data client (WIP)

1 files changed, 72 insertions, 37 deletions

diff --git a/data/server.c b/data/server.c
index 2d96b81..ea94364 100644
--- a/data/server.c
+++ b/data/server.c
@@ -1,6 +1,7 @@
 #include <arpa/inet.h>
 #include <json-c/json.h>
 #include <signal.h>
+#include <sqlite3.h>
 #include <string.h>
 #include <threads.h>
 
@@ -8,34 +9,46 @@
 
 #define BACKLOG 10
 
-struct Client {
+struct Socket {
     int fd;
     struct sockaddr_in addr;
 };
 
+sqlite3 *g_sim_db;
+void (*g_info)(const char *fmt, ...) = log_info;
+void (*g_warn)(const char *fmt, ...) = log_warn;
+#include "sql.c"
+
+// ----------------------------------------------------------------------------
+// SQL functions
+// ----------------------------------------------------------------------------
+
+// ----------------------------------------------------------------------------
+// Main functions
+// ----------------------------------------------------------------------------
 void sig_handler(int signo) {
     log_warn("Signal %d received, shutting down data server", signo);
     exit(0);
 }
 
-void respond_name(int client_fd) {
+void respond_name(int socket_fd) {
     log_info("Client requested simulation name");
 
     struct json_object *sim_name = json_object_new_object();
     json_object_object_add(sim_name, "name", json_object_new_string(NAME));
-    json_object_to_fd(client_fd, sim_name, JSON_C_TO_STRING_PRETTY);
+    json_object_to_fd(socket_fd, sim_name, 0);
     json_object_put(sim_name);
 }
 
-void respond_opts(int client_fd) {
+void respond_opts(int socket_fd) {
     log_info("Client requested simulation options");
 
     struct json_object *sim_opts = json_object_from_file(SIM_OPTS);
-    json_object_to_fd(client_fd, sim_opts, JSON_C_TO_STRING_PRETTY);
+    json_object_to_fd(socket_fd, sim_opts, 0);
     json_object_put(sim_opts);
 }
 
-void respond_hash(int client_fd) {
+void respond_hash(int socket_fd) {
     log_info("Client requested git hash");
 
     char buff[41] = { 0 };
@@ -45,23 +58,34 @@ void respond_hash(int client_fd) {
 
     struct json_object *git_hash = json_object_new_object();
     json_object_object_add(git_hash, "hash", json_object_new_string(buff));
-    json_object_to_fd(client_fd, git_hash, JSON_C_TO_STRING_PRETTY);
+    json_object_to_fd(socket_fd, git_hash, 0);
     json_object_put(git_hash);
 }
 
-void respond_data(int client_fd, struct json_object *request_json) {
-    assert(request_json);
-    (void)client_fd;
+void respond_data(int socket_fd, struct json_object *request) {
+    assert(request);
+
+    const char *request_str = json_object_to_json_string(request);
+    log_info("Client requested simulation data with the following parameters: %s", request_str);
+
+    struct json_object *response = json_object_new_object();
+    json_object_object_add(response, "response", json_object_new_string("hello!"));
+    const char *response_str = json_object_to_json_string(response);
+    log_info("Sending response to client: %s", response_str);
+    json_object_to_fd(socket_fd, response, 0);
+
+    shutdown(socket_fd, SHUT_WR);
+    json_object_put(response);
 }
 
-int handle_client(struct Client *client) {
-    assert(client);
+int handle_client(struct Socket *socket) {
+    assert(socket);
 
-    char client_ip[INET_ADDRSTRLEN];
-    inet_ntop(AF_INET, &client->addr.sin_addr, client_ip, INET_ADDRSTRLEN);
-    log_info("Client connected: %s:%d", client_ip, ntohs(client->addr.sin_port));
+    char socket_ip[INET_ADDRSTRLEN];
+    inet_ntop(AF_INET, &socket->addr.sin_addr, socket_ip, INET_ADDRSTRLEN);
+    log_info("Client connected: %s:%d", socket_ip, ntohs(socket->addr.sin_port));
 
-    struct json_object *request_json = json_object_from_fd(client->fd);
+    struct json_object *request_json = json_object_from_fd(socket->fd);
     struct json_object *request_str = NULL;
 
     if (!json_object_object_get_ex(request_json, "request", &request_str)) assert(false);
@@ -70,23 +94,23 @@ int handle_client(struct Client *client) {
     assert(request);
 
     if (!strcmp(request, "name")) {
-        respond_name(client->fd);
+        respond_name(socket->fd);
     } else if (!strcmp(request, "opts")) {
-        respond_opts(client->fd);
+        respond_opts(socket->fd);
     } else if (!strcmp(request, "hash")) {
-        respond_hash(client->fd);
+        respond_hash(socket->fd);
     } else if (!strcmp(request, "data")) {
-        respond_data(client->fd, request_json);
+        respond_data(socket->fd, request_json);
     } else {
         assert(false);
     }
 
     json_object_put(request_json);
 
-    log_info("Client disconnected: %s:%d", client_ip, ntohs(client->addr.sin_port));
-    close(client->fd);
+    log_info("Client disconnected: %s:%d", socket_ip, ntohs(socket->addr.sin_port));
+    close(socket->fd);
 
-    free(client);
+    free(socket);
     return 0;
 }
 
@@ -95,30 +119,41 @@ int main(void) {
     signal(SIGTERM, sig_handler);
 
     log_info("Initializing salis data server");
-    int opt = 1;
-    int server_fd = socket(AF_INET, SOCK_STREAM, 0);
-    setsockopt(server_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+    log_info("Connecting to database in: %s", DATA_PUSH_PATH);
+    sqlite3_open(DATA_PUSH_PATH, &g_sim_db);
+    assert(g_sim_db);
+
+    // Install busy handler to retry transactions if DB is locked
+    sqlite3_busy_timeout(g_sim_db, DATA_PUSH_BUSY_TIMEOUT);
+
+    // Enable Write-Ahead Logging (WAL)
+    // This seems to help prevent DB locks when displaying live data.
+    // See: https://sqlite.org/wal.html
+    salis_exec_sql(0, NULL, NULL, "pragma journal_mode=wal;");
 
     log_info("Binding to port: %d", PORT);
-    struct sockaddr_in server_addr = { 0 };
-    server_addr.sin_family = AF_INET;
-    server_addr.sin_addr.s_addr = INADDR_ANY;
-    server_addr.sin_port = htons(PORT);
-    bind(server_fd, (struct sockaddr *)&server_addr, sizeof(struct sockaddr_in));
+    int opt = 1;
+    int socket_fd = socket(AF_INET, SOCK_STREAM, 0);
+    setsockopt(socket_fd, SOL_SOCKET, SO_REUSEADDR, &opt, sizeof(opt));
+    struct sockaddr_in socket_addr = { 0 };
+    socket_addr.sin_family = AF_INET;
+    socket_addr.sin_addr.s_addr = INADDR_ANY;
+    socket_addr.sin_port = htons(PORT);
+    bind(socket_fd, (struct sockaddr *)&socket_addr, sizeof(struct sockaddr_in));
 
     log_info("Listening...");
-    listen(server_fd, BACKLOG);
+    listen(socket_fd, BACKLOG);
 
     while (true) {
-        struct Client *client = calloc(1, sizeof(struct Client));
-        socklen_t client_len = sizeof(struct sockaddr_in);
-        client->fd = accept(server_fd, (struct sockaddr *)&client->addr, &client_len);
+        struct Socket *socket = calloc(1, sizeof(struct Socket));
+        socklen_t socket_len = sizeof(struct sockaddr_in);
+        socket->fd = accept(socket_fd, (struct sockaddr *)&socket->addr, &socket_len);
 
         thrd_t thrd;
-        thrd_create(&thrd, (thrd_start_t)handle_client, client);
+        thrd_create(&thrd, (thrd_start_t)handle_client, socket);
         thrd_detach(thrd);
     }
 
-    close(server_fd);
+    close(socket_fd);
     return 0;
 }