From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1MzdR2-0004AA-JE for qemu-devel@nongnu.org; Sun, 18 Oct 2009 17:37:04 -0400 Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1MzdQy-00049e-3Z for qemu-devel@nongnu.org; Sun, 18 Oct 2009 17:37:04 -0400 Received: from [199.232.76.173] (port=54768 helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1MzdQx-00049b-Uu for qemu-devel@nongnu.org; Sun, 18 Oct 2009 17:36:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8262) by monty-python.gnu.org with esmtp (Exim 4.60) (envelope-from ) id 1MzdQx-0001Ti-ES for qemu-devel@nongnu.org; Sun, 18 Oct 2009 17:36:59 -0400 Date: Sun, 18 Oct 2009 19:36:52 -0200 From: Luiz Capitulino Subject: Re: [Qemu-devel] [PATCH 01/11] Add append method to qstring and empty constructor Message-ID: <20091018193652.3d1eb6f1@doriath> In-Reply-To: <1255786571-3528-2-git-send-email-aliguori@us.ibm.com> References: <1255786571-3528-1-git-send-email-aliguori@us.ibm.com> <1255786571-3528-2-git-send-email-aliguori@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Anthony Liguori Cc: qemu-devel@nongnu.org On Sat, 17 Oct 2009 08:36:01 -0500 Anthony Liguori wrote: > This allows qstring to be used for dynamic string construction. > > Signed-off-by: Anthony Liguori > --- > qstring.c | 37 ++++++++++++++++++++++++++++++++++++- > qstring.h | 4 ++++ > 2 files changed, 40 insertions(+), 1 deletions(-) > > diff --git a/qstring.c b/qstring.c > index 6d411da..441a9e6 100644 > --- a/qstring.c > +++ b/qstring.c > @@ -21,6 +21,16 @@ static const QType qstring_type = { > }; > > /** > + * qstring_new(): Create a new empty QString > + * > + * Return strong reference. > + */ > +QString *qstring_new(void) > +{ > + return qstring_from_str(""); > +} > + > +/** > * qstring_from_str(): Create a new QString from a regular C string > * > * Return strong reference. > @@ -30,12 +40,37 @@ QString *qstring_from_str(const char *str) > QString *qstring; > > qstring = qemu_malloc(sizeof(*qstring)); > - qstring->string = qemu_strdup(str); > + > + qstring->length = strlen(str); > + qstring->capacity = qstring->length; > + > + qstring->string = qemu_malloc(qstring->capacity + 1); > + memcpy(qstring->string, str, qstring->length); > + qstring->string[qstring->length] = 0; Couldn't this be: qstring->string = qemu_strdup(str); qstring->length = qstring->capacity = strlen(str); > + > QOBJECT_INIT(qstring, &qstring_type); > > return qstring; > } > > +/* qstring_append(): Append a C string to a QString > + */ Forgot the 'little roof' in the comment style. :-) > +void qstring_append(QString *qstring, const char *str) > +{ > + size_t len = strlen(str); > + > + if (qstring->capacity < (qstring->length + len)) { > + qstring->capacity += len; > + qstring->capacity *= 2; /* use exponential growth */ > + > + qstring->string = qemu_realloc(qstring->string, qstring->capacity + 1); > + } Why do we need to double it? Wouldn't be enough to only keep track of the current string length and add 'len' to it? We could drop 'capacity' then. > + > + memcpy(qstring->string + qstring->length, str, len); > + qstring->length += len; > + qstring->string[qstring->length] = 0; I would use strcat(). > +} > + > /** > * qobject_to_qstring(): Convert a QObject to a QString > */ > diff --git a/qstring.h b/qstring.h > index e012cb7..65905d4 100644 > --- a/qstring.h > +++ b/qstring.h > @@ -6,10 +6,14 @@ > typedef struct QString { > QObject_HEAD; > char *string; > + size_t length; > + size_t capacity; > } QString; > > +QString *qstring_new(void); > QString *qstring_from_str(const char *str); > const char *qstring_get_str(const QString *qstring); > +void qstring_append(QString *qstring, const char *str); > QString *qobject_to_qstring(const QObject *obj); > > #endif /* QSTRING_H */