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      1 /*
      2  * Copyright (c) 2014-2019 Pavel Kalvoda <me (at) pavelkalvoda.com>
      3  *
      4  * libcbor is free software; you can redistribute it and/or modify
      5  * it under the terms of the MIT license. See LICENSE for details.
      6  */
      7 
      8 #include "encoders.h"
      9 #include <string.h>
     10 
     11 size_t _cbor_encode_uint8(uint8_t value, unsigned char *buffer,
     12                           size_t buffer_size, uint8_t offset) {
     13   if (value <= 23) {
     14     if (buffer_size >= 1) {
     15       buffer[0] = value + offset;
     16       return 1;
     17     }
     18   } else {
     19     if (buffer_size >= 2) {
     20       buffer[0] = 0x18 + offset;
     21       buffer[1] = value;
     22       return 2;
     23     }
     24   }
     25   return 0;
     26 }
     27 
     28 size_t _cbor_encode_uint16(uint16_t value, unsigned char *buffer,
     29                            size_t buffer_size, uint8_t offset) {
     30   if (buffer_size >= 3) {
     31     buffer[0] = 0x19 + offset;
     32 
     33 #ifdef IS_BIG_ENDIAN
     34     memcpy(buffer + 1, &value, 2);
     35 #else
     36     buffer[1] = value >> 8;
     37     buffer[2] = value;
     38 #endif
     39 
     40     return 3;
     41   } else
     42     return 0;
     43 }
     44 
     45 size_t _cbor_encode_uint32(uint32_t value, unsigned char *buffer,
     46                            size_t buffer_size, uint8_t offset) {
     47   if (buffer_size >= 5) {
     48     buffer[0] = 0x1A + offset;
     49 
     50 #ifdef IS_BIG_ENDIAN
     51     memcpy(buffer + 1, &value, 4);
     52 #else
     53     buffer[1] = value >> 24;
     54     buffer[2] = value >> 16;
     55     buffer[3] = value >> 8;
     56     buffer[4] = value;
     57 #endif
     58 
     59     return 5;
     60   } else
     61     return 0;
     62 }
     63 
     64 size_t _cbor_encode_uint64(uint64_t value, unsigned char *buffer,
     65                            size_t buffer_size, uint8_t offset) {
     66   if (buffer_size >= 9) {
     67     buffer[0] = 0x1B + offset;
     68 
     69 #ifdef IS_BIG_ENDIAN
     70       memcpy(buffer + 1, &value, 8);
     71 #else
     72     buffer[1] = value >> 56;
     73     buffer[2] = value >> 48;
     74     buffer[3] = value >> 40;
     75     buffer[4] = value >> 32;
     76     buffer[5] = value >> 24;
     77     buffer[6] = value >> 16;
     78     buffer[7] = value >> 8;
     79     buffer[8] = value;
     80 #endif
     81 
     82     return 9;
     83   } else
     84     return 0;
     85 }
     86 
     87 size_t _cbor_encode_uint(uint64_t value, unsigned char *buffer,
     88                          size_t buffer_size, uint8_t offset) {
     89   if (value <= UINT16_MAX)
     90     if (value <= UINT8_MAX)
     91       return _cbor_encode_uint8((uint8_t)value, buffer, buffer_size, offset);
     92     else
     93       return _cbor_encode_uint16((uint16_t)value, buffer, buffer_size, offset);
     94   else if (value <= UINT32_MAX)
     95     return _cbor_encode_uint32((uint32_t)value, buffer, buffer_size, offset);
     96   else
     97     return _cbor_encode_uint64((uint64_t)value, buffer, buffer_size, offset);
     98 }
     99