From 3b0fced0a85b3f40e7138340dfb1ddcc630d2d07 Mon Sep 17 00:00:00 2001
From: Martin Quinson <martin.quinson@loria.fr>
Date: Thu, 10 May 2012 10:40:10 +0200
Subject: [PATCH] new function xbt_dynar_search_or_negative()

It is useful when you have less than 2 million elements in your dynar
and don't want of the extra complexity of catching exceptions when the
element is not found.
---
 ChangeLog           |  5 +++++
 include/xbt/dynar.h |  1 +
 src/xbt/dynar.c     | 24 +++++++++++++++++++++++-
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 095ef382ec..607038f753 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -110,6 +110,11 @@ SimGrid (3.7) NOT RELEASED; urgency=low
       deprecated in the next release.
     - Dicts of scalar elements (xbt_dicti_*) are deprecated.
     - Multi-level dictionaries are deprecated.
+  * Dynars:
+    - new function xbt_dynar_search_or_negative() that is useful when
+      you have less than 2 million elements in your dynar and don't
+      want of the extra complexity of catching exceptions when the
+      element is not found.
   * mmalloc module:
     - Cleanups and simplifications to make it maintainable again.
     - Exotic features (such as memalign and valloc) were removed.
diff --git a/include/xbt/dynar.h b/include/xbt/dynar.h
index c86b868a23..87b501c655 100644
--- a/include/xbt/dynar.h
+++ b/include/xbt/dynar.h
@@ -94,6 +94,7 @@ XBT_PUBLIC(void) xbt_dynar_remove_at(xbt_dynar_t const dynar,
                                      const int idx, void *const dst);
 
 XBT_PUBLIC(unsigned int) xbt_dynar_search(xbt_dynar_t const dynar, void *elem);
+XBT_PUBLIC(signed int) xbt_dynar_search_or_negative(xbt_dynar_t const dynar, void *const elem);
 XBT_PUBLIC(int) xbt_dynar_member(xbt_dynar_t const dynar, void *elem);
 XBT_PUBLIC(void) xbt_dynar_sort(xbt_dynar_t const dynar,
                                 int_f_cpvoid_cpvoid_t compar_fn);
diff --git a/src/xbt/dynar.c b/src/xbt/dynar.c
index 2b6a2873d7..f979c2188a 100644
--- a/src/xbt/dynar.c
+++ b/src/xbt/dynar.c
@@ -523,7 +523,9 @@ xbt_dynar_remove_at(xbt_dynar_t const dynar,
 
 /** @brief Returns the position of the element in the dynar
  *
- * Raises not_found_error if not found.
+ * Raises not_found_error if not found. If you have less than 2 millions elements,
+ * you probably want to use #xbt_dynar_search_or_negative() instead, so that you
+ * don't have to TRY/CATCH on element not found.
  */
 unsigned int xbt_dynar_search(xbt_dynar_t const dynar, void *const elem)
 {
@@ -541,6 +543,26 @@ unsigned int xbt_dynar_search(xbt_dynar_t const dynar, void *const elem)
          dynar);
 }
 
+/** @brief Returns the position of the element in the dynar (or -1 if not found)
+ *
+ * Note that usually, the dynar indices are unsigned integers. If you have more
+ * than 2 million elements in your dynar, this very function will not work (but the other will).
+ */
+signed int xbt_dynar_search_or_negative(xbt_dynar_t const dynar, void *const elem)
+{
+  unsigned long it;
+
+  _dynar_lock(dynar);
+  for (it = 0; it < dynar->used; it++)
+    if (!memcmp(_xbt_dynar_elm(dynar, it), elem, dynar->elmsize)) {
+      _dynar_unlock(dynar);
+      return it;
+    }
+
+  _dynar_unlock(dynar);
+  return -1;
+}
+
 /** @brief Returns a boolean indicating whether the element is part of the dynar */
 int xbt_dynar_member(xbt_dynar_t const dynar, void *const elem)
 {
-- 
2.20.1