subsurface/core/table.h
Berthold Stoeger ebdb3e3c30 media: create sort_picture_table function via macro
This needs a slight change to the macro, because here we sort by
value type. Yes, from a C-programming point of view this is horrible,
however a decent compiler should just inline everything and not
pass around value types.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2020-05-06 13:58:09 -07:00

113 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* This header defines a number of macros that generate table-manipulation functions.
* There is no design behind these macros - the functions were take as-is and transformed
* into macros. Thus, this whole header could do with some redesign. */
#ifndef CORE_TABLE_H
#define CORE_TABLE_H
#define MAKE_GROW_TABLE(table_type, item_type, array_name) \
item_type *grow_##table_type(struct table_type *table) \
{ \
int nr = table->nr, allocated = table->allocated; \
item_type *items = table->array_name; \
\
if (nr >= allocated) { \
allocated = (nr + 32) * 3 / 2; \
items = realloc(items, allocated * sizeof(item_type)); \
if (!items) \
exit(1); \
table->array_name = items; \
table->allocated = allocated; \
} \
return items; \
}
/* get the index where we want to insert an object so that everything stays
* ordered according to a comparison function() */
#define MAKE_GET_INSERTION_INDEX(table_type, item_type, array_name, fun) \
int table_type##_get_insertion_index(struct table_type *table, item_type item) \
{ \
/* we might want to use binary search here */ \
for (int i = 0; i < table->nr; i++) { \
if (fun(item, table->array_name[i])) \
return i; \
} \
return table->nr; \
}
/* add object at the given index to a table. */
#define MAKE_ADD_TO(table_type, item_type, array_name) \
void add_to_##table_type(struct table_type *table, int idx, item_type item) \
{ \
int i; \
grow_##table_type(table); \
table->nr++; \
\
for (i = idx; i < table->nr; i++) { \
item_type tmp = table->array_name[i]; \
table->array_name[i] = item; \
item = tmp; \
} \
}
#define MAKE_REMOVE_FROM(table_type, array_name) \
void remove_from_##table_type(struct table_type *table, int idx) \
{ \
int i; \
for (i = idx; i < table->nr - 1; i++) \
table->array_name[i] = table->array_name[i + 1]; \
memset(&table->array_name[--table->nr], 0, sizeof(table->array_name[0])); \
}
#define MAKE_GET_IDX(table_type, item_type, array_name) \
int get_idx_in_##table_type(const struct table_type *table, const item_type item) \
{ \
for (int i = 0; i < table->nr; ++i) { \
if (table->array_name[i] == item) \
return i; \
} \
return -1; \
}
#define MAKE_SORT(table_type, item_type, array_name, fun) \
static int sortfn_##table_type(const void *_a, const void *_b) \
{ \
const item_type a = *(const item_type *)_a; \
const item_type b = *(const item_type *)_b; \
return fun(a, b); \
} \
\
void sort_##table_type(struct table_type *table) \
{ \
qsort(table->array_name, table->nr, sizeof(item_type), sortfn_##table_type); \
}
#define MAKE_REMOVE(table_type, item_type, item_name) \
int remove_##item_name(const item_type item, struct table_type *table) \
{ \
int idx = get_idx_in_##table_type(table, item); \
if (idx >= 0) \
remove_from_##table_type(table, idx); \
return idx; \
}
#define MAKE_CLEAR_TABLE(table_type, array_name, item_name) \
void clear_##table_type(struct table_type *table) \
{ \
for (int i = 0; i < table->nr; i++) \
free_##item_name(table->array_name[i]); \
table->nr = 0; \
}
/* Move data of one table to the other - source table is empty after call. */
#define MAKE_MOVE_TABLE(table_type, array_name) \
void move_##table_type(struct table_type *src, struct table_type *dst) \
{ \
clear_##table_type(dst); \
free(dst->array_name); \
*dst = *src; \
src->nr = src->allocated = 0; \
src->array_name = NULL; \
}
#endif