text: /**
   * Copyright (c) 2014, Timothy Stack
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * * Redistributions of source code must retain the above copyright notice, this
   * list of conditions and the following disclaimer.
   * * Redistributions in binary form must reproduce the above copyright notice,
   * this list of conditions and the following disclaimer in the documentation
   * and/or other materials provided with the distribution.
   * * Neither the name of Timothy Stack nor the names of its contributors
   * may be used to endorse or promote products derived from this software
   * without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY TIMOTHY STACK AND CONTRIBUTORS ''AS IS'' AND ANY
   * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
   * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
   * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   * @file drive_json_op.cc
   */
  
  #include "config.h"
  
  #include <errno.h>
  #include <stdlib.h>
  
  #include "yajl/api/yajl_gen.h"
  
  #include "yajlpp/json_op.hh"
  #include "base/lnav_log.hh"
  
  static void printer(void *ctx, const char *numberVal, size_t numberLen)
  {
      log_perror(write(STDOUT_FILENO, numberVal, numberLen));
  }
  
  static int handle_start_map(void *ctx)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_map_open(gen);
  
      return 1;
  }
  
  static int handle_map_key(void *ctx, const unsigned char * key, size_t len)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_string(gen, key, len);
  
      return 1;
  }
  
  static int handle_end_map(void *ctx)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_map_close(gen);
  
      return 1;
  }
  
  static int handle_null(void *ctx)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_null(gen);
  
      return 1;
  }
  
  static int handle_boolean(void *ctx, int boolVal)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_bool(gen, boolVal);
  
      return 1;
  }
  
  static int handle_number(void *ctx, const char *numberVal, size_t numberLen)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_number(gen, numberVal, numberLen);
  
      return 1;
  }
  
  static int handle_string(void *ctx, const unsigned char * stringVal, size_t len)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_string(gen, stringVal, len);
  
      return 1;
  }
  
  static int handle_start_array(void *ctx)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_array_open(gen);
  
      return 1;
  }
  
  static int handle_end_array(void *ctx)
  {
      json_op *jo = (json_op *)ctx;
      yajl_gen gen = (yajl_gen)jo->jo_ptr_data;
  
      yajl_gen_array_close(gen);
  
      return 1;
  }
  
  int main(int argc, char *argv[])
  {
      int retval = EXIT_SUCCESS;
  
      log_argv(argc, argv);
  
      if (argc != 3) {
          fprintf(stderr, "error: expecting operation and json-pointer\n");
          retval = EXIT_FAILURE;
      }
      else if (strcmp(argv[1], "get") == 0) {
          unsigned char buffer[1024];
          json_ptr jptr(argv[2]);
          json_op jo(jptr);
          yajl_handle handle;
          yajl_status status;
          yajl_gen gen;
          ssize_t rc;
  
          gen = yajl_gen_alloc(nullptr);
          yajl_gen_config(gen, yajl_gen_print_callback, printer, nullptr);
          yajl_gen_config(gen, yajl_gen_beautify, true);
  
          jo.jo_ptr_callbacks.yajl_start_map = handle_start_map;
          jo.jo_ptr_callbacks.yajl_map_key = handle_map_key;
          jo.jo_ptr_callbacks.yajl_end_map = handle_end_map;
          jo.jo_ptr_callbacks.yajl_start_array = handle_start_array;
          jo.jo_ptr_callbacks.yajl_end_array = handle_end_array;
          jo.jo_ptr_callbacks.yajl_null = handle_null;
          jo.jo_ptr_callbacks.yajl_boolean = handle_boolean;
          jo.jo_ptr_callbacks.yajl_number = handle_number;
          jo.jo_ptr_callbacks.yajl_string = handle_string;
          jo.jo_ptr_data = gen;
  
          handle = yajl_alloc(&json_op::ptr_callbacks, nullptr, &jo);
          while ((rc = read(STDIN_FILENO, buffer, sizeof(buffer))) > 0) {
              status = yajl_parse(handle, buffer, rc);
              if (status == yajl_status_error) {
                  fprintf(stderr, "error:cannot parse JSON input -- %s\n",
                      yajl_get_error(handle, 1, buffer, rc));
                  retval = EXIT_FAILURE;
                  break;
              }
              else if (status == yajl_status_client_canceled) {
                  fprintf(stderr, "client cancel\n");
                  break;
              }
          }
          status = yajl_complete_parse(handle);
          if (status == yajl_status_error) {
              fprintf(stderr, "error:cannot parse JSON input -- %s\n",
                  yajl_get_error(handle, 1, buffer, rc));
              retval = EXIT_FAILURE;
          }
          else if (status == yajl_status_client_canceled) {
              fprintf(stderr, "client cancel\n");
          }
          yajl_free(handle);
      }
      else {
          fprintf(stderr, "error: unknown operation -- %s\n", argv[1]);
          retval = EXIT_FAILURE;
      }
  
      return retval;
  }
  