SQLite3Wrapper.cc

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#include "art/Framework/IO/Root/RootDB/SQLite3Wrapper.h"

#include "art/Framework/IO/Root/RootDB/SQLErrMsg.h"
#include "art/Framework/IO/Root/RootDB/tkeyvfs.h"
#include "canvas/Utilities/Exception.h"
#include "messagefacility/MessageLogger/MessageLogger.h"

#include <cassert>
#include <cstddef>

namespace {

  enum DBTYPE { SQLITE3_TKEYDB, SQLITE3_MEMDB, SQLITE3_FILEDB, SQLITE3_TMPDB };

  std::string
  dbTypeAsString(DBTYPE type)
  {
    std::string result;
    switch (type) {
      case SQLITE3_TKEYDB:
        result = "tkeyvfs";
        break;
      case SQLITE3_MEMDB:
        result = "in-memory";
        break;
      case SQLITE3_FILEDB:
        result = "file";
        break;
      case SQLITE3_TMPDB:
        result = "tmp";
        break;
      default:
        result = "UNKNOWN";
        break;
    }
    return result;
  }

  void
  traceit(void* string_ptr, const char* zSQL)
  {
    assert(string_ptr);
    mf::LogAbsolute("SQLTrace")
      << "+ SQLTrace (" << *reinterpret_cast<std::string*>(string_ptr)
      << "): " << zSQL;
  }
}

art::SQLite3Wrapper::SQLite3Wrapper() : db_(0), key_() {}

art::SQLite3Wrapper::SQLite3Wrapper(std::string const& key, int flags)
  : db_(0), key_(key)
{
  initDB(flags);
}

art::SQLite3Wrapper::SQLite3Wrapper(TFile* tfile,
                                    std::string const& key,
                                    int flags)
  : db_(0), key_(key)
{
  initDB(flags, tfile);
}

bool
art::SQLite3Wrapper::wantTracing()
{
  static char const* s_debug = getenv("ART_DEBUG_SQL");
  return s_debug;
}

void
art::SQLite3Wrapper::reset()
{
  SQLite3Wrapper tmp;
  swap(tmp);
}

void
art::SQLite3Wrapper::reset(std::string const& key, int flags)
{
  SQLite3Wrapper tmp{key, flags};
  swap(tmp);
}

void
art::SQLite3Wrapper::reset(TFile* tfile, std::string const& key, int flags)
{
  SQLite3Wrapper tmp{tfile, key, flags};
  swap(tmp);
}

art::SQLite3Wrapper::~SQLite3Wrapper()
{
  if (db_) {
    sqlite3_close(db_);
  }
}

void
art::SQLite3Wrapper::swap(SQLite3Wrapper& other)
{
  using std::swap;
  swap(db_, other.db_);
  swap(key_, other.key_);
}

void
art::SQLite3Wrapper::initDB(int flags, TFile* tfile)
{
  int err = 0;
  DBTYPE type = tfile ? SQLITE3_TKEYDB :
                        key_.size() ?
                        (key_ == ":memory:" ? SQLITE3_MEMDB : SQLITE3_FILEDB) :
                        SQLITE3_TMPDB;
  switch (type) {
    case SQLITE3_TKEYDB:
      if (!key_.size()) {
        throw Exception{errors::FileOpenError}
          << "Failed to open TKEYVFS DB due to empty key spec.\n";
      }
      err = tkeyvfs_open_v2(key_.c_str(), &db_, flags, tfile);
      break;
    case SQLITE3_MEMDB:
      err = sqlite3_open(key_.c_str(), &db_);
      break;
    case SQLITE3_FILEDB:
      err = sqlite3_open_v2(key_.c_str(), &db_, flags, nullptr);
      break;
    case SQLITE3_TMPDB:
      err = sqlite3_open(key_.c_str(), &db_);
      break;
  }
  if (err) {
    throw Exception{errors::FileOpenError}
      << "Failed to open requested DB, \"" << key_ << "\" of type, \""
      << dbTypeAsString(type) << "\" -- " << sqlite3_errmsg(db_) << "\n";
  }
  maybeTrace();
}

void
art::SQLite3Wrapper::maybeTrace() const
{
  if (wantTracing()) {
    // Cast away constness for C interface.
    sqlite3_trace(db_, traceit, const_cast<std::string*>(&key_));
  }
}