feature: e_uuid_store: Add infrastructure to store window/surface properties.

e_uuid_store provides an API to store various window/surface properties
in a mmapped shm memory object based on an assigned UUID. Its main purpose
will be to provide storage of these properties during session recovery when
E acts as a wayland compositor.

@feature

src/bin/Makefile.mk

@@ -214,6 +214,7 @@ src/bin/e_zone.h
 
 if HAVE_WAYLAND_CLIENTS
 ENLIGHTENMENTHEADERS += \
+src/bin/e_uuid_store.h \
 src/bin/e_comp_wl.h
 endif
 
@@ -386,6 +387,7 @@ endif
 
 if HAVE_WAYLAND_CLIENTS
 enlightenment_src += \
+src/bin/e_uuid_store.c \
 src/bin/e_comp_wl.c
 endif
 

src/bin/e_includes.h

@@ -155,3 +155,6 @@
 #include "e_comp_canvas.h"
 #include "e_utils.h"
 #include "e_hints.h"
+#ifdef HAVE_WAYLAND_CLIENTS
+#  include "e_uuid_store.h"
+#endif

src/bin/e_uuid_store.c

@@ -0,0 +1,144 @@
+/* vim:ts=8 sw=3 sts=3 expandtab cino=>5n-3f0^-2{2(0W1st0
+ */
+
+/* 1. Create mmaped memory blob, name the memory object
+ * 2. Fill in table and keep it up-to-date
+ * 3. (optional) Write the whole blob into a file on disk for later use)
+ */
+
+#include <sys/types.h>
+#include <sys/mman.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <Eina.h>
+
+#include <e.h>
+
+/* Use anonymous mapping if we don't want a persistent file on the disk */
+#define OBJECT_NAME "/e_uuid_store"
+#define TABLE_SIZE 10*eina_cpu_page_size()
+
+struct uuid_store *store;
+
+EINTERN int
+e_uuid_store_init(void)
+ {
+   /* FIXME think about refcounting here */
+   eina_init();
+
+   store = calloc(1, sizeof(struct uuid_store));
+   if (store == NULL) return 0;
+
+   store->shmfd = shm_open(OBJECT_NAME, O_CREAT | O_RDWR, S_IRWXU | S_IRWXG);
+   if (store->shmfd < 0)
+    {
+       ERR("shm_open failed");
+       return 0;
+    }
+
+   /* Adjust in memory blob to our given table size */
+   /* FIXME: How can we make sure we have the right size for our given table? */
+   ftruncate(store->shmfd, TABLE_SIZE);
+
+   store->table = (struct uuid_table *)mmap(NULL, TABLE_SIZE, PROT_READ | PROT_WRITE, MAP_SHARED, store->shmfd, 0);
+   if (store->table == NULL)
+    {
+       ERR("mmap failed");
+       return 0;
+    }
+
+   INF("mmaped blob with size %i created", TABLE_SIZE);
+   return 1;
+ }
+
+EINTERN int
+e_uuid_store_shutdown(void)
+ {
+   /* Cleanup for shutdown */
+   if (shm_unlink(OBJECT_NAME) != 0)
+    {
+       ERR("shm_unlink failed");
+       return 0;
+    }
+
+   free(store);
+   eina_shutdown();
+   return 1;
+ }
+
+Eina_Bool
+e_uuid_store_reload(void)
+ {
+   /* After crash reload the table with its POSIX object name from memory */
+   return EINA_FALSE;
+ }
+
+Eina_Bool
+e_uuid_store_entry_del(long uuid)
+ {
+   struct uuid_table *table;
+   struct table_entry *entry;
+   Eina_List *l;
+
+   if (store == NULL) return EINA_FALSE;
+
+   table = store->table;
+   if (table == NULL) return EINA_FALSE;
+
+   /* Search through uuid list and delete if found */
+   EINA_LIST_FOREACH(table->entries, l, entry)
+    {
+      if (entry->uuid == uuid)
+       {
+         table->entries = eina_list_remove(table->entries, entry);
+         free(entry);
+         DBG("Removed entry with UUID %li", uuid);
+         return EINA_TRUE;
+       }
+    }
+   DBG("NOT removed entry with UUID %li. Entry not found.", uuid);
+   return EINA_FALSE;
+ }
+
+/* FIXME: Think about having _add  and _update functions instead only update */
+
+Eina_Bool
+e_uuid_store_entry_update(long uuid, E_Client *ec)
+ {
+   struct uuid_table *table;
+   struct table_entry *entry;
+   Eina_List *l;
+
+   if (store == NULL) return EINA_FALSE;
+
+   table = store->table;
+   if (table == NULL) return EINA_FALSE;
+
+   /* Search through uuid list if it already exist if yes update */
+   EINA_LIST_FOREACH(table->entries, l, entry)
+    {
+      if (entry->uuid == uuid)
+       {
+         entry->x = ec->x;
+         entry->y = ec->y;
+         entry->width = ec->client.w;
+         entry->heigth = ec->client.h;
+         DBG("Updated entry with UUID %li", uuid);
+         return EINA_TRUE;
+       }
+    }
+
+   /* We do not have this UUID in the table yet. Create it */
+   entry = calloc(1, sizeof(struct table_entry));
+   entry->uuid = uuid;
+   entry->x = ec->x;
+   entry->y = ec->y;
+   entry->width = ec->client.w;
+   entry->heigth = ec->client.h;
+   table->entries = eina_list_append(table->entries, entry);
+   table->entry_count = eina_list_count(table->entries);
+   DBG("Created entry with UUID %li", uuid);
+
+   return EINA_TRUE;
+ }

src/bin/e_uuid_store.h

@@ -0,0 +1,33 @@
+#ifndef E_UUID_STORE_H
+#define E_UUID_STORE_H
+
+/* vim:ts=8 sw=3 sts=3 expandtab cino=>5n-3f0^-2{2(0W1st0
+ */
+
+struct uuid_table {
+   int version; /* Version to allow future extensions */
+   unsigned int entry_count; /* Entry counter to allow excat memory consuptions needs? */
+   /* Global settings like current virtual desktop, screen setup, etc */
+   Eina_List *entries;
+};
+
+struct table_entry {
+   long uuid;
+   /* data structure for per application properties */
+   Evas_Coord x, y;
+   Evas_Coord width, heigth;
+   unsigned int virtual_desktop;
+   int flags;
+};
+
+struct uuid_store {
+   struct uuid_table *table;
+   int shmfd;
+};
+
+EINTERN int e_uuid_store_init(void);
+EINTERN int e_uuid_store_shutdown(void);
+EAPI Eina_Bool e_uuid_store_reload(void);
+EAPI Eina_Bool e_uuid_store_entry_del(long uuid);
+EAPI Eina_Bool e_uuid_store_entry_update(long uuid, E_Client *ec);
+#endif