text: /*
   * 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.
   */
  
  
  #ifndef BSON_OID_H
  #define BSON_OID_H
  
  
  #if !defined(BSON_INSIDE) && !defined(BSON_COMPILATION)
  #error "Only <bson.h> can be included directly."
  #endif
  
  
  #include <time.h>
  
  #include "bson-context.h"
  #include "bson-macros.h"
  #include "bson-types.h"
  #include "bson-endian.h"
  
  
  BSON_BEGIN_DECLS
  
  
  BSON_EXPORT (int)
  bson_oid_compare (const bson_oid_t *oid1, const bson_oid_t *oid2);
  BSON_EXPORT (void)
  bson_oid_copy (const bson_oid_t *src, bson_oid_t *dst);
  BSON_EXPORT (bool)
  bson_oid_equal (const bson_oid_t *oid1, const bson_oid_t *oid2);
  BSON_EXPORT (bool)
  bson_oid_is_valid (const char *str, size_t length);
  BSON_EXPORT (time_t)
  bson_oid_get_time_t (const bson_oid_t *oid);
  BSON_EXPORT (uint32_t)
  bson_oid_hash (const bson_oid_t *oid);
  BSON_EXPORT (void)
  bson_oid_init (bson_oid_t *oid, bson_context_t *context);
  BSON_EXPORT (void)
  bson_oid_init_from_data (bson_oid_t *oid, const uint8_t *data);
  BSON_EXPORT (void)
  bson_oid_init_from_string (bson_oid_t *oid, const char *str);
  BSON_EXPORT (void)
  bson_oid_init_sequence (bson_oid_t *oid, bson_context_t *context);
  BSON_EXPORT (void)
  bson_oid_to_string (const bson_oid_t *oid, char str[25]);
  
  
  /**
   * bson_oid_compare_unsafe:
   * @oid1: A bson_oid_t.
   * @oid2: A bson_oid_t.
   *
   * Performs a qsort() style comparison between @oid1 and @oid2.
   *
   * This function is meant to be as fast as possible and therefore performs
   * no argument validation. That is the callers responsibility.
   *
   * Returns: An integer < 0 if @oid1 is less than @oid2. Zero if they are equal.
   *          An integer > 0 if @oid1 is greater than @oid2.
   */
  static BSON_INLINE int
  bson_oid_compare_unsafe (const bson_oid_t *oid1, const bson_oid_t *oid2)
  {
     return memcmp (oid1, oid2, sizeof *oid1);
  }
  
  
  /**
   * bson_oid_equal_unsafe:
   * @oid1: A bson_oid_t.
   * @oid2: A bson_oid_t.
   *
   * Checks the equality of @oid1 and @oid2.
   *
   * This function is meant to be as fast as possible and therefore performs
   * no checks for argument validity. That is the callers responsibility.
   *
   * Returns: true if @oid1 and @oid2 are equal; otherwise false.
   */
  static BSON_INLINE bool
  bson_oid_equal_unsafe (const bson_oid_t *oid1, const bson_oid_t *oid2)
  {
     return !memcmp (oid1, oid2, sizeof *oid1);
  }
  
  /**
   * bson_oid_hash_unsafe:
   * @oid: A bson_oid_t.
   *
   * This function performs a DJB style hash upon the bytes contained in @oid.
   * The result is a hash key suitable for use in a hashtable.
   *
   * This function is meant to be as fast as possible and therefore performs no
   * validation of arguments. The caller is responsible to ensure they are
   * passing valid arguments.
   *
   * Returns: A uint32_t containing a hash code.
   */
  static BSON_INLINE uint32_t
  bson_oid_hash_unsafe (const bson_oid_t *oid)
  {
     uint32_t hash = 5381;
     uint32_t i;
  
     for (i = 0; i < sizeof oid->bytes; i++) {
        hash = ((hash << 5) + hash) + oid->bytes[i];
     }
  
     return hash;
  }
  
  
  /**
   * bson_oid_copy_unsafe:
   * @src: A bson_oid_t to copy from.
   * @dst: A bson_oid_t to copy into.
   *
   * Copies the contents of @src into @dst. This function is meant to be as
   * fast as possible and therefore performs no argument checking. It is the
   * callers responsibility to ensure they are passing valid data into the
   * function.
   */
  static BSON_INLINE void
  bson_oid_copy_unsafe (const bson_oid_t *src, bson_oid_t *dst)
  {
     memcpy (dst, src, sizeof *src);
  }
  
  
  /**
   * bson_oid_parse_hex_char:
   * @hex: A character to parse to its integer value.
   *
   * This function contains a jump table to return the integer value for a
   * character containing a hexidecimal value (0-9, a-f, A-F). If the character
   * is not a hexidecimal character then zero is returned.
   *
   * Returns: An integer between 0 and 15.
   */
  static BSON_INLINE uint8_t
  bson_oid_parse_hex_char (char hex)
  {
     switch (hex) {
     case '0':
        return 0;
     case '1':
        return 1;
     case '2':
        return 2;
     case '3':
        return 3;
     case '4':
        return 4;
     case '5':
        return 5;
     case '6':
        return 6;
     case '7':
        return 7;
     case '8':
        return 8;
     case '9':
        return 9;
     case 'a':
     case 'A':
        return 0xa;
     case 'b':
     case 'B':
        return 0xb;
     case 'c':
     case 'C':
        return 0xc;
     case 'd':
     case 'D':
        return 0xd;
     case 'e':
     case 'E':
        return 0xe;
     case 'f':
     case 'F':
        return 0xf;
     default:
        return 0;
     }
  }
  
  
  /**
   * bson_oid_init_from_string_unsafe:
   * @oid: A bson_oid_t to store the result.
   * @str: A 24-character hexidecimal encoded string.
   *
   * Parses a string containing 24 hexidecimal encoded bytes into a bson_oid_t.
   * This function is meant to be as fast as possible and inlined into your
   * code. For that purpose, the function does not perform any sort of bounds
   * checking and it is the callers responsibility to ensure they are passing
   * valid input to the function.
   */
  static BSON_INLINE void
  bson_oid_init_from_string_unsafe (bson_oid_t *oid, const char *str)
  {
     int i;
  
     for (i = 0; i < 12; i++) {
        oid->bytes[i] = ((bson_oid_parse_hex_char (str[2 * i]) << 4) |
                         (bson_oid_parse_hex_char (str[2 * i + 1])));
     }
  }
  
  
  /**
   * bson_oid_get_time_t_unsafe:
   * @oid: A bson_oid_t.
   *
   * Fetches the time @oid was generated.
   *
   * Returns: A time_t containing the UNIX timestamp of generation.
   */
  static BSON_INLINE time_t
  bson_oid_get_time_t_unsafe (const bson_oid_t *oid)
  {
     uint32_t t;
  
     memcpy (&t, oid, sizeof (t));
     return BSON_UINT32_FROM_BE (t);
  }
  
  
  BSON_END_DECLS
  
  
  #endif /* BSON_OID_H */
  