Delete osp_base and move files to new homes

This patch is the second and major patch in the process of removing the
osp_base folder from Open Screen. Based on the design plan here:

https://docs.google.com/document/d/1LGV8tXdDeIH38MYlNF2XJNG49pec-64nWkS0jjnJNk4/edit#heading=h.ny8tc2v4ek9m

This patch moves most of the files in osp_base to new homes in platform,
excepting files that have been moved to the new util/ folder.

Change-Id: I6e5f1d13cf20806bcc41185a842eb0b293606306
Reviewed-on: https://chromium-review.googlesource.com/c/openscreen/+/1695736
Reviewed-by: Jordan Bayles <jophba@chromium.org>
Reviewed-by: mark a. foltz <mfoltz@chromium.org>
Commit-Queue: Jordan Bayles <jophba@chromium.org>

7 files changed, 246 insertions, 0 deletions

diff --git a/util/json/DEPS b/util/json/DEPS
new file mode 100644
index 00000000..2defcf11
--- /dev/null
+++ b/util/json/DEPS
@@ -0,0 +1,8 @@
+# Copyright  2019 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_rules = [
+    '+platform/api',
+    '+json'
+]
diff --git a/util/json/json_reader.cc b/util/json/json_reader.cc
new file mode 100644
index 00000000..a128a367
--- /dev/null
+++ b/util/json/json_reader.cc
@@ -0,0 +1,40 @@
+// Copyright 2019 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 "util/json/json_reader.h"
+
+#include <memory>
+#include <string>
+
+#include "json/value.h"
+#include "platform/api/logging.h"
+#include "platform/base/error.h"
+
+namespace openscreen {
+namespace {
+// A reasonable maximum stack depth, may need to adjust as needs change.
+constexpr int kMaxStackDepth = 64;
+}  // namespace
+
+JsonReader::JsonReader() {
+  builder_["stackLimit"] = kMaxStackDepth;
+}
+
+ErrorOr<Json::Value> JsonReader::Read(absl::string_view document) {
+  if (document.empty()) {
+    return ErrorOr<Json::Value>(Error::Code::kJsonParseError, "empty document");
+  }
+
+  Json::Value root_node;
+  std::string error_msg;
+  std::unique_ptr<Json::CharReader> reader(builder_.newCharReader());
+  const bool succeeded =
+      reader->parse(document.begin(), document.end(), &root_node, &error_msg);
+  if (!succeeded) {
+    return ErrorOr<Json::Value>(Error::Code::kJsonParseError, error_msg);
+  }
+
+  return root_node;
+}
+}  // namespace openscreen
diff --git a/util/json/json_reader.h b/util/json/json_reader.h
new file mode 100644
index 00000000..cb7cded0
--- /dev/null
+++ b/util/json/json_reader.h
@@ -0,0 +1,33 @@
+// Copyright 2019 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.
+
+#ifndef UTIL_JSON_JSON_READER_H_
+#define UTIL_JSON_JSON_READER_H_
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "json/reader.h"
+
+namespace Json {
+class Value;
+}
+
+namespace openscreen {
+template <typename T>
+class ErrorOr;
+
+class JsonReader {
+ public:
+  JsonReader();
+
+  ErrorOr<Json::Value> Read(absl::string_view document);
+
+ private:
+  Json::CharReaderBuilder builder_;
+};
+
+}  // namespace openscreen
+
+#endif  // UTIL_JSON_JSON_READER_H_
\ No newline at end of file
diff --git a/util/json/json_reader_unittest.cc b/util/json/json_reader_unittest.cc
new file mode 100644
index 00000000..b94cca13
--- /dev/null
+++ b/util/json/json_reader_unittest.cc
@@ -0,0 +1,53 @@
+// Copyright 2019 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 "util/json/json_reader.h"
+
+#include <string>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "platform/base/error.h"
+
+namespace openscreen {
+namespace {
+template <typename Value>
+void AssertError(ErrorOr<Value> error_or, Error::Code code) {
+  EXPECT_EQ(error_or.error().code(), code);
+}
+}  // namespace
+
+TEST(JsonReaderTest, MalformedDocumentReturnsParseError) {
+  JsonReader reader;
+
+  const std::array<std::string, 4> kMalformedDocuments{
+      {"", "{", "{ foo: bar }", R"({"foo": "bar", "foo": baz})"}};
+
+  for (auto& document : kMalformedDocuments) {
+    AssertError(reader.Read(document), Error::Code::kJsonParseError);
+  }
+}
+
+TEST(JsonReaderTest, ValidEmptyDocumentParsedCorrectly) {
+  JsonReader reader;
+
+  const auto actual = reader.Read("{}");
+
+  EXPECT_TRUE(actual.is_value());
+  EXPECT_EQ(actual.value().getMemberNames().size(), 0);
+}
+
+// Jsoncpp has its own suite of tests ensure that things are parsed correctly,
+// so we only do some rudimentary checks here to make sure we didn't mangle
+// the value.
+TEST(JsonReaderTest, ValidDocumentParsedCorrectly) {
+  JsonReader reader;
+
+  const auto actual = reader.Read(R"({"foo": "bar", "baz": 1337})");
+
+  EXPECT_TRUE(actual.is_value());
+  EXPECT_EQ(actual.value().getMemberNames().size(), 2);
+}
+
+}  // namespace openscreen
diff --git a/util/json/json_writer.cc b/util/json/json_writer.cc
new file mode 100644
index 00000000..c2d01521
--- /dev/null
+++ b/util/json/json_writer.cc
@@ -0,0 +1,46 @@
+// Copyright 2019 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 "util/json/json_writer.h"
+
+#include <memory>
+#include <sstream>
+#include <string>
+#include <utility>
+
+#include "json/value.h"
+#include "platform/api/logging.h"
+#include "platform/base/error.h"
+
+namespace openscreen {
+JsonWriter::JsonWriter() {
+#ifndef _DEBUG
+  // Default is to "pretty print" the output JSON in a human readable
+  // format. On non-debug builds, we can remove pretty printing by simply
+  // getting rid of all indentation.
+  factory_["indentation"] = "";
+#endif
+}
+
+ErrorOr<std::string> JsonWriter::Write(const Json::Value& value) {
+  if (value.empty()) {
+    return ErrorOr<std::string>(Error::Code::kJsonWriteError, "Empty value");
+  }
+
+  std::unique_ptr<Json::StreamWriter> const writer(factory_.newStreamWriter());
+  std::stringstream stream;
+  writer->write(value, &stream);
+  stream << std::endl;
+
+  if (!stream) {
+    // Note: jsoncpp doesn't give us more information about what actually
+    // went wrong, just says to "check the stream". However, failures on
+    // the stream should be rare, as we do not throw any errors in the jsoncpp
+    // library.
+    return ErrorOr<std::string>(Error::Code::kJsonWriteError, "Invalid stream");
+  }
+
+  return stream.str();
+}
+}  // namespace openscreen
diff --git a/util/json/json_writer.h b/util/json/json_writer.h
new file mode 100644
index 00000000..df37d9a0
--- /dev/null
+++ b/util/json/json_writer.h
@@ -0,0 +1,34 @@
+// Copyright 2019 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.
+
+#ifndef UTIL_JSON_JSON_WRITER_H_
+#define UTIL_JSON_JSON_WRITER_H_
+
+#include <memory>
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "json/writer.h"
+
+namespace Json {
+class Value;
+}
+
+namespace openscreen {
+template <typename T>
+class ErrorOr;
+
+class JsonWriter {
+ public:
+  JsonWriter();
+
+  ErrorOr<std::string> Write(const Json::Value& value);
+
+ private:
+  Json::StreamWriterBuilder factory_;
+};
+
+}  // namespace openscreen
+
+#endif  // UTIL_JSON_JSON_WRITER_H_
diff --git a/util/json/json_writer_unittest.cc b/util/json/json_writer_unittest.cc
new file mode 100644
index 00000000..8b75c82e
--- /dev/null
+++ b/util/json/json_writer_unittest.cc
@@ -0,0 +1,32 @@
+// Copyright 2019 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 "util/json/json_writer.h"
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "platform/base/error.h"
+
+namespace openscreen {
+
+TEST(JsonWriterTest, NullValueReturnsError) {
+  JsonWriter writer;
+
+  const auto null_value = Json::Value();
+  const auto actual = writer.Write(null_value);
+
+  EXPECT_TRUE(actual.is_error());
+  EXPECT_EQ(actual.error().code(), Error::Code::kJsonWriteError);
+}
+
+TEST(JsonWriterTest, ValidValueReturnsString) {
+  JsonWriter writer;
+
+  const Json::Int64 value = 31337;
+  const auto actual = writer.Write(value);
+
+  EXPECT_TRUE(actual.is_value());
+  EXPECT_EQ(actual.value(), "31337\n");
+}
+}  // namespace openscreen