irm: Revise naming API

This revises the naming API to treat names (or reg_name in the source)
as first-class citizens of the architecture. This is more in line with
the way they are described in the article.

Operations have been added to create/destroy names independently of
registering. This was previously done only as part of register, and
there was no way to delete a name from the IRMd.  The create call now
allows specifying a policy for load-balancing incoming flows for a
name. The default is the new round-robin load-balancer, the previous
behaviour is still available as a spillover load-balancer.

The register calls will still create a name if it doesn't exist, with
the default round-robin load-balancer.

The tools now have a "name" section, so the format is now

irm name <operation> <name> ...

Signed-off-by: Dimitri Staessens <dimitri@ouroboros.rocks>
Signed-off-by: Sander Vrijders <sander@ouroboros.rocks>

1 files changed, 115 insertions, 0 deletions

diff --git a/src/tools/irm/irm_name_list.c b/src/tools/irm/irm_name_list.c
new file mode 100644
index 00000000..2e4c3194
--- /dev/null
+++ b/src/tools/irm/irm_name_list.c
@@ -0,0 +1,115 @@
+/*
+ * Ouroboros - Copyright (C) 2016 - 2020
+ *
+ * List names
+ *
+ *    Dimitri Staessens <dimitri.staessens@ugent.be>
+ *    Sander Vrijders   <sander.vrijders@ugent.be>
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
+ * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
+ * OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <ouroboros/irm.h>
+#include <ouroboros/errno.h>
+
+#include "irm_ops.h"
+#include "irm_utils.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#define RR    "round-robin"
+#define SPILL "spillover"
+
+static char * str_pol(enum pol_balance p)
+{
+        switch(p) {
+        case LB_RR:
+                return RR;
+        case LB_SPILL:
+                return SPILL;
+        default:
+                return "UNKNOWN";
+        }
+};
+
+int do_list_name(int     argc,
+                 char ** argv)
+{
+        char *             name = NULL;
+        struct name_info * names;
+        ssize_t            len;
+        ssize_t            i;
+
+        while (argc > 0) {
+                if (matches(*argv, "list") == 0) {
+                        name = *(argv + 1);
+                } else {
+                        printf("\"%s\" is unknown, try \"irm "
+                               "name list.\n", *argv);
+                        return -1;
+                }
+
+                argc -= 2;
+                argv += 2;
+        }
+
+        len = irm_list_names(&names);
+        if (len == 0) {
+                printf("No names in system.\n\n");
+                return 0;
+        } else if (len == -EIRMD) {
+                printf("Failed to communicate with the "
+                       "Ouroboros IPC Resource Manager daemon.\n");
+                return -1;
+        } else if (len < 0)
+                return len;
+
+        printf("+----------------------------------------------------"
+               "+----------------------+\n");
+        printf("| %50s | %20s |\n", "name", "load-balance policy");
+        printf("+----------------------------------------------------"
+               "+----------------------+\n");
+
+        for (i = 0; i < len; i++) {
+                if (name != NULL && matches(names[i].name, name))
+                        continue;
+                printf("| %50s | %20s |\n",
+                       names[i].name,
+                       str_pol(names[i].pol_lb));
+        }
+        printf("+----------------------------------------------------"
+               "+----------------------+\n");
+
+        free(names);
+
+        return 0;
+}