Adding upstream version 3.2.6.upstream/3.2.6upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 50 insertions, 0 deletions

diff --git a/src/contrib/ucw/binsearch.h b/src/contrib/ucw/binsearch.h
new file mode 100644
index 0000000..b791d39
--- /dev/null
+++ b/src/contrib/ucw/binsearch.h
@@ -0,0 +1,50 @@
+/*
+ *	UCW Library -- Generic Binary Search
+ *
+ *	(c) 2005 Martin Mares <mj@ucw.cz>
+ *
+ *	This software may be freely distributed and used according to the terms
+ *	of the GNU Lesser General Public License.
+ */
+
+#pragma once
+
+/***
+ * [[defs]]
+ * Definitions
+ * -----------
+ ***/
+
+/**
+ * Find the first element not lower than \p x in the sorted array \p ary of \p N elements (non-decreasing order).
+ * Returns the index of the found element or \p N if no exists. Uses `ary_lt_x(ary,i,x)` to compare the i'th element with \p x.
+ * The time complexity is `O(log(N))`.
+ **/
+#define BIN_SEARCH_FIRST_GE_CMP(ary, N, ary_lt_x, x, ...)  ({	\
+  unsigned l = 0, r = (N);						\
+  while (l < r)							\
+    {								\
+      unsigned m = (l+r)/2;						\
+      if (ary_lt_x(ary, m, x, __VA_ARGS__))			\
+        l = m+1;						\
+      else							\
+        r = m;							\
+    }								\
+  l;								\
+})
+
+/**
+ * The default comparison macro for \ref BIN_SEARCH_FIRST_GE_CMP().
+ **/
+#define ARY_LT_NUM(ary,i,x) (ary)[i] < (x)
+
+/**
+ * Same as \ref BIN_SEARCH_FIRST_GE_CMP(), but uses the default `<` operator for comparisons.
+ **/
+#define BIN_SEARCH_FIRST_GE(ary,N,x) BIN_SEARCH_FIRST_GE_CMP(ary,N,ARY_LT_NUM,x)
+
+/**
+ * Search the sorted array \p ary of \p N elements (non-decreasing) for the first occurrence of \p x.
+ * Returns the index or -1 if no such element exists. Uses the `<` operator for comparisons.
+ **/
+#define BIN_SEARCH_EQ(ary,N,x) ({ int i = BIN_SEARCH_FIRST_GE(ary,N,x); if (i >= (N) || (ary)[i] != (x)) i=-1; i; })