Refactor parse_command

parse_command returns a struct that contains useful information about
the result of a command as a whole (instead of the intermediate
representation used during parsing).

parse_command now requires the caller to allocate the yajl_gen used for
generating a json reply. This is passed as the second parameter to
parse_command. If NULL is passed, no json reply will be generated.
next
Tony Crisci 2014-05-28 02:01:50 -04:00 committed by Michael Stapelberg
parent 62ea60ba42
commit c7aae56030
6 changed files with 99 additions and 32 deletions

View File

@ -17,7 +17,7 @@
* internally use this struct when calling cmd_floating and cmd_border.
*/
struct CommandResultIR {
/* The JSON generator to append a reply to. */
/* The JSON generator to append a reply to (may be NULL). */
yajl_gen json_gen;
/* The next state to transition to. Passed to the function so that we can
@ -29,4 +29,31 @@ struct CommandResultIR {
bool needs_tree_render;
};
struct CommandResultIR *parse_command(const char *input);
typedef struct CommandResult CommandResult;
/**
* A struct that contains useful information about the result of a command as a
* whole (e.g. a compound command like "floating enable, border none").
* needs_tree_render is true if needs_tree_render of any individual command was
* true.
*/
struct CommandResult {
bool parse_error;
/* the error_message is currently only set for parse errors */
char *error_message;
bool needs_tree_render;
};
/**
* Parses and executes the given command. If a caller-allocated yajl_gen is
* passed, a json reply will be generated in the format specified by the ipc
* protocol. Pass NULL if no json reply is required.
*
* Free the returned CommandResult with command_result_free().
*/
CommandResult *parse_command(const char *input, yajl_gen gen);
/**
* Frees a CommandResult
*/
void command_result_free(CommandResult *result);

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@ -45,13 +45,13 @@ void run_assignments(i3Window *window) {
DLOG("execute command %s\n", current->dest.command);
char *full_command;
sasprintf(&full_command, "[id=\"%d\"] %s", window->id, current->dest.command);
struct CommandResultIR *command_output = parse_command(full_command);
CommandResult *result = parse_command(full_command, NULL);
free(full_command);
if (command_output->needs_tree_render)
if (result->needs_tree_render)
needs_tree_render = true;
yajl_gen_free(command_output->json_gen);
command_result_free(result);
}
/* Store that we ran this assignment to not execute it again */

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@ -16,21 +16,25 @@
#include "shmlog.h"
// Macros to make the YAJL API a bit easier to use.
#define y(x, ...) yajl_gen_ ## x (cmd_output->json_gen, ##__VA_ARGS__)
#define ystr(str) yajl_gen_string(cmd_output->json_gen, (unsigned char*)str, strlen(str))
#define y(x, ...) (cmd_output->json_gen != NULL ? yajl_gen_ ## x (cmd_output->json_gen, ##__VA_ARGS__) : 0)
#define ystr(str) (cmd_output->json_gen != NULL ? yajl_gen_string(cmd_output->json_gen, (unsigned char*)str, strlen(str)) : 0)
#define ysuccess(success) do { \
y(map_open); \
ystr("success"); \
y(bool, success); \
y(map_close); \
if (cmd_output->json_gen != NULL) { \
y(map_open); \
ystr("success"); \
y(bool, success); \
y(map_close); \
} \
} while (0)
#define yerror(message) do { \
y(map_open); \
ystr("success"); \
y(bool, false); \
ystr("error"); \
ystr(message); \
y(map_close); \
if (cmd_output->json_gen != NULL) { \
y(map_open); \
ystr("success"); \
y(bool, false); \
ystr("error"); \
ystr(message); \
y(map_close); \
} \
} while (0)
/** When the command did not include match criteria (!), we use the currently

View File

@ -35,8 +35,8 @@
#include "all.h"
// Macros to make the YAJL API a bit easier to use.
#define y(x, ...) yajl_gen_ ## x (command_output.json_gen, ##__VA_ARGS__)
#define ystr(str) yajl_gen_string(command_output.json_gen, (unsigned char*)str, strlen(str))
#define y(x, ...) (command_output.json_gen != NULL ? yajl_gen_ ## x (command_output.json_gen, ##__VA_ARGS__) : 0)
#define ystr(str) (command_output.json_gen != NULL ? yajl_gen_string(command_output.json_gen, (unsigned char*)str, strlen(str)) : 0)
/*******************************************************************************
* The data structures used for parsing. Essentially the current state and a
@ -205,12 +205,20 @@ static void next_state(const cmdp_token *token) {
}
}
struct CommandResultIR *parse_command(const char *input) {
/*
* Parses and executes the given command. If a caller-allocated yajl_gen is
* passed, a json reply will be generated in the format specified by the ipc
* protocol. Pass NULL if no json reply is required.
*
* Free the returned CommandResult with command_result_free().
*/
CommandResult *parse_command(const char *input, yajl_gen gen) {
DLOG("COMMAND: *%s*\n", input);
state = INITIAL;
CommandResult *result = scalloc(sizeof(CommandResult));
/* A YAJL JSON generator used for formatting replies. */
command_output.json_gen = yajl_gen_alloc(NULL);
command_output.json_gen = gen;
y(array_open);
command_output.needs_tree_render = false;
@ -378,6 +386,9 @@ struct CommandResultIR *parse_command(const char *input) {
ELOG("Your command: %s\n", input);
ELOG(" %s\n", position);
result->parse_error = true;
result->error_message = errormessage;
/* Format this error message as a JSON reply. */
y(map_open);
ystr("success");
@ -396,7 +407,6 @@ struct CommandResultIR *parse_command(const char *input) {
y(map_close);
free(position);
free(errormessage);
clear_stack();
break;
}
@ -404,7 +414,19 @@ struct CommandResultIR *parse_command(const char *input) {
y(array_close);
return &command_output;
result->needs_tree_render = command_output.needs_tree_render;
return result;
}
/*
* Frees a CommandResult
*/
void command_result_free(CommandResult *result) {
if (result == NULL)
return;
FREE(result->error_message);
FREE(result);
}
/*******************************************************************************
@ -442,6 +464,12 @@ int main(int argc, char *argv[]) {
fprintf(stderr, "Syntax: %s <command>\n", argv[0]);
return 1;
}
parse_command(argv[1]);
yajl_gen gen = yajl_gen_alloc(NULL);
CommandResult *result = parse_command(argv[1], gen);
command_result_free(result);
yajl_gen_free(gen);
}
#endif

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@ -117,20 +117,24 @@ IPC_HANDLER(command) {
char *command = scalloc(message_size + 1);
strncpy(command, (const char*)message, message_size);
LOG("IPC: received: *%s*\n", command);
struct CommandResultIR *command_output = parse_command((const char*)command);
yajl_gen gen = yajl_gen_alloc(NULL);
CommandResult *result = parse_command((const char*)command, gen);
free(command);
if (command_output->needs_tree_render)
if (result->needs_tree_render)
tree_render();
command_result_free(result);
const unsigned char *reply;
ylength length;
yajl_gen_get_buf(command_output->json_gen, &reply, &length);
yajl_gen_get_buf(gen, &reply, &length);
ipc_send_message(fd, length, I3_IPC_REPLY_TYPE_COMMAND,
(const uint8_t*)reply);
yajl_gen_free(command_output->json_gen);
yajl_gen_free(gen);
}
static void dump_rect(yajl_gen gen, const char *name, Rect r) {

View File

@ -72,19 +72,23 @@ void handle_key_press(xcb_key_press_event_t *event) {
if (bind == NULL)
return;
yajl_gen gen = yajl_gen_alloc(NULL);
char *command_copy = sstrdup(bind->command);
struct CommandResultIR *command_output = parse_command(command_copy);
CommandResult *result = parse_command(command_copy, gen);
free(command_copy);
if (command_output->needs_tree_render)
if (result->needs_tree_render)
tree_render();
command_result_free(result);
/* We parse the JSON reply to figure out whether there was an error
* ("success" being false in on of the returned dictionaries). */
const unsigned char *reply;
size_t length;
yajl_handle handle = yajl_alloc(&command_error_callbacks, NULL, NULL);
yajl_gen_get_buf(command_output->json_gen, &reply, &length);
yajl_gen_get_buf(gen, &reply, &length);
current_nesting_level = 0;
parse_error_key = false;
@ -116,5 +120,5 @@ void handle_key_press(xcb_key_press_event_t *event) {
yajl_free(handle);
yajl_gen_free(command_output->json_gen);
yajl_gen_free(gen);
}