--- /dev/null
+/* $Id$ */
+
+/* cbps - persistant states for callbacks */
+
+/* Authors: Olivier Aumage, Martin Quinson */
+/* Copyright (C) 2003, 2004 da GRAS posse. */
+
+/* This program is free software; you can redistribute it and/or modify it
+ under the terms of the license (GNU LGPL) which comes with this package. */
+
+#include "DataDesc/datadesc_private.h"
+
+typedef struct {
+ gras_datadesc_type_t *type;
+ void *data;
+} gras_dd_cbps_elm_t;
+
+struct s_gras_dd_cbps {
+ gras_dict_t *space;
+ gras_dynar_t *stack;
+ gras_dynar_t *globals;
+
+};
+
+/**
+ * gras_dd_cbps_push:
+ *
+ * Declare a new element in the PS, and give it a value. If an element of that name already exists,
+ * it becomes masked by the one given here, and will be seable again only after a pop to remove the
+ * value this push adds.
+ */
+void
+gras_dd_cbps_push(gras_dd_cbps_t *ps,
+ const char *name,
+ void *data,
+ gras_datadesc_type_t *ddt) {
+
+ gras_dynar_t *p_dynar = NULL;
+ gras_dd_cbps_elm_t *p_var = NULL;
+
+ gras_dict_retrieve(ps->space, name, (void **)&p_dynar);
+
+ if (!p_dynar) {
+ gras_dynar_new(&p_dynar, sizeof (gras_dd_cbps_elm_t *), NULL);
+ gras_dict_insert(ps->space, name, (void **)p_dynar, NULL);
+ /* FIXME: leaking on dynar. Insert in dict with a way to free it */
+ }
+
+ p_var = calloc(1, sizeof(gras_dd_cbps_elm_t));
+ p_var->type = ddt;
+ p_var->data = data;
+
+ gras_dynar_push(p_dynar, &p_var);
+
+ gras_dynar_pop(ps->stack, &p_dynar);
+ gras_dynar_push(p_dynar, &name);
+ gras_dynar_push(ps->stack, &p_dynar);
+}
+
+/**
+ * gras_dd_cbps_pop:
+ *
+ * Retrieve an element from the PS, and remove it from the PS. If it's not present in the current block,
+ * it will fail (with abort) and not search in upper blocks since this denotes a programmation error.
+ */
+void *
+gras_dd_cbps_pop (gras_dd_cbps_t *ps,
+ const char *name,
+ gras_datadesc_type_t **ddt) {
+ gras_dynar_t *p_dynar = NULL;
+ gras_dd_cbps_elm_t *p_elm = NULL;
+ void *data = NULL;
+
+ /* FIXME: Error handling */
+ gras_dict_retrieve(ps->space, name, (void **)&p_dynar);
+ gras_dynar_pop(p_dynar, &p_elm);
+
+ if (!gras_dynar_length(p_dynar)) {
+ gras_dict_remove(ps->space, name);
+ gras_dynar_free_container(p_dynar);
+ }
+
+ if (ddt) {
+ *ddt = p_elm->type;
+ }
+
+ data = p_elm->data;
+
+ free(p_elm);
+
+ gras_dynar_pop(ps->stack, &p_dynar);
+ {
+ int l = gras_dynar_length(p_dynar);
+
+ while (l--) {
+ char *_name = NULL;
+
+ gras_dynar_get(p_dynar, l, &_name);
+ if (!strcmp(name, _name)) {
+ gras_dynar_remove_at(p_dynar, l, &_name);
+ free(_name);
+ break;
+ }
+ }
+ }
+ gras_dynar_push(ps->stack, &p_dynar);
+
+
+ return data;
+}
+
+/**
+ * gras_dd_cbps_set:
+ *
+ * Change the value of an element in the PS. If it's not present in the current block, look in the upper ones.
+ * If it's not present in any of them, look in the globals (FIXME: which no function of this API allows to set).
+ * If not present there neither, the code may segfault (Oli?).
+ *
+ * Once a reference to an element of that name is found somewhere in the PS, its value is changed.
+ */
+void
+gras_dd_cbps_set (gras_dd_cbps_t *ps,
+ const char *name,
+ void *data,
+ gras_datadesc_type_t *ddt) {
+
+ gras_dynar_t *p_dynar = NULL;
+ gras_dd_cbps_elm_t *p_elm = NULL;
+
+ gras_dict_retrieve(ps->space, name, (void **)&p_dynar);
+
+ if (!p_dynar) {
+ gras_dynar_new(&p_dynar, sizeof (gras_dd_cbps_elm_t *), NULL);
+ gras_dict_insert(ps->space, name, (void **)p_dynar, NULL);
+
+ p_elm = calloc(1, sizeof(gras_dd_cbps_elm_t));
+ gras_dynar_push(ps->globals, &name);
+ } else {
+ gras_dynar_pop(p_dynar, &p_elm);
+ }
+
+ p_elm->type = ddt;
+ p_elm->data = data;
+
+ gras_dynar_push(p_dynar, &p_elm);
+
+}
+
+/**
+ * gras_dd_cbps_get:
+ *
+ * Get the value of an element in the PS without modifying it.
+ * If it's not present in the current block, look in the upper ones.
+ * If it's not present in any of them, look in the globals (FIXME: which no function of this API allows to set).
+ * If not present there neither, the code may segfault (Oli?).
+ */
+void *
+gras_dd_cbps_get (gras_dd_cbps_t *ps,
+ const char *name,
+ gras_datadesc_type_t **ddt) {
+
+ gras_dynar_t *p_dynar = NULL;
+ gras_dd_cbps_elm_t *p_elm = NULL;
+
+ /* FIXME: Error handling */
+ gras_dict_retrieve(ps->space, name, (void **)&p_dynar);
+ gras_dynar_pop(p_dynar, &p_elm);
+ gras_dynar_push(p_dynar, &p_elm);
+
+ if (ddt) {
+ *ddt = p_elm->type;
+ }
+
+ return p_elm->data;
+
+}
+
+/**
+ * gras_dd_cbps_block_begin:
+ *
+ * Begins a new block.
+ *
+ * Blocks are usefull to remove a whole set of declarations you don't even know.
+ *
+ * For example, they constitute a very elegent solution to recursive data structures.
+ * push/pop may be used in some cases for that, but if your recursive data struct contains
+ * other structs needing themselves callbacks, you have to use block_{begin,end} to do the trick.
+ */
+
+void
+gras_dd_cbps_block_begin(gras_dd_cbps_t *ps) {
+
+ gras_dynar_t *p_dynar = NULL;
+
+ gras_dynar_new(&p_dynar, sizeof (char *), NULL);
+ gras_dynar_push(ps->stack, &p_dynar);
+}
+
+/**
+ * gras_dd_cbps_block_begin:
+ *
+ * End the current block, and go back to the upper one.
+ */
+void
+gras_dd_cbps_block_end(gras_dd_cbps_t *ps) {
+
+ gras_dynar_t *p_dynar = NULL;
+ int cursor = 0;
+ char *name = NULL;
+
+ gras_dynar_pop(ps->stack, &p_dynar);
+
+ gras_dynar_foreach(p_dynar, cursor, name) {
+ /* inline the code of _gs_vars_pop(p_vars, name), which was used only once */
+
+ gras_dynar_t *p_dynar_elm = NULL;
+ gras_dd_cbps_elm_t *p_elm = NULL;
+
+ gras_dict_retrieve(ps->space, name, (void **)&p_dynar_elm);
+ gras_dynar_pop(p_dynar_elm, &p_elm);
+
+ if (!gras_dynar_length(p_dynar_elm)) {
+ gras_dict_remove(ps->space, name);
+ gras_dynar_free_container(p_dynar_elm);
+ }
+
+ free(p_elm);
+ free(name);
+ }
+
+ gras_dynar_free_container(p_dynar);
+}
+
+
+
