archive.cpp

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/*
 *  GiNaC Copyright (C) 1999-2011 Johannes Gutenberg University Mainz, Germany
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

#include "archive.h"
#include "registrar.h"
#include "ex.h"
#include "lst.h"
#include "config.h"
#include "tostring.h"

#include <iostream>
#include <stdexcept>

namespace GiNaC {


void archive::archive_ex(const ex &e, const char *name)
{
    // Create root node (which recursively archives the whole expression tree)
    // and add it to the archive
    archive_node_id id = add_node(archive_node(*this, e));

    // Add root node ID to list of archived expressions
    archived_ex ae = archived_ex(atomize(name), id);
    exprs.push_back(ae);
}


archive_node_id archive::add_node(const archive_node &n)
{
    // Look if expression is known to be in some node already.
    if (n.has_ex()) {
        mapit i = exprtable.find(n.get_ex());
        if (i != exprtable.end())
            return i->second;
        nodes.push_back(n);
        exprtable[n.get_ex()] = nodes.size() - 1;
        return nodes.size() - 1;
    }

    // Not found, add archive_node to nodes vector
    nodes.push_back(n);
    return nodes.size()-1;
}


archive_node &archive::get_node(archive_node_id id)
{
    if (id >= nodes.size())
        throw (std::range_error("archive::get_node(): archive node ID out of range"));

    return nodes[id];
}


ex archive::unarchive_ex(const lst &sym_lst, const char *name) const
{
    // Find root node
    std::string name_string = name;
    archive_atom id = atomize(name_string);
    std::vector<archived_ex>::const_iterator i = exprs.begin(), iend = exprs.end();
    while (i != iend) {
        if (i->name == id)
            goto found;
        i++;
    }
    throw (std::runtime_error("expression with name '" + name_string + "' not found in archive"));

found:
    // Recursively unarchive all nodes, starting at the root node
    lst sym_lst_copy = sym_lst;
    return nodes[i->root].unarchive(sym_lst_copy);
}

ex archive::unarchive_ex(const lst &sym_lst, unsigned index) const
{
    if (index >= exprs.size())
        throw (std::range_error("index of archived expression out of range"));

    // Recursively unarchive all nodes, starting at the root node
    lst sym_lst_copy = sym_lst;
    return nodes[exprs[index].root].unarchive(sym_lst_copy);
}

ex archive::unarchive_ex(const lst &sym_lst, std::string &name, unsigned index) const
{
    if (index >= exprs.size())
        throw (std::range_error("index of archived expression out of range"));

    // Return expression name
    name = unatomize(exprs[index].name);

    // Recursively unarchive all nodes, starting at the root node
    lst sym_lst_copy = sym_lst;
    return nodes[exprs[index].root].unarchive(sym_lst_copy);
}

unsigned archive::num_expressions() const
{
    return exprs.size();
}

const archive_node &archive::get_top_node(unsigned index) const
{
    if (index >= exprs.size())
        throw (std::range_error("index of archived expression out of range"));

    return nodes[exprs[index].root];
}


/*
 *  Archive file format
 *
 *   - 4 bytes signature 'GARC'
 *   - unsigned version number
 *   - unsigned number of atoms
 *      - atom strings (each zero-terminated)
 *   - unsigned number of expressions
 *      - unsigned name atom
 *      - unsigned root node ID
 *   - unsigned number of nodes
 *      - unsigned number of properties
 *        - unsigned containing type (PTYPE_*) in its lower 3 bits and
 *          name atom in the upper bits
 *        - unsigned property value
 *
 *  Unsigned quantities are stored in a compressed format:
 *   - numbers in the range 0x00..0x7f are stored verbatim (1 byte)
 *   - numbers larger than 0x7f are stored in 7-bit packets (1 byte per
 *     packet), starting with the LSBs; all bytes except the last one have
 *     their upper bit set
 *
 *  Examples:
 *   0x00           =   0x00
 *    ..                 ..
 *   0x7f           =   0x7f
 *   0x80 0x01      =   0x80
 *    ..   ..            ..
 *   0xff 0x01      =   0xff
 *   0x80 0x02      =  0x100
 *    ..   ..            ..
 *   0xff 0x02      =  0x17f
 *   0x80 0x03      =  0x180
 *    ..   ..            ..
 *   0xff 0x7f      = 0x3fff
 *   0x80 0x80 0x01 = 0x4000
 *    ..   ..   ..       ..
 */

static void write_unsigned(std::ostream &os, unsigned val)
{
    while (val >= 0x80) {
        os.put((val & 0x7f) | 0x80);
        val >>= 7;
    }
    os.put(val);
}

static unsigned read_unsigned(std::istream &is)
{
    unsigned char b;
    unsigned ret = 0;
    unsigned shift = 0;
    do {
        char b2;
        is.get(b2);
        b = b2;
        ret |= (b & 0x7f) << shift;
        shift += 7;
    } while (b & 0x80);
    return ret;
}

std::ostream &operator<<(std::ostream &os, const archive_node &n)
{
    // Write properties
    unsigned num_props = n.props.size();
    write_unsigned(os, num_props);
    for (unsigned i=0; i<num_props; i++) {
        write_unsigned(os, n.props[i].type | (n.props[i].name << 3));
        write_unsigned(os, n.props[i].value);
    }
    return os;
}

std::ostream &operator<<(std::ostream &os, const archive &ar)
{
    // Write header
    os.put('G');    // Signature
    os.put('A');
    os.put('R');
    os.put('C');
    write_unsigned(os, ARCHIVE_VERSION);

    // Write atoms
    unsigned num_atoms = ar.atoms.size();
    write_unsigned(os, num_atoms);
    for (unsigned i=0; i<num_atoms; i++)
        os << ar.atoms[i] << std::ends;

    // Write expressions
    unsigned num_exprs = ar.exprs.size();
    write_unsigned(os, num_exprs);
    for (unsigned i=0; i<num_exprs; i++) {
        write_unsigned(os, ar.exprs[i].name);
        write_unsigned(os, ar.exprs[i].root);
    }

    // Write nodes
    unsigned num_nodes = ar.nodes.size();
    write_unsigned(os, num_nodes);
    for (unsigned i=0; i<num_nodes; i++)
        os << ar.nodes[i];
    return os;
}

std::istream &operator>>(std::istream &is, archive_node &n)
{
    // Read properties
    unsigned num_props = read_unsigned(is);
    n.props.resize(num_props);
    for (unsigned i=0; i<num_props; i++) {
        unsigned name_type = read_unsigned(is);
        n.props[i].type = (archive_node::property_type)(name_type & 7);
        n.props[i].name = name_type >> 3;
        n.props[i].value = read_unsigned(is);
    }
    return is;
}

std::istream &operator>>(std::istream &is, archive &ar)
{
    // Read header
    char c1, c2, c3, c4;
    is.get(c1); is.get(c2); is.get(c3); is.get(c4);
    if (c1 != 'G' || c2 != 'A' || c3 != 'R' || c4 != 'C')
        throw (std::runtime_error("not a GiNaC archive (signature not found)"));
    unsigned version = read_unsigned(is);
    if (version > ARCHIVE_VERSION || version < ARCHIVE_VERSION - ARCHIVE_AGE)
        throw (std::runtime_error("archive version " + ToString(version) + " cannot be read by this GiNaC library (which supports versions " + ToString(ARCHIVE_VERSION-ARCHIVE_AGE) + " thru " + ToString(ARCHIVE_VERSION)));

    // Read atoms
    unsigned num_atoms = read_unsigned(is);
    ar.atoms.resize(num_atoms);
    for (unsigned i=0; i<num_atoms; i++) {
        getline(is, ar.atoms[i], '\0');
        ar.inverse_atoms[ar.atoms[i]] = i;
    }

    // Read expressions
    unsigned num_exprs = read_unsigned(is);
    ar.exprs.resize(num_exprs);
    for (unsigned i=0; i<num_exprs; i++) {
        archive_atom name = read_unsigned(is);
        archive_node_id root = read_unsigned(is);
        ar.exprs[i] = archive::archived_ex(name, root);
    }

    // Read nodes
    unsigned num_nodes = read_unsigned(is);
    ar.nodes.resize(num_nodes, ar);
    for (unsigned i=0; i<num_nodes; i++)
        is >> ar.nodes[i];
    return is;
}


archive_atom archive::atomize(const std::string &s) const
{
    // Search for string in inverse_atoms map.
    inv_at_cit i = inverse_atoms.find(s);
    if (i!=inverse_atoms.end())
        return i->second;

    // Not found, add to atoms vector
    archive_atom id = atoms.size();
    atoms.push_back(s);
    inverse_atoms[s] = id;
    return id;
}

const std::string &archive::unatomize(archive_atom id) const
{
    if (id >= atoms.size())
        throw (std::range_error("archive::unatomizee(): atom ID out of range"));

    return atoms[id];
}


const archive_node &archive_node::operator=(const archive_node &other)
{
    if (this != &other) {
        // archive &a member doesn't get copied
        props = other.props;
        has_expression = other.has_expression;
        e = other.e;
    }
    return *this;
}


archive_node::archive_node(archive &ar, const ex &expr)
  : a(ar), has_expression(true), e(expr)
{
    expr.bp->archive(*this);
}


bool archive_node::has_same_ex_as(const archive_node &other) const
{
    if (!has_expression || !other.has_expression)
        return false;
    return e.bp == other.e.bp;
}

archive_node::archive_node_cit
        archive_node::find_first(const std::string &name) const
{   
    archive_atom name_atom = a.atomize(name);
    for (archive_node_cit i=props.begin(); i!=props.end(); ++i)
        if (i->name == name_atom)
            return i;
    return props.end();;
}

archive_node::archive_node_cit
        archive_node::find_last(const std::string &name) const
{
    archive_atom name_atom = a.atomize(name);
    for (archive_node_cit i=props.end(); i!=props.begin();) {
        --i;
        if (i->name == name_atom)
            return i;
    }
    return props.end();
}

void archive_node::add_bool(const std::string &name, bool value)
{
    props.push_back(property(a.atomize(name), PTYPE_BOOL, value));
}

void archive_node::add_unsigned(const std::string &name, unsigned value)
{
    props.push_back(property(a.atomize(name), PTYPE_UNSIGNED, value));
}

void archive_node::add_string(const std::string &name, const std::string &value)
{
    props.push_back(property(a.atomize(name), PTYPE_STRING, a.atomize(value)));
}

void archive_node::add_ex(const std::string &name, const ex &value)
{
    // Recursively create an archive_node and add its ID to the properties of this node
    archive_node_id id = a.add_node(archive_node(a, value));
    props.push_back(property(a.atomize(name), PTYPE_NODE, id));
}


bool archive_node::find_bool(const std::string &name, bool &ret, unsigned index) const
{
    archive_atom name_atom = a.atomize(name);
    archive_node_cit i = props.begin(), iend = props.end();
    unsigned found_index = 0;
    while (i != iend) {
        if (i->type == PTYPE_BOOL && i->name == name_atom) {
            if (found_index == index) {
                ret = i->value;
                return true;
            }
            found_index++;
        }
        i++;
    }
    return false;
}

bool archive_node::find_unsigned(const std::string &name, unsigned &ret, unsigned index) const
{
    archive_atom name_atom = a.atomize(name);
    archive_node_cit i = props.begin(), iend = props.end();
    unsigned found_index = 0;
    while (i != iend) {
        if (i->type == PTYPE_UNSIGNED && i->name == name_atom) {
            if (found_index == index) {
                ret = i->value;
                return true;
            }
            found_index++;
        }
        i++;
    }
    return false;
}

bool archive_node::find_string(const std::string &name, std::string &ret, unsigned index) const
{
    archive_atom name_atom = a.atomize(name);
    archive_node_cit i = props.begin(), iend = props.end();
    unsigned found_index = 0;
    while (i != iend) {
        if (i->type == PTYPE_STRING && i->name == name_atom) {
            if (found_index == index) {
                ret = a.unatomize(i->value);
                return true;
            }
            found_index++;
        }
        i++;
    }
    return false;
}

void archive_node::find_ex_by_loc(archive_node_cit loc, ex &ret, lst &sym_lst)
        const
{
    ret = a.get_node(loc->value).unarchive(sym_lst);
}

bool archive_node::find_ex(const std::string &name, ex &ret, lst &sym_lst, unsigned index) const
{
    archive_atom name_atom = a.atomize(name);
    archive_node_cit i = props.begin(), iend = props.end();
    unsigned found_index = 0;
    while (i != iend) {
        if (i->type == PTYPE_NODE && i->name == name_atom) {
            if (found_index == index) {
                ret = a.get_node(i->value).unarchive(sym_lst);
                return true;
            }
            found_index++;
        }
        i++;
    }
    return false;
}

const archive_node &archive_node::find_ex_node(const std::string &name, unsigned index) const
{
    archive_atom name_atom = a.atomize(name);
    archive_node_cit i = props.begin(), iend = props.end();
    unsigned found_index = 0;
    while (i != iend) {
        if (i->type == PTYPE_NODE && i->name == name_atom) {
            if (found_index == index)
                return a.get_node(i->value);
            found_index++;
        }
        i++;
    }
    throw (std::runtime_error("property with name '" + name + "' not found in archive node"));
}


void archive_node::get_properties(propinfovector &v) const
{
    v.clear();
    archive_node_cit i = props.begin(), iend = props.end();
    while (i != iend) {
        property_type type = i->type;
        std::string name = a.unatomize(i->name);

        propinfovector::iterator a = v.begin(), aend = v.end();
        bool found = false;
        while (a != aend) {
            if (a->type == type && a->name == name) {
                a->count++;
                found = true;
                break;
            }
            ++a;
        }
        if (!found)
            v.push_back(property_info(type, name));
        i++;
    }   
}

static synthesize_func find_factory_fcn(const std::string& name)
{
    static unarchive_table_t the_table;
    synthesize_func ret = the_table.find(name);
    return ret;
}

ex archive_node::unarchive(lst &sym_lst) const
{
    // Already unarchived? Then return cached unarchived expression.
    if (has_expression)
        return e;

    // Find instantiation function for class specified in node
    std::string class_name;
    if (!find_string("class", class_name))
        throw (std::runtime_error("archive node contains no class name"));

    // Call instantiation function
    synthesize_func factory_fcn = find_factory_fcn(class_name);
    ptr<basic> obj(factory_fcn());
    obj->setflag(status_flags::dynallocated);
    obj->read_archive(*this, sym_lst);
    e = ex(*obj);
    has_expression = true;
    return e;
}

int unarchive_table_t::usecount = 0;
unarchive_map_t* unarchive_table_t::unarch_map = 0;

unarchive_table_t::unarchive_table_t()
{
    if (usecount == 0)
        unarch_map = new unarchive_map_t();
    ++usecount;
}

synthesize_func unarchive_table_t::find(const std::string& classname) const
{
    unarchive_map_t::const_iterator i = unarch_map->find(classname);
    if (i != unarch_map->end())
        return i->second;
    throw std::runtime_error(std::string("no unarchiving function for \"")
            + classname + "\" class");
}

void unarchive_table_t::insert(const std::string& classname, synthesize_func f)
{
    if (unarch_map->find(classname) != unarch_map->end())
        throw std::runtime_error(std::string("Class \"" + classname
                    + "\" is already registered"));
    unarch_map->operator[](classname) = f;
}

unarchive_table_t::~unarchive_table_t()
{
    if (--usecount == 0)
        delete unarch_map;
}


void archive::clear()
{
    atoms.clear();
    inverse_atoms.clear();
    exprs.clear();
    nodes.clear();
    exprtable.clear();
}


void archive::forget()
{
    for_each(nodes.begin(), nodes.end(), std::mem_fun_ref(&archive_node::forget));
}

void archive_node::forget()
{
    has_expression = false;
    e = 0;
}


void archive::printraw(std::ostream &os) const
{
    // Dump atoms
    os << "Atoms:\n";
    {
        std::vector<std::string>::const_iterator i = atoms.begin(), iend = atoms.end();
        archive_atom id = 0;
        while (i != iend) {
            os << " " << id << " " << *i << std::endl;
            i++; id++;
        }
    }
    os << std::endl;

    // Dump expressions
    os << "Expressions:\n";
    {
        std::vector<archived_ex>::const_iterator i = exprs.begin(), iend = exprs.end();
        unsigned index = 0;
        while (i != iend) {
            os << " " << index << " \"" << unatomize(i->name) << "\" root node " << i->root << std::endl;
            i++; index++;
        }
    }
    os << std::endl;

    // Dump nodes
    os << "Nodes:\n";
    {
        std::vector<archive_node>::const_iterator i = nodes.begin(), iend = nodes.end();
        archive_node_id id = 0;
        while (i != iend) {
            os << " " << id << " ";
            i->printraw(os);
            i++; id++;
        }
    }
}

void archive_node::printraw(std::ostream &os) const
{
    // Dump cached unarchived expression
    if (has_expression)
        os << "(basic * " << e.bp << " = " << e << ")\n";
    else
        os << "\n";

    // Dump properties
    archive_node_cit i = props.begin(), iend = props.end();
    while (i != iend) {
        os << "  ";
        switch (i->type) {
            case PTYPE_BOOL: os << "bool"; break;
            case PTYPE_UNSIGNED: os << "unsigned"; break;
            case PTYPE_STRING: os << "string"; break;
            case PTYPE_NODE: os << "node"; break;
            default: os << "<unknown>"; break;
        }
        os << " \"" << a.unatomize(i->name) << "\" " << i->value << std::endl;
        i++;
    }
}

archive* archive_node::dummy_ar_creator()
{
    static archive* some_ar = new archive;
    return some_ar;
}


} // namespace GiNaC