+
−/**
+
− * Orthanc - A Lightweight, RESTful DICOM Store
+
− * Copyright (C) 2012-2016 Sebastien Jodogne, Medical Physics
+
− * Department, University Hospital of Liege, Belgium
+
− * Copyright (C) 2017-2018 Osimis S.A., Belgium
+
− *
+
− * This program is free software: you can redistribute it and/or
+
− * modify it under the terms of the GNU Affero General Public License
+
− * as published by the Free Software Foundation, either version 3 of
+
− * the License, or (at your option) any later version.
+
− *
+
− * This program is distributed in the hope that it will be useful, but
+
− * WITHOUT ANY WARRANTY; without even the implied warranty of
+
− * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+
− * Affero General Public License for more details.
+
− * 
+
− * You should have received a copy of the GNU Affero General Public License
+
− * along with this program. If not, see <http://www.gnu.org/licenses/>.
+
− **/
+
−
+
−
+
−// http://www.postgresql.org/docs/9.1/static/lo-interfaces.html#AEN33102
+
−
+
−#include "PostgreSQLLargeObject.h"
+
−
+
−#include "PostgreSQLException.h"
+
−
+
−#include <boost/lexical_cast.hpp>
+
−#include <libpq/libpq-fs.h>
+
−
+
−
+
−namespace OrthancPlugins
+
−{  
+
−  void PostgreSQLLargeObject::Create()
+
−  {
+
−    PGconn* pg = reinterpret_cast<PGconn*>(connection_.pg_);
+
−
+
−    oid_ = lo_creat(pg, INV_WRITE);
+
−    if (oid_ == 0)
+
−    {
+
−      throw PostgreSQLException("Cannot create a large object");
+
−    }
+
−  }
+
−
+
−
+
−  void PostgreSQLLargeObject::Write(const void* data, 
+
−                                    size_t size)
+
−  {
+
−    static int MAX_CHUNK_SIZE = 16 * 1024 * 1024;
+
−
+
−    PGconn* pg = reinterpret_cast<PGconn*>(connection_.pg_);
+
−
+
−    int fd = lo_open(pg, oid_, INV_WRITE);
+
−    if (fd < 0)
+
−    {
+
−      throw PostgreSQLException();
+
−    }
+
−
+
−    const char* position = reinterpret_cast<const char*>(data);
+
−    while (size > 0)
+
−    {
+
−      int chunk = (size > static_cast<size_t>(MAX_CHUNK_SIZE) ? MAX_CHUNK_SIZE : static_cast<int>(size));
+
−      int nbytes = lo_write(pg, fd, position, chunk);
+
−      if (nbytes <= 0)
+
−      {
+
−        lo_close(pg, fd);
+
−        throw PostgreSQLException();
+
−      }
+
−
+
−      size -= nbytes;
+
−      position += nbytes;
+
−    }
+
−
+
−    lo_close(pg, fd);
+
−  }
+
−
+
−
+
−  PostgreSQLLargeObject::PostgreSQLLargeObject(PostgreSQLConnection& connection,
+
−                                               const void* data,
+
−                                               size_t size) : 
+
−    connection_(connection)
+
−  {
+
−    Create();
+
−    Write(data, size);
+
−  }
+
−
+
−
+
−  PostgreSQLLargeObject::PostgreSQLLargeObject(PostgreSQLConnection& connection,
+
−                                               const std::string& s) : 
+
−    connection_(connection)
+
−  {
+
−    Create();
+
−
+
−    if (s.size() != 0)
+
−    {
+
−      Write(s.c_str(), s.size());
+
−    }
+
−    else
+
−    {
+
−      Write(NULL, 0);
+
−    }
+
−  }
+
−
+
−
+
−  class PostgreSQLLargeObject::Reader
+
−  {
+
−  private: 
+
−    PGconn* pg_;
+
−    int fd_;
+
−    size_t size_;
+
−
+
−  public:
+
−    Reader(PostgreSQLConnection& connection,
+
−           const std::string& oid)
+
−    {
+
−      pg_ = reinterpret_cast<PGconn*>(connection.pg_);
+
−      Oid id = boost::lexical_cast<Oid>(oid);
+
−
+
−      fd_ = lo_open(pg_, id, INV_READ);
+
−
+
−      if (fd_ < 0 ||
+
−          lo_lseek(pg_, fd_, 0, SEEK_END) < 0)
+
−      {
+
−        throw PostgreSQLException("No such large object in the connection; Make sure you use a transaction");
+
−      }
+
−
+
−      // Get the size of the large object
+
−      int size = lo_tell(pg_, fd_);
+
−      if (size < 0)
+
−      {
+
−        throw PostgreSQLException("Internal error");
+
−      }
+
−      size_ = static_cast<size_t>(size);
+
−
+
−      // Go to the first byte of the object
+
−      lo_lseek(pg_, fd_, 0, SEEK_SET);
+
−    }
+
−
+
−    ~Reader()
+
−    {
+
−      lo_close(pg_, fd_);
+
−    }
+
−
+
−    size_t GetSize() const
+
−    {
+
−      return size_;
+
−    }
+
−
+
−    void Read(char* target)
+
−    {
+
−      for (size_t position = 0; position < size_; )
+
−      {
+
−        size_t remaining = size_ - position;
+
−
+
−        int nbytes = lo_read(pg_, fd_, target + position, remaining);
+
−        if (nbytes < 0)
+
−        {
+
−          throw PostgreSQLException("Unable to read the large object in the database");
+
−        }
+
−
+
−        position += static_cast<size_t>(nbytes);
+
−      }
+
−    }
+
−  };
+
−  
+
−
+
−  void PostgreSQLLargeObject::Read(std::string& target,
+
−                                   PostgreSQLConnection& connection,
+
−                                   const std::string& oid)
+
−  {
+
−    Reader reader(connection, oid);
+
−    target.resize(reader.GetSize());    
+
−
+
−    if (target.size() > 0)
+
−    {
+
−      reader.Read(&target[0]);
+
−    }
+
−  }
+
−
+
−
+
−  void PostgreSQLLargeObject::Read(void*& target,
+
−                                   size_t& size,
+
−                                   PostgreSQLConnection& connection,
+
−                                   const std::string& oid)
+
−  {
+
−    Reader reader(connection, oid);
+
−    size = reader.GetSize();
+
−
+
−    if (size == 0)
+
−    {
+
−      target = NULL;
+
−    }
+
−    else
+
−    {
+
−      target = malloc(size);
+
−      reader.Read(reinterpret_cast<char*>(target));
+
−    }
+
−  }
+
−
+
−
+
−  std::string PostgreSQLLargeObject::GetOid() const
+
−  {
+
−    return boost::lexical_cast<std::string>(oid_);
+
−  }
+
−
+
−
+
−  void PostgreSQLLargeObject::Delete(PostgreSQLConnection& connection,
+
−                                     const std::string& oid)
+
−  {
+
−    PGconn* pg = reinterpret_cast<PGconn*>(connection.pg_);
+
−    Oid id = boost::lexical_cast<Oid>(oid);
+
−
+
−    if (lo_unlink(pg, id) < 0)
+
−    {
+
−      throw PostgreSQLException("Unable to delete the large object from the database");
+
−    }
+
−  }
+
−}