From 1cf1ec9a8f893a41910a300d9d8f1e6c20288287 Mon Sep 17 00:00:00 2001 From: Nick Wellnhofer Date: Wed, 19 Nov 2014 20:24:08 +0100 Subject: Stackless HTML rendering Now that every node has a parent pointer, it's possible to implement the HTML rendering functions without render stacks and any dynamic memory allocations. This commit also adds some minor optimizations that eliminate some strbuf_put* calls for the common case and avoid printf for headers. --- src/html/html.c | 463 +++++++++++++++++++++++++++----------------------------- 1 file changed, 226 insertions(+), 237 deletions(-) (limited to 'src/html/html.c') diff --git a/src/html/html.c b/src/html/html.c index 76d488a..96fce66 100644 --- a/src/html/html.c +++ b/src/html/html.c @@ -7,58 +7,12 @@ #include "cmark.h" #include "node.h" #include "buffer.h" -#include "debug.h" #include "html/houdini.h" -typedef struct RenderStack { - struct RenderStack *previous; - const char* literal; - cmark_node* next_sibling; - bool tight; - bool trim; -} render_stack; +// Functions to convert cmark_nodes to HTML strings. -static void free_render_stack(render_stack * rstack) -{ - render_stack * tempstack; - while (rstack) { - tempstack = rstack; - rstack = rstack->previous; - free(tempstack); - } -} - -static render_stack* push_render_stack(render_stack* rstack, - cmark_node* node, - const char* literal) -{ - render_stack* newstack; - newstack = (render_stack*)malloc(sizeof(render_stack)); - if (newstack == NULL) { - return NULL; - } - newstack->previous = rstack; - newstack->next_sibling = node; - newstack->literal = literal; - newstack->tight = false; - newstack->trim = false; - return newstack; -} - -static render_stack* pop_render_stack(render_stack* rstack) -{ - render_stack* top = rstack; - - if (rstack == NULL) { - return NULL; - } - rstack = rstack->previous; - top->previous = NULL; - free_render_stack(top); - return rstack; -} - -// Functions to convert cmark_node and inline lists to HTML strings. +static bool +finish_node(strbuf *html, cmark_node *node, bool tight); static void escape_html(strbuf *dest, const unsigned char *source, int length) { @@ -82,65 +36,163 @@ static inline void cr(strbuf *html) strbuf_putc(html, '\n'); } -// Convert an inline list to HTML. Returns 0 on success, and sets result. -static void inlines_to_plain_html(strbuf *html, cmark_node* ils) +// Convert the inline children of a node to a plain string. +static void inlines_to_plain_html(strbuf *html, cmark_node* node) { - cmark_node* children; - bool visit_children; - render_stack* rstack = NULL; + cmark_node* cur = node->first_child; - while(ils != NULL) { - visit_children = false; - switch(ils->type) { + if (cur == NULL) { + return; + } + + while (true) { + switch(cur->type) { case NODE_STRING: case NODE_INLINE_CODE: case NODE_INLINE_HTML: - escape_html(html, ils->as.literal.data, ils->as.literal.len); + escape_html(html, cur->as.literal.data, cur->as.literal.len); break; case NODE_LINEBREAK: case NODE_SOFTBREAK: - strbuf_putc(html, '\n'); + strbuf_putc(html, ' '); break; - case NODE_LINK: - case NODE_IMAGE: - case NODE_STRONG: - case NODE_EMPH: - children = ils->first_child; - visit_children = true; - rstack = push_render_stack(rstack, ils->next, ""); - break; default: break; } - if (visit_children) { - ils = children; - } else { - ils = ils->next; + + if (cur->first_child) { + cur = cur->first_child; + continue; } - while (ils == NULL && rstack != NULL) { - strbuf_puts(html, rstack->literal); - ils = rstack->next_sibling; - rstack = pop_render_stack(rstack); + + next_sibling: + if (cur->next) { + cur = cur->next; + continue; } + cur = cur->parent; + if (cur == node) { + break; + } + goto next_sibling; } - - free_render_stack(rstack); } -// Convert an inline list to HTML. Returns 0 on success, and sets result. -static void inlines_to_html(strbuf *html, cmark_node* ils) +// Convert a cmark_node to HTML. +static void node_to_html(strbuf *html, cmark_node *node) { + cmark_node *cur; + char start_header[] = ""; + bool tight = false; bool visit_children; - render_stack* rstack = NULL; - while(ils != NULL) { - visit_children = false; - switch(ils->type) { + if (node == NULL) { + return; + } + + cur = node; + while (true) { + // Only NODE_IMAGE wants to skip its children. + visit_children = true; + + switch(cur->type) { + case NODE_DOCUMENT: + break; + + case NODE_PARAGRAPH: + if (!tight) { + cr(html); + strbuf_puts(html, "

"); + } + break; + + case NODE_BQUOTE: + cr(html); + strbuf_puts(html, "

\n"); + // BQUOTE doesn't use any of the 'as' structs, + // so the 'list' member can be used to store the + // current value of 'tight'. + cur->as.list.tight = tight; + tight = false; + break; + + case NODE_LIST_ITEM: + cr(html); + strbuf_puts(html, "
  • "); + break; + + case NODE_LIST: { + cmark_list *list = &cur->as.list; + bool tmp; + + // make sure a list starts at the beginning of the line: + cr(html); + + if (list->list_type == CMARK_BULLET_LIST) { + strbuf_puts(html, "
      \n"); + } + else if (list->start == 1) { + strbuf_puts(html, "
        \n"); + } + else { + strbuf_printf(html, "
          \n", + list->start); + } + + // Store the current value of 'tight' by swapping. + tmp = list->tight; + list->tight = tight; + tight = tmp; + break; + } + + case NODE_ATX_HEADER: + case NODE_SETEXT_HEADER: + cr(html); + start_header[2] = '0' + cur->as.header.level; + strbuf_puts(html, start_header); + break; + + case NODE_INDENTED_CODE: + case NODE_FENCED_CODE: { + strbuf *info = &cur->as.code.info; + cr(html); + + if (cur->type != NODE_FENCED_CODE + || strbuf_len(info) == 0) { + strbuf_puts(html, "
          ");
          +			}
          +			else {
          +				int first_tag = strbuf_strchr(info, ' ', 0);
          +				if (first_tag < 0)
          +					first_tag = strbuf_len(info);
          +
          +				strbuf_puts(html,
          +					    "
          ptr, first_tag);
          +				strbuf_puts(html, "\">");
          +			}
          +
          +			escape_html(html, cur->string_content.ptr, cur->string_content.size);
          +			break;
          +		}
          +
          +		case NODE_HTML:
          +			strbuf_put(html, cur->string_content.ptr, cur->string_content.size);
          +			break;
          +
          +		case NODE_HRULE:
          +			strbuf_puts(html, "
          \n"); + break; + + case NODE_REFERENCE_DEF: + break; + case NODE_STRING: - escape_html(html, ils->as.literal.data, ils->as.literal.len); + escape_html(html, cur->as.literal.data, cur->as.literal.len); break; case NODE_LINEBREAK: @@ -153,217 +205,154 @@ static void inlines_to_html(strbuf *html, cmark_node* ils) case NODE_INLINE_CODE: strbuf_puts(html, ""); - escape_html(html, ils->as.literal.data, ils->as.literal.len); - strbuf_puts(html, ""); + escape_html(html, cur->as.literal.data, cur->as.literal.len); break; case NODE_INLINE_HTML: strbuf_put(html, - ils->as.literal.data, - ils->as.literal.len); + cur->as.literal.data, + cur->as.literal.len); break; case NODE_LINK: strbuf_puts(html, "as.link.url) - escape_href(html, ils->as.link.url, -1); + if (cur->as.link.url) + escape_href(html, cur->as.link.url, -1); - if (ils->as.link.title) { + if (cur->as.link.title) { strbuf_puts(html, "\" title=\""); - escape_html(html, ils->as.link.title, -1); + escape_html(html, cur->as.link.title, -1); } strbuf_puts(html, "\">"); - visit_children = true; - rstack = push_render_stack(rstack, ils->next, ""); break; case NODE_IMAGE: strbuf_puts(html, "as.link.url) - escape_href(html, ils->as.link.url, -1); + if (cur->as.link.url) + escape_href(html, cur->as.link.url, -1); strbuf_puts(html, "\" alt=\""); - inlines_to_plain_html(html, ils->first_child); + inlines_to_plain_html(html, cur); - if (ils->as.link.title) { + if (cur->as.link.title) { strbuf_puts(html, "\" title=\""); - escape_html(html, ils->as.link.title, -1); + escape_html(html, cur->as.link.title, -1); } strbuf_puts(html, "\" />"); + visit_children = false; break; case NODE_STRONG: strbuf_puts(html, ""); - visit_children = true; - rstack = push_render_stack(rstack, ils->next, ""); break; case NODE_EMPH: strbuf_puts(html, ""); - visit_children = true; - rstack = push_render_stack(rstack, ils->next, ""); break; + default: - break; + assert(false); } - if (visit_children) { - ils = ils->first_child; - } else { - ils = ils->next; + + if (visit_children && cur->first_child) { + cur = cur->first_child; + continue; + } + + next_sibling: + tight = finish_node(html, cur, tight); + if (cur == node) { + break; } - while (ils == NULL && rstack != NULL) { - strbuf_puts(html, rstack->literal); - ils = rstack->next_sibling; - rstack = pop_render_stack(rstack); + if (cur->next) { + cur = cur->next; + continue; } + cur = cur->parent; + goto next_sibling; } - - free_render_stack(rstack); } -// Convert a cmark_node list to HTML. Returns 0 on success, and sets result. -static void blocks_to_html(strbuf *html, cmark_node *b) +// Returns the restored value of 'tight'. +static bool +finish_node(strbuf *html, cmark_node *node, bool tight) { - cmark_list *data; - render_stack* rstack = NULL; - bool visit_children = false; - bool tight = false; - - while(b != NULL) { - visit_children = false; - switch(b->type) { - case NODE_DOCUMENT: - rstack = push_render_stack(rstack, b->next, ""); - rstack->tight = false; - rstack->trim = false; - visit_children = true; - break; - - case NODE_PARAGRAPH: - if (tight) { - inlines_to_html(html, b->first_child); - } else { - cr(html); - strbuf_puts(html, "

          "); - inlines_to_html(html, b->first_child); - strbuf_puts(html, "

          \n"); - } - break; + char end_header[] = "\n"; - case NODE_BQUOTE: - cr(html); - strbuf_puts(html, "
          \n"); - rstack = push_render_stack(rstack, b->next, "
          \n"); - rstack->tight = tight; - rstack->trim = false; - tight = false; - visit_children = true; - break; - - case NODE_LIST_ITEM: - cr(html); - strbuf_puts(html, "
        1. "); - rstack = push_render_stack(rstack, b->next, "
        2. \n"); - rstack->tight = tight; - rstack->trim = true; - visit_children = true; - break; - - case NODE_LIST: - // make sure a list starts at the beginning of the line: - cr(html); - data = &(b->as.list); - - if (data->start > 1) { - strbuf_printf(html, "<%s start=\"%d\">\n", - data->list_type == CMARK_BULLET_LIST ? "ul" : "ol", - data->start); - } else { - strbuf_puts(html, data->list_type == CMARK_BULLET_LIST ? "
            \n" : "
              \n"); - } - - rstack = push_render_stack(rstack, b->next, - data->list_type == CMARK_BULLET_LIST ? - "\n
          \n" : "\n
        \n"); - rstack->tight = tight; - rstack->trim = false; - tight = data->tight; - visit_children = true; - break; - - case NODE_ATX_HEADER: - case NODE_SETEXT_HEADER: - cr(html); - strbuf_printf(html, "", b->as.header.level); - inlines_to_html(html, b->first_child); - strbuf_printf(html, "\n", b->as.header.level); - break; - - case NODE_INDENTED_CODE: - case NODE_FENCED_CODE: - cr(html); - - strbuf_puts(html, "
        type) {
        +	case NODE_PARAGRAPH:
        +		if (!tight) {
        +			strbuf_puts(html, "

        \n"); + } + break; + + case NODE_BQUOTE: { + cmark_list *list = &node->as.list; + strbuf_puts(html, "
  • \n"); + // Restore old 'tight' value. + tight = list->tight; + list->tight = false; + break; + } - if (b->type == NODE_FENCED_CODE) { - strbuf *info = &b->as.code.info; + case NODE_LIST_ITEM: + strbuf_puts(html, "\n"); + break; + + case NODE_LIST: { + cmark_list *list = &node->as.list; + bool tmp; + strbuf_puts(html, + list->list_type == CMARK_BULLET_LIST ? + "\n" : "\n"); + // Restore old 'tight' value. + tmp = tight; + tight = list->tight; + list->tight = tmp; + break; + } - if (strbuf_len(info) > 0) { - int first_tag = strbuf_strchr(info, ' ', 0); - if (first_tag < 0) - first_tag = strbuf_len(info); + case NODE_ATX_HEADER: + case NODE_SETEXT_HEADER: + end_header[3] = '0' + node->as.header.level; + strbuf_puts(html, end_header); + break; - strbuf_puts(html, " class=\"language-"); - escape_html(html, info->ptr, first_tag); - strbuf_putc(html, '"'); - } - } + case NODE_INDENTED_CODE: + case NODE_FENCED_CODE: + strbuf_puts(html, "\n"); + break; - strbuf_putc(html, '>'); - escape_html(html, b->string_content.ptr, b->string_content.size); - strbuf_puts(html, "\n"); - break; + case NODE_INLINE_CODE: + strbuf_puts(html, ""); + break; - case NODE_HTML: - strbuf_put(html, b->string_content.ptr, b->string_content.size); - break; + case NODE_LINK: + strbuf_puts(html, ""); + break; - case NODE_HRULE: - strbuf_puts(html, "
    \n"); - break; + case NODE_STRONG: + strbuf_puts(html, ""); + break; - case NODE_REFERENCE_DEF: - break; + case NODE_EMPH: + strbuf_puts(html, ""); + break; - default: - assert(false); - } - if (visit_children) { - b = b->first_child; - } else { - b = b->next; - } - while (b == NULL && rstack != NULL) { - strbuf_puts(html, rstack->literal); - if (rstack->trim) { - strbuf_rtrim(html); - } - tight = rstack->tight; - b = rstack->next_sibling; - rstack = pop_render_stack(rstack); - } + default: + break; } - free_render_stack(rstack); + return tight; } unsigned char *cmark_render_html(cmark_node *root) { unsigned char *result; strbuf html = GH_BUF_INIT; - blocks_to_html(&html, root); + node_to_html(&html, root); result = strbuf_detach(&html); strbuf_free(&html); return result; -- cgit v1.2.3