Blimp: add packet-level DEFLATE compression using zlib.

blimp/net/compressed_packet_unittest.cc

Index: blimp/net/compressed_packet_unittest.cc
diff --git a/blimp/net/compressed_packet_unittest.cc b/blimp/net/compressed_packet_unittest.cc
new file mode 100644
index 0000000000000000000000000000000000000000..36a6b1fff72ac0fe090dca7543852b25fc6561d1
--- /dev/null
+++ b/blimp/net/compressed_packet_unittest.cc
@@ -0,0 +1,216 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/sys_byteorder.h"
+#include "blimp/net/common.h"
+#include "blimp/net/compressed_packet_reader.h"
+#include "blimp/net/compressed_packet_writer.h"
+#include "blimp/net/test_common.h"
+#include "net/base/test_completion_callback.h"
+#include "testing/gmock/include/gmock/gmock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+using testing::_;
+using testing::DoAll;
+using testing::InvokeArgument;
+using testing::SaveArg;
+
+namespace blimp {
+namespace {
+
+// Calls the CompletionCallback (indicated by the 0-based index cb_idx)
+// with the value |result|.
+ACTION_TEMPLATE(InvokeCompletionCallback,
+                HAS_1_TEMPLATE_PARAMS(int, cb_idx),
+                AND_1_VALUE_PARAMS(result)) {
+  testing::get<cb_idx>(args).Run(result);
+}
+
+// Copies a DrainableIOBuffer to a GrowableIOBuffer.
+// |dest_buf_idx|: The 0-based index of a GrowableIOBuffer.
+// |src_buf|: A DrainableIOBuffer.
+ACTION_TEMPLATE(CopyBuffer,
+                HAS_1_TEMPLATE_PARAMS(int, dest_buf_idx),
+                AND_1_VALUE_PARAMS(src_buf)) {
+  const auto& dest_buf = testing::get<dest_buf_idx>(args);
+  ASSERT_TRUE(dest_buf);
+  ASSERT_TRUE(src_buf);
+  ASSERT_EQ(0, dest_buf->offset());
+  src_buf->SetOffset(0);
+  dest_buf->SetCapacity(src_buf->BytesRemaining());
+  memcpy(dest_buf->data(), src_buf->data(), src_buf->BytesRemaining());
+}
+
+class CompressedPacketTest : public testing::Test {
+ public:
+  CompressedPacketTest()
+      : mock_reader_(new MockPacketReader),
+        mock_writer_(new MockPacketWriter),
+        compressed_reader_(
+            new CompressedPacketReader(make_scoped_ptr(mock_reader_))),
+        compressed_writer_(
+            new CompressedPacketWriter(make_scoped_ptr(mock_writer_))) {}
+  ~CompressedPacketTest() override {}
+
+ protected:
+  // Returns the compressed result of |content|.
+  std::string Compress(const std::string& content) {
+    scoped_refptr<net::StringIOBuffer> content_str_buf(
+        new net::StringIOBuffer(content));
+    scoped_refptr<net::DrainableIOBuffer> content_buf(
+        new net::DrainableIOBuffer(content_str_buf.get(),
+                                   content_str_buf->size()));
+    scoped_refptr<net::DrainableIOBuffer> compressed_buf;
+    EXPECT_CALL(*mock_writer_, WritePacket(_, _))
+        .WillOnce(DoAll(SaveArg<0>(&compressed_buf),
+                        InvokeCompletionCallback<1>(net::OK)));
+    net::TestCompletionCallback completion_cb_1;
+    compressed_writer_->WritePacket(content_buf, completion_cb_1.callback());
+    EXPECT_EQ(net::OK, completion_cb_1.WaitForResult());
+    return std::string(compressed_buf->data(),
+                       compressed_buf->BytesRemaining());
+  }
+
+  // Returns the decompressed result of |compressed|.
+  std::string Decompress(const std::string& compressed) {
+    scoped_refptr<net::StringIOBuffer> compressed_str_buf(
+        new net::StringIOBuffer(compressed));
+    scoped_refptr<net::DrainableIOBuffer> compressed_buf(
+        new net::DrainableIOBuffer(compressed_str_buf.get(),
+                                   compressed_str_buf->size()));
+    scoped_refptr<net::GrowableIOBuffer> decompressed_buf(
+        new net::GrowableIOBuffer);
+    EXPECT_CALL(*mock_reader_, ReadPacket(_, _))
+        .WillOnce(DoAll(
+            CopyBuffer<0>(compressed_buf),
+            InvokeCompletionCallback<1>(compressed_buf->BytesRemaining())));
+    net::TestCompletionCallback completion_cb_2;
+    compressed_reader_->ReadPacket(decompressed_buf,
+                                   completion_cb_2.callback());
+    int size = completion_cb_2.WaitForResult();
+    return std::string(decompressed_buf->data(), size);
+  }
+
+  bool CheckRoundTrip(const std::string& content) {
+    return Decompress(Compress(content)) == content;
+  }
+
+  MockPacketReader* mock_reader_;
+  MockPacketWriter* mock_writer_;
+  scoped_ptr<CompressedPacketReader> compressed_reader_;
+  scoped_ptr<CompressedPacketWriter> compressed_writer_;
+  testing::InSequence s;
+};
+
+TEST_F(CompressedPacketTest, Empty) {
+  EXPECT_TRUE(CheckRoundTrip("1234"));
+  EXPECT_TRUE(CheckRoundTrip(""));
+  EXPECT_TRUE(CheckRoundTrip("1234"));
+}
+
+TEST_F(CompressedPacketTest, Simple) {
+  std::string source = "AAAAAAAAAAAAAAAAAAAAAAAAA";
+  std::string compressed = Compress(source);
+  std::string decompressed = Decompress(compressed);
+  EXPECT_GT(source.size(), compressed.size());
+  EXPECT_EQ(source, decompressed);
+}
+
+TEST_F(CompressedPacketTest, DisjointSequences) {
+  EXPECT_TRUE(CheckRoundTrip("1234"));
+  EXPECT_TRUE(CheckRoundTrip("5678"));
+  EXPECT_TRUE(CheckRoundTrip("ABCD"));
+}
+
+TEST_F(CompressedPacketTest, AdditiveSequences) {
+  EXPECT_TRUE(CheckRoundTrip("12"));
+  EXPECT_TRUE(CheckRoundTrip("123"));
+  EXPECT_TRUE(CheckRoundTrip("1234"));
+  EXPECT_TRUE(CheckRoundTrip("12345"));
+  EXPECT_TRUE(CheckRoundTrip("123456"));
+}
+
+TEST_F(CompressedPacketTest, ReversedSequences) {
+  EXPECT_TRUE(CheckRoundTrip("123456"));
+  EXPECT_TRUE(CheckRoundTrip("12345"));
+  EXPECT_TRUE(CheckRoundTrip("1234"));
+  EXPECT_TRUE(CheckRoundTrip("123"));
+  EXPECT_TRUE(CheckRoundTrip("12"));
+}
+
+TEST_F(CompressedPacketTest, CompressionStateRetainedAcrossCalls) {
+  // Ensure that a character sequence is encoded in a more compact manner
+  // if it is compressed more than once.
+  int size_1 = Compress("1234").size();
+  int size_2 = Compress("1234").size();
+  EXPECT_GT(size_1, size_2);
+}
+
+TEST_F(CompressedPacketTest, LargeInput) {
+  std::string big_str(kMaxPacketPayloadSizeBytes, 'A');  // 3MB of A's.
+  EXPECT_TRUE(CheckRoundTrip(big_str));
+}
+
+TEST_F(CompressedPacketTest, DecompressIllegallyLargePayload) {
+  // We can't use the compressor to compress an illegally sized payload, however
+  // we can concatenate the output of smaller payloads to form an uber-payload.
+  std::string huge_block =
+      Compress(std::string(kMaxPacketPayloadSizeBytes, 'A')) +
+      Compress("1337 payl0ad 0verfl0w 'spl0it");
+
+  scoped_refptr<net::StringIOBuffer> compressed_str_buf(
+      new net::StringIOBuffer(huge_block));
+  scoped_refptr<net::DrainableIOBuffer> compressed_buf(
+      new net::DrainableIOBuffer(compressed_str_buf.get(),
+                                 compressed_str_buf->size()));
+  scoped_refptr<net::GrowableIOBuffer> decompressed_buf(
+      new net::GrowableIOBuffer);
+  EXPECT_CALL(*mock_reader_, ReadPacket(_, _))
+      .WillOnce(
+          DoAll(CopyBuffer<0>(compressed_buf),
+                InvokeCompletionCallback<1>(compressed_buf->BytesRemaining())));
+  net::TestCompletionCallback completion_cb_2;
+  compressed_reader_->ReadPacket(decompressed_buf, completion_cb_2.callback());
+  EXPECT_EQ(net::ERR_FILE_TOO_BIG, completion_cb_2.WaitForResult());
+}
+
+TEST_F(CompressedPacketTest, CompressIllegallyLargePayload) {
+  scoped_refptr<net::IOBuffer> big_buf(
+      new net::IOBuffer(kMaxPacketPayloadSizeBytes + 1));
+  scoped_refptr<net::DrainableIOBuffer> content_buf(new net::DrainableIOBuffer(
+      big_buf.get(), kMaxPacketPayloadSizeBytes + 1));
+  net::TestCompletionCallback completion_cb_1;
+  compressed_writer_->WritePacket(content_buf, completion_cb_1.callback());
+  EXPECT_EQ(net::ERR_FILE_TOO_BIG, completion_cb_1.WaitForResult());
+}
+
+TEST_F(CompressedPacketTest, PayloadSmallerThanDeclared) {
+  scoped_refptr<net::StringIOBuffer> content_str_buf(
+      new net::StringIOBuffer("Just a small payload"));
+  scoped_refptr<net::DrainableIOBuffer> content_buf(new net::DrainableIOBuffer(
+      content_str_buf.get(), content_str_buf->size()));
+  scoped_refptr<net::DrainableIOBuffer> compressed_buf;
+  EXPECT_CALL(*mock_writer_, WritePacket(_, _))
+      .WillOnce(DoAll(SaveArg<0>(&compressed_buf),
+                      InvokeCompletionCallback<1>(net::OK)));
+  net::TestCompletionCallback completion_cb_1;
+  compressed_writer_->WritePacket(content_buf, completion_cb_1.callback());
+  EXPECT_EQ(net::OK, completion_cb_1.WaitForResult());
+
+  // Increase the payload size header significantly.
+  *(reinterpret_cast<uint32_t*>(compressed_buf->data())) =
+      base::HostToNet32(kMaxPacketPayloadSizeBytes - 1);
+
+  EXPECT_CALL(*mock_reader_, ReadPacket(_, _))
+      .WillOnce(
+          DoAll(CopyBuffer<0>(compressed_buf),
+                InvokeCompletionCallback<1>(compressed_buf->BytesRemaining())));
+  net::TestCompletionCallback completion_cb_2;
+  compressed_reader_->ReadPacket(make_scoped_refptr(new net::GrowableIOBuffer),
+                                 completion_cb_2.callback());
+  EXPECT_EQ(net::ERR_UNEXPECTED, completion_cb_2.WaitForResult());
+}
+
+}  // namespace
+}  // namespace blimp