Bounds-checking iterator wrapper, for use with Codec::encode/decode.

git-svn-id: https://svn.apache.org/repos/asf/incubator/qpid/trunk/qpid@641315 13f79535-47bb-0310-9956-ffa450edef68

4 files changed, 143 insertions, 1 deletions

diff --git a/cpp/src/Makefile.am b/cpp/src/Makefile.am
index fce2788662..d40bbf699e 100644
--- a/cpp/src/Makefile.am
+++ b/cpp/src/Makefile.am
@@ -145,6 +145,7 @@ libqpidcommon_la_SOURCES = \
   qpid/framing/MaxMethodBodySize.h \
   qpid/framing/TransferContent.cpp \
   qpid/assert.cpp qpid/assert.h \
+  qpid/BoundedIterator.h \
   qpid/Exception.cpp \
   qpid/Plugin.cpp \
   qpid/Url.cpp \
diff --git a/cpp/src/qpid/BoundedIterator.h b/cpp/src/qpid/BoundedIterator.h
new file mode 100644
index 0000000000..1ff0f01ede
--- /dev/null
+++ b/cpp/src/qpid/BoundedIterator.h
@@ -0,0 +1,67 @@
+#ifndef QPID_BOUNDEDITERATOR_H
+#define QPID_BOUNDEDITERATOR_H
+
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include <boost/iterator/iterator_adaptor.hpp>
+#include "qpid/Exception.h"
+
+namespace qpid {
+
+struct OutOfBoundsException : public Exception {};
+    
+
+/**
+ * Iterator wrapper that throws an exception if iterated beyound the bounds.
+ */
+template <class Iter>
+class BoundedIterator :
+        public boost::iterator_adaptor<BoundedIterator<Iter>, Iter>
+{
+  public:
+    BoundedIterator(const Iter& begin, const Iter& end_) :
+        BoundedIterator::iterator_adaptor_(begin), end(end_) {}
+
+    operator Iter() const { return this->base_reference(); }
+    
+  private:
+    typename boost::iterator_reference<Iter>::type dereference() const {
+        if (this->base_reference() == end) throw OutOfBoundsException();
+        return *(this->base_reference());
+    }
+    
+    void increment() {
+        if (this->base_reference() == end) throw OutOfBoundsException();
+        ++this->base_reference();
+    }
+
+    /** Advance requires Iter to be comparable */
+    void advance(typename boost::iterator_difference<Iter>::type n) {
+        this->base_reference() += n;
+        if (this->base_reference() > end) throw OutOfBoundsException();
+    }
+    
+    Iter end;
+    friend class boost::iterator_core_access;
+};
+} // namespace qpid
+
+#endif  /*!QPID_BOUNDEDITERATOR_H*/
diff --git a/cpp/src/tests/BoundedIterator.cpp b/cpp/src/tests/BoundedIterator.cpp
new file mode 100644
index 0000000000..34e1a99cd8
--- /dev/null
+++ b/cpp/src/tests/BoundedIterator.cpp
@@ -0,0 +1,74 @@
+/*
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * 
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+#include "unit_test.h"
+#include "qpid/BoundedIterator.h"
+
+using namespace std;
+using namespace qpid;
+
+QPID_AUTO_TEST_SUITE(BoundedIteratorTestSuite)
+
+BOOST_AUTO_TEST_CASE(testIncrement) {
+    char* b="ab";
+    char* e=b+strlen(b);
+    BoundedIterator<char*> i(b,e);
+    BOOST_CHECK_EQUAL('a', *i);
+    ++i;
+    BOOST_CHECK_EQUAL('b', *i);
+    ++i;
+    BOOST_CHECK(static_cast<char*>(i) == e);
+    try {
+        ++i;
+        BOOST_FAIL("Expected exception");
+    }
+    catch (const OutOfBoundsException&) {}
+}
+
+BOOST_AUTO_TEST_CASE(testAdvance) {
+    char* b="abc";
+    char* e=b+strlen(b);
+    BoundedIterator<char*> i(b,e);
+    i += 2;
+    BOOST_CHECK_EQUAL('c', *i);
+    try {
+        i += 2;
+        BOOST_FAIL("Expected exception");
+    }
+    catch (const OutOfBoundsException&) {}
+}
+
+BOOST_AUTO_TEST_CASE(testDeref) {
+    char* b="ab";
+    char* e=b+strlen(b);
+    BoundedIterator<char*> i(b,e);
+    i += 2;
+    BOOST_CHECK(static_cast<char*>(i) == e);
+    try {
+        (void)*i;
+        BOOST_FAIL("Expected exception");
+    }
+    catch (const OutOfBoundsException&) {}
+}
+
+
+
+
+QPID_AUTO_TEST_SUITE_END()
diff --git a/cpp/src/tests/Makefile.am b/cpp/src/tests/Makefile.am
index 0baf1a2763..b246694b63 100644
--- a/cpp/src/tests/Makefile.am
+++ b/cpp/src/tests/Makefile.am
@@ -40,7 +40,7 @@ unit_test_SOURCES= unit_test.cpp unit_test.h \
 	ClientSessionTest.cpp \
 	SequenceSet.cpp \
 	serialize.cpp \
-	ProxyTemplate.cpp apply.cpp
+	ProxyTemplate.cpp apply.cpp BoundedIterator.cpp
 # FIXME aconway 2008-02-20: removed RefCountedMap.cpp  due to valgrind error.
 
 check_LTLIBRARIES += libshlibtest.la