Provide our own impl of str[n]casecmp()

This simply provides it. Next step is to change all uses of
str[n]casecmp to ap_str[n]casecmp and *then* remove those silly
logic paths where we check the 1st char of a string before
we do the strcasecmp (since this is no longer expensive).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1715401 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/include/ap_mmn.h b/include/ap_mmn.h
index ea2e0f148f7eda70b41005fb74994e6c7e400626..acbb5a5feae9ee66a5eac5bb5a5265eb5e2dddd0 100644 (file)
--- a/include/ap_mmn.h
+++ b/include/ap_mmn.h
@@ -495,6 +495,7 @@
  *                         ap_filter_should_yield(). Add empty and filters to
  *                         conn_rec.
  * 20150222.6 (2.5.0-dev)  Add async_filter to conn_rec.
+ * 20150222.7 (2.5.0-dev)  Add ap_str[n]casecmp();
  */
 
 #define MODULE_MAGIC_COOKIE 0x41503235UL /* "AP25" */

diff --git a/include/httpd.h b/include/httpd.h
index c986e3b887f46bf1f8b800295fd694419aeb8379..38438bfb6af9ce30d1bdbe4b986ece63b75e1876 100644 (file)
--- a/include/httpd.h
+++ b/include/httpd.h
@@ -2438,6 +2438,27 @@ AP_DECLARE(int) ap_array_str_index(const apr_array_header_t *array,
 AP_DECLARE(int) ap_array_str_contains(const apr_array_header_t *array, 
                                       const char *s);
 
+/**
+ * Known-fast version of strcasecmp()
+ * @param s1 The 1st string to compare
+ * @param s2 The 2nd string to compare
+ * @return integer greater than, equal to, or less than 0, depending on
+ *         if s1 is lexicographically greater than, equal to, or less
+ *         than s2 ignoring case.
+ */
+AP_DECLARE(int) ap_strcasecmp(const char *s1, const char *s2);
+
+/**
+ * Known-fast version of strncasecmp()
+ * @param s1 The 1st string to compare
+ * @param s2 The 2nd string to compare
+ * @param n  Maximum number of characters in the strings to compare
+ * @return integer greater than, equal to, or less than 0, depending on
+ *         if s1 is lexicographically greater than, equal to, or less
+ *         than s2 ignoring case.
+ */
+AP_DECLARE(int) ap_strncasecmp(const char *s1, const char *s2, apr_size_t n);
+
 #ifdef __cplusplus
 }
 #endif

diff --git a/server/util.c b/server/util.c
index cd7997295d365d022ef00eb25bccb26112332315..f531bf323e1538723f4b4aa979d88fda04605746 100644 (file)
--- a/server/util.c
+++ b/server/util.c
@@ -97,7 +97,6 @@
 #undef APLOG_MODULE_INDEX
 #define APLOG_MODULE_INDEX AP_CORE_MODULE_INDEX
 
-
 /*
  * Examine a field value (such as a media-/content-type) string and return
  * it sans any parameters; e.g., strip off any ';charset=foo' and the like.
@@ -3173,3 +3172,71 @@ AP_DECLARE(int) ap_array_str_contains(const apr_array_header_t *array,
     return (ap_array_str_index(array, s, 0) >= 0);
 }
 
+/*
+ * Provide our own known-fast implementation of str[n]casecmp()
+ */
+static const unsigned char ucharmap[] = {
+    0x0,  0x1,  0x2,  0x3,  0x4,  0x5,  0x6,  0x7,
+    0x8,  0x9,  0xa,  0xb,  0xc,  0xd,  0xe,  0xf,
+    0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+    0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
+    0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27,
+    0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+    0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
+    0x40,  'a',  'b',  'c',  'd',  'e',  'f',  'g',
+     'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
+     'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
+     'x',  'y',  'z', 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
+    0x60,  'a',  'b',  'c',  'd',  'e',  'f',  'g',
+     'h',  'i',  'j',  'k',  'l',  'm',  'n',  'o',
+     'p',  'q',  'r',  's',  't',  'u',  'v',  'w',
+     'x',  'y',  'z', 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
+    0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87,
+    0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f,
+    0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97,
+    0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f,
+    0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7,
+    0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf,
+    0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7,
+    0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf,
+    0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7,
+    0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf,
+    0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7,
+    0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf,
+    0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7,
+    0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef,
+    0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
+    0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
+};
+
+AP_DECLARE(int) ap_strcasecmp(const char *s1, const char *s2)
+{
+    const unsigned char *ps1 = (const unsigned char *) s1;
+    const unsigned char *ps2 = (const unsigned char *) s2;
+
+    while (ucharmap[*ps1] == ucharmap[*ps2++]) {
+        if (*ps1++ == '\0') {
+            return (0);
+        }
+    }
+    return (ucharmap[*ps1] - ucharmap[*--ps2]);
+}
+
+AP_DECLARE(int) ap_strncasecmp(const char *s1, const char *s2, apr_size_t n)
+{
+    const unsigned char *ps1 = (const unsigned char *) s1;
+    const unsigned char *ps2 = (const unsigned char *) s2;
+    if (n) {
+        do {
+            if (ucharmap[*ps1] != ucharmap[*ps2++]) {
+                return (ucharmap[*ps1] - ucharmap[*--ps2]);
+            }
+            if (*ps1++ == '\0') {
+                /* we know both end here */
+                return (0);
+            }
+        } while (!--n);
+    }
+    return (0);
+}