[1697] 1st update: make MessageRenderer constructors parameter-free.

AbstractMessageRenderer now creates and holds its own buffer internally.
adjusted unittests and the python wrapper in a straightforward manner.

38 files changed, 114 insertions, 128 deletions

diff --git a/src/lib/dns/benchmarks/rdatarender_bench.cc b/src/lib/dns/benchmarks/rdatarender_bench.cc
index d1fb0f27b7..368ea6a61d 100644
--- a/src/lib/dns/benchmarks/rdatarender_bench.cc
+++ b/src/lib/dns/benchmarks/rdatarender_bench.cc
@@ -42,7 +42,7 @@ template <typename T>
 class RdataRenderBenchMark {
 public:
     RdataRenderBenchMark(const vector<T>& dataset) :
-        dataset_(dataset), buffer_(4096), renderer_(buffer_)
+        dataset_(dataset)
     {}
     unsigned int run() {
         typename vector<T>::const_iterator data;
@@ -55,7 +55,6 @@ public:
     }
 private:
     const vector<T>& dataset_;
-    OutputBuffer buffer_;
     MessageRenderer renderer_;
 };
 
diff --git a/src/lib/dns/messagerenderer.cc b/src/lib/dns/messagerenderer.cc
index 1378ba9076..61418ce00b 100644
--- a/src/lib/dns/messagerenderer.cc
+++ b/src/lib/dns/messagerenderer.cc
@@ -171,8 +171,8 @@ struct MessageRenderer::MessageRendererImpl {
     CompressMode compress_mode_;
 };
 
-MessageRenderer::MessageRenderer(OutputBuffer& buffer) :
-    AbstractMessageRenderer(buffer),
+MessageRenderer::MessageRenderer() :
+    AbstractMessageRenderer(),
     impl_(new MessageRendererImpl)
 {}
 
@@ -273,9 +273,14 @@ MessageRenderer::writeName(const Name& name, const bool compress) {
     }
 }
 
+AbstractMessageRenderer::AbstractMessageRenderer() :
+    local_buffer_(0), buffer_(&local_buffer_)
+{
+}
+
 void
 AbstractMessageRenderer::clear() {
-    buffer_.clear();
+    buffer_->clear();
 }
 
 }
diff --git a/src/lib/dns/messagerenderer.h b/src/lib/dns/messagerenderer.h
index 52d9245211..4673861674 100644
--- a/src/lib/dns/messagerenderer.h
+++ b/src/lib/dns/messagerenderer.h
@@ -102,29 +102,32 @@ protected:
     /// This is intentionally defined as \c protected as this base class should
     /// never be instantiated (except as part of a derived class).
     /// \param buffer The buffer where the data should be rendered into.
+    ///
+    /// We are now doing this:
     /// \todo We might want to revisit this API at some point and remove the
     ///     buffer parameter. In that case it would create it's own buffer and
     ///     a function to extract the data would be available instead. It seems
     ///     like a cleaner design, but it's left undone until we would actually
     ///     benefit from the change.
-    AbstractMessageRenderer(isc::util::OutputBuffer& buffer) :
-        buffer_(buffer)
-    {}
+    AbstractMessageRenderer();
 public:
     /// \brief The destructor.
     virtual ~AbstractMessageRenderer() {}
     //@}
 protected:
     /// \brief Return the output buffer we render into.
-    const isc::util::OutputBuffer& getBuffer() const { return (buffer_); }
-    isc::util::OutputBuffer& getBuffer() { return (buffer_); }
+    const isc::util::OutputBuffer& getBuffer() const { return (*buffer_); }
+    isc::util::OutputBuffer& getBuffer() { return (*buffer_); }
 private:
+    /// \short Local (default) buffer to store data.
+    isc::util::OutputBuffer local_buffer_;
+
     /// \short Buffer to store data
     ///
     /// It was decided that there's no need to have this in every subclass,
     /// at least not now, and this reduces code size and gives compiler a better
     /// chance to optimise.
-    isc::util::OutputBuffer& buffer_;
+    isc::util::OutputBuffer* buffer_;
 public:
     ///
     /// \name Getter Methods
@@ -136,12 +139,12 @@ public:
     /// This method works exactly same as the same method of the \c OutputBuffer
     /// class; all notes for \c OutputBuffer apply.
     const void* getData() const {
-        return (buffer_.getData());
+        return (buffer_->getData());
     }
 
     /// \brief Return the length of data written in the internal buffer.
     size_t getLength() const {
-        return (buffer_.getLength());
+        return (buffer_->getLength());
     }
 
     /// \brief Return whether truncation has occurred while rendering.
@@ -209,7 +212,7 @@ public:
     ///
     /// \param len The length of the gap to be inserted in bytes.
     void skip(size_t len) {
-        buffer_.skip(len);
+        buffer_->skip(len);
     }
 
     /// \brief Trim the specified length of data from the end of the internal
@@ -223,7 +226,7 @@ public:
     ///
     /// \param len The length of data that should be trimmed.
     void trim(size_t len) {
-        buffer_.trim(len);
+        buffer_->trim(len);
     }
 
     /// \brief Clear the internal buffer and other internal resources.
@@ -236,7 +239,7 @@ public:
     ///
     /// \param data The 8-bit integer to be written into the internal buffer.
     void writeUint8(const uint8_t data) {
-        buffer_.writeUint8(data);
+        buffer_->writeUint8(data);
     }
 
     /// \brief Write an unsigned 16-bit integer in host byte order into the
@@ -244,7 +247,7 @@ public:
     ///
     /// \param data The 16-bit integer to be written into the buffer.
     void writeUint16(uint16_t data) {
-        buffer_.writeUint16(data);
+        buffer_->writeUint16(data);
     }
 
     /// \brief Write an unsigned 16-bit integer in host byte order at the
@@ -259,7 +262,7 @@ public:
     /// \param data The 16-bit integer to be written into the internal buffer.
     /// \param pos The beginning position in the buffer to write the data.
     void writeUint16At(uint16_t data, size_t pos) {
-        buffer_.writeUint16At(data, pos);
+        buffer_->writeUint16At(data, pos);
     }
 
     /// \brief Write an unsigned 32-bit integer in host byte order into the
@@ -267,7 +270,7 @@ public:
     ///
     /// \param data The 32-bit integer to be written into the buffer.
     void writeUint32(uint32_t data) {
-        buffer_.writeUint32(data);
+        buffer_->writeUint32(data);
     }
 
     /// \brief Copy an arbitrary length of data into the internal buffer
@@ -278,7 +281,7 @@ public:
     /// \param data A pointer to the data to be copied into the internal buffer.
     /// \param len The length of the data in bytes.
     void writeData(const void *data, size_t len) {
-        buffer_.writeData(data, len);
+        buffer_->writeData(data, len);
     }
 
     /// \brief Write a \c Name object into the internal buffer in wire format,
@@ -316,10 +319,7 @@ public:
     using AbstractMessageRenderer::CASE_SENSITIVE;
 
     /// \brief Constructor from an output buffer.
-    ///
-    /// \param buffer An \c OutputBuffer object to which wire format data is
-    /// written.
-    MessageRenderer(isc::util::OutputBuffer& buffer);
+    MessageRenderer();
 
     virtual ~MessageRenderer();
     virtual bool isTruncated() const;
diff --git a/src/lib/dns/python/messagerenderer_python.cc b/src/lib/dns/python/messagerenderer_python.cc
index bb896228b2..5561c12c34 100644
--- a/src/lib/dns/python/messagerenderer_python.cc
+++ b/src/lib/dns/python/messagerenderer_python.cc
@@ -36,7 +36,6 @@ namespace {
 class s_MessageRenderer : public PyObject {
 public:
     s_MessageRenderer();
-    isc::util::OutputBuffer* outputbuffer;
     MessageRenderer* cppobj;
 };
 
@@ -78,17 +77,14 @@ PyMethodDef MessageRenderer_methods[] = {
 
 int
 MessageRenderer_init(s_MessageRenderer* self) {
-    self->outputbuffer = new OutputBuffer(4096);
-    self->cppobj = new MessageRenderer(*self->outputbuffer);
+    self->cppobj = new MessageRenderer;
     return (0);
 }
 
 void
 MessageRenderer_destroy(s_MessageRenderer* self) {
     delete self->cppobj;
-    delete self->outputbuffer;
     self->cppobj = NULL;
-    self->outputbuffer = NULL;
     Py_TYPE(self)->tp_free(self);
 }
 
diff --git a/src/lib/dns/rdatafields.cc b/src/lib/dns/rdatafields.cc
index af9ba2e886..94c9dbf41d 100644
--- a/src/lib/dns/rdatafields.cc
+++ b/src/lib/dns/rdatafields.cc
@@ -70,8 +70,7 @@ namespace {
 // it's hopefully an acceptable practice.
 class RdataFieldComposer : public AbstractMessageRenderer {
 public:
-    RdataFieldComposer(OutputBuffer& buffer) :
-        AbstractMessageRenderer(buffer),
+    RdataFieldComposer() :
         truncated_(false), length_limit_(65535),
         mode_(CASE_INSENSITIVE), last_data_pos_(0)
     {}
@@ -128,8 +127,7 @@ public:
 }
 
 RdataFields::RdataFields(const Rdata& rdata) {
-    OutputBuffer buffer(0);
-    RdataFieldComposer field_composer(buffer);
+    RdataFieldComposer field_composer;
     rdata.toWire(field_composer);
     nfields_ = field_composer.getFields().size();
     data_length_ = field_composer.getLength();
diff --git a/src/lib/dns/tests/edns_unittest.cc b/src/lib/dns/tests/edns_unittest.cc
index 26cc01c343..de2d2447dd 100644
--- a/src/lib/dns/tests/edns_unittest.cc
+++ b/src/lib/dns/tests/edns_unittest.cc
@@ -43,9 +43,7 @@ const uint8_t EDNS::SUPPORTED_VERSION;
 namespace {
 class EDNSTest : public ::testing::Test {
 protected:
-    EDNSTest() : rrtype(RRType::OPT()), buffer(NULL, 0), obuffer(0),
-                 renderer(obuffer), rcode(0)
-    {
+    EDNSTest() : rrtype(RRType::OPT()), buffer(NULL, 0), obuffer(0), rcode(0) {
         opt_rdata = ConstRdataPtr(new generic::OPT());
         edns_base.setUDPSize(4096);
     }
diff --git a/src/lib/dns/tests/message_unittest.cc b/src/lib/dns/tests/message_unittest.cc
index c5bc7fd840..3be1436caa 100644
--- a/src/lib/dns/tests/message_unittest.cc
+++ b/src/lib/dns/tests/message_unittest.cc
@@ -79,7 +79,6 @@ namespace {
 class MessageTest : public ::testing::Test {
 protected:
     MessageTest() : test_name("test.example.com"), obuffer(0),
-                    renderer(obuffer),
                     message_parse(Message::PARSE),
                     message_render(Message::RENDER),
                     bogus_section(static_cast<Message::Section>(
@@ -731,8 +730,8 @@ TEST_F(MessageTest, toWire) {
     message_render.toWire(renderer);
     vector<unsigned char> data;
     UnitTestUtil::readWireData("message_toWire1", data);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, obuffer.getData(),
-                        obuffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageTest, toWireInParseMode) {
@@ -961,9 +960,6 @@ TEST_F(MessageTest, toWireTSIGNoTruncation) {
 // rendering fail unexpectedly in the test that follows.
 class BadRenderer : public MessageRenderer {
 public:
-    BadRenderer(isc::util::OutputBuffer& buffer) :
-        MessageRenderer(buffer)
-    {}
     virtual void setLengthLimit(size_t len) {
         if (getLength() > 0) {
             MessageRenderer::setLengthLimit(getLength());
@@ -994,8 +990,7 @@ TEST_F(MessageTest, toWireTSIGLengthErrors) {
                  InvalidParameter);
 
     // Trying to render a message with TSIG using a buggy renderer.
-    obuffer.clear();
-    BadRenderer bad_renderer(obuffer);
+    BadRenderer bad_renderer;
     bad_renderer.setLengthLimit(512);
     message_render.clear(Message::RENDER);
     EXPECT_THROW(commonTSIGToWireCheck(message_render, bad_renderer, tsig_ctx,
diff --git a/src/lib/dns/tests/messagerenderer_unittest.cc b/src/lib/dns/tests/messagerenderer_unittest.cc
index fe790fe837..575b484a12 100644
--- a/src/lib/dns/tests/messagerenderer_unittest.cc
+++ b/src/lib/dns/tests/messagerenderer_unittest.cc
@@ -30,15 +30,13 @@ using isc::util::OutputBuffer;
 namespace {
 class MessageRendererTest : public ::testing::Test {
 protected:
-    MessageRendererTest() : expected_size(0), buffer(0), renderer(buffer)
-    {
+    MessageRendererTest() : expected_size(0) {
         data16 = (2 << 8) | 3;
         data32 = (4 << 24) | (5 << 16) | (6 << 8) | 7;
     }
     size_t expected_size;
     uint16_t data16;
     uint32_t data32;
-    OutputBuffer buffer;
     MessageRenderer renderer;
     std::vector<unsigned char> data;
     static const uint8_t testdata[5];
@@ -60,21 +58,22 @@ TEST_F(MessageRendererTest, writeName) {
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("b.example.com."));
     renderer.writeName(Name("a.example.org."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, writeNameInLargeBuffer) {
     size_t offset = 0x3fff;
-    buffer.skip(offset);
+    renderer.skip(offset);
 
     UnitTestUtil::readWireData("name_toWire2", data);
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("b.example.com."));
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t*>(buffer.getData()) + offset,
-                        buffer.getLength() - offset,
+                        static_cast<const uint8_t*>(renderer.getData()) +
+                        offset,
+                        renderer.getLength() - offset,
                         &data[0], data.size());
 }
 
@@ -83,8 +82,8 @@ TEST_F(MessageRendererTest, writeNameWithUncompressed) {
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("b.example.com."), false);
     renderer.writeName(Name("b.example.com."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, writeNamePointerChain) {
@@ -92,8 +91,8 @@ TEST_F(MessageRendererTest, writeNamePointerChain) {
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("b.example.com."));
     renderer.writeName(Name("b.example.com."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, compressMode) {
@@ -120,8 +119,8 @@ TEST_F(MessageRendererTest, writeNameCaseCompress) {
     // this should match the first name in terms of compression:
     renderer.writeName(Name("b.exAmple.CoM."));
     renderer.writeName(Name("a.example.org."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, writeNameCaseSensitiveCompress) {
@@ -132,8 +131,8 @@ TEST_F(MessageRendererTest, writeNameCaseSensitiveCompress) {
     renderer.writeName(Name("a.example.com."));
     renderer.writeName(Name("b.eXample.com."));
     renderer.writeName(Name("c.eXample.com."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, writeNameMixedCaseCompress) {
@@ -147,8 +146,8 @@ TEST_F(MessageRendererTest, writeNameMixedCaseCompress) {
     // allowed in this API.
     renderer.setCompressMode(MessageRenderer::CASE_INSENSITIVE);
     renderer.writeName(Name("c.b.EXAMPLE.com."));
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(MessageRendererTest, writeRootName) {
@@ -164,8 +163,8 @@ TEST_F(MessageRendererTest, writeRootName) {
     renderer.writeName(Name("."));
     renderer.writeName(example_name);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t*>(buffer.getData()),
-                        buffer.getLength(),
+                        static_cast<const uint8_t*>(renderer.getData()),
+                        renderer.getLength(),
                         static_cast<const uint8_t*>(expected.getData()),
                         expected.getLength());
 }
diff --git a/src/lib/dns/tests/name_unittest.cc b/src/lib/dns/tests/name_unittest.cc
index 6434229dd9..5216c49bc2 100644
--- a/src/lib/dns/tests/name_unittest.cc
+++ b/src/lib/dns/tests/name_unittest.cc
@@ -357,13 +357,12 @@ TEST_F(NameTest, toWireBuffer) {
 //
 TEST_F(NameTest, toWireRenderer) {
     vector<unsigned char> data;
-    OutputBuffer buffer(0);
-    MessageRenderer renderer(buffer);
+    MessageRenderer renderer;
 
     UnitTestUtil::readWireData(string("01610376697803636f6d00"), data);
     Name("a.vix.com.").toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, &data[0], data.size(),
-                        buffer.getData(), buffer.getLength());
+                        renderer.getData(), renderer.getLength());
 }
 
 //
@@ -524,8 +523,8 @@ TEST_F(NameTest, at) {
 
     example_name.toWire(buffer_expected);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        &data[0], data.size(),
-                        buffer_expected.getData(), buffer_expected.getLength());
+                        &data[0], data.size(), buffer_expected.getData(),
+                        buffer_expected.getLength());
 
     // Out-of-range access: should trigger an exception.
     EXPECT_THROW(example_name.at(example_name.getLength()), OutOfRange);
diff --git a/src/lib/dns/tests/question_unittest.cc b/src/lib/dns/tests/question_unittest.cc
index 1d483f2591..54d0942de1 100644
--- a/src/lib/dns/tests/question_unittest.cc
+++ b/src/lib/dns/tests/question_unittest.cc
@@ -37,7 +37,7 @@ using namespace isc::util;
 namespace {
 class QuestionTest : public ::testing::Test {
 protected:
-    QuestionTest() : obuffer(0), renderer(obuffer),
+    QuestionTest() : obuffer(0),
                      example_name1(Name("foo.example.com")),
                      example_name2(Name("bar.example.com")),
                      test_question1(example_name1, RRClass::IN(),
@@ -102,8 +102,8 @@ TEST_F(QuestionTest, toWireRenderer) {
     test_question1.toWire(renderer);
     test_question2.toWire(renderer);
     UnitTestUtil::readWireData("question_toWire2", wiredata);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, obuffer.getData(),
-                        obuffer.getLength(), &wiredata[0], wiredata.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &wiredata[0], wiredata.size());
 }
 
 TEST_F(QuestionTest, toWireTruncated) {
diff --git a/src/lib/dns/tests/rdata_afsdb_unittest.cc b/src/lib/dns/tests/rdata_afsdb_unittest.cc
index 7df8d83659..521bec5d05 100644
--- a/src/lib/dns/tests/rdata_afsdb_unittest.cc
+++ b/src/lib/dns/tests/rdata_afsdb_unittest.cc
@@ -162,7 +162,7 @@ TEST_F(Rdata_AFSDB_Test, toWireRenderer) {
     renderer.clear();
 
     // construct actual data
-    Name("example.com.").toWire(obuffer);
+    renderer.writeName(Name("example.com."));
     rdata_afsdb2.toWire(renderer);
 
     // construct expected data
diff --git a/src/lib/dns/tests/rdata_cname_unittest.cc b/src/lib/dns/tests/rdata_cname_unittest.cc
index d6b02aa49b..2cce9bc849 100644
--- a/src/lib/dns/tests/rdata_cname_unittest.cc
+++ b/src/lib/dns/tests/rdata_cname_unittest.cc
@@ -97,11 +97,11 @@ TEST_F(Rdata_CNAME_Test, toWireBuffer) {
 TEST_F(Rdata_CNAME_Test, toWireRenderer) {
     rdata_cname.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_cname, sizeof(wiredata_cname));
     rdata_cname2.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_cname2, sizeof(wiredata_cname2));
 }
 
diff --git a/src/lib/dns/tests/rdata_dname_unittest.cc b/src/lib/dns/tests/rdata_dname_unittest.cc
index ebd9e0e04f..cf3001c876 100644
--- a/src/lib/dns/tests/rdata_dname_unittest.cc
+++ b/src/lib/dns/tests/rdata_dname_unittest.cc
@@ -97,11 +97,11 @@ TEST_F(Rdata_DNAME_Test, toWireBuffer) {
 TEST_F(Rdata_DNAME_Test, toWireRenderer) {
     rdata_dname.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_dname, sizeof(wiredata_dname));
     rdata_dname2.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_dname2, sizeof(wiredata_dname2));
 }
 
diff --git a/src/lib/dns/tests/rdata_dnskey_unittest.cc b/src/lib/dns/tests/rdata_dnskey_unittest.cc
index f0596ed989..86b8f69725 100644
--- a/src/lib/dns/tests/rdata_dnskey_unittest.cc
+++ b/src/lib/dns/tests/rdata_dnskey_unittest.cc
@@ -90,8 +90,8 @@ TEST_F(Rdata_DNSKEY_Test, toWireRenderer) {
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_dnskey_fromWire", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()) + 2,
-                        obuffer.getLength() - 2, &data[2], data.size() - 2);
+                        static_cast<const uint8_t *>(renderer.getData()) + 2,
+                        renderer.getLength() - 2, &data[2], data.size() - 2);
 }
 
 TEST_F(Rdata_DNSKEY_Test, toWireBuffer) {
diff --git a/src/lib/dns/tests/rdata_ds_like_unittest.cc b/src/lib/dns/tests/rdata_ds_like_unittest.cc
index 9b294460d6..6172431d77 100644
--- a/src/lib/dns/tests/rdata_ds_like_unittest.cc
+++ b/src/lib/dns/tests/rdata_ds_like_unittest.cc
@@ -115,8 +115,8 @@ TYPED_TEST(Rdata_DS_LIKE_Test, toWireRenderer) {
     UnitTestUtil::readWireData("rdata_ds_fromWire", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
                         static_cast<const uint8_t*>
-                        (this->obuffer.getData()) + 2,
-                        this->obuffer.getLength() - 2,
+                        (this->renderer.getData()) + 2,
+                        this->renderer.getLength() - 2,
                         &data[2], data.size() - 2);
 }
 
diff --git a/src/lib/dns/tests/rdata_hinfo_unittest.cc b/src/lib/dns/tests/rdata_hinfo_unittest.cc
index c52b2a05ed..c934a4ff19 100644
--- a/src/lib/dns/tests/rdata_hinfo_unittest.cc
+++ b/src/lib/dns/tests/rdata_hinfo_unittest.cc
@@ -94,8 +94,9 @@ TEST_F(Rdata_HINFO_Test, toWireRenderer) {
     HINFO hinfo(hinfo_str);
 
     hinfo.toWire(renderer);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, obuffer.getData(),
-                        obuffer.getLength(), hinfo_rdata, sizeof(hinfo_rdata));
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), hinfo_rdata,
+                        sizeof(hinfo_rdata));
 }
 
 TEST_F(Rdata_HINFO_Test, compare) {
diff --git a/src/lib/dns/tests/rdata_in_a_unittest.cc b/src/lib/dns/tests/rdata_in_a_unittest.cc
index 47e2bfa480..af4369d0bc 100644
--- a/src/lib/dns/tests/rdata_in_a_unittest.cc
+++ b/src/lib/dns/tests/rdata_in_a_unittest.cc
@@ -78,7 +78,7 @@ TEST_F(Rdata_IN_A_Test, toWireBuffer) {
 TEST_F(Rdata_IN_A_Test, toWireRenderer) {
     rdata_in_a.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_in_a, sizeof(wiredata_in_a));
 }
 
diff --git a/src/lib/dns/tests/rdata_in_aaaa_unittest.cc b/src/lib/dns/tests/rdata_in_aaaa_unittest.cc
index 6fd4d0ed61..c3e1e165a3 100644
--- a/src/lib/dns/tests/rdata_in_aaaa_unittest.cc
+++ b/src/lib/dns/tests/rdata_in_aaaa_unittest.cc
@@ -76,7 +76,7 @@ TEST_F(Rdata_IN_AAAA_Test, toWireBuffer) {
 TEST_F(Rdata_IN_AAAA_Test, toWireRenderer) {
     rdata_in_aaaa.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_in_aaaa, sizeof(wiredata_in_aaaa));
 }
 
diff --git a/src/lib/dns/tests/rdata_minfo_unittest.cc b/src/lib/dns/tests/rdata_minfo_unittest.cc
index 30c7c3945f..78e8325f1c 100644
--- a/src/lib/dns/tests/rdata_minfo_unittest.cc
+++ b/src/lib/dns/tests/rdata_minfo_unittest.cc
@@ -142,15 +142,15 @@ TEST_F(Rdata_MINFO_Test, toWireRenderer) {
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_minfo_toWire1.wire", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()),
-                        obuffer.getLength(), &data[0], data.size());
+                        static_cast<const uint8_t *>(renderer.getData()),
+                        renderer.getLength(), &data[0], data.size());
     renderer.clear();
     rdata_minfo2.toWire(renderer);
     vector<unsigned char> data2;
     UnitTestUtil::readWireData("rdata_minfo_toWire2.wire", data2);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()),
-                        obuffer.getLength(), &data2[0], data2.size());
+                        static_cast<const uint8_t *>(renderer.getData()),
+                        renderer.getLength(), &data2[0], data2.size());
 }
 
 TEST_F(Rdata_MINFO_Test, toText) {
diff --git a/src/lib/dns/tests/rdata_mx_unittest.cc b/src/lib/dns/tests/rdata_mx_unittest.cc
index c4c9757a35..36814ea1d2 100644
--- a/src/lib/dns/tests/rdata_mx_unittest.cc
+++ b/src/lib/dns/tests/rdata_mx_unittest.cc
@@ -68,12 +68,12 @@ TEST_F(Rdata_MX_Test, toWireRenderer) {
 
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_mx_toWire1", data);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, obuffer.getData(),
-                        obuffer.getLength(), &data[0], data.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &data[0], data.size());
 }
 
 TEST_F(Rdata_MX_Test, toWireBuffer) {
-    renderer.writeName(Name("example.com"));
+    Name("example.com").toWire(obuffer);
     rdata_mx.toWire(obuffer);
 
     vector<unsigned char> data;
diff --git a/src/lib/dns/tests/rdata_naptr_unittest.cc b/src/lib/dns/tests/rdata_naptr_unittest.cc
index f905943ec5..5abcaefaa2 100644
--- a/src/lib/dns/tests/rdata_naptr_unittest.cc
+++ b/src/lib/dns/tests/rdata_naptr_unittest.cc
@@ -140,8 +140,9 @@ TEST_F(Rdata_NAPTR_Test, toWireRenderer) {
     NAPTR naptr(naptr_str);
 
     naptr.toWire(renderer);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, obuffer.getData(),
-                        obuffer.getLength(), naptr_rdata, sizeof(naptr_rdata));
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), naptr_rdata,
+                        sizeof(naptr_rdata));
 }
 
 TEST_F(Rdata_NAPTR_Test, toText) {
diff --git a/src/lib/dns/tests/rdata_ns_unittest.cc b/src/lib/dns/tests/rdata_ns_unittest.cc
index b8057831b9..47582ce00f 100644
--- a/src/lib/dns/tests/rdata_ns_unittest.cc
+++ b/src/lib/dns/tests/rdata_ns_unittest.cc
@@ -96,11 +96,11 @@ TEST_F(Rdata_NS_Test, toWireBuffer) {
 TEST_F(Rdata_NS_Test, toWireRenderer) {
     rdata_ns.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_ns, sizeof(wiredata_ns));
     rdata_ns2.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_ns2, sizeof(wiredata_ns2));
 }
 
diff --git a/src/lib/dns/tests/rdata_nsec3param_like_unittest.cc b/src/lib/dns/tests/rdata_nsec3param_like_unittest.cc
index 30110df397..51fef01bf7 100644
--- a/src/lib/dns/tests/rdata_nsec3param_like_unittest.cc
+++ b/src/lib/dns/tests/rdata_nsec3param_like_unittest.cc
@@ -40,7 +40,7 @@ protected:
     NSEC3PARAMLikeTest() :
         salt_txt("1 1 1 D399EAAB" + getCommonText()),
         nosalt_txt("1 1 1 -" + getCommonText()),
-        obuffer(0), renderer(obuffer)
+        obuffer(0)
     {}
 
     RDATA_TYPE fromText(const string& rdata_text) {
diff --git a/src/lib/dns/tests/rdata_nsec3param_unittest.cc b/src/lib/dns/tests/rdata_nsec3param_unittest.cc
index 90313d0527..7558b42a74 100644
--- a/src/lib/dns/tests/rdata_nsec3param_unittest.cc
+++ b/src/lib/dns/tests/rdata_nsec3param_unittest.cc
@@ -94,8 +94,8 @@ TEST_F(Rdata_NSEC3PARAM_Test, toWireRenderer) {
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_nsec3param_fromWire1", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()) + 2,
-                        obuffer.getLength() - 2, &data[2], data.size() - 2);
+                        static_cast<const uint8_t *>(renderer.getData()) + 2,
+                        renderer.getLength() - 2, &data[2], data.size() - 2);
 }
 
 TEST_F(Rdata_NSEC3PARAM_Test, toWireBuffer) {
diff --git a/src/lib/dns/tests/rdata_nsec_unittest.cc b/src/lib/dns/tests/rdata_nsec_unittest.cc
index feb70c210d..88c6201b65 100644
--- a/src/lib/dns/tests/rdata_nsec_unittest.cc
+++ b/src/lib/dns/tests/rdata_nsec_unittest.cc
@@ -74,8 +74,8 @@ TEST_F(Rdata_NSEC_Test, toWireRenderer_NSEC) {
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_nsec_fromWire1", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()) + 2,
-                        obuffer.getLength() - 2, &data[2], data.size() - 2);
+                        static_cast<const uint8_t *>(renderer.getData()) + 2,
+                        renderer.getLength() - 2, &data[2], data.size() - 2);
 }
 
 TEST_F(Rdata_NSEC_Test, toWireBuffer_NSEC) {
diff --git a/src/lib/dns/tests/rdata_nsecbitmap_unittest.cc b/src/lib/dns/tests/rdata_nsecbitmap_unittest.cc
index 426a69e907..d7bce964d6 100644
--- a/src/lib/dns/tests/rdata_nsecbitmap_unittest.cc
+++ b/src/lib/dns/tests/rdata_nsecbitmap_unittest.cc
@@ -264,7 +264,7 @@ TEST_F(NSEC3BitmapTest, emptyMap) {
 
     // Same for MessageRenderer.
     obuffer.clear();
-    MessageRenderer renderer(obuffer);
+    MessageRenderer renderer;
     renderer.writeUint16(rdlen);
     empty_nsec3.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
diff --git a/src/lib/dns/tests/rdata_ptr_unittest.cc b/src/lib/dns/tests/rdata_ptr_unittest.cc
index 7f5de2056b..86160fbab7 100644
--- a/src/lib/dns/tests/rdata_ptr_unittest.cc
+++ b/src/lib/dns/tests/rdata_ptr_unittest.cc
@@ -100,11 +100,11 @@ TEST_F(Rdata_PTR_Test, toWireBuffer) {
 TEST_F(Rdata_PTR_Test, toWireRenderer) {
     rdata_ptr.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_ptr, sizeof(wiredata_ptr));
     rdata_ptr2.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_ptr2, sizeof(wiredata_ptr2));
 }
 
diff --git a/src/lib/dns/tests/rdata_rp_unittest.cc b/src/lib/dns/tests/rdata_rp_unittest.cc
index 07f5a932aa..20f32b9539 100644
--- a/src/lib/dns/tests/rdata_rp_unittest.cc
+++ b/src/lib/dns/tests/rdata_rp_unittest.cc
@@ -38,7 +38,7 @@ protected:
         // this also serves as a test for "from text" constructor in a normal
         // case.
         rdata_rp("root.example.com. rp-text.example.com."),
-        obuffer(0), renderer(obuffer)
+        obuffer(0)
     {}
 
     const Name mailbox_name, text_name;
diff --git a/src/lib/dns/tests/rdata_soa_unittest.cc b/src/lib/dns/tests/rdata_soa_unittest.cc
index 07c24d5074..a9d782c2be 100644
--- a/src/lib/dns/tests/rdata_soa_unittest.cc
+++ b/src/lib/dns/tests/rdata_soa_unittest.cc
@@ -56,8 +56,8 @@ TEST_F(Rdata_SOA_Test, toWireRenderer) {
     vector<unsigned char> data;
     UnitTestUtil::readWireData("rdata_soa_fromWire", data);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        static_cast<const uint8_t *>(obuffer.getData()) + 2,
-                        obuffer.getLength() - 2, &data[2], data.size() - 2);
+                        static_cast<const uint8_t *>(renderer.getData()) + 2,
+                        renderer.getLength() - 2, &data[2], data.size() - 2);
 }
 
 TEST_F(Rdata_SOA_Test, toWireBuffer) {
diff --git a/src/lib/dns/tests/rdata_srv_unittest.cc b/src/lib/dns/tests/rdata_srv_unittest.cc
index 3394f43aef..b194b1c945 100644
--- a/src/lib/dns/tests/rdata_srv_unittest.cc
+++ b/src/lib/dns/tests/rdata_srv_unittest.cc
@@ -134,12 +134,12 @@ TEST_F(Rdata_SRV_Test, toWireBuffer) {
 TEST_F(Rdata_SRV_Test, toWireRenderer) {
     rdata_srv.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_srv, sizeof(wiredata_srv));
     renderer.clear();
     rdata_srv2.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_srv2, sizeof(wiredata_srv2));
 }
 
diff --git a/src/lib/dns/tests/rdata_unittest.cc b/src/lib/dns/tests/rdata_unittest.cc
index fa791dc053..5be06e8693 100644
--- a/src/lib/dns/tests/rdata_unittest.cc
+++ b/src/lib/dns/tests/rdata_unittest.cc
@@ -38,8 +38,7 @@ namespace isc {
 namespace dns {
 namespace rdata {
 RdataTest::RdataTest() :
-    obuffer(0), renderer(obuffer),
-    rdata_nomatch(createRdata(RRType(0), RRClass(1), "\\# 0"))
+    obuffer(0), rdata_nomatch(createRdata(RRType(0), RRClass(1), "\\# 0"))
 {}
 
 RdataPtr
@@ -245,7 +244,7 @@ TEST_F(Rdata_Unknown_Test, toWireBuffer) {
 TEST_F(Rdata_Unknown_Test, toWireRenderer) {
     rdata_unknown.toWire(renderer);
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata_unknown, sizeof(wiredata_unknown));
 }
 
diff --git a/src/lib/dns/tests/rdatafields_unittest.cc b/src/lib/dns/tests/rdatafields_unittest.cc
index d6192209ff..ef83ed4b26 100644
--- a/src/lib/dns/tests/rdatafields_unittest.cc
+++ b/src/lib/dns/tests/rdatafields_unittest.cc
@@ -36,9 +36,7 @@ using isc::util::InputBuffer;
 namespace {
 class RdataFieldsTest : public ::testing::Test {
 protected:
-    RdataFieldsTest() : obuffer(0), renderer_buffer(0),
-                        renderer(renderer_buffer),
-                        ns_name("example.com"),
+    RdataFieldsTest() : obuffer(0), ns_name("example.com"),
                         other_name("www.example.com")
     {}
     void constructCommonTests(const RdataFields& fields,
@@ -49,7 +47,6 @@ protected:
     void constructCommonTestsRRSIG(const RdataFields& fields);
     void constructCommonTestsOPT(const RdataFields& fields);
     OutputBuffer obuffer;
-    OutputBuffer renderer_buffer;
     MessageRenderer renderer;
     const Name ns_name;
     const Name other_name;
diff --git a/src/lib/dns/tests/rrclass_unittest.cc b/src/lib/dns/tests/rrclass_unittest.cc
index 15f9a8c6e1..6156be5fcc 100644
--- a/src/lib/dns/tests/rrclass_unittest.cc
+++ b/src/lib/dns/tests/rrclass_unittest.cc
@@ -28,7 +28,7 @@ using namespace isc::util;
 namespace {
 class RRClassTest : public ::testing::Test {
 protected:
-    RRClassTest() : obuffer(0), renderer(obuffer) {}
+    RRClassTest() : obuffer(0) {}
 
     OutputBuffer obuffer;
     MessageRenderer renderer;
@@ -116,7 +116,7 @@ TEST_F(RRClassTest, toWireRenderer) {
     rrclass_max.toWire(renderer);
 
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata, sizeof(wiredata));
 }
 
diff --git a/src/lib/dns/tests/rrset_unittest.cc b/src/lib/dns/tests/rrset_unittest.cc
index f9513411c7..a6bfe5695b 100644
--- a/src/lib/dns/tests/rrset_unittest.cc
+++ b/src/lib/dns/tests/rrset_unittest.cc
@@ -38,7 +38,7 @@ using namespace isc::dns::rdata;
 namespace {
 class RRsetTest : public ::testing::Test {
 protected:
-    RRsetTest() : buffer(0), renderer(buffer),
+    RRsetTest() : buffer(0),
                   test_name("test.example.com"),
                   test_domain("example.com"),
                   test_nsname("ns.example.com"),
@@ -201,8 +201,8 @@ TEST_F(RRsetTest, toWireRenderer) {
     rrset_ns.toWire(renderer);
 
     UnitTestUtil::readWireData("rrset_toWire2", wiredata);
-    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, buffer.getData(),
-                        buffer.getLength(), &wiredata[0], wiredata.size());
+    EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData, renderer.getData(),
+                        renderer.getLength(), &wiredata[0], wiredata.size());
 
     // toWire() cannot be performed for an empty RRset.
     renderer.clear();
diff --git a/src/lib/dns/tests/rrttl_unittest.cc b/src/lib/dns/tests/rrttl_unittest.cc
index fe75eb62e5..1c1ae9765b 100644
--- a/src/lib/dns/tests/rrttl_unittest.cc
+++ b/src/lib/dns/tests/rrttl_unittest.cc
@@ -28,7 +28,7 @@ using namespace isc::util;
 namespace {
 class RRTTLTest : public ::testing::Test {
 protected:
-    RRTTLTest() : obuffer(0), renderer(obuffer) {}       
+    RRTTLTest() : obuffer(0) {}
 
     OutputBuffer obuffer;
     MessageRenderer renderer;
@@ -114,7 +114,7 @@ TEST_F(RRTTLTest, toWireRenderer) {
     ttl_max.toWire(renderer);
 
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata, sizeof(wiredata));
 }
 
diff --git a/src/lib/dns/tests/rrtype_unittest.cc b/src/lib/dns/tests/rrtype_unittest.cc
index 12f6001f92..28ecee65d4 100644
--- a/src/lib/dns/tests/rrtype_unittest.cc
+++ b/src/lib/dns/tests/rrtype_unittest.cc
@@ -28,7 +28,7 @@ using namespace isc::util;
 namespace {
 class RRTypeTest : public ::testing::Test {
 protected:
-    RRTypeTest() : obuffer(0), renderer(obuffer) {}
+    RRTypeTest() : obuffer(0) {}
 
     OutputBuffer obuffer;
     MessageRenderer renderer;
@@ -120,7 +120,7 @@ TEST_F(RRTypeTest, toWireRenderer) {
     rrtype_max.toWire(renderer);
 
     EXPECT_PRED_FORMAT4(UnitTestUtil::matchWireData,
-                        obuffer.getData(), obuffer.getLength(),
+                        renderer.getData(), renderer.getLength(),
                         wiredata, sizeof(wiredata));
 }
 
diff --git a/src/lib/dns/tests/tsig_unittest.cc b/src/lib/dns/tests/tsig_unittest.cc
index 7944b2939e..ac503e50d8 100644
--- a/src/lib/dns/tests/tsig_unittest.cc
+++ b/src/lib/dns/tests/tsig_unittest.cc
@@ -71,7 +71,7 @@ protected:
     TSIGTest() :
         tsig_ctx(NULL), qid(0x2d65), test_name("www.example.com"),
         badkey_name("badkey.example.com"), test_class(RRClass::IN()),
-        test_ttl(86400), message(Message::RENDER), buffer(0), renderer(buffer),
+        test_ttl(86400), message(Message::RENDER),
         dummy_data(1024, 0xdd),  // should be sufficiently large for all tests
         dummy_record(badkey_name, any::TSIG(TSIGKey::HMACMD5_NAME(),
                                             0x4da8877a,
@@ -125,7 +125,6 @@ protected:
     const RRClass test_class;
     const RRTTL test_ttl;
     Message message;
-    OutputBuffer buffer;
     MessageRenderer renderer;
     vector<uint8_t> secret;
     vector<uint8_t> dummy_data;
diff --git a/src/lib/dns/tests/tsigrecord_unittest.cc b/src/lib/dns/tests/tsigrecord_unittest.cc
index e1b3e9318c..532681ac2d 100644
--- a/src/lib/dns/tests/tsigrecord_unittest.cc
+++ b/src/lib/dns/tests/tsigrecord_unittest.cc
@@ -46,7 +46,7 @@ protected:
                              test_mac.size(), &test_mac[0],
                              0x2d65, 0, 0, NULL)),
         test_record(test_name, test_rdata),
-        buffer(0), renderer(buffer)
+        buffer(0)
     {}
     const Name test_name;
     vector<unsigned char> test_mac;