* Copyright (C) 2012, 2013
* Dale Weiler
* Wolfgang Bumiller
- *
+ *
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
+#include <string.h>
#include "gmqcc.h"
/*
* Bayesian interpretation. You can read more about it from here:
* http://www.celiagreen.com/charlesmccreery/statistics/bayestutorial.pdf
* (which is probably the only good online documentation for bayes theroy
- * no lie. Everything else just sucks ..)
- *
+ * no lie. Everything else just sucks ..)
+ *
* Bayes' Thereom suggests something like the following:
* AC P(I|C) P(C) / P(I)
- *
+ *
* However since P(I) is the same for every possibility of I, we can
* completley ignore it giving just:
* AC P(I|C) P(C)
* 3: AC, the control mechanisim, an enumerator if you will, one that
* enumerates all feasible values of C, to determine the one that
* gives the greatest probability score.
- *
+ *
* In reality the requirement for a more complex expression involving
* two seperate models is considerably a waste. But one must recognize
* that P(C|I) is already conflating two factors. It's just much simpler
* distance no greater than one. Knowing this we can optimize for most
* cases of mistakes without taking a performance hit. Which is what we
* base longer edit distances off of. Opposed to the original method of
- * I had concieved of checking everything.
- *
+ * I had concieved of checking everything.
+ *
* A little information on additional algorithms used:
*
* Initially when I implemented this corrector, it was very slow.
* char-to-index map into the branches. We've complelty made the trie
* accesses entierly constant in lookup time. No really, a lookup is
* literally trie[str[0]] [str[1]] [2] .... .value.
- *
- *
+ *
+ *
* Future Work (If we really need it)
*
* Currently we can only distinguish one source of error in the
* Currently the error model has been fairly trivial, the smaller the
* edit distance the smaller the error. This usually causes some un-
* expected problems. e.g reciet->recite yields recipt. For QuakeC
- * this could become a problem when lots of identifiers are involved.
- *
- * Our control mechanisim could use a limit, i.e limit the number of
- * sets of edits for distance X. This would also increase execution
- * speed considerably.
+ * this could become a problem when lots of identifiers are involved.
*/
return t;
}
-void correct_trie_del_sub(correct_trie_t *t) {
+static GMQCC_INLINE void correct_trie_del_sub(correct_trie_t *t) {
size_t i;
if (!t->entries)
return;
mem_d(t->entries);
}
-void correct_trie_del(correct_trie_t *t) {
+static GMQCC_INLINE void correct_trie_del(correct_trie_t *t) {
size_t i;
if (t->entries) {
for (i = 0; i < sizeof(correct_alpha)-1; ++i)
mem_d(t);
}
-void* correct_trie_get(const correct_trie_t *t, const char *key) {
+static GMQCC_INLINE void* correct_trie_get(const correct_trie_t *t, const char *key) {
const unsigned char *data = (const unsigned char*)key;
while (*data) {
return t->value;
}
-void correct_trie_set(correct_trie_t *t, const char *key, void * const value) {
+static GMQCC_INLINE void correct_trie_set(correct_trie_t *t, const char *key, void * const value) {
const unsigned char *data = (const unsigned char*)key;
while (*data) {
if (!t->entries) {
* not in the mood to figure out that logic. This is a reminder to
* do it, or for someone else to :-) correct_edit however would also
* need to take a size_t ** to carry it along (would all the argument
- * overhead be worth it?)
+ * overhead be worth it?)
*/
-static size_t correct_deletion(const char *ident, char **array) {
+static GMQCC_INLINE size_t correct_deletion(const char *ident, char **array) {
size_t itr = 0;
const size_t len = strlen(ident);
return itr;
}
-static size_t correct_transposition(const char *ident, char **array) {
+static GMQCC_INLINE size_t correct_transposition(const char *ident, char **array) {
size_t itr = 0;
const size_t len = strlen(ident);
return itr;
}
-static size_t correct_alteration(const char *ident, char **array) {
+static GMQCC_INLINE size_t correct_alteration(const char *ident, char **array) {
size_t itr = 0;
size_t jtr = 0;
size_t ktr = 0;
return ktr;
}
-static size_t correct_insertion(const char *ident, char **array) {
+static GMQCC_INLINE size_t correct_insertion(const char *ident, char **array) {
size_t itr = 0;
size_t jtr = 0;
const size_t len = strlen(ident);
return (len) + (len - 1) + (len * (sizeof(correct_alpha)-1)) + ((len + 1) * (sizeof(correct_alpha)-1));
}
-static char **correct_edit(const char *ident) {
+static GMQCC_INLINE char **correct_edit(const char *ident, size_t **lens) {
size_t next;
- char **find = (char**)correct_pool_alloc(correct_size(ident) * sizeof(char*));
+ size_t size = correct_size(ident);
+ char **find = (char**)correct_pool_alloc(size * sizeof(char*));
- if (!find)
+ if (!find || !(*lens = (size_t*)correct_pool_alloc(size * sizeof(size_t))))
return NULL;
next = correct_deletion (ident, find);
next += correct_alteration (ident, find+next);
/*****/ correct_insertion (ident, find+next);
+ /* precompute lengths */
+ for (next = 0; next < size; next++)
+ (*lens)[next] = strlen(find[next]);
+
return find;
}
-/*
- * We could use a hashtable but the space complexity isn't worth it
- * since we're only going to determine the "did you mean?" identifier
- * on error.
- */
-static int correct_exist(char **array, size_t rows, char *ident) {
+static GMQCC_INLINE int correct_exist(char **array, register size_t *sizes, size_t rows, char *ident, register size_t len) {
size_t itr;
- /*
- * As an experiment I tried the following assembly for memcmp here:
- *
- * correct_cmp_loop:
- * incl %eax ; eax = LHS
- * incl %edx ; edx = LRS
- * cmpl %eax, %ebx ; ebx = &LHS[END_POS]
- *
- * jbe correct_cmp_eq
- * movb (%edx), %cl ; micro-optimized even on atoms :-)
- * cmpb %cl, (%eax) ; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- * jg correct_cmp_gt
- * jge correct_cmp_loop
- * ...
- *
- * Despite how much optimization went in to this, the speed was
- * being conflicted by the strlen(ident) used for &LHS[END_POS]
- * If we could eliminate the strlen with what I suggested on line
- * 311 ... we can accelerate this whole damn thing quite a bit.
- *
- * However there is still something we can do here that does give
- * us a little more speed. Although one more branch, we know for
- * sure there is at least one byte to compare, if that one byte
- * simply isn't the same we can skip the full check. Which means
- * we skip a whole strlen call.
- */
for (itr = 0; itr < rows; itr++) {
- if (!memcmp(array[itr], ident, strlen(ident)))
+ /*
+ * We can save tons of calls to memcmp if we simply ignore comparisions
+ * that we know cannot contain the same length.
+ */
+ if (sizes[itr] == len && !memcmp(array[itr], ident, len))
return 1;
}
if (size < oldallocated)
return res;
- out = correct_pool_alloc(sizeof(*res) * oldallocated + 32);
+ out = (char**)correct_pool_alloc(sizeof(*res) * oldallocated + 32);
memcpy(out, res, sizeof(*res) * oldallocated);
*allocated += 32;
size_t len = 0;
size_t row = 0;
size_t nxt = 8;
- char **res = correct_pool_alloc(sizeof(char *) * nxt);
- char **end = NULL;
+ char **res = (char**)correct_pool_alloc(sizeof(char *) * nxt);
+ char **end = NULL;
+ size_t *bit = NULL;
for (; itr < rows; itr++) {
if (!array[itr][0])
continue;
- if (vec_size(corr->edits) > itr+1)
+ if (vec_size(corr->edits) > itr+1) {
end = corr->edits[itr+1];
- else {
- end = correct_edit(array[itr]);
+ bit = corr->lens [itr+1];
+ } else {
+ end = correct_edit(array[itr], &bit);
vec_push(corr->edits, end);
+ vec_push(corr->lens, bit);
}
row = correct_size(array[itr]);
for (jtr = 0; jtr < row; jtr++) {
- if (correct_find(table, end[jtr]) && !correct_exist(res, len, end[jtr])) {
+ if (correct_find(table, end[jtr]) && !correct_exist(res, bit, len, end[jtr], bit[jtr])) {
res = correct_known_resize(res, &nxt, len+1);
res[len++] = end[jtr];
}
return res;
}
-static char *correct_maximum(correct_trie_t* table, char **array, size_t rows) {
+static GMQCC_INLINE char *correct_maximum(correct_trie_t* table, char **array, size_t rows) {
char *str = NULL;
size_t *itm = NULL;
size_t itr = 0;
{
correct_pool_new();
c->edits = NULL;
+ c->lens = NULL;
}
void correct_free(correction_t *c)
{
vec_free(c->edits);
+ vec_free(c->lens);
correct_pool_delete();
}
char *e2ident = NULL;
size_t e1rows = 0;
size_t e2rows = 0;
+ size_t *bits = NULL;
/* needs to be allocated for free later */
if (correct_find(table, ident))
if (vec_size(corr->edits) > 0)
e1 = corr->edits[0];
else {
- e1 = correct_edit(ident);
+ e1 = correct_edit(ident, &bits);
vec_push(corr->edits, e1);
+ vec_push(corr->lens, bits);
}
if ((e1ident = correct_maximum(table, e1, e1rows)))