SERVER-17629 Implemented Bounded Data View/Cursor

Implements DataRange and DataRangeCursor, bounded Status returning
variants of DataView and DataCursor.

Implements DataType::Handler<> to allow for specialization by type.
* Endian specializations
* BSONObj specialization

Fix for endian conversions for floats and doubles to avoid some
signaling bit patterns.

1 files changed, 81 insertions, 0 deletions

diff --git a/src/mongo/base/data_range_cursor_test.cpp b/src/mongo/base/data_range_cursor_test.cpp
new file mode 100644
index 00000000000..f40bfdbc4bf
--- /dev/null
+++ b/src/mongo/base/data_range_cursor_test.cpp
@@ -0,0 +1,81 @@
+/**
+ *    Copyright (C) 2015 MongoDB Inc.
+ *
+ *    This program is free software: you can redistribute it and/or  modify
+ *    it under the terms of the GNU Affero General Public License, version 3,
+ *    as published by the Free Software Foundation.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ *    As a special exception, the copyright holders give permission to link the
+ *    code of portions of this program with the OpenSSL library under certain
+ *    conditions as described in each individual source file and distribute
+ *    linked combinations including the program with the OpenSSL library. You
+ *    must comply with the GNU Affero General Public License in all respects
+ *    for all of the code used other than as permitted herein. If you modify
+ *    file(s) with this exception, you may extend this exception to your
+ *    version of the file(s), but you are not obligated to do so. If you do not
+ *    wish to do so, delete this exception statement from your version. If you
+ *    delete this exception statement from all source files in the program,
+ *    then also delete it in the license file.
+ */
+
+#include "mongo/base/data_range_cursor.h"
+
+#include "mongo/base/data_type_endian.h"
+#include "mongo/platform/endian.h"
+#include "mongo/unittest/unittest.h"
+
+namespace mongo {
+
+    TEST(DataRangeCursor, ConstDataRangeCursor) {
+        char buf[14];
+
+        DataView(buf).write<uint16_t>(1);
+        DataView(buf).write<LittleEndian<uint32_t>>(2, sizeof(uint16_t));
+        DataView(buf).write<BigEndian<uint64_t>>(3, sizeof(uint16_t) + sizeof(uint32_t));
+
+        ConstDataRangeCursor cdrc(buf, buf + sizeof(buf));
+        ConstDataRangeCursor backup(cdrc);
+
+        ASSERT_EQUALS(static_cast<uint16_t>(1), cdrc.readAndAdvance<uint16_t>().getValue());
+        ASSERT_EQUALS(static_cast<uint32_t>(2),
+                      cdrc.readAndAdvance<LittleEndian<uint32_t>>().getValue());
+        ASSERT_EQUALS(static_cast<uint64_t>(3),
+                      cdrc.readAndAdvance<BigEndian<uint64_t>>().getValue());
+        ASSERT_EQUALS(false, cdrc.readAndAdvance<char>().isOK());
+
+        // test skip()
+        cdrc = backup;
+        ASSERT_EQUALS(true, cdrc.skip<uint32_t>().isOK());;
+        ASSERT_EQUALS(true, cdrc.advance(10).isOK());
+        ASSERT_EQUALS(false, cdrc.readAndAdvance<char>().isOK());
+    }
+
+    TEST(DataRangeCursor, DataRangeCursor) {
+        char buf[100] = { 0 };
+
+        DataRangeCursor dc(buf, buf + 14);
+
+        ASSERT_EQUALS(true, dc.writeAndAdvance<uint16_t>(1).isOK());
+        ASSERT_EQUALS(true, dc.writeAndAdvance<LittleEndian<uint32_t>>(2).isOK());
+        ASSERT_EQUALS(true, dc.writeAndAdvance<BigEndian<uint64_t>>(3).isOK());
+        ASSERT_EQUALS(false, dc.writeAndAdvance<char>(1).isOK());
+
+        ConstDataRangeCursor cdrc(buf, buf + sizeof(buf));
+
+        ASSERT_EQUALS(static_cast<uint16_t>(1), cdrc.readAndAdvance<uint16_t>().getValue());
+        ASSERT_EQUALS(static_cast<uint32_t>(2),
+                      cdrc.readAndAdvance<LittleEndian<uint32_t>>().getValue());
+        ASSERT_EQUALS(static_cast<uint64_t>(3),
+                      cdrc.readAndAdvance<BigEndian<uint64_t>>().getValue());
+        ASSERT_EQUALS(static_cast<char>(0), cdrc.readAndAdvance<char>().getValue());
+    }
+
+} // namespace mongo