diff options
Diffstat (limited to 'AppPkg/Applications/Python/Python-2.7.10/Objects/stringlib/fastsearch.h')
| -rw-r--r-- | AppPkg/Applications/Python/Python-2.7.10/Objects/stringlib/fastsearch.h | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/AppPkg/Applications/Python/Python-2.7.10/Objects/stringlib/fastsearch.h b/AppPkg/Applications/Python/Python-2.7.10/Objects/stringlib/fastsearch.h new file mode 100644 index 0000000000..6255b36e44 --- /dev/null +++ b/AppPkg/Applications/Python/Python-2.7.10/Objects/stringlib/fastsearch.h @@ -0,0 +1,160 @@ +/* stringlib: fastsearch implementation */
+
+#ifndef STRINGLIB_FASTSEARCH_H
+#define STRINGLIB_FASTSEARCH_H
+
+/* fast search/count implementation, based on a mix between boyer-
+ moore and horspool, with a few more bells and whistles on the top.
+ for some more background, see: http://effbot.org/zone/stringlib.htm */
+
+/* note: fastsearch may access s[n], which isn't a problem when using
+ Python's ordinary string types, but may cause problems if you're
+ using this code in other contexts. also, the count mode returns -1
+ if there cannot possible be a match in the target string, and 0 if
+ it has actually checked for matches, but didn't find any. callers
+ beware! */
+
+#define FAST_COUNT 0
+#define FAST_SEARCH 1
+#define FAST_RSEARCH 2
+
+#if LONG_BIT >= 128
+#define STRINGLIB_BLOOM_WIDTH 128
+#elif LONG_BIT >= 64
+#define STRINGLIB_BLOOM_WIDTH 64
+#elif LONG_BIT >= 32
+#define STRINGLIB_BLOOM_WIDTH 32
+#else
+#error "LONG_BIT is smaller than 32"
+#endif
+
+#define STRINGLIB_BLOOM_ADD(mask, ch) \
+ ((mask |= (1UL << ((ch) & (STRINGLIB_BLOOM_WIDTH -1)))))
+#define STRINGLIB_BLOOM(mask, ch) \
+ ((mask & (1UL << ((ch) & (STRINGLIB_BLOOM_WIDTH -1)))))
+
+Py_LOCAL_INLINE(Py_ssize_t)
+fastsearch(const STRINGLIB_CHAR* s, Py_ssize_t n,
+ const STRINGLIB_CHAR* p, Py_ssize_t m,
+ Py_ssize_t maxcount, int mode)
+{
+ unsigned long mask;
+ Py_ssize_t skip, count = 0;
+ Py_ssize_t i, j, mlast, w;
+
+ w = n - m;
+
+ if (w < 0 || (mode == FAST_COUNT && maxcount == 0))
+ return -1;
+
+ /* look for special cases */
+ if (m <= 1) {
+ if (m <= 0)
+ return -1;
+ /* use special case for 1-character strings */
+ if (mode == FAST_COUNT) {
+ for (i = 0; i < n; i++)
+ if (s[i] == p[0]) {
+ count++;
+ if (count == maxcount)
+ return maxcount;
+ }
+ return count;
+ } else if (mode == FAST_SEARCH) {
+ for (i = 0; i < n; i++)
+ if (s[i] == p[0])
+ return i;
+ } else { /* FAST_RSEARCH */
+ for (i = n - 1; i > -1; i--)
+ if (s[i] == p[0])
+ return i;
+ }
+ return -1;
+ }
+
+ mlast = m - 1;
+ skip = mlast - 1;
+ mask = 0;
+
+ if (mode != FAST_RSEARCH) {
+
+ /* create compressed boyer-moore delta 1 table */
+
+ /* process pattern[:-1] */
+ for (i = 0; i < mlast; i++) {
+ STRINGLIB_BLOOM_ADD(mask, p[i]);
+ if (p[i] == p[mlast])
+ skip = mlast - i - 1;
+ }
+ /* process pattern[-1] outside the loop */
+ STRINGLIB_BLOOM_ADD(mask, p[mlast]);
+
+ for (i = 0; i <= w; i++) {
+ /* note: using mlast in the skip path slows things down on x86 */
+ if (s[i+m-1] == p[m-1]) {
+ /* candidate match */
+ for (j = 0; j < mlast; j++)
+ if (s[i+j] != p[j])
+ break;
+ if (j == mlast) {
+ /* got a match! */
+ if (mode != FAST_COUNT)
+ return i;
+ count++;
+ if (count == maxcount)
+ return maxcount;
+ i = i + mlast;
+ continue;
+ }
+ /* miss: check if next character is part of pattern */
+ if (!STRINGLIB_BLOOM(mask, s[i+m]))
+ i = i + m;
+ else
+ i = i + skip;
+ } else {
+ /* skip: check if next character is part of pattern */
+ if (!STRINGLIB_BLOOM(mask, s[i+m]))
+ i = i + m;
+ }
+ }
+ } else { /* FAST_RSEARCH */
+
+ /* create compressed boyer-moore delta 1 table */
+
+ /* process pattern[0] outside the loop */
+ STRINGLIB_BLOOM_ADD(mask, p[0]);
+ /* process pattern[:0:-1] */
+ for (i = mlast; i > 0; i--) {
+ STRINGLIB_BLOOM_ADD(mask, p[i]);
+ if (p[i] == p[0])
+ skip = i - 1;
+ }
+
+ for (i = w; i >= 0; i--) {
+ if (s[i] == p[0]) {
+ /* candidate match */
+ for (j = mlast; j > 0; j--)
+ if (s[i+j] != p[j])
+ break;
+ if (j == 0)
+ /* got a match! */
+ return i;
+ /* miss: check if previous character is part of pattern */
+ if (i > 0 && !STRINGLIB_BLOOM(mask, s[i-1]))
+ i = i - m;
+ else
+ i = i - skip;
+ } else {
+ /* skip: check if previous character is part of pattern */
+ if (i > 0 && !STRINGLIB_BLOOM(mask, s[i-1]))
+ i = i - m;
+ }
+ }
+ }
+
+ if (mode != FAST_COUNT)
+ return -1;
+ return count;
+}
+
+#endif
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