compress_cpp.cpp

#include "compress_cpp.h"
#include <stdlib.h>
#include "bundle/bundle.h"

using namespace std;
using namespace bundle;

static const std::string base64_chars =
             "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
             "abcdefghijklmnopqrstuvwxyz"
             "0123456789+/";


static inline bool is_base64(unsigned char c) {
  return (isalnum(c) || (c == '+') || (c == '/'));
}

std::string base64_encode(char const* bytes_to_encode, unsigned int in_len) {
  std::string ret;
  int i = 0;
  int j = 0;
  unsigned char char_array_3[3];
  unsigned char char_array_4[4];

  while (in_len--) {
    char_array_3[i++] = *(bytes_to_encode++);
    if (i == 3) {
      char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
      char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
      char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
      char_array_4[3] = char_array_3[2] & 0x3f;

      for(i = 0; (i <4) ; i++)
        ret += base64_chars[char_array_4[i]];
      i = 0;
    }
  }

  if (i)
  {
    for(j = i; j < 3; j++)
      char_array_3[j] = '\0';

    char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
    char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
    char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
    char_array_4[3] = char_array_3[2] & 0x3f;

    for (j = 0; (j < i + 1); j++)
      ret += base64_chars[char_array_4[j]];

    while((i++ < 3))
      ret += '=';

  }
  return ret;
}

std::string base64_decode(std::string const& encoded_string) {
  int in_len = encoded_string.size();
  int i = 0;
  int j = 0;
  int in_ = 0;
  unsigned char char_array_4[4], char_array_3[3];
  std::string ret;

  while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
    char_array_4[i++] = encoded_string[in_]; in_++;
    if (i ==4) {
      for (i = 0; i <4; i++)
        char_array_4[i] = base64_chars.find(char_array_4[i]);

      char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
      char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
      char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

      for (i = 0; (i < 3); i++)
        ret += char_array_3[i];
      i = 0;
    }
  }

  if (i) {
    for (j = i; j <4; j++)
      char_array_4[j] = 0;

    for (j = 0; j <4; j++)
      char_array_4[j] = base64_chars.find(char_array_4[j]);

    char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
    char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
    char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];

    for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
  }

  return ret;
}

// file_num     -- в zip архиве может быть несколько файлов.
extern "C" int unzip_base64_cpp(const char* packed, const int packed_len, char** unpacked, int *unpacked_len, const int file_num)
{
  try
  {
    archive pak;
    if ( ! pak.zip(base64_decode(string(packed, packed_len))) )
      return 1; // Неудалось разархивировать

    *unpacked_len = pak[file_num]["data"].length();
    *unpacked = (char*) malloc(*unpacked_len  * sizeof(char));
    if (*unpacked == NULL)
      return 2; // Ошибка выделения памяти
    copy(pak[file_num]["data"].begin(), pak[file_num]["data"].end(), *unpacked);
  }
  catch(...)
  {
    return 3;
  }

  return 0;
}

// compress_level: 10 (fast), 50 (middle), 90 (slow, best compression)
extern "C" int zip_base64_cpp(const char* file_name, const int file_name_len, const char* data, const int data_len, char** packed, int *packed_len, const int compress_level)
{
  try
  {
    file data_file;
    data_file["name"] = string(file_name, file_name_len);
    data_file["data"] = string(data, data_len);

    archive pak;
    pak.push_back(data_file);
    string packed_str = pak.zip(compress_level);

    string packed_base64_str = base64_encode(packed_str.data(), packed_str.length());

    *packed_len = packed_base64_str.length();
    *packed = (char*) malloc(*packed_len  * sizeof(char));
    if (*packed == NULL)
      return 2; // Ошибка выделения памяти
    copy(packed_base64_str.begin(), packed_base64_str.end(), *packed);
  }
  catch(...)
  {
    return 3;
  }

  return 0;
}