From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=47407 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PwPAR-0007Tv-EN for qemu-devel@nongnu.org; Sun, 06 Mar 2011 20:23:24 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PwPAP-0000ND-OF for qemu-devel@nongnu.org; Sun, 06 Mar 2011 20:23:23 -0500 Received: from e8.ny.us.ibm.com ([32.97.182.138]:56410) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PwPAP-0000MV-Hi for qemu-devel@nongnu.org; Sun, 06 Mar 2011 20:23:21 -0500 Received: from d01dlp02.pok.ibm.com (d01dlp02.pok.ibm.com [9.56.224.85]) by e8.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p26L4JWR007838 for ; Sun, 6 Mar 2011 16:04:19 -0500 Received: from d01relay03.pok.ibm.com (d01relay03.pok.ibm.com [9.56.227.235]) by d01dlp02.pok.ibm.com (Postfix) with ESMTP id A896D6E8036 for ; Sun, 6 Mar 2011 20:23:13 -0500 (EST) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay03.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p271NDCB265348 for ; Sun, 6 Mar 2011 20:23:13 -0500 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p271ND6R020519 for ; Sun, 6 Mar 2011 20:23:13 -0500 From: Anthony Liguori Date: Sun, 6 Mar 2011 19:22:45 -0600 Message-Id: <1299460984-15849-4-git-send-email-aliguori@us.ibm.com> In-Reply-To: <1299460984-15849-1-git-send-email-aliguori@us.ibm.com> References: <1299460984-15849-1-git-send-email-aliguori@us.ibm.com> Subject: [Qemu-devel] [PATCH 03/22] qapi: add Error object List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Adam Litke , Anthony Liguori , Markus Armbruster , Luiz Capitulino The Error class is similar to QError (now deprecated) except that it supports propagation. This allows for higher quality error handling. It's losely modeled after glib style GErrors. Signed-off-by: Anthony Liguori diff --git a/Makefile.objs b/Makefile.objs index 0ba02c7..da31530 100644 --- a/Makefile.objs +++ b/Makefile.objs @@ -15,6 +15,7 @@ oslib-obj-$(CONFIG_POSIX) += oslib-posix.o block-obj-y = cutils.o cache-utils.o qemu-malloc.o qemu-option.o module.o block-obj-y += nbd.o block.o aio.o aes.o qemu-config.o +block-obj-y += error.o block-obj-$(CONFIG_POSIX) += posix-aio-compat.o block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o diff --git a/error.c b/error.c new file mode 100644 index 0000000..5d84106 --- /dev/null +++ b/error.c @@ -0,0 +1,122 @@ +/* + * QEMU Error Objects + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Anthony Liguori + * + * This work is licensed under the terms of the GNU LGPL, version 2. See + * the COPYING.LIB file in the top-level directory. + */ +#include "error.h" +#include "error_int.h" +#include "qemu-objects.h" +#include "qerror.h" +#include + +struct Error +{ + QDict *obj; + const char *fmt; + char *msg; +}; + +void error_set(Error **errp, const char *fmt, ...) +{ + Error *err; + va_list ap; + + if (errp == NULL) { + return; + } + + err = qemu_mallocz(sizeof(*err)); + + va_start(ap, fmt); + err->obj = qobject_to_qdict(qobject_from_jsonv(fmt, &ap)); + va_end(ap); + err->fmt = fmt; + + *errp = err; +} + +bool error_is_set(Error **errp) +{ + return (errp && *errp); +} + +const char *error_get_pretty(Error *err) +{ + if (err->msg == NULL) { + QString *str; + str = qerror_format(err->fmt, err->obj); + err->msg = qemu_strdup(qstring_get_str(str)); + } + + return err->msg; +} + +const char *error_get_field(Error *err, const char *field) +{ + if (strcmp(field, "class") == 0) { + return qdict_get_str(err->obj, field); + } else { + QDict *dict = qdict_get_qdict(err->obj, "data"); + return qdict_get_str(dict, field); + } +} + +void error_free(Error *err) +{ + QDECREF(err->obj); + qemu_free(err->msg); + qemu_free(err); +} + +bool error_is_type(Error *err, const char *fmt) +{ + char *ptr; + char *end; + char classname[1024]; + + ptr = strstr(fmt, "'class': '"); + assert(ptr != NULL); + ptr += strlen("'class': '"); + + end = strchr(ptr, '\''); + assert(end != NULL); + + memcpy(classname, ptr, (end - ptr)); + classname[(end - ptr)] = 0; + + return strcmp(classname, error_get_field(err, "class")) == 0; +} + +void error_propagate(Error **dst_err, Error *local_err) +{ + if (dst_err) { + *dst_err = local_err; + } else if (local_err) { + error_free(local_err); + } +} + +QObject *error_get_qobject(Error *err) +{ + QINCREF(err->obj); + return QOBJECT(err->obj); +} + +void error_set_qobject(Error **errp, QObject *obj) +{ + Error *err; + if (errp == NULL) { + return; + } + err = qemu_mallocz(sizeof(*err)); + err->obj = qobject_to_qdict(obj); + qobject_incref(obj); + + *errp = err; +} diff --git a/error.h b/error.h new file mode 100644 index 0000000..317d487 --- /dev/null +++ b/error.h @@ -0,0 +1,65 @@ +/* + * QEMU Error Objects + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Anthony Liguori + * + * This work is licensed under the terms of the GNU LGPL, version 2. See + * the COPYING.LIB file in the top-level directory. + */ +#ifndef ERROR_H +#define ERROR_H + +#include + +/** + * A class representing internal errors within QEMU. An error has a string + * typename and optionally a set of named string parameters. + */ +typedef struct Error Error; + +/** + * Set an indirect pointer to an error given a printf-style format parameter. + * Currently, qerror.h defines these error formats. This function is not + * meant to be used outside of QEMU. + */ +void error_set(Error **err, const char *fmt, ...) + __attribute__((format(printf, 2, 3))); + +/** + * Returns true if an indirect pointer to an error is pointing to a valid + * error object. + */ +bool error_is_set(Error **err); + +/** + * Get a human readable representation of an error object. + */ +const char *error_get_pretty(Error *err); + +/** + * Get an individual named error field. + */ +const char *error_get_field(Error *err, const char *field); + +/** + * Propagate an error to an indirect pointer to an error. This function will + * always transfer ownership of the error reference and handles the case where + * dst_err is NULL correctly. + */ +void error_propagate(Error **dst_err, Error *local_err); + +/** + * Free an error object. + */ +void error_free(Error *err); + +/** + * Determine if an error is of a speific type (based on the qerror format). + * Non-QEMU users should get the `class' field to identify the error type. + */ +bool error_is_type(Error *err, const char *fmt); + +#endif diff --git a/error_int.h b/error_int.h new file mode 100644 index 0000000..eaba65e --- /dev/null +++ b/error_int.h @@ -0,0 +1,27 @@ +/* + * QEMU Error Objects + * + * Copyright IBM, Corp. 2011 + * + * Authors: + * Anthony Liguori + * + * This work is licensed under the terms of the GNU LGPL, version 2. See + * the COPYING.LIB file in the top-level directory. + */ +#ifndef QEMU_ERROR_INT_H +#define QEMU_ERROR_INT_H + +#include "qemu-common.h" +#include "qobject.h" +#include "error.h" + +/** + * Internal QEMU functions for working with Error. + * + * These are used to convert QErrors to Errors + */ +QObject *error_get_qobject(Error *err); +void error_set_qobject(Error **errp, QObject *obj); + +#endif -- 1.7.0.4