/*
* 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
int bson_oid_compare (const bson_oid_t *oid1,
const bson_oid_t *oid2);
void bson_oid_copy (const bson_oid_t *src,
bson_oid_t *dst);
bool bson_oid_equal (const bson_oid_t *oid1,
const bson_oid_t *oid2);
bool bson_oid_is_valid (const char *str,
size_t length);
time_t bson_oid_get_time_t (const bson_oid_t *oid);
uint32_t bson_oid_hash (const bson_oid_t *oid);
void bson_oid_init (bson_oid_t *oid,
bson_context_t *context);
void bson_oid_init_from_data (bson_oid_t *oid,
const uint8_t *data);
void bson_oid_init_from_string (bson_oid_t *oid,
const char *str);
void bson_oid_init_sequence (bson_oid_t *oid,
bson_context_t *context);
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 */