Defined basic DOM operations.

6 files changed, 167 insertions, 10 deletions

diff --git a/.gitignore b/.gitignore
index c0b8288..083c749 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,6 @@
 **/*a.out
 **/*.swp
 **/*.core
+
+**/*.o
+webview
diff --git a/Makefile b/Makefile
index 7c9c6c3..f10ad4c 100644
--- a/Makefile
+++ b/Makefile
@@ -2,8 +2,8 @@ CC = cc
 CFLAGS = -std=c11 -Wall -Wextra -Wpedantic -g -O0
 LDFLAGS = 
 
-HDRS = wv_mem.h wv_err.h
-SRCS = wv_mem.c wv_main.c
+HDRS = wv_mem.h wv_err.h wv_dom.h
+SRCS = wv_mem.c wv_dom.c wv_main.c
 OBJS = $(SRCS:.c=.o)
 TARGET = webview
 
diff --git a/wv_dom.c b/wv_dom.c
new file mode 100644
index 0000000..ee24e98
--- /dev/null
+++ b/wv_dom.c
@@ -0,0 +1,88 @@
+#include <string.h>
+#include <stdio.h>
+
+#include "wv_dom.h"
+
+wv_ref wv_node_new(struct wv_arena *arena, wv_node_type type)
+{
+	wv_ref ref;
+	struct wv_node *node;
+
+	ref = wv_alloc(arena, sizeof(struct wv_node));
+	node = (struct wv_node *)WV_ADDR(arena, ref);
+	memset(node, 0, sizeof(struct wv_node));
+	node->type = type;
+
+	return ref;
+}
+
+void wv_node_append(struct wv_arena *arena, wv_ref parent_ref, 
+	wv_ref child_ref)
+{
+	struct wv_node *p, *c, *last;
+
+	if (!parent_ref || !child_ref)
+		return;
+
+	p = (struct wv_node *)WV_ADDR(arena, parent_ref);
+	c = (struct wv_node *)WV_ADDR(arena, child_ref);
+
+	c->parent = parent_ref;
+
+	if (!p->first_child) {
+		/* This is the parent's only child */
+		p->first_child = child_ref;
+	} else {
+		/* Link to the current tail of the child list */
+		last = (struct wv_node *)WV_ADDR(arena, p->last_child);
+		last->next_sibling = child_ref;
+		c->prev_sibling = p->last_child;
+	}
+
+	p->last_child = child_ref;
+}
+
+void wv_attr_set(struct wv_arena *arena, wv_ref node_ref, 
+	wv_ref key_str, wv_ref val_str)
+{
+	wv_ref attr_ref;
+	struct wv_node *n;
+	struct wv_attr *a;
+
+	n = (struct wv_node *)WV_ADDR(arena, node_ref);
+	if (n->type != WV_NODE_ELEMENT) return;
+
+	attr_ref = wv_alloc(arena, sizeof(struct wv_attr));
+	a = (struct wv_attr *)WV_ADDR(arena, attr_ref);
+
+	a->key = key_str;
+	a->val = val_str;
+	
+	// Link attribute to the head of the list (prepend)
+	a->next = n->u.element.attr_head;
+	n->u.element.attr_head = attr_ref;
+}
+
+wv_ref wv_attr_get(struct wv_arena *arena, wv_ref node_ref, 
+	const char *key_name)
+{
+	wv_ref curr;
+	struct wv_node *n;
+	struct wv_attr *a;
+
+	n = (struct wv_node *)WV_ADDR(arena, node_ref);
+	if (n->type != WV_NODE_ELEMENT)
+		return 0;
+
+	curr = n->u.element.attr_head;
+	while (curr != 0) {
+		a = (struct wv_attr *)WV_ADDR(arena, curr);
+		const char *attr_key = (const char *)WV_ADDR(arena, a->key);
+		if (strcmp(attr_key, key_name) == 0)
+			return a->val;
+		curr = a->next;
+	}
+
+	return 0;
+}
+
diff --git a/wv_dom.h b/wv_dom.h
new file mode 100644
index 0000000..9a2c281
--- /dev/null
+++ b/wv_dom.h
@@ -0,0 +1,69 @@
+#ifndef WV_DOM_H
+#define WV_DOM_H
+
+#include "wv_mem.h"
+
+typedef enum {
+	WV_TAG_UNKNOWN = 0,
+	WV_TAG_DOCUMENT,
+	WV_TAG_HTML,
+	WV_TAG_HEAD,
+	WV_TAG_META,
+	WV_TAG_TITLE,
+	WV_TAG_LINK,
+	WV_TAG_BODY,
+	WV_TAG_HEADER,
+	WV_TAG_H1,
+	WV_TAG_A,
+	WV_TAG_ARTICLE,
+	WV_TAG_UL,
+	WV_TAG_LI,
+	WV_TAG_TIME,
+	WV_TAG_FOOTER,
+	WV_TAG_P
+} wv_tag_id;
+
+typedef enum {
+	WV_NODE_DOCUMENT,
+	WV_NODE_ELEMENT,
+	WV_NODE_TEXT
+} wv_node_type;
+
+struct wv_attr {
+	wv_ref key;   /* E.g., "href" */
+	wv_ref val;   /* E.g., "/log/vcs-1/" */
+	wv_ref next;  /* Next attribute in the list */
+};
+
+struct wv_node {
+	wv_node_type type;
+
+	wv_ref parent;
+	wv_ref first_child;
+	wv_ref last_child;
+	wv_ref prev_sibling;
+	wv_ref next_sibling;
+
+	union {
+		struct {
+			wv_tag_id tag_id;
+			wv_ref attr_head;
+		} element;
+
+		struct {
+			wv_ref str;
+			size_t len;
+		} text;
+	} u;
+};
+
+/* DOM operations */
+wv_ref  wv_node_new(struct wv_arena *arena, wv_node_type type);
+void    wv_node_append(struct wv_arena *arena, wv_ref parent, wv_ref child);
+
+/* Attribute operations */
+wv_ref  wv_attr_get(struct wv_arena *arena, wv_ref node_ref, const char *key_name);
+void    wv_attr_set(struct wv_arena *arena, wv_ref node_ref, wv_ref key_str, wv_ref val_str);
+
+#endif /* WV_DOM_H */
+
diff --git a/wv_mem.c b/wv_mem.c
index 1f6542b..7bf54d6 100644
--- a/wv_mem.c
+++ b/wv_mem.c
@@ -20,11 +20,11 @@ struct wv_arena *wv_arena_create(size_t n)
 		n = WV_ARENA_MIN_SIZE;
 
 	arena = malloc(sizeof(struct wv_arena));
-	if (arena == NULL)
+	if (!arena)
 		err(1, "malloc arena struct");
 
 	arena->buf = malloc(n);
-	if (arena->buf == NULL)
+	if (!arena->buf)
 		err(1, "malloc arena buffer");
 
 	arena->size = n;
@@ -59,7 +59,7 @@ wv_ref wv_alloc(struct wv_arena *arena, size_t n)
 		}
 
 		new_buf = realloc(arena->buf, new_size);
-		if (new_buf == NULL)
+		if (!new_buf)
 			err(1, "realloc arena failed at %zu bytes", new_size);
 
 		arena->buf  = new_buf;
@@ -73,7 +73,7 @@ wv_ref wv_alloc(struct wv_arena *arena, size_t n)
 
 void wv_arena_reset(struct wv_arena *arena)
 {
-	if (arena == NULL)
+	if (!arena)
 		return;
 
 	memset(arena->buf, 0, arena->offset);
@@ -82,7 +82,7 @@ void wv_arena_reset(struct wv_arena *arena)
 
 void wv_arena_destroy(struct wv_arena *arena)
 {
-	if (arena == NULL)
+	if (!arena)
 		return;
 
 	free(arena->buf);
diff --git a/wv_mem.h b/wv_mem.h
index 9d23ae8..dc95c7c 100644
--- a/wv_mem.h
+++ b/wv_mem.h
@@ -7,9 +7,6 @@
 /* Relative offset into the arena */
 typedef uint32_t wv_ref;
 
-/* 0 is our 'NULL' */
-#define WV_REF_NULL 0
-
 /* Resolve a ref into a memory address */
 #define WV_ADDR(arena, ref) ((void *)((arena)->buf + (ref)))