Subversion Repositories SmartDukaan

/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements. See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership. The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License. You may obtain a copy of the License at

 *

 *   http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing,

 * software distributed under the License is distributed on an

 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

 * KIND, either express or implied. See the License for the

 * specific language governing permissions and limitations

 * under the License.

 *

 * Contains some contributions under the Thrift Software License.

 * Please see doc/old-thrift-license.txt in the Thrift distribution for

 * details.

 */

#include <string>

#include <fstream>

#include <iostream>

#include <vector>

#include <stdlib.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sstream>

#include <boost/tokenizer.hpp>

#include "t_oop_generator.h"

#include "platform.h"

using namespace std;

/**

 * Ruby code generator.

 *

 */

class t_rb_generator : public t_oop_generator {

 public:

  t_rb_generator(

      t_program* program,

      const std::map<std::string, std::string>& parsed_options,

      const std::string& option_string)

    : t_oop_generator(program)

  {

    out_dir_base_ = "gen-rb";

  }

  /**

   * Init and close methods

   */

  void init_generator();

  void close_generator();

  /**

   * Program-level generation functions

   */

  void generate_typedef     (t_typedef*  ttypedef);

  void generate_enum        (t_enum*     tenum);

  void generate_const       (t_const*    tconst);

  void generate_struct      (t_struct*   tstruct);

  void generate_xception    (t_struct*   txception);

  void generate_service     (t_service*  tservice);

  std::string render_const_value(t_type* type, t_const_value* value);

  /**

   * Struct generation code

   */

  void generate_rb_struct(std::ofstream& out, t_struct* tstruct, bool is_exception);

  void generate_rb_struct_required_validator(std::ofstream& out, t_struct* tstruct);

  void generate_rb_function_helpers(t_function* tfunction);

  void generate_rb_simple_constructor(std::ofstream& out, t_struct* tstruct);

  void generate_rb_simple_exception_constructor(std::ofstream& out, t_struct* tstruct);

  void generate_field_constants (std::ofstream& out, t_struct* tstruct);

  void generate_accessors   (std::ofstream& out, t_struct* tstruct);

  void generate_field_defns (std::ofstream& out, t_struct* tstruct);

  void generate_field_data  (std::ofstream& out, t_type* field_type, const std::string& field_name, t_const_value* field_value, bool optional);

  /**

   * Service-level generation functions

   */

  void generate_service_helpers   (t_service*  tservice);

  void generate_service_interface (t_service* tservice);

  void generate_service_client    (t_service* tservice);

  void generate_service_server    (t_service* tservice);

  void generate_process_function  (t_service* tservice, t_function* tfunction);

  /**

   * Serialization constructs

   */

  void generate_deserialize_field        (std::ofstream &out,

                                          t_field*    tfield,

                                          std::string prefix="",

                                          bool inclass=false);

  void generate_deserialize_struct       (std::ofstream &out,

                                          t_struct*   tstruct,

                                          std::string prefix="");

  void generate_deserialize_container    (std::ofstream &out,

                                          t_type*     ttype,

                                          std::string prefix="");

  void generate_deserialize_set_element  (std::ofstream &out,

                                          t_set*      tset,

                                          std::string prefix="");

  void generate_deserialize_map_element  (std::ofstream &out,

                                          t_map*      tmap,

                                          std::string prefix="");

  void generate_deserialize_list_element (std::ofstream &out,

                                          t_list*     tlist,

                                          std::string prefix="");

  void generate_serialize_field          (std::ofstream &out,

                                          t_field*    tfield,

                                          std::string prefix="");

  void generate_serialize_struct         (std::ofstream &out,

                                          t_struct*   tstruct,

                                          std::string prefix="");

  void generate_serialize_container      (std::ofstream &out,

                                          t_type*     ttype,

                                          std::string prefix="");

  void generate_serialize_map_element    (std::ofstream &out,

                                          t_map*      tmap,

                                          std::string kiter,

                                          std::string viter);

  void generate_serialize_set_element    (std::ofstream &out,

                                          t_set*      tmap,

                                          std::string iter);

  void generate_serialize_list_element   (std::ofstream &out,

                                          t_list*     tlist,

                                          std::string iter);

  void generate_rdoc                     (std::ofstream& out, 

                                          t_doc* tdoc);

  /**

   * Helper rendering functions

   */

  std::string rb_autogen_comment();

  std::string render_includes();

  std::string declare_field(t_field* tfield);

  std::string type_name(t_type* ttype);

  std::string full_type_name(t_type* ttype);

  std::string function_signature(t_function* tfunction, std::string prefix="");

  std::string argument_list(t_struct* tstruct);

  std::string type_to_enum(t_type* ttype);

  std::vector<std::string> ruby_modules(t_program* p) {

    std::string ns = p->get_namespace("rb");

    boost::tokenizer<> tok(ns);

    std::vector<std::string> modules;

    for(boost::tokenizer<>::iterator beg=tok.begin(); beg != tok.end(); ++beg) {

      modules.push_back(capitalize(*beg));

    }

    return modules;

  }

  void begin_namespace(std::ofstream&, std::vector<std::string>);

  void end_namespace(std::ofstream&, std::vector<std::string>);

 private:

  /**

   * File streams

   */

  std::ofstream f_types_;

  std::ofstream f_consts_;

  std::ofstream f_service_;

};

/**

 * Prepares for file generation by opening up the necessary file output

 * streams.

 *

 * @param tprogram The program to generate

 */

void t_rb_generator::init_generator() {

  // Make output directory

  MKDIR(get_out_dir().c_str());

  // Make output file

  string f_types_name = get_out_dir()+underscore(program_name_)+"_types.rb";

  f_types_.open(f_types_name.c_str());

  string f_consts_name = get_out_dir()+underscore(program_name_)+"_constants.rb";

  f_consts_.open(f_consts_name.c_str());

  // Print header

  f_types_ <<

    rb_autogen_comment() << endl <<

    render_includes() << endl;

    begin_namespace(f_types_, ruby_modules(program_));

  f_consts_ <<

    rb_autogen_comment() << endl <<

    "require '" << underscore(program_name_) << "_types'" << endl <<

    endl;

    begin_namespace(f_consts_, ruby_modules(program_));

}

/**

 * Renders all the imports necessary for including another Thrift program

 */

string t_rb_generator::render_includes() {

  const vector<t_program*>& includes = program_->get_includes();

  string result = "";

  for (size_t i = 0; i < includes.size(); ++i) {

    result += "require '" + underscore(includes[i]->get_name()) + "_types'\n";

  }

  if (includes.size() > 0) {

    result += "\n";

  }

  return result;

}

/**

 * Autogen'd comment

 */

string t_rb_generator::rb_autogen_comment() {

  return

    std::string("#\n") +

    "# Autogenerated by Thrift\n" +

    "#\n" +

    "# DO NOT EDIT UNLESS YOU ARE SURE THAT YOU KNOW WHAT YOU ARE DOING\n" +

    "#\n";

}

/**

 * Closes the type files

 */

void t_rb_generator::close_generator() {

  // Close types file

  end_namespace(f_types_, ruby_modules(program_));

  end_namespace(f_consts_, ruby_modules(program_));

  f_types_.close();

  f_consts_.close();

}

/**

 * Generates a typedef. This is not done in Ruby, types are all implicit.

 *

 * @param ttypedef The type definition

 */

void t_rb_generator::generate_typedef(t_typedef* ttypedef) {}

/**

 * Generates code for an enumerated type. Done using a class to scope

 * the values.

 *

 * @param tenum The enumeration

 */

void t_rb_generator::generate_enum(t_enum* tenum) {

  indent(f_types_) <<

    "module " << capitalize(tenum->get_name()) << endl;

  indent_up();

  vector<t_enum_value*> constants = tenum->get_constants();

  vector<t_enum_value*>::iterator c_iter;

  int value = -1;

  for (c_iter = constants.begin(); c_iter != constants.end(); ++c_iter) {

    if ((*c_iter)->has_value()) {

      value = (*c_iter)->get_value();

    } else {

      ++value;

    }

    // Ruby class constants have to be capitalized... omg i am so on the fence

    // about languages strictly enforcing capitalization why can't we just all

    // agree and play nice.

    string name = capitalize((*c_iter)->get_name());

    f_types_ <<

      indent() << name << " = " << value << endl;

  }

  //Create a hash mapping values back to their names (as strings) since ruby has no native enum type

  indent(f_types_) << "VALUE_MAP = {";

  bool first = true;

  value = -1;

  for(c_iter = constants.begin(); c_iter != constants.end(); ++c_iter) {

    //Populate the hash

    //If no value is given, use the next available one

    if ((*c_iter)->has_value())

      value = (*c_iter)->get_value();

    else ++value;

    first ? first = false : f_types_ << ", ";

    f_types_ << value << " => \"" << capitalize((*c_iter)->get_name()) << "\"";

  }

  f_types_ << "}" << endl;

  // Create a set with valid values for this enum

  indent(f_types_) << "VALID_VALUES = Set.new([";

  first = true;

  for (c_iter = constants.begin(); c_iter != constants.end(); ++c_iter) {

    // Populate the set

    first ? first = false: f_types_ << ", ";

    f_types_ << capitalize((*c_iter)->get_name());

  }

  f_types_ << "]).freeze" << endl;

  indent_down();

  indent(f_types_) <<

    "end" << endl << endl;

}

/**

 * Generate a constant value

 */

void t_rb_generator::generate_const(t_const* tconst) {

  t_type* type = tconst->get_type();

  string name = tconst->get_name();

  t_const_value* value = tconst->get_value();

  name[0] = toupper(name[0]);

  indent(f_consts_) << name << " = " << render_const_value(type, value);

  f_consts_ << endl << endl;

}

/**

 * Prints the value of a constant with the given type. Note that type checking

 * is NOT performed in this function as it is always run beforehand using the

 * validate_types method in main.cc

 */

string t_rb_generator::render_const_value(t_type* type, t_const_value* value) {

  type = get_true_type(type);

  std::ostringstream out;

  if (type->is_base_type()) {

    t_base_type::t_base tbase = ((t_base_type*)type)->get_base();

    switch (tbase) {

    case t_base_type::TYPE_STRING:

      out << "%q\"" << get_escaped_string(value) << '"';

      break;

    case t_base_type::TYPE_BOOL:

      out << (value->get_integer() > 0 ? "true" : "false");

      break;

    case t_base_type::TYPE_BYTE:

    case t_base_type::TYPE_I16:

    case t_base_type::TYPE_I32:

    case t_base_type::TYPE_I64:

      out << value->get_integer();

      break;

    case t_base_type::TYPE_DOUBLE:

      if (value->get_type() == t_const_value::CV_INTEGER) {

        out << value->get_integer();

      } else {

        out << value->get_double();

      }

      break;

    default:

      throw "compiler error: no const of base type " + t_base_type::t_base_name(tbase);

    }

  } else if (type->is_enum()) {

    indent(out) << value->get_integer();

  } else if (type->is_struct() || type->is_xception()) {

    out << full_type_name(type) << ".new({" << endl;

    indent_up();

    const vector<t_field*>& fields = ((t_struct*)type)->get_members();

    vector<t_field*>::const_iterator f_iter;

    const map<t_const_value*, t_const_value*>& val = value->get_map();

    map<t_const_value*, t_const_value*>::const_iterator v_iter;

    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {

      t_type* field_type = NULL;

      for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

        if ((*f_iter)->get_name() == v_iter->first->get_string()) {

          field_type = (*f_iter)->get_type();

        }

      }

      if (field_type == NULL) {

        throw "type error: " + type->get_name() + " has no field " + v_iter->first->get_string();

      }

      out << indent();

      out << render_const_value(g_type_string, v_iter->first);

      out << " => ";

      out << render_const_value(field_type, v_iter->second);

      out << "," << endl;

    }

    indent_down();

    indent(out) << "})";

  } else if (type->is_map()) {

    t_type* ktype = ((t_map*)type)->get_key_type();

    t_type* vtype = ((t_map*)type)->get_val_type();

    out << "{" << endl;

    indent_up();

    const map<t_const_value*, t_const_value*>& val = value->get_map();

    map<t_const_value*, t_const_value*>::const_iterator v_iter;

    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {

      out << indent();

      out << render_const_value(ktype, v_iter->first);

      out << " => ";

      out << render_const_value(vtype, v_iter->second);

      out << "," << endl;

    }

    indent_down();

    indent(out) << "}";

  } else if (type->is_list() || type->is_set()) {

    t_type* etype;

    if (type->is_list()) {

      etype = ((t_list*)type)->get_elem_type();

    } else {

      etype = ((t_set*)type)->get_elem_type();

    }

    if (type->is_set()) {

      out << "Set.new([" << endl;

    } else {

      out << "[" << endl;

    }

    indent_up();

    const vector<t_const_value*>& val = value->get_list();

    vector<t_const_value*>::const_iterator v_iter;

    for (v_iter = val.begin(); v_iter != val.end(); ++v_iter) {

      out << indent();

      out << render_const_value(etype, *v_iter);

      out << "," << endl;

    }

    indent_down();

    if (type->is_set()) {

      indent(out) << "])";

    } else {

      indent(out) << "]";

    }

  } else {

    throw "CANNOT GENERATE CONSTANT FOR TYPE: " + type->get_name();

  }

  return out.str();

}

/**

 * Generates a ruby struct

 */

void t_rb_generator::generate_struct(t_struct* tstruct) {

  generate_rb_struct(f_types_, tstruct, false);

}

/**

 * Generates a struct definition for a thrift exception. Basically the same

 * as a struct but extends the Exception class.

 *

 * @param txception The struct definition

 */

void t_rb_generator::generate_xception(t_struct* txception) {

  generate_rb_struct(f_types_, txception, true);

}

/**

 * Generates a ruby struct

 */

void t_rb_generator::generate_rb_struct(std::ofstream& out, t_struct* tstruct, bool is_exception = false) {

  generate_rdoc(out, tstruct);

  indent(out) << "class " << type_name(tstruct);

  if (is_exception) {

    out << " < ::Thrift::Exception";

  }

  out << endl;

  indent_up();

  indent(out) << "include ::Thrift::Struct" << endl;

  if (is_exception) {

    generate_rb_simple_exception_constructor(out, tstruct);

  }

  generate_field_constants(out, tstruct);

  generate_accessors(out, tstruct);

  generate_field_defns(out, tstruct);

  generate_rb_struct_required_validator(out, tstruct);

  indent_down();

  indent(out) << "end" << endl << endl;

}

void t_rb_generator::generate_rb_simple_exception_constructor(std::ofstream& out, t_struct* tstruct) {

  const vector<t_field*>& members = tstruct->get_members();

  if (members.size() == 1) {

    vector<t_field*>::const_iterator m_iter = members.begin();

    if ((*m_iter)->get_type()->is_string()) {

      string name = (*m_iter)->get_name();

      indent(out) << "def initialize(message=nil)" << endl;

      indent_up();

      indent(out) << "super()" << endl;

      indent(out) << "self." << name << " = message" << endl;

      indent_down();

      indent(out) << "end" << endl << endl;

      if (name != "message") {

        indent(out) << "def message; " << name << " end" << endl << endl;

      }

    }

  }

}

void t_rb_generator::generate_field_constants(std::ofstream& out, t_struct* tstruct) {

  const vector<t_field*>& fields = tstruct->get_members();

  vector<t_field*>::const_iterator f_iter;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    std::string field_name = (*f_iter)->get_name();

    std::string cap_field_name = upcase_string(field_name);

    indent(out) << cap_field_name << " = " << (*f_iter)->get_key() << endl;

  }

  out << endl;

}

void t_rb_generator::generate_accessors(std::ofstream& out, t_struct* tstruct) {

  const vector<t_field*>& members = tstruct->get_members();

  vector<t_field*>::const_iterator m_iter;

  if (members.size() > 0) {

    indent(out) << "::Thrift::Struct.field_accessor self";

    for (m_iter = members.begin(); m_iter != members.end(); ++m_iter) {

      out << ", :" << (*m_iter)->get_name();

    }

    out << endl;

  }

}

void t_rb_generator::generate_field_defns(std::ofstream& out, t_struct* tstruct) {

  const vector<t_field*>& fields = tstruct->get_members();

  vector<t_field*>::const_iterator f_iter;

  indent(out) << "FIELDS = {" << endl;

  indent_up();

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    if (f_iter != fields.begin()) {

      out << "," << endl;

    }

    // generate the field docstrings within the FIELDS constant. no real better place...

    generate_rdoc(out, *f_iter);

    indent(out) <<

      upcase_string((*f_iter)->get_name()) << " => ";

    generate_field_data(out, (*f_iter)->get_type(), (*f_iter)->get_name(), (*f_iter)->get_value(), 

      (*f_iter)->get_req() == t_field::T_OPTIONAL);

  }

  indent_down();

  out << endl;

  indent(out) << "}" << endl << endl;

  indent(out) << "def struct_fields; FIELDS; end" << endl << endl;

}

void t_rb_generator::generate_field_data(std::ofstream& out, t_type* field_type,

    const std::string& field_name = "", t_const_value* field_value = NULL, bool optional = false) {

  field_type = get_true_type(field_type);

  // Begin this field's defn

  out << "{:type => " << type_to_enum(field_type);

  if (!field_name.empty()) {

    out << ", :name => '" << field_name << "'";

  }

  if (field_value != NULL) {

    out << ", :default => " << render_const_value(field_type, field_value);

  }

  if (!field_type->is_base_type()) {

    if (field_type->is_struct() || field_type->is_xception()) {

      out << ", :class => " << full_type_name((t_struct*)field_type);

    } else if (field_type->is_list()) {

      out << ", :element => ";

      generate_field_data(out, ((t_list*)field_type)->get_elem_type());

    } else if (field_type->is_map()) {

      out << ", :key => ";

      generate_field_data(out, ((t_map*)field_type)->get_key_type());

      out << ", :value => ";

      generate_field_data(out, ((t_map*)field_type)->get_val_type());

    } else if (field_type->is_set()) {

      out << ", :element => ";

      generate_field_data(out, ((t_set*)field_type)->get_elem_type());

    }

  }

  if(optional) {

    out << ", :optional => true";

  }

  if (field_type->is_enum()) {

    out << ", :enum_class => " << full_type_name(field_type);

  }

  // End of this field's defn

  out << "}";

}

void t_rb_generator::begin_namespace(std::ofstream& out, vector<std::string> modules) {

  for (vector<std::string>::iterator m_iter = modules.begin(); m_iter != modules.end(); ++m_iter) {

    indent(out) << "module " << *m_iter << endl;

    indent_up();

  }

}

void t_rb_generator::end_namespace(std::ofstream& out, vector<std::string> modules) {

  for (vector<std::string>::reverse_iterator m_iter = modules.rbegin(); m_iter != modules.rend(); ++m_iter) {

    indent_down();

    indent(out) << "end" << endl;

  }

}

/**

 * Generates a thrift service.

 *

 * @param tservice The service definition

 */

void t_rb_generator::generate_service(t_service* tservice) {

  string f_service_name = get_out_dir()+underscore(service_name_)+".rb";

  f_service_.open(f_service_name.c_str());

  f_service_ <<

    rb_autogen_comment() << endl <<

    "require 'thrift'" << endl;

  if (tservice->get_extends() != NULL) {

    f_service_ <<

      "require '" << underscore(tservice->get_extends()->get_name()) << "'" << endl;

  }

  f_service_ <<

    "require '" << underscore(program_name_) << "_types'" << endl <<

    endl;

  begin_namespace(f_service_, ruby_modules(tservice->get_program()));

  indent(f_service_) << "module " << capitalize(tservice->get_name()) << endl;

  indent_up();

  // Generate the three main parts of the service (well, two for now in PHP)

  generate_service_client(tservice);

  generate_service_server(tservice);

  generate_service_helpers(tservice);

  indent_down();

  indent(f_service_) << "end" << endl <<

    endl;

  end_namespace(f_service_, ruby_modules(tservice->get_program()));

  // Close service file

  f_service_.close();

}

/**

 * Generates helper functions for a service.

 *

 * @param tservice The service to generate a header definition for

 */

void t_rb_generator::generate_service_helpers(t_service* tservice) {

  vector<t_function*> functions = tservice->get_functions();

  vector<t_function*>::iterator f_iter;

  indent(f_service_) <<

    "# HELPER FUNCTIONS AND STRUCTURES" << endl << endl;

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {

    t_struct* ts = (*f_iter)->get_arglist();

    generate_rb_struct(f_service_, ts);

    generate_rb_function_helpers(*f_iter);

  }

}

/**

 * Generates a struct and helpers for a function.

 *

 * @param tfunction The function

 */

void t_rb_generator::generate_rb_function_helpers(t_function* tfunction) {

  t_struct result(program_, tfunction->get_name() + "_result");

  t_field success(tfunction->get_returntype(), "success", 0);

  if (!tfunction->get_returntype()->is_void()) {

    result.append(&success);

  }

  t_struct* xs = tfunction->get_xceptions();

  const vector<t_field*>& fields = xs->get_members();

  vector<t_field*>::const_iterator f_iter;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    result.append(*f_iter);

  }

  generate_rb_struct(f_service_, &result);

}

/**

 * Generates a service client definition.

 *

 * @param tservice The service to generate a server for.

 */

void t_rb_generator::generate_service_client(t_service* tservice) {

  string extends = "";

  string extends_client = "";

  if (tservice->get_extends() != NULL) {

    extends = full_type_name(tservice->get_extends());

    extends_client = " < " + extends + "::Client ";

  }

  indent(f_service_) <<

    "class Client" << extends_client << endl;

  indent_up();

  indent(f_service_) <<

    "include ::Thrift::Client" << endl << endl;

  // Generate client method implementations

  vector<t_function*> functions = tservice->get_functions();

  vector<t_function*>::const_iterator f_iter;

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {

    t_struct* arg_struct = (*f_iter)->get_arglist();

    const vector<t_field*>& fields = arg_struct->get_members();

    vector<t_field*>::const_iterator fld_iter;

    string funname = (*f_iter)->get_name();

    // Open function

    indent(f_service_) <<

      "def " << function_signature(*f_iter) << endl;

    indent_up();

      indent(f_service_) <<

        "send_" << funname << "(";

      bool first = true;

      for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {

        if (first) {

          first = false;

        } else {

          f_service_ << ", ";

        }

        f_service_ << (*fld_iter)->get_name();

      }

      f_service_ << ")" << endl;

      if (!(*f_iter)->is_oneway()) {

        f_service_ << indent();

        if (!(*f_iter)->get_returntype()->is_void()) {

          f_service_ << "return ";

        }

        f_service_ <<

          "recv_" << funname << "()" << endl;

      }

    indent_down();

    indent(f_service_) << "end" << endl;

    f_service_ << endl;

    indent(f_service_) <<

      "def send_" << function_signature(*f_iter) << endl;

    indent_up();

      std::string argsname = capitalize((*f_iter)->get_name() + "_args");

      indent(f_service_) << "send_message('" << funname << "', " << argsname;

      for (fld_iter = fields.begin(); fld_iter != fields.end(); ++fld_iter) {

        f_service_ << ", :" << (*fld_iter)->get_name() << " => " << (*fld_iter)->get_name();

      }

      f_service_ << ")" << endl;

    indent_down();

    indent(f_service_) << "end" << endl;

    if (!(*f_iter)->is_oneway()) {

      std::string resultname = capitalize((*f_iter)->get_name() + "_result");

      t_struct noargs(program_);

      t_function recv_function((*f_iter)->get_returntype(),

                               string("recv_") + (*f_iter)->get_name(),

                               &noargs);

      // Open function

      f_service_ <<

        endl <<

        indent() << "def " << function_signature(&recv_function) << endl;

      indent_up();

      // TODO(mcslee): Validate message reply here, seq ids etc.

      f_service_ <<

        indent() << "result = receive_message(" << resultname << ")" << endl;

      // Careful, only return _result if not a void function

      if (!(*f_iter)->get_returntype()->is_void()) {

        f_service_ <<

          indent() << "return result.success unless result.success.nil?" << endl;

      }

      t_struct* xs = (*f_iter)->get_xceptions();

      const std::vector<t_field*>& xceptions = xs->get_members();

      vector<t_field*>::const_iterator x_iter;

      for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {

        indent(f_service_) <<

          "raise result." << (*x_iter)->get_name() <<

            " unless result." << (*x_iter)->get_name() << ".nil?" << endl;

      }

      // Careful, only return _result if not a void function

      if ((*f_iter)->get_returntype()->is_void()) {

        indent(f_service_) <<

          "return" << endl;

      } else {

        f_service_ <<

          indent() << "raise ::Thrift::ApplicationException.new(::Thrift::ApplicationException::MISSING_RESULT, '" << (*f_iter)->get_name() << " failed: unknown result')" << endl;

      }

      // Close function

      indent_down();

      indent(f_service_) << "end" << endl << endl;

    }

  }

  indent_down();

  indent(f_service_) << "end" << endl << endl;

}

/**

 * Generates a service server definition.

 *

 * @param tservice The service to generate a server for.

 */

void t_rb_generator::generate_service_server(t_service* tservice) {

  // Generate the dispatch methods

  vector<t_function*> functions = tservice->get_functions();

  vector<t_function*>::iterator f_iter;

  string extends = "";

  string extends_processor = "";

  if (tservice->get_extends() != NULL) {

    extends = full_type_name(tservice->get_extends());

    extends_processor = " < " + extends + "::Processor ";

  }

  // Generate the header portion

  indent(f_service_) <<

    "class Processor" << extends_processor << endl;

  indent_up();

  f_service_ <<

    indent() << "include ::Thrift::Processor" << endl <<

    endl;

  // Generate the process subfunctions

  for (f_iter = functions.begin(); f_iter != functions.end(); ++f_iter) {

    generate_process_function(tservice, *f_iter);

  }

  indent_down();

  indent(f_service_) << "end" << endl << endl;

}

/**

 * Generates a process function definition.

 *

 * @param tfunction The function to write a dispatcher for

 */

void t_rb_generator::generate_process_function(t_service* tservice,

                                               t_function* tfunction) {

  // Open function

  indent(f_service_) <<

    "def process_" << tfunction->get_name() <<

    "(seqid, iprot, oprot)" << endl;

  indent_up();

  string argsname = capitalize(tfunction->get_name()) + "_args";

  string resultname = capitalize(tfunction->get_name()) + "_result";

  f_service_ <<

    indent() << "args = read_args(iprot, " << argsname << ")" << endl;

  t_struct* xs = tfunction->get_xceptions();

  const std::vector<t_field*>& xceptions = xs->get_members();

  vector<t_field*>::const_iterator x_iter;

  // Declare result for non oneway function

  if (!tfunction->is_oneway()) {

    f_service_ <<

      indent() << "result = " << resultname << ".new()" << endl;

  }

  // Try block for a function with exceptions

  if (xceptions.size() > 0) {

    f_service_ <<

      indent() << "begin" << endl;

    indent_up();

  }

  // Generate the function call

  t_struct* arg_struct = tfunction->get_arglist();

  const std::vector<t_field*>& fields = arg_struct->get_members();

  vector<t_field*>::const_iterator f_iter;

  f_service_ << indent();

  if (!tfunction->is_oneway() && !tfunction->get_returntype()->is_void()) {

    f_service_ << "result.success = ";

  }

  f_service_ <<

    "@handler." << tfunction->get_name() << "(";

  bool first = true;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    if (first) {

      first = false;

    } else {

      f_service_ << ", ";

    }

    f_service_ << "args." << (*f_iter)->get_name();

  }

  f_service_ << ")" << endl;

  if (!tfunction->is_oneway() && xceptions.size() > 0) {

    indent_down();

    for (x_iter = xceptions.begin(); x_iter != xceptions.end(); ++x_iter) {

      f_service_ <<

        indent() << "rescue " << full_type_name((*x_iter)->get_type()) << " => " << (*x_iter)->get_name() << endl;

      if (!tfunction->is_oneway()) {

        indent_up();

        f_service_ <<

          indent() << "result." << (*x_iter)->get_name() << " = " << (*x_iter)->get_name() << endl;

        indent_down();

      }

    }

    indent(f_service_) << "end" << endl;

  }

  // Shortcut out here for oneway functions

  if (tfunction->is_oneway()) {

    f_service_ <<

      indent() << "return" << endl;

    indent_down();

    indent(f_service_) << "end" << endl << endl;

    return;

  }

  f_service_ <<

    indent() << "write_result(result, oprot, '" << tfunction->get_name() << "', seqid)" << endl;

  // Close function

  indent_down();

  indent(f_service_) << "end" << endl << endl;

}

/**

 * Renders a function signature of the form 'type name(args)'

 *

 * @param tfunction Function definition

 * @return String of rendered function definition

 */

string t_rb_generator::function_signature(t_function* tfunction,

                                           string prefix) {

  // TODO(mcslee): Nitpicky, no ',' if argument_list is empty

  return

    prefix + tfunction->get_name() +

    "(" +  argument_list(tfunction->get_arglist()) + ")";

}

/**

 * Renders a field list

 */

string t_rb_generator::argument_list(t_struct* tstruct) {

  string result = "";

  const vector<t_field*>& fields = tstruct->get_members();

  vector<t_field*>::const_iterator f_iter;

  bool first = true;

  for (f_iter = fields.begin(); f_iter != fields.end(); ++f_iter) {

    if (first) {

      first = false;

    } else {

      result += ", ";

    }

    result += (*f_iter)->get_name();

  }

  return result;

}