/// <summary>
/// Constructs the LargeObject API.
/// There should only be one LargeObjectManager per Connection. The
/// org.postgresql.Connection class keeps track of the various extension API's
/// and it's advised you use those to gain access, and not going direct.
/// </summary>
/// <param name="conn"></param>
public LargeObjectManager(NpgsqlConnection conn)
{
// We need Fastpath to do anything
// Now get the function oid's for the api
//
// This is an example of Fastpath.addFunctions();
//
//String sql;
StringBuilder sql = null;
try
{
sql = new StringBuilder();
if (conn.PostgreSqlVersion > new Version(7, 3, 0))
{
sql.Append("SELECT p.proname,p.oid ");
sql.Append(" FROM pg_catalog.pg_proc p, pg_catalog.pg_namespace n ");
sql.Append(" WHERE p.pronamespace=n.oid AND n.nspname='pg_catalog' AND (");
}
else
{
sql.Append("SELECT proname,oid FROM pg_proc WHERE ");
}
sql.Append(" proname = 'lo_open'");
sql.Append(" or proname = 'lo_close'");
sql.Append(" or proname = 'lo_creat'");
sql.Append(" or proname = 'lo_unlink'");
sql.Append(" or proname = 'lo_lseek'");
sql.Append(" or proname = 'lo_tell'");
sql.Append(" or proname = 'loread'");
sql.Append(" or proname = 'lowrite'");
if (conn.PostgreSqlVersion > new Version(7, 3, 0))
{
sql.Append(")");
}
using (IDbCommand cmd = new NpgsqlCommand(sql.ToString()))
{
cmd.Connection = conn;
this.fp = new Fastpath(conn, conn.Connector.Stream);
using (IDataReader res = cmd.ExecuteReader())
{
if (res == null)
{
throw new NpgsqlException("postgresql.lo.init");
}
fp.AddFunctions(res);
}
}
}
finally
{
sql = null;
}
}
private Boolean closed = false; // true when we are closed
/// <summary>
/// This opens a large object.
/// If the object does not exist, then an NpgsqlException is thrown.
/// </summary>
/// <param name="fp">FastPath API for the connection to use.</param>
/// <param name="oid">OID of the Large Object to open.</param>
/// <param name="mode">Mode of opening the large object</param>
public LargeObject(Fastpath fp, Int32 oid, Int32 mode)
{
this.fp = fp;
this.oid = oid;
FastpathArg[] args = new FastpathArg[2];
args[0] = new FastpathArg(oid);
args[1] = new FastpathArg(mode);
this.fd = fp.GetInteger("lo_open", args);
}