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sundown/src/markdown.c  view on Meta::CPAN

	unsigned int id;

	struct buf *link;
	struct buf *title;

	struct link_ref *next;
};

/* char_trigger: function pointer to render active chars */
/*   returns the number of chars taken care of */
/*   data is the pointer of the beginning of the span */
/*   offset is the number of valid chars before data */
struct sd_markdown;
typedef size_t
(*char_trigger)(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);

static size_t char_emphasis(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_linebreak(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_codespan(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_escape(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_entity(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_langle_tag(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_autolink_url(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_autolink_email(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_autolink_www(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_link(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);
static size_t char_superscript(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t offset, size_t size);

enum markdown_char_t {
	MD_CHAR_NONE = 0,
	MD_CHAR_EMPHASIS,
	MD_CHAR_CODESPAN,
	MD_CHAR_LINEBREAK,
	MD_CHAR_LINK,
	MD_CHAR_LANGLE,
	MD_CHAR_ESCAPE,
	MD_CHAR_ENTITITY,
	MD_CHAR_AUTOLINK_URL,
	MD_CHAR_AUTOLINK_EMAIL,
	MD_CHAR_AUTOLINK_WWW,
	MD_CHAR_SUPERSCRIPT,
};

static char_trigger markdown_char_ptrs[] = {
	NULL,
	&char_emphasis,
	&char_codespan,
	&char_linebreak,
	&char_link,
	&char_langle_tag,
	&char_escape,
	&char_entity,
	&char_autolink_url,
	&char_autolink_email,
	&char_autolink_www,
	&char_superscript,
};

/* render • structure containing one particular render */
struct sd_markdown {
	struct sd_callbacks	cb;
	void *opaque;

	struct link_ref *refs[REF_TABLE_SIZE];
	uint8_t active_char[256];
	struct stack work_bufs[2];
	unsigned int ext_flags;
	size_t max_nesting;
	int in_link_body;
};

/***************************
 * HELPER FUNCTIONS *
 ***************************/

static inline struct buf *
rndr_newbuf(struct sd_markdown *rndr, int type)
{
	static const size_t buf_size[2] = {256, 64};
	struct buf *work = NULL;
	struct stack *pool = &rndr->work_bufs[type];

	if (pool->size < pool->asize &&
		pool->item[pool->size] != NULL) {
		work = pool->item[pool->size++];
		work->size = 0;
	} else {
		work = bufnew(buf_size[type]);
		stack_push(pool, work);
	}

	return work;
}

static inline void
rndr_popbuf(struct sd_markdown *rndr, int type)
{
	rndr->work_bufs[type].size--;
}

static void
unscape_text(struct buf *ob, struct buf *src)
{
	size_t i = 0, org;
	while (i < src->size) {
		org = i;
		while (i < src->size && src->data[i] != '\\')
			i++;

		if (i > org)
			bufput(ob, src->data + org, i - org);

		if (i + 1 >= src->size)
			break;

		bufputc(ob, src->data[i + 1]);
		i += 2;
	}
}

static unsigned int

sundown/src/markdown.c  view on Meta::CPAN

	if (!line_end || link_end == link_offset)
		return 0; /* garbage after the link empty link */

	/* a valid ref has been found, filling-in return structures */
	if (last)
		*last = line_end;

	if (refs) {
		struct link_ref *ref;

		ref = add_link_ref(refs, data + id_offset, id_end - id_offset);
		if (!ref)
			return 0;

		ref->link = bufnew(link_end - link_offset);
		bufput(ref->link, data + link_offset, link_end - link_offset);

		if (title_end > title_offset) {
			ref->title = bufnew(title_end - title_offset);
			bufput(ref->title, data + title_offset, title_end - title_offset);
		}
	}

	return 1;
}

static void expand_tabs(struct buf *ob, const uint8_t *line, size_t size)
{
	size_t  i = 0, tab = 0;

	while (i < size) {
		size_t org = i;

		while (i < size && line[i] != '\t') {
			i++; tab++;
		}

		if (i > org)
			bufput(ob, line + org, i - org);

		if (i >= size)
			break;

		do {
			bufputc(ob, ' '); tab++;
		} while (tab % 4);

		i++;
	}
}

/**********************
 * EXPORTED FUNCTIONS *
 **********************/

struct sd_markdown *
sd_markdown_new(
	unsigned int extensions,
	size_t max_nesting,
	const struct sd_callbacks *callbacks,
	void *opaque)
{
	struct sd_markdown *md = NULL;

	assert(max_nesting > 0 && callbacks);

	md = malloc(sizeof(struct sd_markdown));
	if (!md)
		return NULL;

	memcpy(&md->cb, callbacks, sizeof(struct sd_callbacks));

	stack_init(&md->work_bufs[BUFFER_BLOCK], 4);
	stack_init(&md->work_bufs[BUFFER_SPAN], 8);

	memset(md->active_char, 0x0, 256);

	if (md->cb.emphasis || md->cb.double_emphasis || md->cb.triple_emphasis) {
		md->active_char['*'] = MD_CHAR_EMPHASIS;
		md->active_char['_'] = MD_CHAR_EMPHASIS;
		if (extensions & MKDEXT_STRIKETHROUGH)
			md->active_char['~'] = MD_CHAR_EMPHASIS;
	}

	if (md->cb.codespan)
		md->active_char['`'] = MD_CHAR_CODESPAN;

	if (md->cb.linebreak)
		md->active_char['\n'] = MD_CHAR_LINEBREAK;

	if (md->cb.image || md->cb.link)
		md->active_char['['] = MD_CHAR_LINK;

	md->active_char['<'] = MD_CHAR_LANGLE;
	md->active_char['\\'] = MD_CHAR_ESCAPE;
	md->active_char['&'] = MD_CHAR_ENTITITY;

	if (extensions & MKDEXT_AUTOLINK) {
		md->active_char[':'] = MD_CHAR_AUTOLINK_URL;
		md->active_char['@'] = MD_CHAR_AUTOLINK_EMAIL;
		md->active_char['w'] = MD_CHAR_AUTOLINK_WWW;
	}

	if (extensions & MKDEXT_SUPERSCRIPT)
		md->active_char['^'] = MD_CHAR_SUPERSCRIPT;

	/* Extension data */
	md->ext_flags = extensions;
	md->opaque = opaque;
	md->max_nesting = max_nesting;
	md->in_link_body = 0;

	return md;
}

void
sd_markdown_render(struct buf *ob, const uint8_t *document, size_t doc_size, struct sd_markdown *md)
{
#define MARKDOWN_GROW(x) ((x) + ((x) >> 1))
	static const char UTF8_BOM[] = {0xEF, 0xBB, 0xBF};

	struct buf *text;
	size_t beg, end;

	text = bufnew(64);
	if (!text)
		return;

	/* Preallocate enough space for our buffer to avoid expanding while copying */
	bufgrow(text, doc_size);