From 9e9633c6b98cc9243ae78cd12ab657d041eaa73e Mon Sep 17 00:00:00 2001 From: Zachary T Welch Date: Thu, 19 Nov 2009 08:38:17 -0800 Subject: refactor command registration Refactors the command registration to use helpers to simplify the code. The unregistration routines were made more flexible by allowing them to operate on a single command, such that one can remove all of a commands children in one step (perhaps before adding back a 'config' subcommand that allows getting the others back). Eliminates a bit of duplicated code and adds full API documentation for these routines. --- src/helper/command.c | 148 ++++++++++++++++++++++++--------------------------- src/helper/command.h | 51 ++++++++++++++++-- 2 files changed, 117 insertions(+), 82 deletions(-) (limited to 'src/helper') diff --git a/src/helper/command.c b/src/helper/command.c index 538c07bb..87a898f2 100644 --- a/src/helper/command.c +++ b/src/helper/command.c @@ -233,33 +233,69 @@ static void command_add_child(struct command **head, struct command *c) cc->next = c; } -struct command* register_command(struct command_context *context, - struct command *parent, char *name, command_handler_t handler, - enum command_mode mode, char *help) +static struct command **command_list_for_parent( + struct command_context *cmd_ctx, struct command *parent) { - if (!context || !name) - return NULL; + return parent ? &parent->children : &cmd_ctx->commands; +} - struct command **head = parent ? &parent->children : &context->commands; - struct command *c = command_find(*head, name); - if (NULL != c) - return c; +static struct command *command_new(struct command_context *cmd_ctx, + struct command *parent, const char *name, + command_handler_t handler, enum command_mode mode, + const char *help) +{ + assert(name); - c = malloc(sizeof(struct command)); + struct command *c = malloc(sizeof(struct command)); + memset(c, 0, sizeof(struct command)); c->name = strdup(name); c->parent = parent; - c->children = NULL; c->handler = handler; c->mode = mode; - c->next = NULL; - command_add_child(head, c); + command_add_child(command_list_for_parent(cmd_ctx, parent), c); command_helptext_add(command_name_list(c), help); - /* just a placeholder, no handler */ - if (c->handler == NULL) + return c; +} +static void command_free(struct command *c) +{ + /// @todo if command has a handler, unregister its jim command! + + while (NULL != c->children) + { + struct command *tmp = c->children; + c->children = tmp->next; + command_free(tmp); + } + + if (c->name) + free(c->name); + free(c); +} + +struct command* register_command(struct command_context *context, + struct command *parent, const char *name, + command_handler_t handler, enum command_mode mode, + const char *help) +{ + if (!context || !name) + return NULL; + + struct command **head = command_list_for_parent(context, parent); + struct command *c = command_find(*head, name); + if (NULL != c) + { + LOG_ERROR("command '%s' is already registered in '%s' context", + name, parent ? parent->name : ""); + return c; + } + + c = command_new(context, parent, name, handler, mode, help); + /* if allocation failed or it is a placeholder (no handler), we're done */ + if (NULL == c || NULL == c->handler) return c; const char *full_name = command_name(c, '_'); @@ -281,85 +317,43 @@ struct command* register_command(struct command_context *context, return c; } -int unregister_all_commands(struct command_context *context) +int unregister_all_commands(struct command_context *context, + struct command *parent) { - struct command *c, *c2; - if (context == NULL) return ERROR_OK; - while (NULL != context->commands) + struct command **head = command_list_for_parent(context, parent); + while (NULL != *head) { - c = context->commands; - - while (NULL != c->children) - { - c2 = c->children; - c->children = c->children->next; - free(c2->name); - c2->name = NULL; - free(c2); - c2 = NULL; - } - - context->commands = context->commands->next; - - free(c->name); - c->name = NULL; - free(c); - c = NULL; + struct command *tmp = *head; + *head = tmp->next; + command_free(tmp); } return ERROR_OK; } -int unregister_command(struct command_context *context, char *name) +int unregister_command(struct command_context *context, + struct command *parent, const char *name) { - struct command *c, *p = NULL, *c2; - if ((!context) || (!name)) return ERROR_INVALID_ARGUMENTS; - /* find command */ - c = context->commands; - - while (NULL != c) + struct command *p = NULL; + struct command **head = command_list_for_parent(context, parent); + for (struct command *c = *head; NULL != c; p = c, c = c->next) { - if (strcmp(name, c->name) == 0) - { - /* unlink command */ - if (p) - { - p->next = c->next; - } - else - { - /* first element in command list */ - context->commands = c->next; - } + if (strcmp(name, c->name) != 0) + continue; - /* unregister children */ - while (NULL != c->children) - { - c2 = c->children; - c->children = c->children->next; - free(c2->name); - c2->name = NULL; - free(c2); - c2 = NULL; - } - - /* delete command */ - free(c->name); - c->name = NULL; - free(c); - c = NULL; - return ERROR_OK; - } + if (p) + p->next = c->next; + else + *head = c->next; - /* remember the last command for unlinking */ - p = c; - c = c->next; + command_free(c); + return ERROR_OK; } return ERROR_OK; diff --git a/src/helper/command.h b/src/helper/command.h index def0935a..a7b422ad 100644 --- a/src/helper/command.h +++ b/src/helper/command.h @@ -176,12 +176,53 @@ struct command */ char *command_name(struct command *c, char delim); -struct command* register_command(struct command_context *context, - struct command *parent, char *name, command_handler_t handler, - enum command_mode mode, char *help); +/** + * Register a command @c handler that can be called from scripts during + * the execution @c mode specified. + * + * If @c parent is non-NULL, the new command will be registered as a + * sub-command under it; otherwise, it will be available as a top-level + * command. + * + * A conventioal format should be used for help strings, to provide both + * usage and basic information: + * @code + * "@ ... - some explanation text" + * @endcode + * + * @param cmd_ctx The command_context in which to register the command. + * @param parent Register this command as a child of this, or NULL to + * register a top-level command. + * @param name The name of the command to register, which must not have + * been registered previously. + * @param handler The callback function that will be called. If NULL, + * then the command serves as a placeholder for its children or a script. + * @param mode The command mode(s) in which this command may be run. + * @param help The help text that will be displayed to the user. + * @returns The new command, if successful; otherwise, NULL. + */ +struct command* register_command(struct command_context *cmd_ctx, + struct command *parent, const char *name, + command_handler_t handler, enum command_mode mode, + const char *help); -int unregister_command(struct command_context *context, char *name); -int unregister_all_commands(struct command_context *context); +/** + * Unregisters command @c name from the given context, @c cmd_ctx. + * @param cmd_ctx The context of the registered command. + * @param parent The parent of the given command, or NULL. + * @param name The name of the command to unregister. + * @returns ERROR_OK on success, or an error code. + */ +int unregister_command(struct command_context *cmd_ctx, + struct command *parent, const char *name); +/** + * Unregisters all commands from the specfied context. + * @param cmd_ctx The context that will be cleared of registered commands. + * @param parent If given, only clear commands from under this one command. + * @returns ERROR_OK on success, or an error code. + */ +int unregister_all_commands(struct command_context *cmd_ctx, + struct command *parent); void command_set_output_handler(struct command_context* context, command_output_handler_t output_handler, void *priv); -- cgit v1.2.3