]> git.ozlabs.org Git - ccan-lca-2011.git/blobdiff - ccan/oserver/oserver.c
lca2011: oserver_restore to restore fields we labelled CDUMP_IGNORE.
[ccan-lca-2011.git] / ccan / oserver / oserver.c
index ad8f31538ec31663c90624490217b1c6936f5294..50b49bd5f94746c8259fb3c609c285c5d68684c9 100644 (file)
@@ -1,8 +1,11 @@
 #include <ccan/oserver/oserver.h>
+#include <ccan/oserver/oserver_types.h>
+#include <ccan/oserver/oserver_cdump.h>
 #include <ccan/read_write_all/read_write_all.h>
 #include <ccan/opt/opt.h>
 #include <ccan/tevent/tevent.h>
 #include <ccan/array_size/array_size.h>
+#include <ccan/grab_file/grab_file.h>
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
 #include <errno.h>
 #include <signal.h>
 #include <assert.h>
-
-enum state {
-       SENDING_GREETING,
-       RECEIVING_USER_QUESTION,
-       SENDING_OTHER_QUESTION_PREFIX,
-       SENDING_OTHER_QUESTION,
-       RECEIVING_OTHER_ANSWER,
-       SENDING_ANSWER_PREFIX,
-       SENDING_ANSWER,
-       FINISHED
-};
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
 
 static uint16_t state_flag_map[] = {
        [SENDING_GREETING]              = TEVENT_FD_WRITE,
@@ -39,33 +34,6 @@ static uint16_t state_flag_map[] = {
        [FINISHED]                      = 0
 };
 
-struct client {
-       /* What are we doing today, brain? */
-       enum state state;
-       /* Our event info, and the file descriptor. */
-       struct tevent_fd *fde;
-       int fd;
-       /* The question we read from client. */
-       char *question;
-       /* The answer to the client. */
-       char *answer;
-       /* How many bytes of the reply we sent so far. */
-       size_t bytes_sent;
-       /* Our server. */
-       struct oserver *oserver;
-       /* Whose question this client is answering. */
-       struct client *subclient;
-       /* Who is answering our question. */
-       struct client *oracle;
-};
-
-struct oserver {
-       /* 5 clients should be enough for anybody! */
-       struct client *clients[5];
-       int fd;
-       struct tevent_fd *fde;
-};
-
 static ssize_t write_string(int fd, const char *str)
 {
        return write(fd, str, strlen(str));
@@ -123,9 +91,9 @@ static bool get_subclient(struct client *me)
                struct client *c = me->oserver->clients[i];
                if (!c || c == me)
                        continue;
-               if (c->oracle == NULL && input_finished(c->question)) {
-                       me->subclient = c;
-                       c->oracle = me;
+               if (c->oracle == -1 && input_finished(c->question)) {
+                       me->subclient = c->id;
+                       c->oracle = me->id;
                        return true;
                }
        }
@@ -140,9 +108,9 @@ static bool get_oracle(struct client *me)
                struct client *c = me->oserver->clients[i];
                if (!c || c == me)
                        continue;
-               if (c->subclient == NULL && input_finished(c->question)) {
-                       me->oracle = c;
-                       c->subclient = me;
+               if (c->subclient == -1 && input_finished(c->question)) {
+                       me->oracle = c->id;
+                       c->subclient = me->id;
                        return true;
                }
        }
@@ -173,27 +141,29 @@ static void service_client(struct tevent_context *ev,
                        set_state(c, SENDING_OTHER_QUESTION_PREFIX);
                break;
        case SENDING_OTHER_QUESTION_PREFIX:
-               if (!c->subclient)
+               if (c->subclient == -1)
                        goto need_subclient;
                if (!send_string(c, "While the Oracle ponders,"
                                 " please answer the following question:\n"))
                        goto fail;
                break;
        case SENDING_OTHER_QUESTION:
-               if (!c->subclient)
+               if (c->subclient == -1)
                        goto need_subclient;
-               if (!send_string(c, c->subclient->question))
+               if (!send_string(c,
+                                c->oserver->clients[c->subclient]->question))
                        goto fail;
                break;
        case RECEIVING_OTHER_ANSWER:
-               if (!c->subclient)
+               if (c->subclient == -1)
                        goto need_subclient;
-               len = read_string(c->fd, &c->subclient->answer);
+               len = read_string(c->fd,
+                                 &c->oserver->clients[c->subclient]->answer);
                if (len <= 0)
                        goto fail;
-               if (input_finished(c->subclient->answer)) {
+               if (input_finished(c->oserver->clients[c->subclient]->answer)) {
                        set_state(c, SENDING_ANSWER_PREFIX);
-                       wakeup(c->subclient);
+                       wakeup(c->oserver->clients[c->subclient]);
                }
                break;
        case SENDING_ANSWER_PREFIX:
@@ -222,14 +192,14 @@ need_subclient:
                tevent_fd_set_flags(c->fde, 0);
        } else
                /* In case they are waiting... */
-               wakeup(c->subclient);
+               wakeup(c->oserver->clients[c->subclient]);
        return;
 
 need_answer:
        /* If we don't have an oracle and find one, that's OK. */
-       if (!c->oracle && get_oracle(c)) {
+       if (c->oracle == -1 && get_oracle(c)) {
                /* In case they are waiting... */
-               wakeup(c->oracle);
+               wakeup(c->oserver->clients[c->oracle]);
                return;
        }
 
@@ -239,25 +209,18 @@ need_answer:
 
 static int cleanup_client(struct client *client)
 {
-       unsigned int i;
 
        /* We were an oracle? */
-       if (client->subclient)
-               client->subclient->oracle = NULL;
+       if (client->subclient >= 0)
+               client->oserver->clients[client->subclient]->oracle = -1;
 
        /* We had an oracle? */
-       if (client->oracle)
-               client->oracle->subclient = NULL;
-
-       for (i = 0; i < ARRAY_SIZE(client->oserver->clients); i++) {
-               if (client->oserver->clients[i] == client) {
-                       client->oserver->clients[i] = NULL;
-                       tevent_fd_set_flags(client->oserver->fde,
-                                           TEVENT_FD_READ);
-                       return 0;
-               }
-       }
-       abort();
+       if (client->oracle >= 0)
+               client->oserver->clients[client->oracle]->subclient = -1;
+
+       assert(client->oserver->clients[client->id] == client);
+       client->oserver->clients[client->id] = NULL;
+       return 0;
 }
 
 static void add_client(struct tevent_context *ev,
@@ -265,7 +228,6 @@ static void add_client(struct tevent_context *ev,
 {
        struct oserver *oserver = _oserver;
        struct client *client;
-       unsigned int i;
 
        client = talloc(oserver, struct client);
        client->fd = accept(oserver->fd, NULL, 0);
@@ -276,8 +238,8 @@ static void add_client(struct tevent_context *ev,
        client->bytes_sent = 0;
        client->question = talloc_strdup(client, "");
        client->oserver = oserver;
-       client->oracle = NULL;
-       client->subclient = NULL;
+       client->oracle = -1;
+       client->subclient = -1;
        client->answer = talloc_strdup(client, "");
        client->fde = tevent_add_fd(ev, client, client->fd,
                                    state_flag_map[client->state],
@@ -285,12 +247,12 @@ static void add_client(struct tevent_context *ev,
        tevent_fd_set_auto_close(client->fde);
 
        /* Find empty slot in array for this client. */
-       for (i = 0; oserver->clients[i]; i++);
-       oserver->clients[i] = client;
+       for (client->id = 0; oserver->clients[client->id]; client->id++);
+       oserver->clients[client->id] = client;
        talloc_set_destructor(client, cleanup_client);
 
        /* Full?  Stop listening... */
-       if (i == ARRAY_SIZE(oserver->clients)-1)
+       if (client->id == ARRAY_SIZE(oserver->clients)-1)
                tevent_fd_set_flags(oserver->fde, 0);
 }
 
@@ -327,7 +289,96 @@ static void talloc_dump(struct tevent_context *ev,
        }
 }
 
-struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
+static void dump(struct tevent_context *ev,
+                struct tevent_signal *se,
+                int signum,
+                int count,
+                void *siginfo,
+                void *_oserver)
+{
+       struct oserver *oserver = _oserver;
+       char *str;
+       int fd;
+
+       str = cdump_bundle(ev, cdump_struct_oserver, oserver);
+       fd = open(oserver->dumpfile, O_CREAT|O_TRUNC|O_WRONLY, 0600);
+       write(fd, str, strlen(str));
+       close(fd);
+       talloc_free(str);
+}
+
+static bool load_file(struct oserver *oserver, const char *file)
+{
+       char *str;
+
+       if (!file)
+               return false;
+
+       str = grab_file(oserver, file, NULL);
+       if (!str)
+               return false;
+
+       if (!cdump_unbundle(oserver, cdump_struct_oserver, oserver, str)) {
+               talloc_free(str);
+               return false;
+       }
+       talloc_free(str);
+       return true;
+}
+
+static bool complete_server(struct tevent_context *ev,
+                           struct oserver *oserver, const char *dumpfile)
+{
+       /* Re-set this even if restored from file, in case it changed. */
+       oserver->dumpfile = dumpfile;
+       if (oserver->dumpfile)
+               tevent_add_signal(ev, oserver, SIGHUP, SA_RESTART,
+                                 dump, oserver);
+
+       /* Don't kill us if client dies. */
+       signal(SIGPIPE, SIG_IGN);
+
+       /* Show talloc tree on SIGUSR1. */
+       tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
+                         talloc_dump, oserver);
+
+       oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
+                                    TEVENT_FD_READ, add_client, oserver);
+       if (!oserver->fde)
+               return false;
+       return true;
+}
+
+struct oserver *oserver_restore(struct tevent_context *ev, const char *dumpfile)
+{
+       unsigned int i;
+       struct oserver *oserver = talloc(ev, struct oserver);
+       if (!load_file(oserver, dumpfile)) {
+               talloc_free(oserver);
+               return NULL;
+       }
+
+       /* Restore ignored fields in clients (fde and oserver). */
+       for (i = 0; i < ARRAY_SIZE(oserver->clients); i++) {
+               struct client *client = oserver->clients[i];
+               if (!client)
+                       continue;
+               client->oserver = oserver;
+               client->fde = tevent_add_fd(ev, client, client->fd,
+                                           state_flag_map[client->state],
+                                           service_client, client);
+               tevent_fd_set_auto_close(client->fde);
+       }
+
+       if (!complete_server(ev, oserver, dumpfile)) {
+               talloc_free(oserver);
+               return NULL;
+       }
+       return oserver;
+}
+
+struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port,
+                             const char *dumpfile)
 {
        struct oserver *oserver;
        int one = 1;
@@ -363,19 +414,10 @@ struct oserver *oserver_setup(struct tevent_context *ev, unsigned short port)
                return NULL;
        }
 
-       oserver->fde = tevent_add_fd(ev, oserver, oserver->fd,
-                                    TEVENT_FD_READ, add_client, oserver);
-       if (!oserver->fde) {
+       if (!complete_server(ev, oserver, dumpfile)) {
                talloc_free(oserver);
                return NULL;
        }
 
-       /* Don't kill us if client dies. */
-       signal(SIGPIPE, SIG_IGN);
-
-       /* Show talloc tree on SIGUSR1. */
-       tevent_add_signal(ev, oserver, SIGUSR1, SA_RESTART,
-                         talloc_dump, oserver);
-
        return oserver;
 }