Quoting Mark Wu (2013-10-08 22:25:07) > In the original code, qmp_get_command_list is used to construct > a list of all commands' name. To get the information of all qga > commands, it traverses the name list and search the command info > with its name. So it can cause O(n^2) in the number of commands. > > This patch adds an interface to traverse the qmp command list by > QmpCommand to replace qmp_get_command_list. It can decrease the > complexity from O(n^2) to O(n). > > Signed-off-by: Mark Wu <wu...@linux.vnet.ibm.com>
Thanks, applied to qga tree: https://github.com/mdroth/qemu/commits/qga > --- > v4: > Add the missing change from cmd->namd to qmp_command_name(cmd) > v3: > Add an accessor for cmd->name to avoid exposing internals of QmpCommand > v2: > 1. Keep the signature of qmp_command_is_enabled (per Eric and Michael) > 2. Remove the unnecessary pointer castings (per Eric) > include/qapi/qmp/dispatch.h | 6 ++-- > qapi/qmp-registry.c | 30 +++++------------- > qga/commands.c | 38 +++++++++-------------- > qga/main.c | 75 > ++++++++++++++++++--------------------------- > 4 files changed, 57 insertions(+), 92 deletions(-) > > diff --git a/include/qapi/qmp/dispatch.h b/include/qapi/qmp/dispatch.h > index 1ce11f5..7d759ef 100644 > --- a/include/qapi/qmp/dispatch.h > +++ b/include/qapi/qmp/dispatch.h > @@ -47,9 +47,11 @@ QmpCommand *qmp_find_command(const char *name); > QObject *qmp_dispatch(QObject *request); > void qmp_disable_command(const char *name); > void qmp_enable_command(const char *name); > -bool qmp_command_is_enabled(const char *name); > -char **qmp_get_command_list(void); > +bool qmp_command_is_enabled(const QmpCommand *cmd); > +const char *qmp_command_name(const QmpCommand *cmd); > QObject *qmp_build_error_object(Error *errp); > +typedef void (*qmp_cmd_callback_fn)(QmpCommand *cmd, void *opaque); > +void qmp_for_each_command(qmp_cmd_callback_fn fn, void *opaque); > > #endif > > diff --git a/qapi/qmp-registry.c b/qapi/qmp-registry.c > index 28bbbe8..5e26710 100644 > --- a/qapi/qmp-registry.c > +++ b/qapi/qmp-registry.c > @@ -66,35 +66,21 @@ void qmp_enable_command(const char *name) > qmp_toggle_command(name, true); > } > > -bool qmp_command_is_enabled(const char *name) > +bool qmp_command_is_enabled(const QmpCommand *cmd) > { > - QmpCommand *cmd; > - > - QTAILQ_FOREACH(cmd, &qmp_commands, node) { > - if (strcmp(cmd->name, name) == 0) { > - return cmd->enabled; > - } > - } > + return cmd->enabled; > +} > > - return false; > +const char *qmp_command_name(const QmpCommand *cmd) > +{ > + return cmd->name; > } > > -char **qmp_get_command_list(void) > +void qmp_for_each_command(qmp_cmd_callback_fn fn, void *opaque) > { > QmpCommand *cmd; > - int count = 1; > - char **list_head, **list; > - > - QTAILQ_FOREACH(cmd, &qmp_commands, node) { > - count++; > - } > - > - list_head = list = g_malloc0(count * sizeof(char *)); > > QTAILQ_FOREACH(cmd, &qmp_commands, node) { > - *list = g_strdup(cmd->name); > - list++; > + fn(cmd, opaque); > } > - > - return list_head; > } > diff --git a/qga/commands.c b/qga/commands.c > index 528b082..e87cbf8 100644 > --- a/qga/commands.c > +++ b/qga/commands.c > @@ -45,35 +45,27 @@ void qmp_guest_ping(Error **err) > slog("guest-ping called"); > } > > -struct GuestAgentInfo *qmp_guest_info(Error **err) > +static void qmp_command_info(QmpCommand *cmd, void *opaque) > { > - GuestAgentInfo *info = g_malloc0(sizeof(GuestAgentInfo)); > + GuestAgentInfo *info = opaque; > GuestAgentCommandInfo *cmd_info; > GuestAgentCommandInfoList *cmd_info_list; > - char **cmd_list_head, **cmd_list; > - > - info->version = g_strdup(QEMU_VERSION); > - > - cmd_list_head = cmd_list = qmp_get_command_list(); > - if (*cmd_list_head == NULL) { > - goto out; > - } > > - while (*cmd_list) { > - cmd_info = g_malloc0(sizeof(GuestAgentCommandInfo)); > - cmd_info->name = g_strdup(*cmd_list); > - cmd_info->enabled = qmp_command_is_enabled(cmd_info->name); > + cmd_info = g_malloc0(sizeof(GuestAgentCommandInfo)); > + cmd_info->name = g_strdup(qmp_command_name(cmd)); > + cmd_info->enabled = qmp_command_is_enabled(cmd); > > - cmd_info_list = g_malloc0(sizeof(GuestAgentCommandInfoList)); > - cmd_info_list->value = cmd_info; > - cmd_info_list->next = info->supported_commands; > - info->supported_commands = cmd_info_list; > + cmd_info_list = g_malloc0(sizeof(GuestAgentCommandInfoList)); > + cmd_info_list->value = cmd_info; > + cmd_info_list->next = info->supported_commands; > + info->supported_commands = cmd_info_list; > +} > > - g_free(*cmd_list); > - cmd_list++; > - } > +struct GuestAgentInfo *qmp_guest_info(Error **err) > +{ > + GuestAgentInfo *info = g_malloc0(sizeof(GuestAgentInfo)); > > -out: > - g_free(cmd_list_head); > + info->version = g_strdup(QEMU_VERSION); > + qmp_for_each_command(qmp_command_info, info); > return info; > } > diff --git a/qga/main.c b/qga/main.c > index 6c746c8..c58b26a 100644 > --- a/qga/main.c > +++ b/qga/main.c > @@ -347,48 +347,35 @@ static gint ga_strcmp(gconstpointer str1, gconstpointer > str2) > } > > /* disable commands that aren't safe for fsfreeze */ > -static void ga_disable_non_whitelisted(void) > +static void ga_disable_non_whitelisted(QmpCommand *cmd, void *opaque) > { > - char **list_head, **list; > - bool whitelisted; > - int i; > - > - list_head = list = qmp_get_command_list(); > - while (*list != NULL) { > - whitelisted = false; > - i = 0; > - while (ga_freeze_whitelist[i] != NULL) { > - if (strcmp(*list, ga_freeze_whitelist[i]) == 0) { > - whitelisted = true; > - } > - i++; > - } > - if (!whitelisted) { > - g_debug("disabling command: %s", *list); > - qmp_disable_command(*list); > + bool whitelisted = false; > + int i = 0; > + const char *name = qmp_command_name(cmd); > + > + while (ga_freeze_whitelist[i] != NULL) { > + if (strcmp(name, ga_freeze_whitelist[i]) == 0) { > + whitelisted = true; > } > - g_free(*list); > - list++; > + i++; > + } > + if (!whitelisted) { > + g_debug("disabling command: %s", name); > + qmp_disable_command(name); > } > - g_free(list_head); > } > > /* [re-]enable all commands, except those explicitly blacklisted by user */ > -static void ga_enable_non_blacklisted(GList *blacklist) > +static void ga_enable_non_blacklisted(QmpCommand *cmd, void *opaque) > { > - char **list_head, **list; > - > - list_head = list = qmp_get_command_list(); > - while (*list != NULL) { > - if (g_list_find_custom(blacklist, *list, ga_strcmp) == NULL && > - !qmp_command_is_enabled(*list)) { > - g_debug("enabling command: %s", *list); > - qmp_enable_command(*list); > - } > - g_free(*list); > - list++; > + GList *blacklist = opaque; > + const char *name = qmp_command_name(cmd); > + > + if (g_list_find_custom(blacklist, name, ga_strcmp) == NULL && > + !qmp_command_is_enabled(cmd)) { > + g_debug("enabling command: %s", name); > + qmp_enable_command(name); > } > - g_free(list_head); > } > > static bool ga_create_file(const char *path) > @@ -424,7 +411,7 @@ void ga_set_frozen(GAState *s) > return; > } > /* disable all non-whitelisted (for frozen state) commands */ > - ga_disable_non_whitelisted(); > + qmp_for_each_command(ga_disable_non_whitelisted, NULL); > g_warning("disabling logging due to filesystem freeze"); > ga_disable_logging(s); > s->frozen = true; > @@ -460,7 +447,7 @@ void ga_unset_frozen(GAState *s) > } > > /* enable all disabled, non-blacklisted commands */ > - ga_enable_non_blacklisted(s->blacklist); > + qmp_for_each_command(ga_enable_non_blacklisted, s->blacklist); > s->frozen = false; > if (!ga_delete_file(s->state_filepath_isfrozen)) { > g_warning("unable to delete %s, fsfreeze may not function properly", > @@ -920,6 +907,11 @@ int64_t ga_get_fd_handle(GAState *s, Error **errp) > return handle; > } > > +static void ga_print_cmd(QmpCommand *cmd, void *opaque) > +{ > + printf("%s\n", qmp_command_name(cmd)); > +} > + > int main(int argc, char **argv) > { > const char *sopt = "hVvdm:p:l:f:F::b:s:t:"; > @@ -996,15 +988,8 @@ int main(int argc, char **argv) > daemonize = 1; > break; > case 'b': { > - char **list_head, **list; > if (is_help_option(optarg)) { > - list_head = list = qmp_get_command_list(); > - while (*list != NULL) { > - printf("%s\n", *list); > - g_free(*list); > - list++; > - } > - g_free(list_head); > + qmp_for_each_command(ga_print_cmd, NULL); > return 0; > } > for (j = 0, i = 0, len = strlen(optarg); i < len; i++) { > @@ -1126,7 +1111,7 @@ int main(int argc, char **argv) > s->deferred_options.log_filepath = log_filepath; > } > ga_disable_logging(s); > - ga_disable_non_whitelisted(); > + qmp_for_each_command(ga_disable_non_whitelisted, NULL); > } else { > if (daemonize) { > become_daemon(pid_filepath); > -- > 1.8.3.1
