Implement a linked list struct

2 files changed, 132 insertions, 0 deletions

diff --git a/src/ll.c b/src/ll.c
new file mode 100644
index 0000000..c94a45b
--- /dev/null
+++ b/src/ll.c
@@ -0,0 +1,97 @@
+#include "ll.h"
+
+#include <stddef.h>
+
+void dlinkedlist_init(dlinkedlist **ll) {
+    (*ll) = xcalloc(1, sizeof(**ll));
+    
+    (*ll)->start = NULL;
+    (*ll)->end = NULL;
+    (*ll)->size = 0;
+
+    return;
+}
+
+void dlinkedlist_free(dlinkedlist **ll) {
+    dllnode *p = (*ll)->start, *n;
+    while(p != NULL) {
+        n = p->next;
+        
+        if(p->dfreecb != NULL)
+            p->dfreecb(p->data);
+        free(p);
+
+        p = n;
+    }
+
+    free(*ll);
+    (*ll) = NULL;
+    return;
+}
+
+int dlinkedlist_firstitem(dlinkedlist * const ll, void *data, int (*dfreecb)(void*)) {
+    if(!ll)
+        return -1;
+    if(ll->size != 0)
+        return 0;
+
+    dllnode *n = xcalloc(1, sizeof(*n));
+    n->next = NULL;
+    n->prev = NULL;
+    n->data = data;
+    n->dfreecb = dfreecb;
+
+    ll->start = n;
+    ll->end = n;
+    ll->size = 1;
+
+    return 1;
+}
+
+int dlinkedlist_insert(dlinkedlist * const ll, void *data, int (*dfreecb)(void*)) {
+    if(!ll)
+        return -1;
+    if(dlinkedlist_firstitem(ll, data, dfreecb) > 0)
+        return 0;
+
+    dllnode *n = xcalloc(1, sizeof(*n));
+    n->data = data;
+    n->dfreecb = dfreecb;
+    n->prev = NULL;
+    n->next = ll->start;
+
+    ll->start->prev = n;
+    ll->start = n;
+    ll->size++;
+
+    return 0;
+}
+
+int dlinkedlist_append(dlinkedlist * const ll, void *data, int (*dfreecb)(void*)) {
+    if(!ll)
+        return -1;
+    if(dlinkedlist_firstitem(ll, data, dfreecb) > 0)
+        return 0;
+
+    dllnode *n = xcalloc(1, sizeof(*n));
+    n->data = data;
+    n->dfreecb = dfreecb;
+    n->prev = ll->end;
+    n->next = NULL;
+
+    ll->end->next = n;
+    ll->end = n;
+    ll->size++;
+
+    return 0;
+}
+
+dllnode *dlinkedlist_get(const dlinkedlist * const ll, size_t index) {
+    if(index >= ll->size)
+        return NULL;
+
+    dllnode *p = ll->start;
+    for(size_t i = 0; i < index && p != NULL; i++, p = p->next);
+
+    return p;
+}
\ No newline at end of file
diff --git a/src/ll.h b/src/ll.h
new file mode 100644
index 0000000..5e47bd9
--- /dev/null
+++ b/src/ll.h
@@ -0,0 +1,35 @@
+#ifndef __VXGG_REWRITE___SHARED_H___28542989122405___
+#define __VXGG_REWRITE___SHARED_H___28542989122405___
+
+#include <stddef.h>
+
+typedef struct dll {
+    void *data;
+    int (*dfreecb)(void*);
+
+    struct dll *next;
+    struct dll *prev;
+} dllnode;
+
+typedef struct {
+    dllnode *start;
+    dllnode *end;
+    size_t size;
+} dlinkedlist;
+
+// Initialize a dlinkedlist
+void dlinkedlist_init(dlinkedlist **ll);
+
+// Free a dlinkedlist and its elements
+void dlinkedlist_free(dlinkedlist **ll);
+
+// Insert an element to the beginning of the list
+int dlinkedlist_insert(dlinkedlist * const ll, void *data, int (*dfreecb)(void*));
+
+// Insert an element to the end of the list
+int dlinkedlist_append(dlinkedlist * const ll, void *data, int (*dfreecb)(void*));
+
+// Get the element from a dlinkedlist at index
+dllnode *dlinkedlist_get(const dlinkedlist * const ll, size_t index);
+
+#endif
\ No newline at end of file