bson_json_reader_t

Bulk JSON to BSON conversion

Synopsis

#include <bson.h>

typedef struct _bson_json_reader_t bson_json_reader_t;

typedef enum {
   BSON_JSON_ERROR_READ_CORRUPT_JS = 1,
   BSON_JSON_ERROR_READ_INVALID_PARAM,
   BSON_JSON_ERROR_READ_CB_FAILURE,
} bson_json_error_code_t;

Description

The bson_json_reader_t structure is used for reading a sequence of JSON documents and transforming them to bson_t documents.

This can often be useful if you want to perform bulk operations that are defined in a file containing JSON documents.

Tip

bson_json_reader_t works upon JSON documents formatted in MongoDB extended JSON format.

Example

/*
 * Copyright 2013 MongoDB, Inc.
 *
 * Licensed 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.
 */


/*
 * This program will print each JSON document contained in the provided files
 * as a BSON string to STDOUT.
 */


#include <bson.h>
#include <stdlib.h>
#include <stdio.h>


int
main (int argc, char *argv[])
{
   bson_json_reader_t *reader;
   bson_error_t error;
   const char *filename;
   bson_t doc = BSON_INITIALIZER;
   int i;
   int b;

   /*
    * Print program usage if no arguments are provided.
    */
   if (argc == 1) {
      fprintf (stderr, "usage: %s FILE...\n", argv[0]);
      return 1;
   }

   /*
    * Process command line arguments expecting each to be a filename.
    */
   for (i = 1; i < argc; i++) {
      filename = argv[i];

      /*
       * Open the filename provided in command line arguments.
       */
      if (0 == strcmp (filename, "-")) {
         reader = bson_json_reader_new_from_fd (STDIN_FILENO, false);
      } else {
         if (!(reader = bson_json_reader_new_from_file (filename, &error))) {
            fprintf (
               stderr, "Failed to open \"%s\": %s\n", filename, error.message);
            continue;
         }
      }

      /*
       * Convert each incoming document to BSON and print to stdout.
       */
      while ((b = bson_json_reader_read (reader, &doc, &error))) {
         if (b < 0) {
            fprintf (stderr, "Error in json parsing:\n%s\n", error.message);
            abort ();
         }

         if (fwrite (bson_get_data (&doc), 1, doc.len, stdout) != doc.len) {
            fprintf (stderr, "Failed to write to stdout, exiting.\n");
            exit (1);
         }
         bson_reinit (&doc);
      }

      bson_json_reader_destroy (reader);
      bson_destroy (&doc);
   }

   return 0;
}