implemented Ptr functionality

include/hepnos/DataSet.hpp

@@ -103,6 +103,11 @@ class DataSet : public KeyValueContainer {
      */
     ~DataSet();
 
+    /**
+     * @brief Overrides getDataStore from KeyValueContainer class.
+     */
+    DataStore* getDataStore() const override;
+
     /**
      * @brief Name of the DataSet.
      *
@@ -153,10 +158,10 @@ class DataSet : public KeyValueContainer {
      * @param key Key.
      * @param buffer Binary data to insert.
      *
-     * @return true if the key did not already exist and the write succeeded,
-     *      false otherwise.
+     * @return a valid ProductID if the key did not already exist and the write succeeded,
+     *      an invalid one otherwise.
      */
-    bool storeRawData(const std::string& key, const std::vector<char>& buffer);
+    ProductID storeRawData(const std::string& key, const std::vector<char>& buffer) override;
 
     /**
      * @brief Loads binary data associated with a particular key from the DataSet.
@@ -169,7 +174,7 @@ class DataSet : public KeyValueContainer {
      * @return true if the key exists and the read succeeded,
      *      false otherwise.
      */
-    bool loadRawData(const std::string& key, std::vector<char>& buffer) const;
+    bool loadRawData(const std::string& key, std::vector<char>& buffer) const override;
 
     /**
      * @brief Comparison operator.

include/hepnos/DataStore.hpp

@@ -12,11 +12,13 @@
 
 namespace hepnos {
 
+class ProductID;
 class DataSet;
 class RunSet;
 class Run;
 class SubRun;
 class Event;
+template<typename T, typename C = std::vector<T>> class Ptr;
 
 /**
  * The DataStore class is the main handle referencing an HEPnOS service.
@@ -24,6 +26,7 @@ class Event;
  */
 class DataStore {
 
+    friend class ProductID;
     friend class DataSet;
     friend class RunSet;
     friend class Run;
@@ -246,6 +249,15 @@ class DataStore {
      */
     DataSet createDataSet(const std::string& name);
 
+    template<typename T>
+    Ptr<T> makePtr(const ProductID& productID);
+
+    template<typename T, typename C = std::vector<T>>
+    Ptr<T,C> makePtr(const ProductID& productID, std::size_t index);
+
+    template<typename T>
+    bool loadProduct(const ProductID& productID, T& t);
+
     /**
      * @brief Shuts down the HEPnOS service.
      */
@@ -258,6 +270,8 @@ class DataStore {
      */
     class Impl;
     std::unique_ptr<Impl> m_impl; /*!< Pointer to implementation */
+
+    bool loadRawProduct(const ProductID& productID, std::vector<char>& buffer);
 };
 
 class DataStore::const_iterator {
@@ -485,4 +499,38 @@ class DataStore::iterator : public DataStore::const_iterator {
 
 }
 
+#include <hepnos/ProductID.hpp>
+#include <hepnos/Ptr.hpp>
+
+namespace hepnos {
+
+template<typename T>
+Ptr<T> DataStore::makePtr(const ProductID& productID) {
+    return Ptr<T>(this, productID);
+}
+
+template<typename T, typename C = std::vector<T>>
+Ptr<T,C> DataStore::makePtr(const ProductID& productID, std::size_t index) {
+    return Ptr<T,C>(this, productID, index);
+}
+
+template<typename T>
+bool DataStore::loadProduct(const ProductID& productID, T& t) {
+    std::vector<char> buffer;
+    if(!loadRawProduct(productID, buffer)) {
+        return false;
+    }
+    std::string serialized(buffer.begin(), buffer.end());
+    std::stringstream ss(serialized);
+    InputArchive ia(this, ss);
+    try {
+        ia >> t;
+    } catch(...) {
+        throw Exception("Exception occured during serialization");
+    }
+    return true;
+}
+
+}
+
 #endif

include/hepnos/Event.hpp

@@ -8,10 +8,10 @@
 
 #include <memory>
 #include <string>
-#include <hepnos/KeyValueContainer.hpp>
 #include <hepnos/DataStore.hpp>
 #include <hepnos/EventNumber.hpp>
 #include <hepnos/Exception.hpp>
+#include <hepnos/KeyValueContainer.hpp>
 
 namespace hepnos {
 
@@ -78,6 +78,11 @@ class Event : public KeyValueContainer {
      */
     ~Event();
 
+    /**
+     * @brief Overrides getDataStore from KeyValueContainer class.
+     */
+    DataStore* getDataStore() const override;
+
     /**
      * @brief Returns the next Event in the same container,
      * sorted by event number. If no such event exists, an Event instance
@@ -102,9 +107,9 @@ class Event : public KeyValueContainer {
      * @param key Key
      * @param buffer Value
      *
-     * @return true if the key did not already exist, false otherwise.
+     * @return a valid ProductID if the key did not already exist, an invalid one otherwise.
      */
-    bool storeRawData(const std::string& key, const std::vector<char>& buffer);
+    ProductID storeRawData(const std::string& key, const std::vector<char>& buffer) override;
 
     /**
      * @brief Loads raw key/value data from this Event.
@@ -114,7 +119,7 @@ class Event : public KeyValueContainer {
      *
      * @return true if the key exists, false otherwise.
      */
-    bool loadRawData(const std::string& key, std::vector<char>& buffer) const;
+    bool loadRawData(const std::string& key, std::vector<char>& buffer) const override;
 
     /**
      * @brief Compares this Event with another Event. The Events must point to

include/hepnos/InputArchive.hpp

+/*
+ * (C) 2018 The University of Chicago
+ * 
+ * See COPYRIGHT in top-level directory.
+ */
+#ifndef __HEPNOS_INPUT_ARCHIVE_H
+#define __HEPNOS_INPUT_ARCHIVE_H
+
+#include <boost/archive/binary_iarchive.hpp>
+#include <boost/archive/impl/basic_binary_iprimitive.ipp>
+#include <boost/archive/impl/basic_binary_iarchive.ipp>
+
+namespace hepnos {
+
+class DataStore;
+class InputArchive;
+
+using iarchive = boost::archive::binary_iarchive_impl<InputArchive, std::istream::char_type, std::istream::traits_type>;
+
+/**
+ * @brief This InputArchive class derives from boost's binary input archive.
+ * It lets caller embed a pointer to the DataStore storing the object.
+ * This is necessary to deserialize Ptr instances, for example.
+ */
+class InputArchive : public iarchive {
+
+    friend class boost::archive::detail::interface_iarchive<InputArchive>;
+    friend class boost::archive::basic_binary_iarchive<InputArchive>;
+    friend class boost::archive::load_access;
+
+    private:
+
+    DataStore* m_datastore = nullptr;
+
+    public:
+
+    template<typename ... Args>
+    InputArchive(DataStore* datastore, Args&& ... args)
+    : iarchive(std::forward<Args>(args)..., 0)
+    , m_datastore(datastore) {}
+
+    DataStore* getDataStore() const {
+        return m_datastore;
+    }
+
+};
+
+}
+
+#endif

include/hepnos/KeyValueContainer.hpp

@@ -8,11 +8,12 @@
 
 #include <memory>
 #include <string>
+#include <sstream>
 #include <boost/archive/binary_oarchive.hpp>
 #include <boost/archive/binary_iarchive.hpp>
-#include <boost/archive/text_oarchive.hpp>
-#include <boost/archive/text_iarchive.hpp>
 #include <boost/serialization/string.hpp>
+#include <hepnos/InputArchive.hpp>
+#include <hepnos/ProductID.hpp>
 #include <hepnos/Demangle.hpp>
 #include <hepnos/Exception.hpp>
 
@@ -52,6 +53,13 @@ class KeyValueContainer {
      */
     virtual ~KeyValueContainer() = default;
 
+    /**
+     * @brief Gets the DataStore to which this instance of KeyValueContainer belongs.
+     *
+     * @return DataStore.
+     */
+    virtual DataStore* getDataStore() const = 0;
+
     /**
      * @brief Stores raw key/value data in this KeyValueContainer.
      * This function is virtual and must be overloaded in the child class.
@@ -59,9 +67,9 @@ class KeyValueContainer {
      * @param key Key
      * @param buffer Value
      *
-     * @return true if the key did not already exist, false otherwise.
+     * @return A valid ProductID if the key did not already exist, an invalid one otherwise.
      */
-    virtual bool storeRawData(const std::string& key, const std::vector<char>& buffer) = 0;
+    virtual ProductID storeRawData(const std::string& key, const std::vector<char>& buffer) = 0;
 
     /**
      * @brief Loads raw key/value data from this KeyValueContainer.
@@ -90,7 +98,7 @@ class KeyValueContainer {
      * @return true if the key was found. false otherwise.
      */
     template<typename K, typename V>
-    bool store(const K& key, const V& value) {
+    ProductID store(const K& key, const V& value) {
         std::stringstream ss_value;
         std::stringstream ss_key;
         ss_key << key << "#" << demangle<V>();
@@ -131,7 +139,8 @@ class KeyValueContainer {
         try {
             std::string serialized(buffer.begin(), buffer.end());
             std::stringstream ss(serialized);
-            boost::archive::binary_iarchive ia(ss);
+            //boost::archive::binary_iarchive ia(ss);
+            InputArchive ia(getDataStore(), ss);
             ia >> value;
         } catch(...) {
             throw Exception("Exception occured during serialization");

include/hepnos/ProductID.hpp

+/*
+ * (C) 2018 The University of Chicago
+ * 
+ * See COPYRIGHT in top-level directory.
+ */
+#ifndef __HEPNOS_PRODUCT_ID_H
+#define __HEPNOS_PRODUCT_ID_H
+
+#include <string>
+
+#include <boost/serialization/access.hpp>
+#include <boost/serialization/string.hpp>
+
+#include <hepnos/DataStore.hpp>
+
+namespace hepnos {
+
+class ProductID {
+
+    friend class DataStore;
+    friend class DataStore::Impl;
+    friend class boost::serialization::access;
+
+    private:
+
+    std::uint8_t m_level;
+    std::string  m_containerName;
+    std::string  m_objectName;
+
+    ProductID(std::uint8_t level, const std::string& containerName, const std::string& objectName)
+    : m_level(level)
+    , m_containerName(containerName)
+    , m_objectName(objectName) {}
+
+    public:
+
+    ProductID() = default;
+
+    /**
+     * @brief Copy constructor.
+     *
+     * @param other ProductID to copy.
+     */
+    ProductID(const ProductID& other) = default;
+
+    /**
+     * @brief Move constructor.
+     *
+     * @param other ProductID to move.
+     */
+    ProductID(ProductID&& other) = default;
+
+    /**
+     * @brief Copy-assignment operator.
+     *
+     * @param other ProductID to assign.
+     *
+     * @return Reference to this ProductID.
+     */
+    ProductID& operator=(const ProductID& other) = default;
+
+    /**
+     * @brief Move-assignment operator.
+     *
+     * @param other ProductID to move from.
+     *
+     * @return Reference to this ProductID.
+     */
+    ProductID& operator=(ProductID&& other) = default;
+
+    /**
+     * @brief Destructor.
+     */
+    ~ProductID() = default;
+
+    /**
+     * @brief Indicates whether this ProductID instance points to a valid
+     * product in the underlying storage service.
+     *
+     * @return True if the ProductID instance points to a valid product in the
+     * underlying service, false otherwise.
+     */
+    bool valid() const {
+        return m_objectName.size() != 0;
+    }
+
+    /**
+     * @brief Conversion to bool.
+     *
+     * @return True if the ProductID instance points to a valid product in the
+     * underlying service, false otherwise.
+     */
+    inline operator bool() const {
+        return valid();
+    }
+
+    /**
+     * @brief Compares this ProductID with another ProductID.
+     *
+     * @param other ProductID instance to compare against.
+     *
+     * @return true if the ProductIDs are the same, false otherwise.
+     */
+    bool operator==(const ProductID& other) const {
+        return m_level == other.m_level
+            && m_containerName == other.m_containerName
+            && m_objectName == other.m_objectName;
+    }
+
+    /**
+     * @brief Compares this ProductID with another ProductID.
+     *
+     * @param other ProductID instance to compare against.
+     *
+     * @return true if the ProductIDs are different, false otherwise.
+     */
+    bool operator!=(const ProductID& other) const {
+        return !(*this == other);
+    }
+
+    private:
+
+    template<typename Archive>
+    void serialize(Archive& ar, const unsigned int version) {
+        ar & m_level;
+        ar & m_containerName;
+        ar & m_objectName;
+    }
+
+};
+
+}
+
+#endif

include/hepnos/Ptr.hpp

+/*
+ * (C) 2018 The University of Chicago
+ * 
+ * See COPYRIGHT in top-level directory.
+ */
+#ifndef __HEPNOS_PTR_H
+#define __HEPNOS_PTR_H
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <boost/serialization/access.hpp>
+#include <boost/serialization/string.hpp>
+#include <boost/serialization/vector.hpp>
+#include <boost/serialization/split_member.hpp>
+
+#include <hepnos/InputArchive.hpp>
+#include <hepnos/ProductID.hpp>
+#include <hepnos/DataStore.hpp>
+#include <hepnos/Exception.hpp>
+
+namespace hepnos {
+
+template<typename T, typename C>
+class Ptr {
+
+    friend class boost::serialization::access;
+    friend class DataStore;
+
+    private:
+
+    DataStore* m_datastore         = nullptr;
+    ProductID   m_product_id       = ProductID();
+    std::size_t m_index            = 0;
+    bool        m_is_in_container  = false;
+    C*          m_container        = nullptr;
+    T*          m_data             = nullptr;
+    size_t*     m_refcount         = nullptr;
+
+    Ptr(DataStore* datastore, const ProductID& product_id)
+    : m_datastore(datastore)
+    , m_product_id(product_id)
+    , m_index(0)
+    , m_is_in_container(false) {}
+
+    Ptr(DataStore* datastore, const ProductID& product_id, std::size_t index)
+    : m_datastore(datastore)
+    , m_product_id(product_id)
+    , m_index(index)
+    , m_is_in_container(true) {};
+
+    public:
+
+    Ptr() = default;
+
+    /**
+     * @brief Copy constructor.
+     *
+     * @param other Ptr to copy.
+     */
+    Ptr(const Ptr& other)
+    : m_datastore(other.m_datastore)
+    , m_product_id(other.m_product_id)
+    , m_index(other.m_index)
+    , m_is_in_container(other.m_is_in_container)
+    , m_data(other.m_data)
+    , m_container(other.m_container)
+    , m_refcount(other.m_refcount) {
+        if(m_refcount) {
+            *m_refcount += 1;
+        }
+    }
+
+    /**
+     * @brief Move constructor.
+     *
+     * @param other Ptr to move.
+     */
+    Ptr(Ptr&& other)
+    : m_datastore(other.m_datastore)
+    , m_product_id(std::move(other.m_product_id))
+    , m_index(other.m_index)
+    , m_is_in_container(other.m_is_in_container)
+    , m_container(other.m_container)
+    , m_refcount(other.m_refcount) {
+        other.m_refcount = nullptr;
+        other.m_container = nullptr;
+        other.m_data = nullptr;
+        other.m_product_id = ProductID();
+    }
+
+    /**
+     * @brief Copy-assignment operator.
+     *
+     * @param other Ptr to assign.
+     *
+     * @return Reference to this Ptr.
+     */
+    Ptr& operator=(const Ptr& other) {
+        if(&other == this) return *this;
+        if(other.m_data == m_data) return *this;
+        if(m_data) {
+            this->~Ptr();
+        }
+        m_datastore       = other.m_datastore;
+        m_product_id      = other.m_product_id;
+        m_index           = other.m_index;
+        m_is_in_container = other.m_is_in_container;
+        m_container       = other.m_container;
+        m_refcount        = other.m_refcount;
+        if(m_refcount) {
+            *m_refcount += 1;
+        }
+        return *this;
+    }
+
+    /**
+     * @brief Move-assignment operator.
+     *
+     * @param other Ptr to move from.
+     *
+     * @return Reference to this Ptr.
+     */
+    Ptr& operator=(Ptr&& other) {
+        if(&other == this) return *this;
+        if(other.m_data == m_data) return *this;
+        if(m_data) {
+            this->~Ptr();
+        }
+        m_datastore       = other.m_datastore;
+        m_product_id      = std::move(other.m_product_id);
+        m_index           = other.m_index;
+        m_is_in_container = other.m_is_in_container;
+        m_container       = other.m_container;
+        m_refcount        = other.m_refcount;
+        other.m_datastore = nullptr;
+        other.m_index     = 0;
+        other.m_container = nullptr;
+        other.m_refcount  = nullptr;
+        return *this;
+    }
+
+    /**
+     * @brief Destructor.
+     */
+    ~Ptr() {
+        if(m_refcount) {
+            *m_refcount -= 1;
+            if(*m_refcount == 0) {
+                delete m_refcount;
+                if(m_is_in_container) {
+                    delete m_container;
+                } else {
+                    delete m_data;
+                }
+            }
+        }
+    }
+
+    /**
+     * @brief Indicates whether this Ptr instance points to a valid
+     * product in the underlying storage service.
+     *
+     * @return True if the Ptr instance points to a valid product in the
+     * underlying service, false otherwise.
+     */
+    bool valid() const {
+        return m_datastore != nullptr && m_product_id.valid();
+    }
+
+    /**
+     * @brief Compares this Ptr with another Ptr. The Ptrs must point to
+     * the same product.
+     *
+     * @param other Ptr instance to compare against.
+     *
+     * @return true if the Ptrs are the same, false otherwise.
+     */
+    bool operator==(const Ptr& other) const {
+        return m_product_id == other.m_product_id;
+    }
+
+    /**
+     * @brief Compares this Ptr with another Ptr.
+     *
+     * @param other Ptr instance to compare against.
+     *
+     * @return true if the Ptrs are different, false otherwise.
+     */
+    bool operator!=(const Ptr& other) const {
+        return m_product_id != other.m_product_id;
+    }
+
+    /**
+     * @brief Dereference operator. This operator will load
+     * the data from the underlying storage if it hasn't been
+     * loaded yet.
+     *
+     * @return Reference to the pointed data.
+     */
+    const T& operator*()
+    {
+        if(m_data)
+            return *m_data;
+        else {
+            loadData();
+        }
+        return *m_data;
+    }
+
+    /**
+     * @brief Dereference operator. This operator will load the data
+     * from the underlying storage if it hasn't been loaded yet.
+     *
+     * @return Pointer to the pointed data.
+     */
+    const T* operator->()
+    {
+        if(m_data)
+            return m_data;
+        else {
+            loadData();
+        }
+        return m_data;
+    }
+
+    private:
+
+    /**
+     * @brief Serialization function for Boost.
+     *
+     * @tparam Archive Archive type.
+     * @param ar Archive.
+     * @param version Version number.
+     */
+    template<typename Archive>
+    void save(Archive& ar, const unsigned int version) const {
+        ar & m_product_id;
+    }
+
+    /**
+     * @brief Serialization function for Boost.
+     *
+     * @tparam Archive Archive type.
+     * @param ar Archive.
+     * @param version Version number.
+     */
+    template<typename Archive>
+    void load(Archive& ar, const unsigned int version) {
+        ar & m_product_id;
+        m_datastore = ar.getDataStore();
+    }
+
+    BOOST_SERIALIZATION_SPLIT_MEMBER()
+
+    /**
+     * @brief This function is called to load the actual data from storage.
+     */
+    void loadData() {
+        if(m_is_in_container) {
+            m_container = new C();
+            if(!(m_datastore->loadProduct(m_product_id, *m_container))) {
+                throw Exception("Could not load product from DataStore");
+            }
+            m_data = &((*m_container)[m_index]);
+        } else {
+            m_data = new T();
+            m_container = nullptr;
+            if(!(m_datastore->loadProduct(m_product_id, *m_data))) {
+                throw Exception("Could not load product from DataStore");
+            }
+        }
+    }
+
+};
+
+}
+
+#endif

include/hepnos/Run.hpp

@@ -8,11 +8,11 @@
 
 #include <memory>
 #include <string>
-#include <hepnos/KeyValueContainer.hpp>
 #include <hepnos/DataStore.hpp>
 #include <hepnos/RunNumber.hpp>
 #include <hepnos/SubRun.hpp>
 #include <hepnos/Exception.hpp>
+#include <hepnos/KeyValueContainer.hpp>
 
 namespace hepnos {
 
@@ -84,6 +84,11 @@ class Run : public KeyValueContainer {
      */
     ~Run();
 
+    /**
+     * @brief Overrides getDataStore from KeyValueContainer class.
+     */
+    DataStore* getDataStore() const override;
+
     /**
      * @brief Returns the next Run in the same container,
      * sorted by run number. If no such run exists, a Run instance
@@ -108,9 +113,9 @@ class Run : public KeyValueContainer {
      * @param key Key
      * @param buffer Value
      *
-     * @return true if the key did not already exist, false otherwise.
+     * @return a valid ProductID if the key did not already exist, an invalid one otherwise.
      */
-    bool storeRawData(const std::string& key, const std::vector<char>& buffer);
+    ProductID storeRawData(const std::string& key, const std::vector<char>& buffer) override;
 
     /**
      * @brief Loads raw key/value data from this Run.
@@ -120,7 +125,7 @@ class Run : public KeyValueContainer {
      *
      * @return true if the key exists, false otherwise.
      */
-    bool loadRawData(const std::string& key, std::vector<char>& buffer) const;