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[Qemu-devel] [PATCH 04/16] qapi: introduce OptsVisitor
From: |
Laszlo Ersek |
Subject: |
[Qemu-devel] [PATCH 04/16] qapi: introduce OptsVisitor |
Date: |
Tue, 22 May 2012 12:45:43 +0200 |
This visitor supports parsing
-option [type=]discriminator[,optarg1=val1][,optarg2=val2][,...]
style QemuOpts objects into "native" C structures. After defining the type
tree in the qapi schema (see below), a root type traversal with this
visitor linked to the underlying QemuOpts object will build the "native" C
representation of the option.
The type tree in the schema, corresponding to an option with a
discriminator, must have the following structure:
struct
scalar member for non-discriminated optarg 1 [*]
list for repeating non-discriminated optarg 2 [*]
wrapper struct
single scalar member
union
struct for discriminator case 1
scalar member for optarg 3 [*]
list for repeating optarg 4 [*]
wrapper struct
single scalar member
scalar member for optarg 5 [*]
struct for discriminator case 2
...
The "type" optarg name is fixed for the discriminator role. Its schema
representation is "union of structures", and each discriminator value must
correspond to a member name in the union.
If the option takes no "type" descriminator, then the type subtree rooted
at the union must be absent from the schema (including the union itself).
Optarg values can be of scalar types str / bool / int / size.
Members marked with [*] may be defined as optional in the schema,
describing an optional optarg.
Repeating an optarg is supported; its schema representation must be "list
of structure with single mandatory scalar member". If an optarg is not
described as repeating in the schema (ie. it is defined as a scalar field
instead of a list), its last occurrence will take effect. Ordering between
differently named optargs is not preserved.
A mandatory list (or an optional one which is reported to be available),
corresponding to a repeating optarg, has at least one element after
successful parsing.
Signed-off-by: Laszlo Ersek <address@hidden>
---
qapi/opts-visitor.h | 31 +++++
qapi/opts-visitor.c | 363 +++++++++++++++++++++++++++++++++++++++++++++++++++
Makefile.objs | 2 +-
3 files changed, 395 insertions(+), 1 deletions(-)
create mode 100644 qapi/opts-visitor.h
create mode 100644 qapi/opts-visitor.c
diff --git a/qapi/opts-visitor.h b/qapi/opts-visitor.h
new file mode 100644
index 0000000..edd6d41
--- /dev/null
+++ b/qapi/opts-visitor.h
@@ -0,0 +1,31 @@
+/*
+ * Options Visitor
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Laszlo Ersek <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef OPTS_VISITOR_H
+#define OPTS_VISITOR_H
+
+#include "qapi-visit-core.h"
+#include "qemu-option.h"
+
+typedef struct OptsVisitor OptsVisitor;
+
+/* Contrarily to qemu-option.c::parse_option_number(), OptsVisitor's "int"
+ * parser relies on strtoll() instead of strtoull(). Consequences:
+ * - string representations of negative numbers are rejected (parsed values
+ * continue to be non-negative),
+ * - values above INT64_MAX or LLONG_MAX are rejected.
+ */
+OptsVisitor *opts_visitor_new(const QemuOpts *opts);
+void opts_visitor_cleanup(OptsVisitor *nv);
+Visitor *opts_get_visitor(OptsVisitor *nv);
+
+#endif
diff --git a/qapi/opts-visitor.c b/qapi/opts-visitor.c
new file mode 100644
index 0000000..a94c67e
--- /dev/null
+++ b/qapi/opts-visitor.c
@@ -0,0 +1,363 @@
+/*
+ * Options Visitor
+ *
+ * Copyright Red Hat, Inc. 2012
+ *
+ * Author: Laszlo Ersek <address@hidden>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "opts-visitor.h"
+#include "qemu-queue.h"
+#include "qemu-option-internal.h"
+#include "qapi-visit-impl.h"
+
+
+struct OptsVisitor
+{
+ Visitor visitor;
+
+ /* Ownership remains with opts_visitor_new()'s caller. */
+ const QemuOpts *opts_root;
+
+ unsigned depth;
+
+ /* Non-null iff depth is positive. Each key is a QemuOpt name. Each value
+ * is a non-empty GQueue, enumerating all QemuOpt occurrences with that
+ * name. */
+ GHashTable *unprocessed_opts;
+
+ /* The list currently being traversed with opts_start_list() /
+ * opts_next_list(). The list must have a struct element type in the
+ * schema, with a single mandatory scalar member. */
+ GQueue *repeated_opts;
+ bool repeated_opts_first;
+};
+
+
+static void
+destroy_list(gpointer list)
+{
+ g_queue_free(list);
+}
+
+
+static void
+opts_start_struct(Visitor *v, void **obj, const char *kind,
+ const char *name, size_t size, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ const QemuOpt *opt;
+
+ *obj = g_malloc0(size);
+ if (ov->depth++ > 0) {
+ return;
+ }
+
+ ov->unprocessed_opts = g_hash_table_new_full(&g_str_hash, &g_str_equal,
+ NULL, &destroy_list);
+ QTAILQ_FOREACH(opt, &ov->opts_root->head, next) {
+ GQueue *list;
+
+ list = g_hash_table_lookup(ov->unprocessed_opts, opt->name);
+ if (list == NULL) {
+ list = g_queue_new();
+
+ /* GHashTable will never try to free the keys -- we supplied NULL
+ * as "key_destroy_func" above. Thus cast away key const-ness in
+ * order to suppress gcc's warning. */
+ g_hash_table_insert(ov->unprocessed_opts, (gpointer)opt->name,
+ list);
+ }
+
+ /* Similarly, destroy_list() doesn't call g_queue_free_full(). */
+ g_queue_push_tail(list, (gpointer)opt);
+ }
+}
+
+
+static gboolean
+ghr_true(gpointer ign_key, gpointer ign_value, gpointer ign_user_data)
+{
+ return TRUE;
+}
+
+
+static void
+opts_end_struct(Visitor *v, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ GQueue *any;
+
+ if (--ov->depth > 0) {
+ return;
+ }
+
+ /* we should have processed all (distinct) QemuOpt instances */
+ any = g_hash_table_find(ov->unprocessed_opts, &ghr_true, NULL);
+ if (any) {
+ const QemuOpt *first;
+
+ first = g_queue_peek_head(any);
+ error_set(errp, QERR_INVALID_PARAMETER, first->name);
+ }
+ g_hash_table_destroy(ov->unprocessed_opts);
+ ov->unprocessed_opts = NULL;
+}
+
+
+static GQueue *
+lookup_distinct(const OptsVisitor *ov, const char *name, Error **errp)
+{
+ GQueue *list;
+
+ list = g_hash_table_lookup(ov->unprocessed_opts, name);
+ if (!list) {
+ error_set(errp, QERR_MISSING_PARAMETER, name);
+ }
+ return list;
+}
+
+
+static void
+opts_start_list(Visitor *v, const char *name, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+
+ /* we can't traverse a list in a list */
+ assert(ov->repeated_opts == NULL);
+ ov->repeated_opts = lookup_distinct(ov, name, errp);
+ ov->repeated_opts_first = (ov->repeated_opts != NULL);
+}
+
+
+static GenericList *
+opts_next_list(Visitor *v, GenericList **list, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ GenericList **link;
+
+ if (ov->repeated_opts_first) {
+ ov->repeated_opts_first = false;
+ link = list;
+ } else {
+ const QemuOpt *opt;
+
+ opt = g_queue_pop_head(ov->repeated_opts);
+ if (g_queue_is_empty(ov->repeated_opts)) {
+ g_hash_table_remove(ov->unprocessed_opts, opt->name);
+ return NULL;
+ }
+ link = &(*list)->next;
+ }
+
+ *link = g_malloc0(sizeof **link);
+ return *link;
+}
+
+
+static void
+opts_end_list(Visitor *v, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+
+ ov->repeated_opts = NULL;
+}
+
+
+static const QemuOpt *
+lookup_scalar(const OptsVisitor *ov, const char *name, Error **errp)
+{
+ if (ov->repeated_opts == NULL) {
+ GQueue *list;
+
+ /* the last occurrence of any QemuOpt takes effect when queried by name
+ */
+ list = lookup_distinct(ov, name, errp);
+ return list ? g_queue_peek_tail(list) : NULL;
+ }
+ return g_queue_peek_head(ov->repeated_opts);
+}
+
+
+static void
+processed(OptsVisitor *ov, const char *name)
+{
+ if (ov->repeated_opts == NULL) {
+ g_hash_table_remove(ov->unprocessed_opts, name);
+ }
+}
+
+
+static void
+opts_type_str(Visitor *v, char **obj, const char *name, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ const QemuOpt *opt;
+
+ opt = lookup_scalar(ov, name, errp);
+ if (!opt) {
+ return;
+ }
+ *obj = g_strdup(opt->str ? opt->str : "");
+ processed(ov, name);
+}
+
+
+/* mimics qemu-option.c::parse_option_bool() */
+static void
+opts_type_bool(Visitor *v, bool *obj, const char *name, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ const QemuOpt *opt;
+
+ opt = lookup_scalar(ov, name, errp);
+ if (!opt) {
+ return;
+ }
+
+ if (opt->str) {
+ if (strcmp(opt->str, "on") == 0 ||
+ strcmp(opt->str, "yes") == 0 ||
+ strcmp(opt->str, "y") == 0) {
+ *obj = true;
+ } else if (strcmp(opt->str, "off") == 0 ||
+ strcmp(opt->str, "no") == 0 ||
+ strcmp(opt->str, "n") == 0) {
+ *obj = false;
+ } else {
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
+ "on|yes|y|off|no|n");
+ return;
+ }
+ } else {
+ *obj = true;
+ }
+
+ processed(ov, name);
+}
+
+
+static void
+opts_type_int(Visitor *v, int64_t *obj, const char *name, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ const QemuOpt *opt;
+ const char *str;
+ long long val;
+ char *endptr;
+
+ opt = lookup_scalar(ov, name, errp);
+ if (!opt) {
+ return;
+ }
+ str = opt->str ? opt->str : "";
+
+ errno = 0;
+ val = strtoll(str, &endptr, 0);
+ if (*str != '\0' && *endptr == '\0' && errno == 0 && 0 <= val &&
+ val <= INT64_MAX) {
+ *obj = val;
+ processed(ov, name);
+ return;
+ }
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
+ "a non-negative int64 value");
+}
+
+
+static void
+opts_type_size(Visitor *v, int64_t *obj, const char *name, Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+ const QemuOpt *opt;
+ int64_t val;
+ char *endptr;
+
+ opt = lookup_scalar(ov, name, errp);
+ if (!opt) {
+ return;
+ }
+
+ val = strtosz_suffix(opt->str ? opt->str : "", &endptr,
+ STRTOSZ_DEFSUFFIX_B);
+ if (val != -1 && *endptr == '\0') {
+ *obj = val;
+ processed(ov, name);
+ return;
+ }
+ error_set(errp, QERR_INVALID_PARAMETER_VALUE, opt->name,
+ "a size value representible as a non-negative int64");
+}
+
+
+static void
+opts_start_optional(Visitor *v, bool *present, const char *name,
+ Error **errp)
+{
+ OptsVisitor *ov = DO_UPCAST(OptsVisitor, visitor, v);
+
+ /* we only support a single mandatory scalar field in a list node */
+ assert(ov->repeated_opts == NULL);
+ *present = (lookup_distinct(ov, name, NULL) != NULL);
+}
+
+
+OptsVisitor *
+opts_visitor_new(const QemuOpts *opts)
+{
+ OptsVisitor *ov;
+
+ ov = g_malloc0(sizeof *ov);
+
+ ov->visitor.start_struct = &opts_start_struct;
+ ov->visitor.end_struct = &opts_end_struct;
+
+ ov->visitor.start_list = &opts_start_list;
+ ov->visitor.next_list = &opts_next_list;
+ ov->visitor.end_list = &opts_end_list;
+
+ /* input_type_enum() covers both "normal" enums and union discriminators.
+ * The union discriminator field is always generated as "type"; it should
+ * match the "type" QemuOpt child of any QemuOpts.
+ *
+ * input_type_enum() will remove the looked-up key from the
+ * "unprocessed_opts" hash even if the lookup fails, because the removal is
+ * done earlier in opts_type_str(). This should be harmless.
+ */
+ ov->visitor.type_enum = &input_type_enum;
+
+ ov->visitor.type_int = &opts_type_int;
+ ov->visitor.type_size = &opts_type_size;
+ ov->visitor.type_bool = &opts_type_bool;
+ ov->visitor.type_str = &opts_type_str;
+
+ /* type_number() is not filled in, but this is not the first visitor to
+ * skip some mandatory methods... */
+
+ ov->visitor.start_optional = &opts_start_optional;
+
+ ov->opts_root = opts;
+
+ return ov;
+}
+
+
+void
+opts_visitor_cleanup(OptsVisitor *ov)
+{
+ if (ov->unprocessed_opts != NULL) {
+ g_hash_table_destroy(ov->unprocessed_opts);
+ }
+ memset(ov, '\0', sizeof *ov);
+}
+
+
+Visitor *
+opts_get_visitor(OptsVisitor *ov)
+{
+ return &ov->visitor;
+}
diff --git a/Makefile.objs b/Makefile.objs
index 70c5c79..5988835 100644
--- a/Makefile.objs
+++ b/Makefile.objs
@@ -448,7 +448,7 @@ libcacard-y = cac.o event.o vcard.o vreader.o
vcard_emul_nss.o vcard_emul_type.o
qapi-nested-y = qapi-visit-core.o qapi-dealloc-visitor.o qmp-input-visitor.o
qapi-nested-y += qmp-output-visitor.o qmp-registry.o qmp-dispatch.o
-qapi-nested-y += string-input-visitor.o string-output-visitor.o
+qapi-nested-y += string-input-visitor.o string-output-visitor.o opts-visitor.o
qapi-obj-y = $(addprefix qapi/, $(qapi-nested-y))
common-obj-y += qmp-marshal.o qapi-visit.o qapi-types.o
--
1.7.1
- [Qemu-devel] [PATCH 00/16] introduce OptsVisitor, rebase -net/-netdev parsing, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 02/16] qapi: introduce "size" type, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 01/16] qapi: fix error propagation, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 03/16] expose QemuOpt and QemuOpts struct definitions to interested parties, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 05/16] qapi schema: remove trailing whitespace, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 04/16] qapi: introduce OptsVisitor,
Laszlo Ersek <=
- [Qemu-devel] [PATCH 08/16] convert net_client_init() to OptsVisitor, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 06/16] qapi schema: add Netdev types, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 09/16] convert net_init_nic() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 10/16] convert net_init_dump() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 15/16] convert net_init_bridge() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 12/16] convert net_init_socket() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 13/16] convert net_init_vde() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 07/16] hw, net: "net_client_type" -> "NetClientOptionsKind" (qapi-generated), Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 14/16] convert net_init_tap() to NetClientOptions, Laszlo Ersek, 2012/05/22
- [Qemu-devel] [PATCH 11/16] convert net_init_slirp() to NetClientOptions, Laszlo Ersek, 2012/05/22