# HG changeset patch
# User Mike Becker <universe@uap-core.de>
# Date 1487859926 -3600
# Node ID 5ba9de6361ff79c4ee6bfe0a9fddd9dcd0569d71
# Parent  ffc6d09103427b72ab19b6165c6d83fddd9c9fea
further performance tweaks to sstrstr() function

diff -r ffc6d0910342 -r 5ba9de6361ff ucx/string.c
--- a/ucx/string.c	Thu Feb 23 14:30:12 2017 +0100
+++ b/ucx/string.c	Thu Feb 23 15:25:26 2017 +0100
@@ -176,21 +176,13 @@
     return n;
 }
 
-typedef size_t(*prefix_table_rfun)(void*,size_t);
-typedef void(*prefix_table_wfun)(void*,size_t,size_t);
+#define ptable_r(dest, useheap, ptable, index) (dest = useheap ? \
+    ((size_t*)ptable)[index] : (size_t) ((uint8_t*)ptable)[index])
 
-static size_t s_prefix_table_r(void* table, size_t index) {
-    return (size_t) ((uint8_t*)table)[index];
-}
-static void s_prefix_table_w(void* table, size_t index, size_t value) {
-    ((uint8_t*)table)[index] = (uint8_t) value;
-}
-static size_t h_prefix_table_r(void* table, size_t index) {
-    return ((size_t*)table)[index];
-}
-static void h_prefix_table_w(void* table, size_t index, size_t value) {
-    ((size_t*)table)[index] = value;
-}
+#define ptable_w(useheap, ptable, index, src) do {\
+    if (!useheap) ((uint8_t*)ptable)[index] = (uint8_t) src;\
+    else ((size_t*)ptable)[index] = src;\
+    } while (0);
 
 sstr_t sstrstr(sstr_t string, sstr_t match) {
     if (match.length == 0) {
@@ -212,39 +204,30 @@
     static uint8_t s_prefix_table[256];
     
     /* check pattern length and use appropriate prefix table */
-    register void* ptable;
-    prefix_table_rfun ptable_r;
-    prefix_table_wfun ptable_w;
-    if (match.length > 255) {
-        /* pattern exceeds static prefix table, allocate on the heap */
-        ptable = calloc(match.length+1, sizeof(size_t));
-        ptable_r = h_prefix_table_r;
-        ptable_w = h_prefix_table_w;
-    } else {
-        ptable = s_prefix_table;
-        ptable_r = s_prefix_table_r;
-        ptable_w = s_prefix_table_w;
-    }
+    /* if the pattern exceeds static prefix table, allocate on the heap */
+    register int useheap = match.length > 255;
+    register void* ptable = useheap ?
+        calloc(match.length+1, sizeof(size_t)): s_prefix_table;
     
     /* keep counter in registers */
     register size_t i, j;
     
     /* fill prefix table */
     i = 0; j = 0;
-    ptable_w(ptable, i, j);
+    ptable_w(useheap, ptable, i, j);
     while (i < match.length) {
         while (j >= 1 && match.ptr[j-1] != match.ptr[i]) {
-            j = ptable_r(ptable, j-i);
+            ptable_r(j, useheap, ptable, j-i);
         }
         i++; j++;
-        ptable_w(ptable, i, j);
+        ptable_w(useheap, ptable, i, j);
     }
 
     /* search */
     i = 0; j = 1;
     while (i < string.length) {
         while (j >= 1 && string.ptr[i] != match.ptr[j-1]) {
-            j = ptable_r(ptable, j-1);
+            ptable_r(j, useheap, ptable, j-1);
         }
         i++; j++;
         if (j-1 == match.length) {
@@ -263,6 +246,9 @@
     return result;
 }
 
+#undef ptable_r
+#undef ptable_w
+
 sstr_t* sstrsplit(sstr_t s, sstr_t d, ssize_t *n) {
     return sstrsplit_a(ucx_default_allocator(), s, d, n);
 }