1
0
mirror of https://github.com/rkd77/elinks.git synced 2024-10-14 05:53:36 -04:00
elinks/src/dom/stack.c
2022-01-26 19:06:38 +01:00

627 lines
15 KiB
C

/* The DOM tree navigation interface */
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include "elinks.h"
#include "dom/node.h"
#include "dom/stack.h"
#include "dom/string.h"
#include "util/memory.h"
/* Navigator states */
#define DOM_STACK_STATE_GRANULARITY 0x7
#define DOM_STACK_CALLBACKS_SIZE (sizeof(dom_stack_callback_T) * DOM_NODES)
static inline struct dom_stack_state *
realloc_dom_stack_states(struct dom_stack_state **states, size_t size)
{
return (struct dom_stack_state *)mem_align_alloc(states, size, size + 1,
DOM_STACK_STATE_GRANULARITY);
}
static inline struct dom_stack_state *
realloc_dom_stack_context(struct dom_stack_context ***contexts, size_t size)
{
return (struct dom_stack_state *)mem_align_alloc(contexts, size, size + 1,
DOM_STACK_STATE_GRANULARITY);
}
static inline char *
realloc_dom_stack_state_objects(struct dom_stack_context *context, size_t depth)
{
#ifdef DEBUG_MEMLEAK
return (char *)mem_align_alloc__(__FILE__, __LINE__, (void **) &context->state_objects,
depth, depth + 1,
context->info->object_size,
DOM_STACK_STATE_GRANULARITY);
#else
return (char *)mem_align_alloc__((void **) &context->state_objects,
depth, depth + 1,
context->info->object_size,
DOM_STACK_STATE_GRANULARITY);
#endif
}
void
init_dom_stack(struct dom_stack *stack, /*enum dom_stack_flag*/ unsigned int flags)
{
assert(stack);
memset(stack, 0, sizeof(*stack));
stack->flags = flags;
}
void
done_dom_stack(struct dom_stack *stack)
{
int i;
assert(stack);
for (i = 0; i < stack->contexts_size; i++) {
mem_free_if(stack->contexts[i]->state_objects);
mem_free(stack->contexts[i]);
}
mem_free_if(stack->contexts);
mem_free_if(stack->states);
memset(stack, 0, sizeof(*stack));
}
struct dom_stack_context *
add_dom_stack_context(struct dom_stack *stack, void *data,
struct dom_stack_context_info *context_info)
{
struct dom_stack_context *context;
if (!realloc_dom_stack_context(&stack->contexts, stack->contexts_size))
return NULL;
context = (struct dom_stack_context *)mem_calloc(1, sizeof(*context));
if (!context)
return NULL;
stack->contexts[stack->contexts_size++] = context;
context->info = context_info;
context->data = data;
return context;
}
void
done_dom_stack_context(struct dom_stack *stack, struct dom_stack_context *context)
{
size_t i;
mem_free_if(context->state_objects);
mem_free(context);
/* Handle the trivial case of temporary contexts optimally by iteration last added first. */
for (i = stack->contexts_size - 1; i >= 0; i--) {
if (stack->contexts[i] != context)
continue;
stack->contexts_size--;
if (i < stack->contexts_size) {
struct dom_stack_context **pos = &stack->contexts[i];
size_t size = stack->contexts_size - i;
memmove(pos, pos + 1, size * sizeof(*pos));
}
break;
}
}
enum dom_stack_action {
DOM_STACK_PUSH,
DOM_STACK_POP,
};
/* Returns whether the node should be freed with done_dom_node(). */
static int
call_dom_stack_callbacks(struct dom_stack *stack, struct dom_stack_state *state,
enum dom_stack_action action)
{
int free_node = 0;
int i;
for (i = 0; i < stack->contexts_size; i++) {
struct dom_stack_context *context = stack->contexts[i];
dom_stack_callback_T callback;
assert(state->node->type < DOM_NODES); /* unsigned comparison */
if_assert_failed {
/* The node type is out of range for the
* callback arrays. The node may have been
* corrupted or already freed. Ignore
* free_node here because attempting to free
* the node would probably just corrupt things
* further. */
return 0;
}
if (action == DOM_STACK_PUSH)
callback = context->info->push[state->node->type];
else
callback = context->info->pop[state->node->type];
if (callback) {
void *data = get_dom_stack_state_data(context, state);
stack->current = context;
switch (callback(stack, state->node, data)) {
case DOM_CODE_FREE_NODE:
free_node = 1;
break;
default:
break;
}
stack->current = NULL;
}
}
return free_node;
}
enum dom_code
push_dom_node(struct dom_stack *stack, struct dom_node *node)
{
struct dom_stack_state *state;
int i;
assert(stack && node);
assert(0 < node->type && node->type < DOM_NODES);
if (stack->depth > DOM_STACK_MAX_DEPTH) {
return DOM_CODE_MAX_DEPTH_ERR;
}
state = realloc_dom_stack_states(&stack->states, stack->depth);
if (!state) {
done_dom_node(node);
return DOM_CODE_ALLOC_ERR;
}
state += stack->depth;
for (i = 0; i < stack->contexts_size; i++) {
struct dom_stack_context *context = stack->contexts[i];
if (context->info->object_size
&& !realloc_dom_stack_state_objects(context, stack->depth)) {
done_dom_node(node);
return DOM_CODE_ALLOC_ERR;
}
}
state->depth = stack->depth;
state->node = node;
/* Grow the state array to the new depth so the state accessors work
* in the callbacks */
stack->depth++;
call_dom_stack_callbacks(stack, state, DOM_STACK_PUSH);
return DOM_CODE_OK;
}
void
pop_dom_node(struct dom_stack *stack)
{
struct dom_stack_state *state;
int i;
assert(stack);
if (dom_stack_is_empty(stack))
return;
state = get_dom_stack_top(stack);
if (state->immutable)
return;
if (call_dom_stack_callbacks(stack, state, DOM_STACK_POP)
|| (stack->flags & DOM_STACK_FLAG_FREE_NODES))
done_dom_node(state->node);
stack->depth--;
assert(stack->depth >= 0);
for (i = 0; i < stack->contexts_size; i++) {
struct dom_stack_context *context = stack->contexts[i];
if (context->info->object_size) {
void *state_data = get_dom_stack_state_data(context, state);
memset(state_data, 0, context->info->object_size);
}
}
memset(state, 0, sizeof(*state));
}
void
pop_dom_nodes(struct dom_stack *stack, enum dom_node_type type,
struct dom_string *string)
{
struct dom_stack_state *state;
assert(stack);
if (dom_stack_is_empty(stack)) return;
state = search_dom_stack(stack, type, string);
if (state)
pop_dom_state(stack, state);
}
void
pop_dom_state(struct dom_stack *stack, struct dom_stack_state *target)
{
struct dom_stack_state *state;
unsigned int pos;
assert(stack);
if (!target) return;
if (dom_stack_is_empty(stack)) return;
foreachback_dom_stack_state (stack, state, pos) {
/* Don't pop past states marked immutable. */
if (state->immutable)
break;
/* Pop until the target state is reached. */
pop_dom_node(stack);
if (state == target)
break;
}
}
struct dom_stack_state *
search_dom_stack(struct dom_stack *stack, enum dom_node_type type,
struct dom_string *string)
{
struct dom_stack_state *state;
int pos;
/* FIXME: Take node subtype and compare if non-zero or something. */
foreachback_dom_stack_state (stack, state, pos) {
struct dom_node *parent = state->node;
if (parent->type == type
&& !dom_string_casecmp(&parent->string, string))
return state;
}
return NULL;
}
struct dom_stack_walk_state {
/* Used for recording which node list are currently being 'decended'
* into. E.g. whether we are iterating all child elements or attributes
* of an element. */
struct dom_node_list *list;
/* The index (in the list above) which are currently being handled. */
size_t index;
};
static struct dom_stack_context_info dom_stack_walk_context_info = {
/* Object size: */ sizeof(struct dom_stack_walk_state),
/* Push: */
{
/* */ NULL,
/* DOM_NODE_ELEMENT */ NULL,
/* DOM_NODE_ATTRIBUTE */ NULL,
/* DOM_NODE_TEXT */ NULL,
/* DOM_NODE_CDATA_SECTION */ NULL,
/* DOM_NODE_ENTITY_REFERENCE */ NULL,
/* DOM_NODE_ENTITY */ NULL,
/* DOM_NODE_PROC_INSTRUCTION */ NULL,
/* DOM_NODE_COMMENT */ NULL,
/* DOM_NODE_DOCUMENT */ NULL,
/* DOM_NODE_DOCUMENT_TYPE */ NULL,
/* DOM_NODE_DOCUMENT_FRAGMENT */ NULL,
/* DOM_NODE_NOTATION */ NULL,
},
/* Pop: */
{
/* */ NULL,
/* DOM_NODE_ELEMENT */ NULL,
/* DOM_NODE_ATTRIBUTE */ NULL,
/* DOM_NODE_TEXT */ NULL,
/* DOM_NODE_CDATA_SECTION */ NULL,
/* DOM_NODE_ENTITY_REFERENCE */ NULL,
/* DOM_NODE_ENTITY */ NULL,
/* DOM_NODE_PROC_INSTRUCTION */ NULL,
/* DOM_NODE_COMMENT */ NULL,
/* DOM_NODE_DOCUMENT */ NULL,
/* DOM_NODE_DOCUMENT_TYPE */ NULL,
/* DOM_NODE_DOCUMENT_FRAGMENT */ NULL,
/* DOM_NODE_NOTATION */ NULL,
}
};
/* FIXME: Instead of walking all nodes in the tree only visit those which are
* of actual interest to the contexts on the stack. */
void
walk_dom_nodes(struct dom_stack *stack, struct dom_node *root)
{
struct dom_stack_context *context;
assert(root && stack);
context = add_dom_stack_context(stack, NULL, &dom_stack_walk_context_info);
if (!context)
return;
if (push_dom_node(stack, root) != DOM_CODE_OK)
return;
while (!dom_stack_is_empty(stack)) {
struct dom_stack_state *state = get_dom_stack_top(stack);
struct dom_stack_walk_state *wstate = (struct dom_stack_walk_state *)get_dom_stack_state_data(context, state);
struct dom_node_list *list = wstate->list;
struct dom_node *node = state->node;
switch (node->type) {
case DOM_NODE_DOCUMENT:
if (!list) list = node->data.document.children;
break;
case DOM_NODE_ELEMENT:
if (!list) list = node->data.element.map;
if (list == node->data.element.children) break;
if (is_dom_node_list_member(list, wstate->index)
&& list == node->data.element.map)
break;
list = node->data.element.children;
break;
case DOM_NODE_PROCESSING_INSTRUCTION:
if (!list) list = node->data.proc_instruction.map;
break;
case DOM_NODE_DOCUMENT_TYPE:
if (!list) list = node->data.document_type.entities;
if (list == node->data.document_type.notations) break;
if (is_dom_node_list_member(list, wstate->index)
&& list == node->data.document_type.entities)
break;
list = node->data.document_type.notations;
break;
case DOM_NODE_ATTRIBUTE:
case DOM_NODE_TEXT:
case DOM_NODE_CDATA_SECTION:
case DOM_NODE_COMMENT:
case DOM_NODE_NOTATION:
case DOM_NODE_DOCUMENT_FRAGMENT:
case DOM_NODE_ENTITY_REFERENCE:
case DOM_NODE_ENTITY:
default:
break;
}
/* Reset list state if it is a new list */
if (list != wstate->list) {
wstate->list = list;
wstate->index = 0;
}
/* If we have next child node */
if (is_dom_node_list_member(list, wstate->index)) {
struct dom_node *child = list->entries[wstate->index++];
if (push_dom_node(stack, child) == DOM_CODE_OK)
continue;
}
pop_dom_node(stack);
}
done_dom_stack_context(stack, context);
}
/* DOM Stack Tracing: */
#ifdef DOM_STACK_TRACE
#include "util/string.h"
/* Compress a string to a single line with newlines etc. replaced with "\\n"
* sequence. */
static inline char *
compress_string(char *string, unsigned int length)
{
struct string buffer;
unsigned char escape[2] = "\\";
if (!init_string(&buffer)) return NULL;
for (; length > 0; string++, length--) {
char *bytes = string;
if (*string == '\n' || *string == '\r' || *string == '\t') {
bytes = escape;
escape[1] = *string == '\n' ? 'n'
: (*string == '\r' ? 'r' : 't');
}
add_bytes_to_string(&buffer, bytes, bytes == escape ? 2 : 1);
}
return buffer.source;
}
/* Set @string to the value of the given @node, however, with strings
* compressed and entity references 'expanded'. */
static void
set_enhanced_dom_node_value(struct dom_string *string, struct dom_node *node)
{
struct dom_string *value;
assert(node);
memset(string, 0, sizeof(*string));
switch (node->type) {
case DOM_NODE_ENTITY_REFERENCE:
/* FIXME: Set to the entity value. */
string->string = null_or_stracpy(string->string);
break;
default:
value = get_dom_node_value(node);
if (!value) {
set_dom_string(string, NULL, 0);
return;
}
string->string = compress_string(value->string, value->length);
}
string->length = string->string ? strlen(string->string) : 0;
}
static unsigned char indent_string[] =
" ";
#define get_indent_offset(stack) \
((stack)->depth < sizeof(indent_string)/2 ? (stack)->depth * 2 : sizeof(indent_string))
enum dom_code
dom_stack_trace_tree(struct dom_stack *stack, struct dom_node *node, void *data)
{
struct dom_string *value = &node->string;
struct dom_string *name = get_dom_node_name(node);
LOG_INFO("%s%.*s %.*s: %.*s",
empty_string_or_(stack->current->data),
get_indent_offset(stack), indent_string,
name->length, name->string,
value->length, value->string);
return DOM_CODE_OK;
}
enum dom_code
dom_stack_trace_id_leaf(struct dom_stack *stack, struct dom_node *node, void *data)
{
struct dom_string value;
struct dom_string *name;
struct dom_string *id;
assert(node);
name = get_dom_node_name(node);
id = get_dom_node_type_name(node->type);
set_enhanced_dom_node_value(&value, node);
LOG_INFO("%s%.*s %.*s: %.*s -> %.*s",
empty_string_or_(stack->current->data),
get_indent_offset(stack), indent_string,
id->length, id->string, name->length, name->string,
value.length, value.string);
done_dom_string(&value);
return DOM_CODE_OK;
}
enum dom_code
dom_stack_trace_leaf(struct dom_stack *stack, struct dom_node *node, void *data)
{
struct dom_string *name;
struct dom_string value;
assert(node);
name = get_dom_node_name(node);
set_enhanced_dom_node_value(&value, node);
LOG_INFO("%s%.*s %.*s: %.*s",
empty_string_or_(stack->current->data),
get_indent_offset(stack), indent_string,
name->length, name->string,
value.length, value.string);
done_dom_string(&value);
return DOM_CODE_OK;
}
enum dom_code
dom_stack_trace_branch(struct dom_stack *stack, struct dom_node *node, void *data)
{
struct dom_string *name;
struct dom_string *id;
assert(node);
name = get_dom_node_name(node);
id = get_dom_node_type_name(node->type);
LOG_INFO("%s%.*s %.*s: %.*s",
empty_string_or_(stack->current->data),
get_indent_offset(stack), indent_string,
id->length, id->string, name->length, name->string);
return DOM_CODE_OK;
}
struct dom_stack_context_info dom_stack_trace_context_info = {
/* Object size: */ 0,
/* Push: */
{
/* */ NULL,
/* DOM_NODE_ELEMENT */ dom_stack_trace_branch,
/* DOM_NODE_ATTRIBUTE */ dom_stack_trace_id_leaf,
/* DOM_NODE_TEXT */ dom_stack_trace_leaf,
/* DOM_NODE_CDATA_SECTION */ dom_stack_trace_id_leaf,
/* DOM_NODE_ENTITY_REFERENCE */ dom_stack_trace_id_leaf,
/* DOM_NODE_ENTITY */ dom_stack_trace_id_leaf,
/* DOM_NODE_PROC_INSTRUCTION */ dom_stack_trace_id_leaf,
/* DOM_NODE_COMMENT */ dom_stack_trace_leaf,
/* DOM_NODE_DOCUMENT */ dom_stack_trace_tree,
/* DOM_NODE_DOCUMENT_TYPE */ dom_stack_trace_id_leaf,
/* DOM_NODE_DOCUMENT_FRAGMENT */ dom_stack_trace_id_leaf,
/* DOM_NODE_NOTATION */ dom_stack_trace_id_leaf,
},
/* Pop: */
{
/* */ NULL,
/* DOM_NODE_ELEMENT */ NULL,
/* DOM_NODE_ATTRIBUTE */ NULL,
/* DOM_NODE_TEXT */ NULL,
/* DOM_NODE_CDATA_SECTION */ NULL,
/* DOM_NODE_ENTITY_REFERENCE */ NULL,
/* DOM_NODE_ENTITY */ NULL,
/* DOM_NODE_PROC_INSTRUCTION */ NULL,
/* DOM_NODE_COMMENT */ NULL,
/* DOM_NODE_DOCUMENT */ NULL,
/* DOM_NODE_DOCUMENT_TYPE */ NULL,
/* DOM_NODE_DOCUMENT_FRAGMENT */ NULL,
/* DOM_NODE_NOTATION */ NULL,
}
};
#endif /* DOM_STACK_TRACE */