1  // Copyright (c) 2015-present The Bitcoin Core developers
 2  // Copyright (c) 2017 The Zcash developers
 3  // Distributed under the MIT software license, see the accompanying
 4  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 5  
 6  #include <util/readwritefile.h>
 7  
 8  #include <util/fs.h>
 9  
10  #include <algorithm>
11  #include <cstdio>
12  #include <string>
13  #include <utility>
14  
15  std::pair<bool,std::string> ReadBinaryFile(const fs::path &filename, size_t maxsize)
16  {
17      FILE *f = fsbridge::fopen(filename, "rb");
18      if (f == nullptr)
19          return std::make_pair(false,"");
20      std::string retval;
21      char buffer[128];
22      do {
23          const size_t n = fread(buffer, 1, std::min(sizeof(buffer), maxsize - retval.size()), f);
24          // Check for reading errors so we don't return any data if we couldn't
25          // read the entire file (or up to maxsize)
26          if (ferror(f)) {
27              fclose(f);
28              return std::make_pair(false,"");
29          }
30          retval.append(buffer, buffer+n);
31      } while (!feof(f) && retval.size() < maxsize);
32      fclose(f);
33      return std::make_pair(true,retval);
34  }
35  
36  bool WriteBinaryFile(const fs::path &filename, const std::string &data)
37  {
38      FILE *f = fsbridge::fopen(filename, "wb");
39      if (f == nullptr)
40          return false;
41      if (fwrite(data.data(), 1, data.size(), f) != data.size()) {
42          fclose(f);
43          return false;
44      }
45      if (fclose(f) != 0) {
46          return false;
47      }
48      return true;
49  }