
+ while ((str = va_arg(ap, char *)) != NULL)
+ virBufferAdd(buf, str, -1);
va_end(ap);
}
Elegant.
diff --git a/tests/virbuftest.c b/tests/virbuftest.c
The tests look fine to me and it's nice to have them.
ACK,
Peter
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