(de)serialisation in server/client goes world_t -> const char *, rather than world_t -> json_t -> const char *

client/src/main.c

@@ -16,29 +16,28 @@ int main(void) {
     if (err) goto handle_error;
 
     char ibuf[1024] = { 0 };
-    char obuf[1024] = { 0 };
-
-    // TODO: I skipped out on most error handling here
     read(sock, ibuf, 1024);
 
-    struct json_error_t json_err;
-    struct json_t *json = json_loads(ibuf, 0, &json_err);
-
     struct world_t world = { 0 };
-    world_deserialise(&world, json);
+    err = world_deserialise(&world, ibuf);
+    if (err != ERR_OK) goto handle_error_sock;
 
-    printf("CLIENT: (%zu %zu)\n", world.height, world.width);
+    printf("CLIENT: (%zu %zu) ->", world.height++, world.width ++);
+    printf(" (%zu %zu)\n", world.height, world.width);
 
-    struct json_t *new_json;
+    char obuf[1024] = { 0 };
-    world_serialise(&world, &new_json);
+    err = world_serialise_buf(&world, obuf, 1024);
+    if (err != ERR_OK) goto handle_error_sock;
 
-    json_dumpb(new_json, obuf, 1024, 0);
     write(sock, obuf, 1024);
 
     close(sock);
     return ERR_OK;
 
+handle_error_sock:
+    close(sock);
+
 handle_error:
-    printf("ERROR: %s\n", ERROR_STRS[err]);
+    printf("CLIENT ERROR: %s\n", ERROR_STRS[err]);
     return err;
 }

common/include/world.h

@@ -22,19 +22,11 @@ struct world_t {
 enum error_t world_init(struct world_t *, size_t, size_t);
 void world_free(struct world_t *);
 
-// json_t doesn't store the json data itself; the value of the pointer is
+// world_*_str() allocates a string that the caller must free()
-// apparently needed for jansson to use the data, so I need a double pointer
+// world_*_buf() uses a pre-existing buffer; results are not zero-terminated
-//
+enum error_t world_serialise_str(struct world_t *, char const **);
-// TODO
+enum error_t world_serialise_buf(struct world_t *, char *, size_t);
-// Right now, to serialise and deserialise again you have to call:
+enum error_t world_deserialise(struct world_t *, char const *);
-// 1. world_serialise()   | world_t -> json_t
-// 2. json_dumpX()        |  json_t -> char *
-// 3. json_loadX()        |  char * -> json_t
-// 4. world_deserialise() |  json_t -> world_t
-//
-// Perhaps these two functions should go directly between world_t and char *
-enum error_t world_serialise(struct world_t *, struct json_t **);
-enum error_t world_deserialise(struct world_t *, struct json_t *);
 
 enum error_t world_register_entity(struct world_t *, char const *, char);
 enum error_t world_place_entity(struct world_t *, size_t, size_t, size_t);

common/src/world.c

@@ -40,7 +40,7 @@ void world_free(struct world_t *self) {
 }
 
 
-enum error_t world_serialise(struct world_t *self, struct json_t **json) {
+static enum error_t serialise(struct world_t *self, struct json_t **json) {
     assert(self != NULL);
     // TODO: (de)serialise the following:
     // struct entity_t entities[MAX_ENTITIES];
@@ -57,7 +57,23 @@ enum error_t world_serialise(struct world_t *self, struct json_t **json) {
 }
 
 
-enum error_t world_deserialise(struct world_t *self, struct json_t *json) {
+enum error_t world_serialise_str(struct world_t *self, char const **strptr) {
+    assert(self != NULL);
+    assert(strptr != NULL);
+
+    struct json_t *json;
+    enum error_t err = serialise(self, &json);
+    if (err != ERR_OK) return ERR_JSON_SERIALISE;
+
+    const char *str = json_dumps(json, 0);
+    if (str == NULL) return ERR_JSON_SERIALISE;
+
+    *strptr = str;
+    return ERR_OK;
+}
+
+
+static enum error_t deserialise(struct world_t *self, struct json_t *json) {
     assert(self != NULL);
     assert(json != NULL);
 
@@ -71,6 +87,36 @@ enum error_t world_deserialise(struct world_t *self, struct json_t *json) {
 }
 
 
+enum error_t world_serialise_buf(struct world_t *self, char *buf, size_t len) {
+    assert(self != NULL);
+    assert(buf != NULL);
+    assert(len > 0);
+
+    struct json_t *json;
+    enum error_t err = serialise(self, &json);
+    if (err != ERR_OK) return ERR_JSON_SERIALISE;
+
+    size_t bytes_written = json_dumpb(json, buf, len, 0);
+    if (bytes_written == 0) return ERR_JSON_SERIALISE;
+
+    return ERR_OK;
+}
+
+
+enum error_t world_deserialise(struct world_t *self, char const *str) {
+    assert(self != NULL);
+    assert(str != NULL);
+
+    struct json_t *json = json_loads(str, 0, NULL);
+    if (json == NULL) return ERR_JSON_DESERIALISE;
+
+    enum error_t err = deserialise(self, json);
+    if (err != ERR_OK) return ERR_JSON_DESERIALISE;
+
+    return ERR_OK;
+}
+
+
 enum error_t world_register_entity(
     struct world_t *self,
     char const *name, char tile

run.sh

@@ -0,0 +1,15 @@
+#!/bin/sh
+
+./build.sh
+
+echo "### DAEMON ###"
+./build/server/simworld-daemon &
+sleep 1
+
+echo "### CLIENT 1 ###"
+./build/client/simworld-client
+
+echo "### CLIENT 2 ###"
+./build/client/simworld-client
+
+killall simworld-daemon

server/src/main.c

@@ -22,33 +22,25 @@ static void handle_signal(int signal_no) {
 }
 
 
-#define LOGMSG(options, fmt, ...) \
-    ((options)->daemonise ? \
-        syslog(LOG_NOTICE, (fmt), __VA_ARGS__) : \
-        (void)printf((fmt), __VA_ARGS__))
-
-
 enum error_t game_loop(struct data_t *data) {
     enum error_t err = ERR_OK;
-    char obuf[1024] = { 0 };
-    char ibuf[1024] = { 0 };
 
-    // TODO: I skipped out on most error handling here
+    char obuf[1024] = { 0 };
-    struct json_t *json;
+    err = world_serialise_buf(&data->world, obuf, 1024);
-    err = world_serialise(&data->world, &json);
     if (err != ERR_OK) return err;
 
-    json_dumpb(json, obuf, 1024, 0);
     write(data->socket_accept, obuf, 1024);
 
+    char ibuf[1024] = { 0 };
     read(data->socket_accept, ibuf, 1024);
-    json = json_loads(ibuf, 0, NULL);
 
-    struct world_t returned_world;
+    struct world_t old_world = data->world;
-    world_deserialise(&returned_world, json);
+    err = world_deserialise(&data->world, ibuf);
-    LOGMSG(&data->options, "SERVER: (%zu %zu) -> (%zu %zu)\n",
+    if (err != ERR_OK) return ERR_OK;
-        data->world.height, data->world.width,
+
-        returned_world.height, returned_world.width
+    printf("SERVER: (%zu %zu) -> (%zu %zu)\n",
+        old_world.height, old_world.width,
+        data->world.height, data->world.width
     );
 
     return ERR_OK;
@@ -100,6 +92,6 @@ handle_error:
     opts_free(&data.options);
 
 handle_error_pre_opts:
-    printf("ERROR: %s\n", ERROR_STRS[err]);
+    printf("SERVER ERROR: %s\n", ERROR_STRS[err]);
     return err;
 }