commit 4f47841c3897b8d764e9f2a971078b514031acd6
author Paul Wankadia <junyer@google.com> Sun Jul 03 23:18:05 2016 +1000
committer Paul Wankadia <junyer@google.com> Sun Jul 03 13:20:31 2016 +0000
tree 250a87edb93cf734c1d335e7b4aa88ef1bbf3578
parent fc6337a382bfd4f7c861abea08f872d3c85b31da

Fix the DFA memory budget logic for RE2::Set.

Change-Id: I10dafc05ba500e218cbb5dfe65c9297944eb7135
Reviewed-on: https://code-review.googlesource.com/5160
Reviewed-by: Paul Wankadia <junyer@google.com>

re2/dfa.cc

diff --git a/re2/dfa.cc b/re2/dfa.cc
index e33bb01..b2a162e 100644
--- a/re2/dfa.cc
+++ b/re2/dfa.cc
@@ -1809,15 +1809,19 @@
     return dfa;
 
   // For a forward DFA, half the memory goes to each DFA.
+  // However, if it is a "many match" DFA, then there is
+  // no counterpart with which the memory must be shared.
+  //
   // For a reverse DFA, all the memory goes to the
   // "longest match" DFA, because RE2 never does reverse
   // "first match" searches.
-  int64 m = dfa_mem_/2;
+  int64 m = dfa_mem_;
   if (reversed_) {
-    if (kind == kLongestMatch || kind == kManyMatch)
-      m = dfa_mem_;
-    else
-      m = 0;
+    DCHECK_EQ(kind, kLongestMatch);
+  } else if (kind == kFirstMatch || kind == kLongestMatch) {
+    m /= 2;
+  } else {
+    DCHECK_EQ(kind, kManyMatch);
   }
   dfa = new DFA(this, kind, m);