CDB.cpp

   1 #include "CDB.hpp"
   2
   3 #include <glog/logging.h>
   4
   5 #include <fcntl.h>
   6 #include <sys/stat.h>
   7 #include <sys/types.h>
   8
   9 CDB::~CDB()
  10 {
  11   if (is_open()) {
  12     close(fd_);
  13     cdb_free(&cdb_);
  14   }
  15 }
  16
  17 bool CDB::open(fs::path db_path)
  18 {
  19   db_path += ".cdb";
  20   auto const db_fn = db_path.string();
  21
  22   fd_ = ::open(db_fn.c_str(), O_RDONLY);
  23   if (fd_ == -1) {
  24     char       err[256]{};
  25     auto const msg = strerror_r(errno, err, sizeof(err));
  26     LOG(WARNING) << "unable to open " << db_fn << ": " << msg;
  27     return false;
  28   }
  29   cdb_init(&cdb_, fd_);
  30   return true;
  31 }
  32
  33 std::optional<std::string> CDB::find(std::string_view key)
  34 {
  35   if (!is_open())
  36     return {};
  37
  38   CHECK_LT(key.length(), std::numeric_limits<unsigned int>::max());
  39   if (cdb_find(&cdb_, key.data(), static_cast<unsigned int>(key.length())) >
  40       0) {
  41     auto const  vpos = cdb_datapos(&cdb_);
  42     auto const  vlen = cdb_datalen(&cdb_);
  43     std::string val;
  44     val.resize(vlen);
  45     cdb_read(&cdb_, &val[0], vlen, vpos);
  46     return val;
  47   }
  48
  49   return {};
  50 }
  51
  52 bool CDB::contains(std::string_view key)
  53 {
  54   if (!is_open())
  55     return false;
  56
  57   CHECK_LT(key.length(), std::numeric_limits<unsigned int>::max());
  58   return cdb_find(&cdb_, key.data(), static_cast<unsigned int>(key.length())) >
  59          0;
  60 }