3 files changed, 162 insertions, 0 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 8a6170257..13277a5c2 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -35,6 +35,7 @@ set(SRCS
             memory_util.cpp
             microprofile.cpp
             misc.cpp
+            param_package.cpp
             scm_rev.cpp
             string_util.cpp
             symbols.cpp
@@ -66,6 +67,7 @@ set(HEADERS
             memory_util.h
             microprofile.h
             microprofileui.h
+            param_package.h
             platform.h
             quaternion.h
             scm_rev.h
diff --git a/src/common/param_package.cpp b/src/common/param_package.cpp
new file mode 100644
index 000000000..3a6ef8c27
--- /dev/null
+++ b/src/common/param_package.cpp
@@ -0,0 +1,120 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <vector>
+#include "common/logging/log.h"
+#include "common/param_package.h"
+#include "common/string_util.h"
+
+namespace Common {
+
+constexpr char KEY_VALUE_SEPARATOR = ':';
+constexpr char PARAM_SEPARATOR = ',';
+constexpr char ESCAPE_CHARACTER = '$';
+const std::string KEY_VALUE_SEPARATOR_ESCAPE{ESCAPE_CHARACTER, '0'};
+const std::string PARAM_SEPARATOR_ESCAPE{ESCAPE_CHARACTER, '1'};
+const std::string ESCAPE_CHARACTER_ESCAPE{ESCAPE_CHARACTER, '2'};
+
+ParamPackage::ParamPackage(const std::string& serialized) {
+    std::vector<std::string> pairs;
+    Common::SplitString(serialized, PARAM_SEPARATOR, pairs);
+
+    for (const std::string& pair : pairs) {
+        std::vector<std::string> key_value;
+        Common::SplitString(pair, KEY_VALUE_SEPARATOR, key_value);
+        if (key_value.size() != 2) {
+            LOG_ERROR(Common, "invalid key pair %s", pair.c_str());
+            continue;
+        }
+
+        for (std::string& part : key_value) {
+            part = Common::ReplaceAll(part, KEY_VALUE_SEPARATOR_ESCAPE, {KEY_VALUE_SEPARATOR});
+            part = Common::ReplaceAll(part, PARAM_SEPARATOR_ESCAPE, {PARAM_SEPARATOR});
+            part = Common::ReplaceAll(part, ESCAPE_CHARACTER_ESCAPE, {ESCAPE_CHARACTER});
+        }
+
+        Set(key_value[0], key_value[1]);
+    }
+}
+
+ParamPackage::ParamPackage(std::initializer_list<DataType::value_type> list) : data(list) {}
+
+std::string ParamPackage::Serialize() const {
+    if (data.empty())
+        return "";
+
+    std::string result;
+
+    for (const auto& pair : data) {
+        std::array<std::string, 2> key_value{{pair.first, pair.second}};
+        for (std::string& part : key_value) {
+            part = Common::ReplaceAll(part, {ESCAPE_CHARACTER}, ESCAPE_CHARACTER_ESCAPE);
+            part = Common::ReplaceAll(part, {PARAM_SEPARATOR}, PARAM_SEPARATOR_ESCAPE);
+            part = Common::ReplaceAll(part, {KEY_VALUE_SEPARATOR}, KEY_VALUE_SEPARATOR_ESCAPE);
+        }
+        result += key_value[0] + KEY_VALUE_SEPARATOR + key_value[1] + PARAM_SEPARATOR;
+    }
+
+    result.pop_back(); // discard the trailing PARAM_SEPARATOR
+    return result;
+}
+
+std::string ParamPackage::Get(const std::string& key, const std::string& default_value) const {
+    auto pair = data.find(key);
+    if (pair == data.end()) {
+        LOG_DEBUG(Common, "key %s not found", key.c_str());
+        return default_value;
+    }
+
+    return pair->second;
+}
+
+int ParamPackage::Get(const std::string& key, int default_value) const {
+    auto pair = data.find(key);
+    if (pair == data.end()) {
+        LOG_DEBUG(Common, "key %s not found", key.c_str());
+        return default_value;
+    }
+
+    try {
+        return std::stoi(pair->second);
+    } catch (const std::logic_error&) {
+        LOG_ERROR(Common, "failed to convert %s to int", pair->second.c_str());
+        return default_value;
+    }
+}
+
+float ParamPackage::Get(const std::string& key, float default_value) const {
+    auto pair = data.find(key);
+    if (pair == data.end()) {
+        LOG_DEBUG(Common, "key %s not found", key.c_str());
+        return default_value;
+    }
+
+    try {
+        return std::stof(pair->second);
+    } catch (const std::logic_error&) {
+        LOG_ERROR(Common, "failed to convert %s to float", pair->second.c_str());
+        return default_value;
+    }
+}
+
+void ParamPackage::Set(const std::string& key, const std::string& value) {
+    data[key] = value;
+}
+
+void ParamPackage::Set(const std::string& key, int value) {
+    data[key] = std::to_string(value);
+}
+
+void ParamPackage::Set(const std::string& key, float value) {
+    data[key] = std::to_string(value);
+}
+
+bool ParamPackage::Has(const std::string& key) const {
+    return data.find(key) != data.end();
+}
+
+} // namespace Common
diff --git a/src/common/param_package.h b/src/common/param_package.h
new file mode 100644
index 000000000..c4c11b221
--- /dev/null
+++ b/src/common/param_package.h
@@ -0,0 +1,40 @@
+// Copyright 2017 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <initializer_list>
+#include <string>
+#include <unordered_map>
+
+namespace Common {
+
+/// A string-based key-value container supporting serializing to and deserializing from a string
+class ParamPackage {
+public:
+    using DataType = std::unordered_map<std::string, std::string>;
+
+    ParamPackage() = default;
+    explicit ParamPackage(const std::string& serialized);
+    ParamPackage(std::initializer_list<DataType::value_type> list);
+    ParamPackage(const ParamPackage& other) = default;
+    ParamPackage(ParamPackage&& other) = default;
+
+    ParamPackage& operator=(const ParamPackage& other) = default;
+    ParamPackage& operator=(ParamPackage&& other) = default;
+
+    std::string Serialize() const;
+    std::string Get(const std::string& key, const std::string& default_value) const;
+    int Get(const std::string& key, int default_value) const;
+    float Get(const std::string& key, float default_value) const;
+    void Set(const std::string& key, const std::string& value);
+    void Set(const std::string& key, int value);
+    void Set(const std::string& key, float value);
+    bool Has(const std::string& key) const;
+
+private:
+    DataType data;
+};
+
+} // namespace Common