serialize.hh

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/* @file
 * Serialization Interface Declarations
 */
 
#ifndef __SERIALIZE_HH__
#define __SERIALIZE_HH__
 
 
#include <algorithm>
#include <fstream>
#include <iostream>
#include <iterator>
#include <stack>
#include <string>
#include <type_traits>
#include <unordered_map>
#include <vector>
 
#include "base/inifile.hh"
#include "base/logging.hh"
#include "sim/serialize_handlers.hh"
 
namespace gem5
{
 
typedef std::ostream CheckpointOut;
 
class CheckpointIn
{
  private:
    IniFile db;
 
    const std::string _cptDir;
 
  public:
    CheckpointIn(const std::string &cpt_dir);
    ~CheckpointIn() = default;
 
    const std::string getCptDir() { return _cptDir; }
 
    bool find(const std::string &section, const std::string &entry,
              std::string &value);
 
    bool entryExists(const std::string &section, const std::string &entry);
    bool sectionExists(const std::string &section);
    void visitSection(const std::string &section,
        IniFile::VisitSectionCallback cb); //end of api_checkout group
 
    // The following static functions have to do with checkpoint
    // creation rather than restoration.  This class makes a handy
    // namespace for them though.  Currently no Checkpoint object is
    // created on serialization (only unserialization) so we track the
    // directory name as a global.  It would be nice to change this
    // someday
 
  private:
    // current directory we're serializing into.
    static std::string currentDirectory;
 
 
  public:
    static std::string setDir(const std::string &base_name);
 
    static std::string dir();
 
    // Filename for base checkpoint file within directory.
    static const char *baseFilename;
};
 
class Serializable
{
  public:
    class ScopedCheckpointSection
    {
      public:
        template<class CP>
        ScopedCheckpointSection(CP &cp, const char *name) {
            pushName(name);
            nameOut(cp);
        }
 
        template<class CP>
        ScopedCheckpointSection(CP &cp, const std::string &name) {
            pushName(name.c_str());
            nameOut(cp);
        } //end of api_serialize group
 
        ~ScopedCheckpointSection();
 
        ScopedCheckpointSection() = delete;
        ScopedCheckpointSection(const ScopedCheckpointSection &) = delete;
        ScopedCheckpointSection &operator=(
            const ScopedCheckpointSection &) = delete;
        ScopedCheckpointSection &operator=(
            ScopedCheckpointSection &&) = delete;
 
      private:
        void pushName(const char *name);
        void nameOut(CheckpointOut &cp);
        void nameOut(CheckpointIn &cp) {};
    };
 
    Serializable();
    virtual ~Serializable();
 
    virtual void serialize(CheckpointOut &cp) const = 0;
 
    virtual void unserialize(CheckpointIn &cp) = 0;
 
    void serializeSection(CheckpointOut &cp, const char *name) const;
 
    void serializeSection(CheckpointOut &cp, const std::string &name) const {
        serializeSection(cp, name.c_str());
    }
 
    void unserializeSection(CheckpointIn &cp, const char *name);
 
    void unserializeSection(CheckpointIn &cp, const std::string &name) {
        unserializeSection(cp, name.c_str());
    }
 
    static const std::string &currentSection();
 
    static void generateCheckpointOut(const std::string &cpt_dir,
        std::ofstream &outstream);
 
  private:
    static std::stack<std::string> path;
};
 
template <class T>
void
paramOut(CheckpointOut &os, const std::string &name, const T &param)
{
    os << name << "=";
    ShowParam<T>::show(os, param);
    os << "\n";
}
 
template <class T>
bool
paramInImpl(CheckpointIn &cp, const std::string &name, T &param)
{
    const std::string &section(Serializable::currentSection());
    std::string str;
    return cp.find(section, name, str) && ParseParam<T>::parse(str, param);
}
 
template <class T>
bool
optParamIn(CheckpointIn &cp, const std::string &name, T &param,
           bool do_warn=true)
{
    if (paramInImpl(cp, name, param))
        return true;
 
    warn_if(do_warn, "optional parameter %s:%s not present",
            Serializable::currentSection(), name);
    return false;
}
 
template <class T>
void
paramIn(CheckpointIn &cp, const std::string &name, T &param)
{
    fatal_if(!paramInImpl(cp, name, param),
        "Can't unserialize '%s:%s'", Serializable::currentSection(), name);
}
 
template <class InputIterator>
void
arrayParamOut(CheckpointOut &os, const std::string &name,
              InputIterator start, InputIterator end)
{
    os << name << "=";
    auto it = start;
    using Elem = std::remove_cv_t<std::remove_reference_t<decltype(*it)>>;
    if (it != end)
        ShowParam<Elem>::show(os, *it++);
    while (it != end) {
        os << " ";
        ShowParam<Elem>::show(os, *it++);
    }
    os << "\n";
}
 
template <class T>
decltype(std::begin(std::declval<const T&>()),
         std::end(std::declval<const T&>()), void())
arrayParamOut(CheckpointOut &os, const std::string &name,
              const T &param)
{
    arrayParamOut(os, name, std::begin(param), std::end(param));
}
 
 
template <class T>
void
arrayParamOut(CheckpointOut &os, const std::string &name,
              const T *param, unsigned size)
{
    arrayParamOut(os, name, param, param + size);
}
 
template <class T, class InsertIterator>
void
arrayParamIn(CheckpointIn &cp, const std::string &name,
             InsertIterator inserter, ssize_t fixed_size=-1)
{
    const std::string &section = Serializable::currentSection();
    std::string str;
    fatal_if(!cp.find(section, name, str),
        "Can't unserialize '%s:%s'.", section, name);
 
    std::vector<std::string> tokens;
    tokenize(tokens, str, ' ');
 
    fatal_if(fixed_size >= 0 && tokens.size() != fixed_size,
             "Array size mismatch on %s:%s (Got %u, expected %u)'\n",
             section, name, tokens.size(), fixed_size);
 
    for (const auto &token: tokens) {
        T value;
        fatal_if(!ParseParam<T>::parse(token, value),
                 "Could not parse \"%s\".", str);
        *inserter = value;
    }
}
 
template <class T>
decltype(std::declval<T>().insert(std::declval<typename T::value_type>()),
         void())
arrayParamIn(CheckpointIn &cp, const std::string &name, T &param)
{
    param.clear();
    arrayParamIn<typename T::value_type>(
            cp, name, std::inserter(param, param.begin()));
}
 
template <class T>
decltype(std::declval<T>().push_back(std::declval<typename T::value_type>()),
         void())
arrayParamIn(CheckpointIn &cp, const std::string &name, T &param)
{
    param.clear();
    arrayParamIn<typename T::value_type>(cp, name, std::back_inserter(param));
}
 
template <class T>
void
arrayParamIn(CheckpointIn &cp, const std::string &name,
             T *param, unsigned size)
{
    struct ArrayInserter
    {
        T *data;
        T &operator *() { return *data++; }
    } insert_it{param};
 
    arrayParamIn<T>(cp, name, insert_it, size);
}
 
template <class T>
void
mappingParamOut(CheckpointOut &os, const char* sectionName,
    const char* const names[], const T *param, unsigned size)
{
    Serializable::ScopedCheckpointSection sec(os, sectionName);
    for (unsigned i = 0; i < size; ++i) {
        paramOut(os, names[i], param[i]);
    }
}
 
template <class T>
void
mappingParamIn(CheckpointIn &cp, const char* sectionName,
    const char* const names[], T *param, unsigned size)
{
    Serializable::ScopedCheckpointSection sec(cp, sectionName);
    std::unordered_map<std::string, size_t> name_to_index;
    for (size_t i = 0; i < size; i++) {
        name_to_index[names[i]] = i;
    }
    for (size_t i = 0; i < size; i++) {
        auto& key = names[i];
        T value;
        if (optParamIn(cp, key, value)) {
            param[name_to_index[key]] = value;
        }
    }
    cp.visitSection(
        Serializable::currentSection(),
        [name_to_index](const std::string& key, const std::string& val)
        {
            if (!name_to_index.count(key)) {
                warn("unknown entry found in checkpoint: %s %s %s\n",
                    Serializable::currentSection(), key, val);
            }
        }
    );
}
 
//
// These macros are streamlined to use in serialize/unserialize
// functions.  It's assumed that serialize() has a parameter 'os' for
// the ostream, and unserialize() has parameters 'cp' and 'section'.
 
 
#define SERIALIZE_SCALAR(scalar)        paramOut(cp, #scalar, scalar)
 
#define UNSERIALIZE_SCALAR(scalar)      paramIn(cp, #scalar, scalar)
 
#define UNSERIALIZE_OPT_SCALAR(scalar)      optParamIn(cp, #scalar, scalar)
 
// ENUMs are like SCALARs, but we cast them to ints on the way out
 
#define SERIALIZE_ENUM(scalar)          paramOut(cp, #scalar, (int)scalar)
 
#define UNSERIALIZE_ENUM(scalar)                        \
    do {                                                \
        int tmp;                                        \
        ::gem5::paramIn(cp, #scalar, tmp);              \
        scalar = static_cast<decltype(scalar)>(tmp);    \
    } while (0)
 
#define SERIALIZE_ARRAY(member, size)           \
        ::gem5::arrayParamOut(cp, #member, member, size)
 
#define UNSERIALIZE_ARRAY(member, size)         \
        ::gem5::arrayParamIn(cp, #member, member, size)
 
#define SERIALIZE_CONTAINER(member)             \
        ::gem5::arrayParamOut(cp, #member, member)
 
#define UNSERIALIZE_CONTAINER(member)           \
        ::gem5::arrayParamIn(cp, #member, member)
 
#define SERIALIZE_OBJ(obj) obj.serializeSection(cp, #obj)
 
#define UNSERIALIZE_OBJ(obj) obj.unserializeSection(cp, #obj)
 
#define SERIALIZE_MAPPING(member, names, size) \
        ::gem5::mappingParamOut(cp, #member, names, member, size)
 
#define UNSERIALIZE_MAPPING(member, names, size) \
        ::gem5::mappingParamIn(cp, #member, names, member, size)
 
} // namespace gem5
 
#endif // __SERIALIZE_HH__