AU: Bzip2 utility functions that mirror Gzip utility functions.

Also, Convert the gzip_unittest into a typed test and use the same
test cases for bzip2.

Review URL: http://codereview.chromium.org/855002
diff --git a/SConstruct b/SConstruct
index e27871a..8854abc 100644
--- a/SConstruct
+++ b/SConstruct
@@ -85,6 +85,7 @@
 
 
 sources = Split("""action_processor.cc
+                   bzip.cc
                    bzip_extent_writer.cc
                    cycle_breaker.cc
                    decompressing_file_writer.cc
@@ -125,7 +126,6 @@
                             filesystem_copier_action_unittest.cc
                             filesystem_iterator_unittest.cc
                             graph_utils_unittest.cc
-                            gzip_unittest.cc
                             http_fetcher_unittest.cc
                             mock_http_fetcher.cc
                             omaha_hash_calculator_unittest.cc
@@ -138,7 +138,8 @@
                             test_utils.cc
                             topological_sort_unittest.cc
                             update_check_action_unittest.cc
-                            utils_unittest.cc""")
+                            utils_unittest.cc
+                            zip_unittest.cc""")
 unittest_main = ['testrunner.cc']
 
 delta_generator_sources = Split("""delta_diff_generator.cc""")
diff --git a/bzip.cc b/bzip.cc
new file mode 100644
index 0000000..4a41980
--- /dev/null
+++ b/bzip.cc
@@ -0,0 +1,116 @@
+// Copyright (c) 2010 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 "update_engine/gzip.h"
+#include <stdlib.h>
+#include <algorithm>
+#include <bzlib.h>
+#include "update_engine/utils.h"
+
+using std::max;
+using std::string;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+namespace {
+
+// BzipData compresses or decompresses the input to the output.
+// Returns true on success.
+// Use one of BzipBuffToBuff*ompress as the template parameter to BzipData().
+int BzipBuffToBuffDecompress(char* out,
+                             size_t* out_length,
+                             const char* in,
+                             size_t in_length) {
+  return BZ2_bzBuffToBuffDecompress(out,
+                                    out_length,
+                                    const_cast<char*>(in),
+                                    in_length,
+                                    0,  // Silent verbosity
+                                    0);  // Normal algorithm
+}
+
+int BzipBuffToBuffCompress(char* out,
+                           size_t* out_length,
+                           const char* in,
+                           size_t in_length) {
+  return BZ2_bzBuffToBuffCompress(out,
+                                  out_length,
+                                  const_cast<char*>(in),
+                                  in_length,
+                                  9,  // Best compression
+                                  0,  // Silent verbosity
+                                  0);  // Default work factor
+}
+
+template<int F(char* out,
+               size_t* out_length,
+               const char* in,
+               size_t in_length)>
+bool BzipData(const char* const in,
+              const size_t in_size,
+              vector<char>* const out) {
+  TEST_AND_RETURN_FALSE(out);
+  out->clear();
+  if (in_size == 0) {
+    return true;
+  }
+  // Try increasing buffer size until it works
+  size_t buf_size = in_size;
+  out->resize(buf_size);
+  
+  for (;;) {
+    size_t data_size = buf_size;
+    int rc = F(&(*out)[0], &data_size, in, in_size);
+    TEST_AND_RETURN_FALSE(rc == BZ_OUTBUFF_FULL || rc == BZ_OK);
+    if (rc == BZ_OK) {
+      // we're done!
+      out->resize(data_size);
+      return true;
+    }
+    
+    // Data didn't fit; double the buffer size.
+    buf_size *= 2;
+    out->resize(buf_size);
+  }
+}
+
+}  // namespace {}
+
+bool BzipDecompress(const std::vector<char>& in, std::vector<char>* out) {
+  return BzipData<BzipBuffToBuffDecompress>(&in[0], in.size(), out);
+}
+
+bool BzipCompress(const std::vector<char>& in, std::vector<char>* out) {
+  return BzipData<BzipBuffToBuffCompress>(&in[0], in.size(), out);
+}
+
+namespace {
+template<bool F(const char* const in,
+                const size_t in_size,
+                vector<char>* const out)>
+bool BzipString(const std::string& str,
+                std::vector<char>* out) {
+  TEST_AND_RETURN_FALSE(out);
+  vector<char> temp;
+  TEST_AND_RETURN_FALSE(F(str.data(),
+                          str.size(),
+                          &temp));
+  out->clear();
+  out->insert(out->end(), temp.begin(), temp.end());
+  return true;
+}
+}  // namespace {}
+
+bool BzipCompressString(const std::string& str,
+                        std::vector<char>* out) {
+  return BzipString<BzipData<BzipBuffToBuffCompress> >(str, out);
+}
+
+bool BzipDecompressString(const std::string& str,
+                          std::vector<char>* out) {
+  return BzipString<BzipData<BzipBuffToBuffDecompress> >(str, out);
+}
+
+} // namespace chromeos_update_engine
diff --git a/bzip.h b/bzip.h
new file mode 100644
index 0000000..ca6e881
--- /dev/null
+++ b/bzip.h
@@ -0,0 +1,16 @@
+// Copyright (c) 2010 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 <string>
+#include <vector>
+
+namespace chromeos_update_engine {
+
+// Bzip2 compresses or decompresses str/in to out.
+bool BzipDecompress(const std::vector<char>& in, std::vector<char>* out);
+bool BzipCompress(const std::vector<char>& in, std::vector<char>* out);
+bool BzipCompressString(const std::string& str, std::vector<char>* out);
+bool BzipDecompressString(const std::string& str, std::vector<char>* out);
+
+}  // namespace chromeos_update_engine
diff --git a/gzip_unittest.cc b/gzip_unittest.cc
deleted file mode 100644
index 298ca9d..0000000
--- a/gzip_unittest.cc
+++ /dev/null
@@ -1,68 +0,0 @@
-// Copyright (c) 2009 The Chromium OS 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 <string.h>
-#include <unistd.h>
-#include <string>
-#include <vector>
-#include <gtest/gtest.h>
-#include "update_engine/gzip.h"
-#include "update_engine/test_utils.h"
-#include "update_engine/utils.h"
-
-using std::string;
-using std::vector;
-
-namespace chromeos_update_engine {
-
-class GzipTest : public ::testing::Test { };
-
-TEST(GzipTest, SimpleTest) {
-  string in("this should compress well xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
-            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
-  vector<char> out;
-  EXPECT_TRUE(GzipCompressString(in, &out));
-  EXPECT_LT(out.size(), in.size());
-  EXPECT_GT(out.size(), 0);
-  vector<char> decompressed;
-  EXPECT_TRUE(GzipDecompress(out, &decompressed));
-  EXPECT_EQ(in.size(), decompressed.size());
-  EXPECT_TRUE(!memcmp(in.data(), &decompressed[0], in.size()));
-}
-
-TEST(GzipTest, PoorCompressionTest) {
-  string in(reinterpret_cast<const char*>(kRandomString),
-            sizeof(kRandomString));
-  vector<char> out;
-  EXPECT_TRUE(GzipCompressString(in, &out));
-  EXPECT_GT(out.size(), in.size());
-  string out_string(&out[0], out.size());
-  vector<char> decompressed;
-  EXPECT_TRUE(GzipDecompressString(out_string, &decompressed));
-  EXPECT_EQ(in.size(), decompressed.size());
-  EXPECT_TRUE(!memcmp(in.data(), &decompressed[0], in.size()));
-}
-
-TEST(GzipTest, MalformedGzipTest) {
-  string in(reinterpret_cast<const char*>(kRandomString),
-            sizeof(kRandomString));
-  vector<char> out;
-  EXPECT_FALSE(GzipDecompressString(in, &out));
-}
-
-TEST(GzipTest, EmptyInputsTest) {
-  string in;
-  vector<char> out;
-  EXPECT_TRUE(GzipDecompressString(in, &out));
-  EXPECT_EQ(0, out.size());
-
-  EXPECT_TRUE(GzipCompressString(in, &out));
-  EXPECT_EQ(0, out.size());
-}
-
-}  // namespace chromeos_update_engine
diff --git a/zip_unittest.cc b/zip_unittest.cc
new file mode 100644
index 0000000..72bd7f3
--- /dev/null
+++ b/zip_unittest.cc
@@ -0,0 +1,132 @@
+// Copyright (c) 2009 The Chromium OS 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 <string.h>
+#include <unistd.h>
+#include <string>
+#include <vector>
+#include <gtest/gtest.h>
+#include "update_engine/bzip.h"
+#include "update_engine/gzip.h"
+#include "update_engine/test_utils.h"
+#include "update_engine/utils.h"
+
+using std::string;
+using std::vector;
+
+namespace chromeos_update_engine {
+
+template <typename T>
+class ZipTest : public ::testing::Test {
+ public:
+  bool ZipDecompress(const std::vector<char>& in,
+                     std::vector<char>* out) const = 0;
+  bool ZipCompress(const std::vector<char>& in,
+                   std::vector<char>* out) const = 0;
+  bool ZipCompressString(const std::string& str,
+                         std::vector<char>* out) const = 0;
+  bool ZipDecompressString(const std::string& str,
+                           std::vector<char>* out) const = 0;
+};
+
+class GzipTest {};
+
+template <>
+class ZipTest<GzipTest> : public ::testing::Test {
+ public:
+  bool ZipDecompress(const std::vector<char>& in,
+                     std::vector<char>* out) const {
+    return GzipDecompress(in, out);
+  }
+  bool ZipCompress(const std::vector<char>& in,
+                   std::vector<char>* out) const {
+    return GzipCompress(in, out);
+  }
+  bool ZipCompressString(const std::string& str,
+                         std::vector<char>* out) const {
+    return GzipCompressString(str, out);
+  }
+  bool ZipDecompressString(const std::string& str,
+                           std::vector<char>* out) const {
+    return GzipDecompressString(str, out);
+  }
+};
+
+class BzipTest {};
+
+template <>
+class ZipTest<BzipTest> : public ::testing::Test {
+ public:
+  bool ZipDecompress(const std::vector<char>& in,
+                     std::vector<char>* out) const {
+    return BzipDecompress(in, out);
+  }
+  bool ZipCompress(const std::vector<char>& in,
+                   std::vector<char>* out) const {
+    return BzipCompress(in, out);
+  }
+  bool ZipCompressString(const std::string& str,
+                         std::vector<char>* out) const {
+    return BzipCompressString(str, out);
+  }
+  bool ZipDecompressString(const std::string& str,
+                           std::vector<char>* out) const {
+    return BzipDecompressString(str, out);
+  }
+};
+
+typedef ::testing::Types<GzipTest, BzipTest>
+    ZipTestTypes;
+TYPED_TEST_CASE(ZipTest, ZipTestTypes);
+
+
+
+TYPED_TEST(ZipTest, SimpleTest) {
+  string in("this should compress well xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+            "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx");
+  vector<char> out;
+  EXPECT_TRUE(this->ZipCompressString(in, &out));
+  EXPECT_LT(out.size(), in.size());
+  EXPECT_GT(out.size(), 0);
+  vector<char> decompressed;
+  EXPECT_TRUE(this->ZipDecompress(out, &decompressed));
+  EXPECT_EQ(in.size(), decompressed.size());
+  EXPECT_TRUE(!memcmp(in.data(), &decompressed[0], in.size()));
+}
+
+TYPED_TEST(ZipTest, PoorCompressionTest) {
+  string in(reinterpret_cast<const char*>(kRandomString),
+            sizeof(kRandomString));
+  vector<char> out;
+  EXPECT_TRUE(this->ZipCompressString(in, &out));
+  EXPECT_GT(out.size(), in.size());
+  string out_string(&out[0], out.size());
+  vector<char> decompressed;
+  EXPECT_TRUE(this->ZipDecompressString(out_string, &decompressed));
+  EXPECT_EQ(in.size(), decompressed.size());
+  EXPECT_TRUE(!memcmp(in.data(), &decompressed[0], in.size()));
+}
+
+TYPED_TEST(ZipTest, MalformedZipTest) {
+  string in(reinterpret_cast<const char*>(kRandomString),
+            sizeof(kRandomString));
+  vector<char> out;
+  EXPECT_FALSE(this->ZipDecompressString(in, &out));
+}
+
+TYPED_TEST(ZipTest, EmptyInputsTest) {
+  string in;
+  vector<char> out;
+  EXPECT_TRUE(this->ZipDecompressString(in, &out));
+  EXPECT_EQ(0, out.size());
+
+  EXPECT_TRUE(this->ZipCompressString(in, &out));
+  EXPECT_EQ(0, out.size());
+}
+
+}  // namespace chromeos_update_engine