+/* env.c - Environment variables */
+/*
+ * GRUB -- GRand Unified Bootloader
+ * Copyright (C) 2003,2005,2006,2007,2008,2009 Free Software Foundation, Inc.
+ *
+ * GRUB is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * GRUB is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with GRUB. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <grub/env.h>
+#include <grub/env_private.h>
+#include <grub/misc.h>
+#include <grub/mm.h>
+
+/* The initial context. */
+static struct grub_env_context initial_context;
+
+/* The current context. */
+struct grub_env_context *grub_current_context = &initial_context;
+
+static grub_env_read_hook_t vtoy_menu_lang_read_hook;
+
+/* Return the hash representation of the string S. */
+static unsigned int
+grub_env_hashval (const char *s)
+{
+ unsigned int i = 0;
+
+ /* XXX: This can be done much more efficiently. */
+ while (*s)
+ i += 5 * *(s++);
+
+ return i % HASHSZ;
+}
+
+static struct grub_env_var *
+grub_env_find (const char *name)
+{
+ struct grub_env_var *var;
+ int idx = grub_env_hashval (name);
+
+ /* Look for the variable in the current context. */
+ for (var = grub_current_context->vars[idx]; var; var = var->next)
+ if (grub_strcmp (var->name, name) == 0)
+ return var;
+
+ return 0;
+}
+
+static void
+grub_env_insert (struct grub_env_context *context,
+ struct grub_env_var *var)
+{
+ int idx = grub_env_hashval (var->name);
+
+ /* Insert the variable into the hashtable. */
+ var->prevp = &context->vars[idx];
+ var->next = context->vars[idx];
+ if (var->next)
+ var->next->prevp = &(var->next);
+ context->vars[idx] = var;
+}
+
+static void
+grub_env_remove (struct grub_env_var *var)
+{
+ /* Remove the entry from the variable table. */
+ *var->prevp = var->next;
+ if (var->next)
+ var->next->prevp = var->prevp;
+}
+
+grub_err_t
+grub_env_set (const char *name, const char *val)
+{
+ struct grub_env_var *var;
+
+ /* If the variable does already exist, just update the variable. */
+ var = grub_env_find (name);
+ if (var)
+ {
+ char *old = var->value;
+
+ if (var->write_hook)
+ var->value = var->write_hook (var, val);
+ else
+ var->value = grub_strdup (val);
+
+ if (! var->value)
+ {
+ var->value = old;
+ return grub_errno;
+ }
+
+ grub_free (old);
+ return GRUB_ERR_NONE;
+ }
+
+ /* The variable does not exist, so create a new one. */
+ var = grub_zalloc (sizeof (*var));
+ if (! var)
+ return grub_errno;
+
+ var->name = grub_strdup (name);
+ if (! var->name)
+ goto fail;
+
+ var->value = grub_strdup (val);
+ if (! var->value)
+ goto fail;
+
+ grub_env_insert (grub_current_context, var);
+
+ return GRUB_ERR_NONE;
+
+ fail:
+ grub_free (var->name);
+ grub_free (var->value);
+ grub_free (var);
+
+ return grub_errno;
+}
+
+const char *
+grub_env_get (const char *name)
+{
+ struct grub_env_var *var;
+
+ if (name && vtoy_menu_lang_read_hook && grub_strncmp(name, "VTLANG_", 7) == 0)
+ return vtoy_menu_lang_read_hook(NULL, name);
+
+ var = grub_env_find (name);
+ if (! var)
+ return 0;
+
+ if (var->read_hook)
+ return var->read_hook (var, var->value);
+
+ return var->value;
+}
+
+void
+grub_env_unset (const char *name)
+{
+ struct grub_env_var *var;
+
+ var = grub_env_find (name);
+ if (! var)
+ return;
+
+ if (var->read_hook || var->write_hook)
+ {
+ grub_env_set (name, "");
+ return;
+ }
+
+ grub_env_remove (var);
+
+ grub_free (var->name);
+ grub_free (var->value);
+ grub_free (var);
+}
+
+struct grub_env_var *
+grub_env_update_get_sorted (void)
+{
+ struct grub_env_var *sorted_list = 0;
+ int i;
+
+ /* Add variables associated with this context into a sorted list. */
+ for (i = 0; i < HASHSZ; i++)
+ {
+ struct grub_env_var *var;
+
+ for (var = grub_current_context->vars[i]; var; var = var->next)
+ {
+ struct grub_env_var *p, **q;
+
+ for (q = &sorted_list, p = *q; p; q = &((*q)->sorted_next), p = *q)
+ {
+ if (grub_strcmp (p->name, var->name) > 0)
+ break;
+ }
+
+ var->sorted_next = *q;
+ *q = var;
+ }
+ }
+
+ return sorted_list;
+}
+
+grub_err_t
+grub_register_variable_hook (const char *name,
+ grub_env_read_hook_t read_hook,
+ grub_env_write_hook_t write_hook)
+{
+ struct grub_env_var *var = grub_env_find (name);
+
+ if (! var)
+ {
+ if (grub_env_set (name, "") != GRUB_ERR_NONE)
+ return grub_errno;
+
+ var = grub_env_find (name);
+ /* XXX Insert an assertion? */
+ }
+
+ var->read_hook = read_hook;
+ var->write_hook = write_hook;
+
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_register_vtoy_menu_lang_hook(grub_env_read_hook_t read_hook)
+{
+ vtoy_menu_lang_read_hook = read_hook;
+ return GRUB_ERR_NONE;
+}
+
+grub_err_t
+grub_env_export (const char *name)
+{
+ struct grub_env_var *var;
+
+ var = grub_env_find (name);
+ if (! var)
+ {
+ grub_err_t err;
+
+ err = grub_env_set (name, "");
+ if (err)
+ return err;
+ var = grub_env_find (name);
+ }
+ var->global = 1;
+
+ return GRUB_ERR_NONE;
+}
projects / Ventoy.git / commitdiff