commit ca0985475b35a3e9053b2c0f5602b9a08a59ecbb
parent a638a4223d5042c5dd50e482d427572ae106f4c2
Author: Martin Mitas <mity@morous.org>
Date: Thu, 20 Jul 2017 15:54:00 +0200
Avoid heap allocations when building trivial MD_ATTRIBUTE.
Diffstat:
| M | md4c/md4c.c | | | 153 | +++++++++++++++++++++++++++++++++++++++++++------------------------------------ |
1 file changed, 84 insertions(+), 69 deletions(-)
diff --git a/md4c/md4c.c b/md4c/md4c.c
@@ -1358,10 +1358,13 @@ md_is_entity(MD_CTX* ctx, OFF beg, OFF max_end, OFF* p_end)
typedef struct MD_ATTRIBUTE_BUILD_tag MD_ATTRIBUTE_BUILD;
struct MD_ATTRIBUTE_BUILD_tag {
+ CHAR* text;
MD_TEXTTYPE* substr_types;
OFF* substr_offsets;
int substr_count;
int substr_alloc;
+ MD_TEXTTYPE trivial_types[1];
+ OFF trivial_offsets[2];
};
@@ -1401,81 +1404,93 @@ md_build_attr_append_substr(MD_CTX* ctx, MD_ATTRIBUTE_BUILD* build,
return 0;
}
+static void
+md_free_attribute(MD_CTX* ctx, MD_ATTRIBUTE_BUILD* build)
+{
+ if(build->substr_alloc > 0) {
+ free(build->text);
+ free(build->substr_types);
+ free(build->substr_offsets);
+ }
+}
+
static int
md_build_attribute(MD_CTX* ctx, const CHAR* raw_text, SZ raw_size,
- unsigned flags, MD_ATTRIBUTE* attr)
+ unsigned flags, MD_ATTRIBUTE* attr, MD_ATTRIBUTE_BUILD* build)
{
- MD_ATTRIBUTE_BUILD build = {0};
- CHAR* text;
- OFF raw_off = 0;
- OFF off = 0;
+ OFF raw_off, off;
+ int is_trivial;
int ret = 0;
- if(raw_size == 0) {
- static const MD_TEXTTYPE empty_types[] = { MD_TEXT_NORMAL };
- static const OFF empty_offsets[] = { 0, 0 };
+ memset(build, 0, sizeof(MD_ATTRIBUTE_BUILD));
- attr->text = NULL;
- attr->size = 0;
- attr->substr_types = empty_types;
- attr->substr_offsets = empty_offsets;
- return 0;
+ /* If there is no backslash and no ampersand, build trivial attribute
+ * without any malloc(). */
+ is_trivial = TRUE;
+ for(raw_off = 0; raw_off < raw_size; raw_off++) {
+ if(ISANYOF2_(raw_text[raw_off], _T('\\'), _T('&'))) {
+ is_trivial = FALSE;
+ break;
+ }
}
- text = (CHAR*) malloc(raw_size * sizeof(CHAR));
- if(text == NULL) {
- MD_LOG("malloc() failed.");
- goto abort;
- }
+ if(is_trivial) {
+ build->text = (CHAR*) raw_text;
+ build->substr_types = build->trivial_types;
+ build->substr_offsets = build->trivial_offsets;
+ build->substr_count = 1;
+ build->substr_alloc = 0;
+ build->trivial_types[0] = MD_TEXT_NORMAL;
+ build->trivial_offsets[0] = 0;
+ build->trivial_offsets[1] = raw_size;
+ off = raw_size;
+ } else {
+ build->text = (CHAR*) malloc(raw_size * sizeof(CHAR));
+ if(build->text == NULL) {
+ MD_LOG("malloc() failed.");
+ goto abort;
+ }
- while(raw_off < raw_size) {
- if(raw_text[raw_off] == _T('&')) {
- OFF ent_end;
+ raw_off = 0;
+ off = 0;
- if(md_is_entity_str(ctx, raw_text, raw_off, raw_size, &ent_end)) {
- MD_CHECK(md_build_attr_append_substr(ctx, &build, MD_TEXT_ENTITY, off));
- memcpy(text + off, raw_text + raw_off, ent_end - raw_off);
- off += ent_end - raw_off;
- raw_off = ent_end;
- continue;
+ while(raw_off < raw_size) {
+ if(raw_text[raw_off] == _T('&')) {
+ OFF ent_end;
+
+ if(md_is_entity_str(ctx, raw_text, raw_off, raw_size, &ent_end)) {
+ MD_CHECK(md_build_attr_append_substr(ctx, build, MD_TEXT_ENTITY, off));
+ memcpy(build->text + off, raw_text + raw_off, ent_end - raw_off);
+ off += ent_end - raw_off;
+ raw_off = ent_end;
+ continue;
+ }
}
- }
- if(build.substr_count == 0 || build.substr_types[build.substr_count-1] != MD_TEXT_NORMAL)
- MD_CHECK(md_build_attr_append_substr(ctx, &build, MD_TEXT_NORMAL, off));
+ if(build->substr_count == 0 || build->substr_types[build->substr_count-1] != MD_TEXT_NORMAL)
+ MD_CHECK(md_build_attr_append_substr(ctx, build, MD_TEXT_NORMAL, off));
- if(!(flags & MD_BUILD_ATTR_NO_ESCAPES) &&
- raw_text[raw_off] == _T('\\') && raw_off+1 < raw_size &&
- (ISPUNCT_(raw_text[raw_off+1]) || ISNEWLINE_(raw_text[raw_off+1])))
- raw_off++;
+ if(!(flags & MD_BUILD_ATTR_NO_ESCAPES) &&
+ raw_text[raw_off] == _T('\\') && raw_off+1 < raw_size &&
+ (ISPUNCT_(raw_text[raw_off+1]) || ISNEWLINE_(raw_text[raw_off+1])))
+ raw_off++;
- text[off++] = raw_text[raw_off++];
+ build->text[off++] = raw_text[raw_off++];
+ }
+ build->substr_offsets[build->substr_count] = off;
}
- build.substr_offsets[build.substr_count] = off;
- attr->text = text;
+ attr->text = build->text;
attr->size = off;
- attr->substr_offsets = build.substr_offsets;
- attr->substr_types = build.substr_types;
+ attr->substr_offsets = build->substr_offsets;
+ attr->substr_types = build->substr_types;
return 0;
abort:
- free(text);
- free(build.substr_offsets);
- free(build.substr_types);
+ md_free_attribute(ctx, build);
return -1;
}
-static void
-md_free_attribute(MD_CTX* ctx, MD_ATTRIBUTE* attr)
-{
- if(attr->size > 0) {
- free((void*) attr->text);
- free((void*) attr->substr_types);
- free((void*) attr->substr_offsets);
- }
-}
-
/*********************************************
*** Dictionary of Reference Definitions ***
@@ -3780,6 +3795,8 @@ md_enter_leave_span_a(MD_CTX* ctx, int enter, MD_SPANTYPE type,
const CHAR* dest, SZ dest_size, int prohibit_escapes_in_dest,
const CHAR* title, SZ title_size)
{
+ MD_ATTRIBUTE_BUILD href_build;
+ MD_ATTRIBUTE_BUILD title_build;
MD_SPAN_A_DETAIL det;
int ret = 0;
@@ -3788,8 +3805,8 @@ md_enter_leave_span_a(MD_CTX* ctx, int enter, MD_SPANTYPE type,
memset(&det, 0, sizeof(MD_SPAN_A_DETAIL));
MD_CHECK(md_build_attribute(ctx, dest, dest_size,
(prohibit_escapes_in_dest ? MD_BUILD_ATTR_NO_ESCAPES : 0),
- &det.href));
- MD_CHECK(md_build_attribute(ctx, title, title_size, 0, &det.title));
+ &det.href, &href_build));
+ MD_CHECK(md_build_attribute(ctx, title, title_size, 0, &det.title, &title_build));
if(enter)
MD_ENTER_SPAN(type, &det);
@@ -3797,8 +3814,8 @@ md_enter_leave_span_a(MD_CTX* ctx, int enter, MD_SPANTYPE type,
MD_LEAVE_SPAN(type, &det);
abort:
- md_free_attribute(ctx, &det.href);
- md_free_attribute(ctx, &det.title);
+ md_free_attribute(ctx, &href_build);
+ md_free_attribute(ctx, &title_build);
return ret;
}
@@ -4303,7 +4320,8 @@ md_process_code_block_contents(MD_CTX* ctx, int is_fenced, const MD_VERBATIMLINE
}
static int
-md_setup_fenced_code_detail(MD_CTX* ctx, const MD_BLOCK* block, MD_BLOCK_CODE_DETAIL* det)
+md_setup_fenced_code_detail(MD_CTX* ctx, const MD_BLOCK* block, MD_BLOCK_CODE_DETAIL* det,
+ MD_ATTRIBUTE_BUILD* info_build, MD_ATTRIBUTE_BUILD* lang_build)
{
const MD_VERBATIMLINE* fence_line = (const MD_VERBATIMLINE*)(block + 1);
OFF beg = fence_line->beg;
@@ -4324,25 +4342,18 @@ md_setup_fenced_code_detail(MD_CTX* ctx, const MD_BLOCK* block, MD_BLOCK_CODE_DE
end--;
/* Build info string attribute. */
- MD_CHECK(md_build_attribute(ctx, STR(beg), end - beg, 0, &det->info));
+ MD_CHECK(md_build_attribute(ctx, STR(beg), end - beg, 0, &det->info, info_build));
/* Build info string attribute. */
lang_end = beg;
while(lang_end < end && !ISWHITESPACE(lang_end))
lang_end++;
- MD_CHECK(md_build_attribute(ctx, STR(beg), lang_end - beg, 0, &det->lang));
+ MD_CHECK(md_build_attribute(ctx, STR(beg), lang_end - beg, 0, &det->lang, lang_build));
abort:
return ret;
}
-static inline void
-md_clean_fenced_code_detail(MD_CTX* ctx, MD_BLOCK_CODE_DETAIL* det)
-{
- md_free_attribute(ctx, &det->info);
- md_free_attribute(ctx, &det->lang);
-}
-
static int
md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
{
@@ -4350,6 +4361,8 @@ md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
MD_BLOCK_H_DETAIL header;
MD_BLOCK_CODE_DETAIL code;
} det;
+ MD_ATTRIBUTE_BUILD info_build;
+ MD_ATTRIBUTE_BUILD lang_build;
int is_in_tight_list;
int clean_fence_code_detail = FALSE;
int ret = 0;
@@ -4371,7 +4384,7 @@ md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
if(block->data != 0) {
memset(&det.code, 0, sizeof(MD_BLOCK_CODE_DETAIL));
clean_fence_code_detail = TRUE;
- MD_CHECK(md_setup_fenced_code_detail(ctx, block, &det.code));
+ MD_CHECK(md_setup_fenced_code_detail(ctx, block, &det.code, &info_build, &lang_build));
}
break;
@@ -4414,8 +4427,10 @@ md_process_leaf_block(MD_CTX* ctx, const MD_BLOCK* block)
MD_LEAVE_BLOCK(block->type, (void*) &det);
abort:
- if(clean_fence_code_detail)
- md_clean_fenced_code_detail(ctx, &det.code);
+ if(clean_fence_code_detail) {
+ md_free_attribute(ctx, &info_build);
+ md_free_attribute(ctx, &lang_build);
+ }
return ret;
}
