Merge branch 'zk/log-graph-showsig'
[gitweb.git] / refs.c
diff --git a/refs.c b/refs.c
index dc457742eade241ec6b0001580d1ce1a880fee31..061d233e4b6404c57ff8d62715758b900d02e051 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -7,21 +7,27 @@
 
 /*
  * How to handle various characters in refnames:
+ * This table is used by both the SIMD and non-SIMD code.  It has
+ * some cases that are only useful for the SIMD; these are handled
+ * equivalently to the listed disposition in the non-SIMD code.
  * 0: An acceptable character for refs
- * 1: End-of-component
- * 2: ., look for a preceding . to reject .. in refs
- * 3: {, look for a preceding @ to reject @{ in refs
- * 4: A bad character: ASCII control characters, "~", "^", ":" or SP
+ * 1: @, look for a following { to reject @{ in refs (SIMD or = 0)
+ * 2: \0: End-of-component and string
+ * 3: /: End-of-component (SIMD or = 2)
+ * 4: ., look for a preceding . to reject .. in refs
+ * 5: {, look for a preceding @ to reject @{ in refs
+ * 6: *, usually a bad character except, once as a wildcard (SIMD or = 7)
+ * 7: A bad character except * (see check_refname_component below)
  */
 static unsigned char refname_disposition[256] = {
-       1, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-       4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
-       4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 2, 1,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0, 0, 0, 4,
+       2, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+       7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7,
+       7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0, 0, 4, 3,
+       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 0, 0, 0, 0, 7,
+       1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 7, 7, 0, 7, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 4, 4, 0, 4, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 3, 0, 0, 4, 4
+       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0, 7, 7
 };
 
 /*
@@ -33,8 +39,9 @@ static unsigned char refname_disposition[256] = {
  * - any path component of it begins with ".", or
  * - it has double dots "..", or
  * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
- * - it ends with a "/".
- * - it ends with ".lock"
+ * - it has pattern-matching notation "*", "?", "[", anywhere, or
+ * - it ends with a "/", or
+ * - it ends with ".lock", or
  * - it contains a "\" (backslash)
  */
 static int check_refname_component(const char *refname, int flags)
@@ -46,17 +53,19 @@ static int check_refname_component(const char *refname, int flags)
                int ch = *cp & 255;
                unsigned char disp = refname_disposition[ch];
                switch (disp) {
-               case 1:
+               case 2: /* fall-through */
+               case 3:
                        goto out;
-               case 2:
+               case 4:
                        if (last == '.')
                                return -1; /* Refname contains "..". */
                        break;
-               case 3:
+               case 5:
                        if (last == '@')
                                return -1; /* Refname contains "@{". */
                        break;
-               case 4:
+               case 6: /* fall-through */
+               case 7:
                        return -1;
                }
                last = ch;
@@ -79,7 +88,7 @@ static int check_refname_component(const char *refname, int flags)
        return cp - refname;
 }
 
-int check_refname_format(const char *refname, int flags)
+static int check_refname_format_bytewise(const char *refname, int flags)
 {
        int component_len, component_count = 0;
 
@@ -115,6 +124,196 @@ int check_refname_format(const char *refname, int flags)
        return 0;
 }
 
+#if defined(__GNUC__) && defined(__x86_64__)
+#define SSE_VECTOR_BYTES 16
+
+/* Vectorized version of check_refname_format. */
+int check_refname_format(const char *refname, int flags)
+{
+       const char *cp = refname;
+
+       const __m128i dot = _mm_set1_epi8('.');
+       const __m128i at = _mm_set1_epi8('@');
+       const __m128i curly = _mm_set1_epi8('{');
+       const __m128i slash = _mm_set1_epi8('/');
+       const __m128i zero = _mm_set1_epi8('\000');
+       const __m128i el = _mm_set1_epi8('l');
+
+       /* below '*', all characters are forbidden or rare */
+       const __m128i star_ub = _mm_set1_epi8('*' + 1);
+
+       const __m128i colon = _mm_set1_epi8(':');
+       const __m128i question = _mm_set1_epi8('?');
+
+       /* '['..'^' contains 4 characters: 3 forbidden and 1 rare */
+       const __m128i bracket_lb = _mm_set1_epi8('[' - 1);
+       const __m128i caret_ub = _mm_set1_epi8('^' + 1);
+
+       /* '~' and above are forbidden */
+       const __m128i tilde_lb = _mm_set1_epi8('~' - 1);
+
+       int component_count = 0;
+       int orig_flags = flags;
+
+       if (refname[0] == 0 || refname[0] == '/') {
+               /* entirely empty ref or initial ref component */
+               return -1;
+       }
+
+       /*
+        * Initial ref component of '.'; below we look for /. so we'll
+        * miss this.
+        */
+       if (refname[0] == '.') {
+               if (refname[1] == '/' || refname[1] == '\0')
+                       return -1;
+               if (!(flags & REFNAME_DOT_COMPONENT))
+                       return -1;
+       }
+       while(1) {
+               __m128i tmp, tmp1, result;
+               uint64_t mask;
+
+               if ((uintptr_t) cp % PAGE_SIZE > PAGE_SIZE - SSE_VECTOR_BYTES  - 1)
+                       /*
+                        * End-of-page; fall back to slow method for
+                        * this entire ref.
+                        */
+                       return check_refname_format_bytewise(refname, orig_flags);
+
+               tmp = _mm_loadu_si128((__m128i *)cp);
+               tmp1 = _mm_loadu_si128((__m128i *)(cp + 1));
+
+               /*
+                * This range (note the lt) contains some
+                * permissible-but-rare characters (including all
+                * characters >= 128), which we handle later.  It also
+                * includes \000.
+                */
+               result = _mm_cmplt_epi8(tmp, star_ub);
+
+               result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, question));
+               result = _mm_or_si128(result, _mm_cmpeq_epi8(tmp, colon));
+
+               /* This range contains the permissible ] as bycatch */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpgt_epi8(tmp, bracket_lb),
+                                             _mm_cmplt_epi8(tmp, caret_ub)));
+
+               result = _mm_or_si128(result, _mm_cmpgt_epi8(tmp, tilde_lb));
+
+               /* .. */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, dot),
+                                             _mm_cmpeq_epi8(tmp1, dot)));
+               /* @{ */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, at),
+                                             _mm_cmpeq_epi8(tmp1, curly)));
+               /* // */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, slash),
+                                             _mm_cmpeq_epi8(tmp1, slash)));
+               /* trailing / */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, slash),
+                                             _mm_cmpeq_epi8(tmp1, zero)));
+               /* .l, beginning of .lock */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, dot),
+                                             _mm_cmpeq_epi8(tmp1, el)));
+               /*
+                * Even though /. is not necessarily an error, we flag
+                * it anyway. If we find it, we'll check if it's valid
+                * and if so we'll advance just past it.
+                */
+               result = _mm_or_si128(result, _mm_and_si128(
+                                             _mm_cmpeq_epi8(tmp, slash),
+                                             _mm_cmpeq_epi8(tmp1, dot)));
+
+               mask = _mm_movemask_epi8(result);
+               if (mask) {
+                       /*
+                        * We've found either end-of-string, or some
+                        * probably-bad character or substring.
+                        */
+                       int i = __builtin_ctz(mask);
+                       switch (refname_disposition[cp[i] & 255]) {
+                       case 0: /* fall-through */
+                       case 5:
+                               /*
+                                * bycatch: a good character that's in
+                                * one of the ranges of mostly-forbidden
+                                * characters
+                                */
+                               cp += i + 1;
+                               break;
+                       case 1:
+                               if (cp[i + 1] == '{')
+                                       return -1;
+                               cp += i + 1;
+                               break;
+                       case 2:
+                               if (!(flags & REFNAME_ALLOW_ONELEVEL)
+                                   && !component_count && !strchr(refname, '/'))
+                                       /* Refname has only one component. */
+                                       return -1;
+                               return 0;
+                       case 3:
+                               component_count ++;
+                               /*
+                                * Even if leading dots are allowed, don't
+                                * allow "." as a component (".." is
+                                * prevented by case 4 below).
+                                */
+                               if (cp[i + 1] == '.') {
+                                       if (cp[i + 2] == '\0')
+                                               return -1;
+                                       if (flags & REFNAME_DOT_COMPONENT) {
+                                               /* skip to just after the /. */
+                                               cp += i + 2;
+                                               break;
+                                       }
+                                       return -1;
+                               } else if (cp[i + 1] == '/' || cp[i + 1] == '\0')
+                                       return -1;
+                               break;
+                       case 4:
+                               if (cp[i + 1] == '.' || cp[i + 1] == '\0')
+                                       return -1;
+                               /* .lock as end-of-component or end-of-string */
+                               if ((!strncmp(cp + i, ".lock", 5))
+                                   && (cp[i + 5] == '/' || cp[i + 5] == 0))
+                                       return -1;
+                               cp += 1;
+                               break;
+                       case 6:
+                               if (((cp == refname + i) || cp[i - 1] == '/')
+                                   && (cp[i + 1] == '/' || cp[i + 1] == 0))
+                                       if (flags & REFNAME_REFSPEC_PATTERN) {
+                                               flags &= ~REFNAME_REFSPEC_PATTERN;
+                                               /* restart after the * */
+                                               cp += i + 1;
+                                               continue;
+                                       }
+                               /* fall-through */
+                       case 7:
+                               return -1;
+                       }
+               } else
+                       cp += SSE_VECTOR_BYTES;
+       }
+}
+
+#else
+
+int check_refname_format (const char *refname, int flags)
+{
+       return check_refname_format_bytewise(refname, flags);
+}
+
+#endif
+
 struct ref_entry;
 
 /*
@@ -1162,7 +1361,7 @@ static void read_loose_refs(const char *dirname, struct ref_dir *dir)
 
                if (de->d_name[0] == '.')
                        continue;
-               if (has_extension(de->d_name, ".lock"))
+               if (ends_with(de->d_name, ".lock"))
                        continue;
                strbuf_addstr(&refname, de->d_name);
                refdir = *refs->name
@@ -3233,7 +3432,7 @@ static int do_for_each_reflog(struct strbuf *name, each_ref_fn fn, void *cb_data
 
                if (de->d_name[0] == '.')
                        continue;
-               if (has_extension(de->d_name, ".lock"))
+               if (ends_with(de->d_name, ".lock"))
                        continue;
                strbuf_addstr(name, de->d_name);
                if (stat(git_path("logs/%s", name->buf), &st) < 0) {