Commit 6bc0b86101e1efa18eaa8d0c045d83982b89ec47
2017-07-18T18:50:07
Merge branch 'hash'
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diff --git a/md4c/md4c.c b/md4c/md4c.c
index 4d07aa4..ac1afac 100644
--- a/md4c/md4c.c
+++ b/md4c/md4c.c
@@ -75,7 +75,7 @@
typedef struct MD_MARK_tag MD_MARK;
typedef struct MD_BLOCK_tag MD_BLOCK;
typedef struct MD_CONTAINER_tag MD_CONTAINER;
-typedef struct MD_LINK_REF_DEF_tag MD_LINK_REF_DEF;
+typedef struct MD_REF_DEF_tag MD_REF_DEF;
/* During analyzes of inline marks, we need to manage some "mark chains",
@@ -101,10 +101,12 @@ struct MD_CTX_tag {
CHAR* buffer;
unsigned alloc_buffer;
- /* Link reference definitions. */
- MD_LINK_REF_DEF* link_ref_defs;
- int n_link_ref_defs;
- int alloc_link_ref_defs;
+ /* Reference definitions. */
+ MD_REF_DEF* ref_defs;
+ int n_ref_defs;
+ int alloc_ref_defs;
+ void** ref_def_hashtable;
+ int ref_def_hashtable_size;
/* Stack of inline/span markers.
* This is only used for parsing a single block contents but by storing it
@@ -910,6 +912,22 @@ md_merge_lines_alloc(MD_CTX* ctx, OFF beg, OFF end, const MD_LINE* lines, int n_
return 0;
}
+static OFF
+md_skip_unicode_whitespace(const CHAR* label, OFF off, SZ size)
+{
+ SZ char_size;
+ int codepoint;
+
+ while(off < size) {
+ codepoint = md_decode_unicode(label, off, size, &char_size);
+ if(!ISUNICODEWHITESPACE_(codepoint) && !ISNEWLINE_(label[off]))
+ break;
+ off += char_size;
+ }
+
+ return off;
+}
+
/******************************
*** Recognizing raw HTML ***
@@ -1459,17 +1477,33 @@ md_free_attribute(MD_CTX* ctx, MD_ATTRIBUTE* attr)
}
-/***************************
- *** Recognizing Links ***
- ***************************/
+/*********************************************
+ *** Dictionary of Reference Definitions ***
+ *********************************************/
-/* Note this code is partially shared between processing inlines and blocks
- * as link reference definitions and links share some helper parser functions.
- */
+#define MD_FNV1A_BASE 2166136261
+#define MD_FNV1A_PRIME 16777619
+
+static inline unsigned
+md_fnv1a(unsigned base, const void* data, size_t n)
+{
+ const unsigned char* buf = (const unsigned char*) data;
+ unsigned hash = base;
+ size_t i;
+
+ for(i = 0; i < n; i++) {
+ hash ^= buf[i];
+ hash *= MD_FNV1A_PRIME;
+ }
+
+ return hash;
+}
-struct MD_LINK_REF_DEF_tag {
+
+struct MD_REF_DEF_tag {
CHAR* label;
CHAR* title;
+ unsigned hash;
SZ label_size : 24;
unsigned label_needs_free : 1;
unsigned title_needs_free : 1;
@@ -1478,6 +1512,323 @@ struct MD_LINK_REF_DEF_tag {
OFF dest_end;
};
+/* Label equivalence is quite complicated with regards to whitespace and case
+ * folding. This complicates computing a hash of it as well as direct comparison
+ * of two labels. */
+
+static unsigned
+md_link_label_hash(const CHAR* label, SZ size)
+{
+ unsigned hash = MD_FNV1A_BASE;
+ OFF off;
+ int codepoint;
+ int is_whitespace = FALSE;
+
+ off = md_skip_unicode_whitespace(label, 0, size);
+ while(off < size) {
+ SZ char_size;
+
+ codepoint = md_decode_unicode(label, off, size, &char_size);
+ is_whitespace = ISUNICODEWHITESPACE_(codepoint) || ISNEWLINE_(label[off]);
+
+ if(is_whitespace) {
+ codepoint = ' ';
+ hash = md_fnv1a(hash, &codepoint, 1 * sizeof(int));
+
+ off = md_skip_unicode_whitespace(label, off, size);
+ } else {
+ MD_UNICODE_FOLD_INFO fold_info;
+
+ md_get_unicode_fold_info(codepoint, &fold_info);
+ hash = md_fnv1a(hash, fold_info.codepoints, fold_info.n_codepoints * sizeof(int));
+
+ off += char_size;
+ }
+ }
+
+ if(!is_whitespace) {
+ codepoint = ' ';
+ hash = md_fnv1a(hash, &codepoint, 1 * sizeof(int));
+ }
+
+ return hash;
+}
+
+static int
+md_link_label_cmp(const CHAR* a_label, SZ a_size, const CHAR* b_label, SZ b_size)
+{
+ OFF a_off;
+ OFF b_off;
+
+ /* The slow path, with Unicode case folding and Unicode whitespace collapsing. */
+ a_off = md_skip_unicode_whitespace(a_label, 0, a_size);
+ b_off = md_skip_unicode_whitespace(b_label, 0, b_size);
+ while(a_off < a_size || b_off < b_size) {
+ int a_codepoint, b_codepoint;
+ SZ a_char_size, b_char_size;
+ int a_is_whitespace, b_is_whitespace;
+
+ if(a_off < a_size) {
+ a_codepoint = md_decode_unicode(a_label, a_off, a_size, &a_char_size);
+ a_is_whitespace = ISUNICODEWHITESPACE_(a_codepoint) || ISNEWLINE_(a_label[a_off]);
+ } else {
+ /* Treat end of label as a whitespace. */
+ a_codepoint = -1;
+ a_is_whitespace = TRUE;
+ }
+
+ if(b_off < b_size) {
+ b_codepoint = md_decode_unicode(b_label, b_off, b_size, &b_char_size);
+ b_is_whitespace = ISUNICODEWHITESPACE_(b_codepoint) || ISNEWLINE_(b_label[b_off]);
+ } else {
+ /* Treat end of label as a whitespace. */
+ b_codepoint = -1;
+ b_is_whitespace = TRUE;
+ }
+
+ if(a_is_whitespace || b_is_whitespace) {
+ if(!a_is_whitespace || !b_is_whitespace)
+ return (a_is_whitespace ? -1 : +1);
+
+ a_off = md_skip_unicode_whitespace(a_label, a_off, a_size);
+ b_off = md_skip_unicode_whitespace(b_label, b_off, b_size);
+ } else {
+ MD_UNICODE_FOLD_INFO a_fold_info, b_fold_info;
+ int cmp;
+
+ md_get_unicode_fold_info(a_codepoint, &a_fold_info);
+ md_get_unicode_fold_info(b_codepoint, &b_fold_info);
+
+ if(a_fold_info.n_codepoints != b_fold_info.n_codepoints)
+ return (a_fold_info.n_codepoints - b_fold_info.n_codepoints);
+ cmp = memcmp(a_fold_info.codepoints, b_fold_info.codepoints, a_fold_info.n_codepoints * sizeof(int));
+ if(cmp != 0)
+ return cmp;
+
+ a_off += a_char_size;
+ b_off += b_char_size;
+ }
+ }
+
+ return 0;
+}
+
+typedef struct MD_REF_DEF_LIST_tag MD_REF_DEF_LIST;
+struct MD_REF_DEF_LIST_tag {
+ int n_ref_defs;
+ int alloc_ref_defs;
+ MD_REF_DEF* ref_defs[]; /* Valid items always point into ctx->ref_defs[] */
+};
+
+static int
+md_ref_def_cmp(const void* a, const void* b)
+{
+ const MD_REF_DEF* a_ref = *(const MD_REF_DEF**)a;
+ const MD_REF_DEF* b_ref = *(const MD_REF_DEF**)b;
+
+ if(a_ref->hash < b_ref->hash)
+ return -1;
+ else if(a_ref->hash > b_ref->hash)
+ return +1;
+ else
+ return md_link_label_cmp(a_ref->label, a_ref->label_size, b_ref->label, b_ref->label_size);
+}
+
+static int
+md_ref_def_cmp_stable(const void* a, const void* b)
+{
+ int cmp;
+
+ cmp = md_ref_def_cmp(a, b);
+
+ /* Ensure stability of the sorting. */
+ if(cmp == 0) {
+ const MD_REF_DEF* a_ref = *(const MD_REF_DEF**)a;
+ const MD_REF_DEF* b_ref = *(const MD_REF_DEF**)b;
+
+ if(a_ref < b_ref)
+ cmp = -1;
+ else if(a_ref > b_ref)
+ cmp = +1;
+ else
+ cmp = 0;
+ }
+
+ return cmp;
+}
+
+static int
+md_build_ref_def_hashtable(MD_CTX* ctx)
+{
+ int i;
+
+ if(ctx->n_ref_defs == 0)
+ return 0;
+
+ ctx->ref_def_hashtable_size = (ctx->n_ref_defs * 5) / 4;
+ ctx->ref_def_hashtable = malloc(ctx->ref_def_hashtable_size * sizeof(void*));
+ if(ctx->ref_def_hashtable == NULL) {
+ MD_LOG("malloc() failed.");
+ goto abort;
+ }
+ memset(ctx->ref_def_hashtable, 0, ctx->ref_def_hashtable_size * sizeof(void*));
+
+ /* Each member of ctx->ref_def_hashtable[] can be:
+ * -- NULL,
+ * -- pointer to the MD_REF_DEF in ctx->ref_defs[], or
+ * -- pointer to a MD_REF_DEF_LIST, which holds multiple pointers to
+ * such MD_REF_DEFs.
+ */
+ for(i = 0; i < ctx->n_ref_defs; i++) {
+ MD_REF_DEF* def = &ctx->ref_defs[i];
+ void* bucket;
+ MD_REF_DEF_LIST* list;
+
+ def->hash = md_link_label_hash(def->label, def->label_size);
+ bucket = ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size];
+
+ if(bucket == NULL) {
+ ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = def;
+ continue;
+ }
+
+ if(ctx->ref_defs <= (MD_REF_DEF*) bucket && (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs) {
+ /* The bucket already contains one ref. def. Lets see whether it
+ * is the same label (ref. def. duplicate) or different one
+ * (hash conflict). */
+ MD_REF_DEF* old_def = (MD_REF_DEF*) bucket;
+
+ if(md_link_label_cmp(def->label, def->label_size, old_def->label, old_def->label_size) == 0) {
+ /* Ignore this ref. def. */
+ continue;
+ }
+
+ /* Make the bucket capable of holding more ref. defs. */
+ list = (MD_REF_DEF_LIST*) malloc(sizeof(MD_REF_DEF_LIST) + 4 * sizeof(MD_REF_DEF));
+ if(list == NULL) {
+ MD_LOG("malloc() failed.");
+ goto abort;
+ }
+ list->ref_defs[0] = old_def;
+ list->ref_defs[1] = def;
+ list->n_ref_defs = 2;
+ list->alloc_ref_defs = 4;
+ ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = list;
+ continue;
+ }
+
+ /* Append the def to the bucket list. */
+ list = (MD_REF_DEF_LIST*) bucket;
+ if(list->n_ref_defs >= list->alloc_ref_defs) {
+ MD_REF_DEF_LIST* list_tmp = (MD_REF_DEF_LIST*) realloc(list,
+ sizeof(MD_REF_DEF_LIST) + 2 * list->alloc_ref_defs * sizeof(MD_REF_DEF));
+ if(list_tmp == NULL) {
+ MD_LOG("realloc() failed.");
+ goto abort;
+ }
+ list = list_tmp;
+ list->alloc_ref_defs *= 2;
+ ctx->ref_def_hashtable[def->hash % ctx->ref_def_hashtable_size] = list;
+ }
+
+ list->ref_defs[list->n_ref_defs] = def;
+ list->n_ref_defs++;
+ }
+
+ /* Sort the complex buckets so we can use bsearch() with them. */
+ for(i = 0; i < ctx->ref_def_hashtable_size; i++) {
+ void* bucket = ctx->ref_def_hashtable[i];
+ MD_REF_DEF_LIST* list;
+
+ if(bucket == NULL)
+ continue;
+ if(ctx->ref_defs <= (MD_REF_DEF*) bucket && (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs)
+ continue;
+
+ list = (MD_REF_DEF_LIST*) bucket;
+ qsort(list->ref_defs, list->n_ref_defs, sizeof(MD_REF_DEF*), md_ref_def_cmp_stable);
+
+ /* Disable duplicates. */
+ for(i = 1; i < list->n_ref_defs; i++) {
+ if(md_ref_def_cmp(&list->ref_defs[i-1], &list->ref_defs[i]) == 0)
+ list->ref_defs[i] = list->ref_defs[i-1];
+ }
+ }
+
+ return 0;
+
+abort:
+ return -1;
+}
+
+static void
+md_free_ref_def_hashtable(MD_CTX* ctx)
+{
+ if(ctx->ref_def_hashtable != NULL) {
+ int i;
+
+ for(i = 0; i < ctx->ref_def_hashtable_size; i++) {
+ void* bucket = ctx->ref_def_hashtable[i];
+ if(bucket == NULL)
+ continue;
+ if(ctx->ref_defs <= (MD_REF_DEF*) bucket && (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs)
+ continue;
+ free(bucket);
+ }
+
+ free(ctx->ref_def_hashtable);
+ }
+}
+
+static const MD_REF_DEF*
+md_lookup_ref_def(MD_CTX* ctx, const CHAR* label, SZ label_size)
+{
+ unsigned hash;
+ void* bucket;
+
+ if(ctx->ref_def_hashtable_size == 0)
+ return NULL;
+
+ hash = md_link_label_hash(label, label_size);
+ bucket = ctx->ref_def_hashtable[hash % ctx->ref_def_hashtable_size];
+
+ if(bucket == NULL) {
+ return NULL;
+ } else if(ctx->ref_defs <= (MD_REF_DEF*) bucket && (MD_REF_DEF*) bucket < ctx->ref_defs + ctx->n_ref_defs) {
+ const MD_REF_DEF* def = (MD_REF_DEF*) bucket;
+
+ if(md_link_label_cmp(def->label, def->label_size, label, label_size) == 0)
+ return def;
+ else
+ return NULL;
+ } else {
+ MD_REF_DEF_LIST* list = (MD_REF_DEF_LIST*) bucket;
+ MD_REF_DEF key_buf;
+ const MD_REF_DEF* key = &key_buf;
+ const MD_REF_DEF** ret;
+
+ key_buf.label = (CHAR*) label;
+ key_buf.label_size = label_size;
+ key_buf.hash = md_link_label_hash(key_buf.label, key_buf.label_size);
+
+ ret = (const MD_REF_DEF**) bsearch(&key, list->ref_defs,
+ list->n_ref_defs, sizeof(MD_REF_DEF*), md_ref_def_cmp);
+ if(ret != NULL)
+ return *ret;
+ else
+ return NULL;
+ }
+}
+
+
+/***************************
+ *** Recognizing Links ***
+ ***************************/
+
+/* Note this code is partially shared between processing inlines and blocks
+ * as reference definitions and links share some helper parser functions.
+ */
+
typedef struct MD_LINK_ATTR_tag MD_LINK_ATTR;
struct MD_LINK_ATTR_tag {
OFF dest_beg;
@@ -1695,9 +2046,9 @@ md_is_link_title(MD_CTX* ctx, const MD_LINE* lines, int n_lines, OFF beg,
return FALSE;
}
-/* Returns 0 if it is not a link reference definition.
+/* Returns 0 if it is not a reference definition.
*
- * Returns N > 0 if it is not a link reference definition (then N corresponds
+ * Returns N > 0 if it is not a reference definition (then N corresponds
* to the number of lines forming it). In this case the definition is stored
* for resolving any links referring to it.
*
@@ -1722,7 +2073,7 @@ md_is_link_reference_definition(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
OFF off;
int line_index = 0;
int tmp_line_index;
- MD_LINK_REF_DEF* def;
+ MD_REF_DEF* def;
int ret;
/* Link label. */
@@ -1786,23 +2137,23 @@ md_is_link_reference_definition(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
label_needs_free = TRUE;
}
- /* Store the link reference definition. */
- if(ctx->n_link_ref_defs >= ctx->alloc_link_ref_defs) {
- MD_LINK_REF_DEF* new_defs;
+ /* Store the reference definition. */
+ if(ctx->n_ref_defs >= ctx->alloc_ref_defs) {
+ MD_REF_DEF* new_defs;
- ctx->alloc_link_ref_defs = (ctx->alloc_link_ref_defs > 0 ? ctx->alloc_link_ref_defs * 2 : 16);
- new_defs = (MD_LINK_REF_DEF*) realloc(ctx->link_ref_defs, ctx->alloc_link_ref_defs * sizeof(MD_LINK_REF_DEF));
+ ctx->alloc_ref_defs = (ctx->alloc_ref_defs > 0 ? ctx->alloc_ref_defs * 2 : 16);
+ new_defs = (MD_REF_DEF*) realloc(ctx->ref_defs, ctx->alloc_ref_defs * sizeof(MD_REF_DEF));
if(new_defs == NULL) {
MD_LOG("realloc() failed.");
ret = -1;
goto abort;
}
- ctx->link_ref_defs = new_defs;
+ ctx->ref_defs = new_defs;
}
- def = &ctx->link_ref_defs[ctx->n_link_ref_defs];
- memset(def, 0, sizeof(MD_LINK_REF_DEF));
+ def = &ctx->ref_defs[ctx->n_ref_defs];
+ memset(def, 0, sizeof(MD_REF_DEF));
def->label = label;
def->label_size = label_size;
@@ -1825,7 +2176,7 @@ md_is_link_reference_definition(MD_CTX* ctx, const MD_LINE* lines, int n_lines)
}
/* Success. */
- ctx->n_link_ref_defs++;
+ ctx->n_ref_defs++;
return line_index + 1;
abort:
@@ -1835,118 +2186,11 @@ abort:
return -1;
}
-
-static OFF
-md_skip_unicode_whitespace(const CHAR* label, OFF off, SZ size)
-{
- SZ char_size;
- int codepoint;
-
- while(off < size) {
- codepoint = md_decode_unicode(label, off, size, &char_size);
- if(!ISUNICODEWHITESPACE_(codepoint) && !ISNEWLINE_(label[off]))
- break;
- off += char_size;
- }
-
- return off;
-}
-
-static int
-md_link_label_cmp(const void* a, const void* b)
-{
- const CHAR* a_label = ((const MD_LINK_REF_DEF*)a)->label;
- const CHAR* b_label = ((const MD_LINK_REF_DEF*)b)->label;
- SZ a_size = ((const MD_LINK_REF_DEF*)a)->label_size;
- SZ b_size = ((const MD_LINK_REF_DEF*)b)->label_size;
- OFF a_off;
- OFF b_off;
-
- /* The slow path, with Unicode case folding and Unicode whitespace collapsing. */
- a_off = md_skip_unicode_whitespace(a_label, 0, a_size);
- b_off = md_skip_unicode_whitespace(b_label, 0, b_size);
- while(a_off < a_size || b_off < b_size) {
- int a_codepoint, b_codepoint;
- SZ a_char_size, b_char_size;
- int a_is_whitespace, b_is_whitespace;
-
- if(a_off < a_size) {
- a_codepoint = md_decode_unicode(a_label, a_off, a_size, &a_char_size);
- a_is_whitespace = ISUNICODEWHITESPACE_(a_codepoint) || ISNEWLINE_(a_label[a_off]);
- } else {
- /* Treat end of label as a whitespace. */
- a_codepoint = -1;
- a_is_whitespace = TRUE;
- }
-
- if(b_off < b_size) {
- b_codepoint = md_decode_unicode(b_label, b_off, b_size, &b_char_size);
- b_is_whitespace = ISUNICODEWHITESPACE_(b_codepoint) || ISNEWLINE_(b_label[b_off]);
- } else {
- /* Treat end of label as a whitespace. */
- b_codepoint = -1;
- b_is_whitespace = TRUE;
- }
-
- if(a_is_whitespace || b_is_whitespace) {
- if(!a_is_whitespace || !b_is_whitespace)
- return (a_is_whitespace ? -1 : +1);
-
- a_off = md_skip_unicode_whitespace(a_label, a_off, a_size);
- b_off = md_skip_unicode_whitespace(b_label, b_off, b_size);
- } else {
- MD_UNICODE_FOLD_INFO a_fold_info, b_fold_info;
- int cmp;
-
- md_get_unicode_fold_info(a_codepoint, &a_fold_info);
- md_get_unicode_fold_info(b_codepoint, &b_fold_info);
-
- if(a_fold_info.n_codepoints != b_fold_info.n_codepoints)
- return (a_fold_info.n_codepoints - b_fold_info.n_codepoints);
- cmp = memcmp(a_fold_info.codepoints, b_fold_info.codepoints, a_fold_info.n_codepoints * sizeof(int));
- if(cmp != 0)
- return cmp;
-
- a_off += a_char_size;
- b_off += b_char_size;
- }
- }
-
- return 0;
-}
-
-static int
-md_link_label_cmp_for_qsort(const void* a, const void* b)
-{
- int cmp;
-
- cmp = md_link_label_cmp(a, b);
- if(cmp != 0)
- return cmp;
-
- /* The specification requests that only first link reference definition
- * with the same label is valid. So make sure we make a stable sort
- * from the qsort(). */
- return ((MD_LINK_REF_DEF*) a - (MD_LINK_REF_DEF*) b);
-}
-
-static inline const MD_LINK_REF_DEF*
-md_lookup_link_ref_def(MD_CTX* ctx, const CHAR* label, SZ label_size)
-{
- MD_LINK_REF_DEF key;
-
- key.label = (CHAR*) label;
- key.label_size = label_size;
-
- return bsearch(&key, ctx->link_ref_defs, ctx->n_link_ref_defs,
- sizeof(MD_LINK_REF_DEF), md_link_label_cmp);
-}
-
static int
md_is_link_reference(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
OFF beg, OFF end, MD_LINK_ATTR* attr)
{
- const MD_LINK_REF_DEF* def;
+ const MD_REF_DEF* def;
const MD_LINE* beg_line;
const MD_LINE* end_line;
CHAR* label;
@@ -1978,7 +2222,7 @@ md_is_link_reference(MD_CTX* ctx, const MD_LINE* lines, int n_lines,
label_size = end - beg;
}
- def = md_lookup_link_ref_def(ctx, label, label_size);
+ def = md_lookup_ref_def(ctx, label, label_size);
if(def != NULL) {
attr->dest_beg = def->dest_beg;
attr->dest_end = def->dest_end;
@@ -2084,12 +2328,12 @@ abort:
}
static void
-md_free_link_ref_defs(MD_CTX* ctx)
+md_free_ref_defs(MD_CTX* ctx)
{
int i;
- for(i = 0; i < ctx->n_link_ref_defs; i++) {
- MD_LINK_REF_DEF* def = &ctx->link_ref_defs[i];
+ for(i = 0; i < ctx->n_ref_defs; i++) {
+ MD_REF_DEF* def = &ctx->ref_defs[i];
if(def->label_needs_free)
free(def->label);
@@ -2097,7 +2341,7 @@ md_free_link_ref_defs(MD_CTX* ctx)
free(def->title);
}
- free(ctx->link_ref_defs);
+ free(ctx->ref_defs);
}
@@ -4335,10 +4579,10 @@ md_start_new_block(MD_CTX* ctx, const MD_LINE_ANALYSIS* line)
return 0;
}
-/* Eat from start of current (textual) block any link reference definitions
- * and remember them so we can resolve any links referring to them.
+/* Eat from start of current (textual) block any reference definitions and
+ * remember them so we can resolve any links referring to them.
*
- * (Link reference definitions can only be at start of it as they cannot break
+ * (Reference definitions can only be at start of it as they cannot break
* a paragraph.)
*/
static int
@@ -4349,17 +4593,17 @@ md_consume_link_reference_definitions(MD_CTX* ctx)
int n = 0;
/* Compute how many lines at the start of the block form one or more
- * link reference definitions. */
+ * reference definitions. */
while(n < n_lines) {
int n_link_ref_lines;
n_link_ref_lines = md_is_link_reference_definition(ctx,
lines + n, n_lines - n);
- /* Not a link reference definition? */
+ /* Not a reference definition? */
if(n_link_ref_lines == 0)
break;
- /* We fail if it is the link ref. def. but it could not be stored due
+ /* We fail if it is the ref. def. but it could not be stored due
* a memory allocation error. */
if(n_link_ref_lines < 0)
return -1;
@@ -4367,7 +4611,7 @@ md_consume_link_reference_definitions(MD_CTX* ctx)
n += n_link_ref_lines;
}
- /* If there was at least one link reference definition, we need to remove
+ /* If there was at least one reference definition, we need to remove
* its lines from the block, or perhaps even the whole block. */
if(n > 0) {
if(n == n_lines) {
@@ -4393,9 +4637,9 @@ md_end_current_block(MD_CTX* ctx)
if(ctx->current_block == NULL)
return ret;
- /* Check whether there is a link reference definition. (We do this here
- * instead of in md_analyze_line() because link reference definition can
- * take multiple lines.) */
+ /* Check whether there is a reference definition. (We do this here instead
+ * of in md_analyze_line() because reference definition can take multiple
+ * lines.) */
if(ctx->current_block->type == MD_BLOCK_P) {
MD_LINE* lines = (MD_LINE*) (ctx->current_block + 1);
if(CH(lines[0].beg) == _T('['))
@@ -5556,9 +5800,7 @@ md_process_doc(MD_CTX *ctx)
md_end_current_block(ctx);
- /* Sort link reference definitions so we can use bsearch() for their lookup. */
- qsort(ctx->link_ref_defs, ctx->n_link_ref_defs, sizeof(MD_LINK_REF_DEF),
- md_link_label_cmp_for_qsort);
+ MD_CHECK(md_build_ref_def_hashtable(ctx));
/* Process all blocks. */
MD_CHECK(md_leave_child_containers(ctx, 0));
@@ -5626,7 +5868,8 @@ md_parse(const MD_CHAR* text, MD_SIZE size, const MD_RENDERER* renderer, void* u
ret = md_process_doc(&ctx);
/* Clean-up. */
- md_free_link_ref_defs(&ctx);
+ md_free_ref_defs(&ctx);
+ md_free_ref_def_hashtable(&ctx);
free(ctx.buffer);
free(ctx.marks);
free(ctx.block_bytes);
diff --git a/test/coverage.txt b/test/coverage.txt
index a801300..b6c868b 100644
--- a/test/coverage.txt
+++ b/test/coverage.txt
@@ -183,3 +183,121 @@ Ditto for Unicode punctuation (here U+00A1).
bar">link</a></p>
</blockquote>
````````````````````````````````
+
+
+### `md_build_ref_def_hashtable()`
+
+All link labels in the following example all have the same FNV1a hash (after
+normalization of the label, which means after converting to a vector of Unicode
+codepoints and lowercase folding).
+
+So the example triggers quite complex code paths which are not otherwise easily
+tested.
+
+```````````````````````````````` example
+[foo]: /foo
+[qnptgbh]: /qnptgbh
+[abgbrwcv]: /abgbrwcv
+[abgbrwcv]: /abgbrwcv2
+[abgbrwcv]: /abgbrwcv3
+[abgbrwcv]: /abgbrwcv4
+[alqadfgn]: /alqadfgn
+
+[foo]
+[qnptgbh]
+[abgbrwcv]
+[alqadfgn]
+[axgydtdu]
+.
+<p><a href="/foo">foo</a>
+<a href="/qnptgbh">qnptgbh</a>
+<a href="/abgbrwcv">abgbrwcv</a>
+<a href="/alqadfgn">alqadfgn</a>
+[axgydtdu]</p>
+````````````````````````````````
+
+For the sake of completeness, the following C program was used to find the hash
+collisions by brute force:
+
+~~~
+
+#include <stdio.h>
+#include <string.h>
+
+
+static unsigned etalon;
+
+
+
+#define MD_FNV1A_BASE 2166136261
+#define MD_FNV1A_PRIME 16777619
+
+static inline unsigned
+fnv1a(unsigned base, const void* data, size_t n)
+{
+ const unsigned char* buf = (const unsigned char*) data;
+ unsigned hash = base;
+ size_t i;
+
+ for(i = 0; i < n; i++) {
+ hash ^= buf[i];
+ hash *= MD_FNV1A_PRIME;
+ }
+
+ return hash;
+}
+
+
+static unsigned
+unicode_hash(const char* data, size_t n)
+{
+ unsigned value;
+ unsigned hash = MD_FNV1A_BASE;
+ int i;
+
+ for(i = 0; i < n; i++) {
+ value = data[i];
+ hash = fnv1a(hash, &value, sizeof(unsigned));
+ }
+
+ return hash;
+}
+
+
+static void
+recurse(char* buffer, size_t off, size_t len)
+{
+ int ch;
+
+ if(off < len - 1) {
+ for(ch = 'a'; ch <= 'z'; ch++) {
+ buffer[off] = ch;
+ recurse(buffer, off+1, len);
+ }
+ } else {
+ for(ch = 'a'; ch <= 'z'; ch++) {
+ buffer[off] = ch;
+ if(unicode_hash(buffer, len) == etalon) {
+ printf("Dup: %.*s\n", (int)len, buffer);
+ }
+ }
+ }
+}
+
+int
+main(int argc, char** argv)
+{
+ char buffer[32];
+ int len;
+
+ if(argc < 2)
+ etalon = unicode_hash("foo", 3);
+ else
+ etalon = unicode_hash(argv[1], strlen(argv[1]));
+
+ for(len = 1; len <= sizeof(buffer); len++)
+ recurse(buffer, 0, len);
+
+ return 0;
+}
+~~~