GSF.IO.BlockAllocatedMemoryStream.Seek C# (CSharp) Method

        public override long Seek(long offset, SeekOrigin origin)
        {
            if (m_disposed)
                throw new ObjectDisposedException("BlockAllocatedMemoryStream", "The stream is closed.");

            switch (origin)
            {
                case SeekOrigin.Begin:
                    if (offset < 0L)
                        throw new IOException("Seek was attempted before the beginning of the stream.");

                    m_position = offset;
                    break;
                case SeekOrigin.Current:
                    if (m_position + offset < 0L)
                        throw new IOException("Seek was attempted before the beginning of the stream.");

                    m_position += offset;
                    break;
                case SeekOrigin.End:
                    if (m_length + offset < 0L)
                        throw new IOException("Seek was attempted before the beginning of the stream.");

                    m_position = m_length + offset;
                    break;
            }

            // Note: the length is not adjusted after this seek to reflect what MemoryStream.Seek does
            return m_position;
        }

        /// <summary>
        /// Reads XML from the configuration file.
        /// </summary>
        /// <param name="reader">The <see cref="System.Xml.XmlReader"/> object, which reads from the configuration file.</param>
        protected override void DeserializeSection(XmlReader reader)
        {
            using (BlockAllocatedMemoryStream configSectionStream = new BlockAllocatedMemoryStream())
            {
                XmlDocument configSection = new XmlDocument();

                configSection.Load(reader);
                configSection.Save(configSectionStream);

                // Adds all the categories that are under the categorizedSettings section of the configuration file
                // to the property collection. Again, this is essentially doing what marking a property with the
                // <ConfigurationProperty()> attribute does. If this is not done, then an exception will be raised
                // when the category elements are being deserialized.
                if ((object)configSection.DocumentElement != null)
                {
                    XmlNodeList categories = configSection.DocumentElement.SelectNodes("*");

                    if ((object)categories != null)
                    {
                        foreach (XmlNode category in categories)
                        {
                            ConfigurationProperty configProperty = new ConfigurationProperty(category.Name, typeof(CategorizedSettingsElementCollection));

                            base.Properties.Add(configProperty);

                            if ((object)m_sections != null)
                            {
                                CategorizedSettingsElementCollection settingsCategory = new CategorizedSettingsElementCollection
                                {
                                    Name = category.Name,
                                    Section = this,
                                };

                                settingsCategory.SetCryptoKey(m_cryptoKey);
                                m_sections.Add(category.Name, settingsCategory);

                                // Read all elements within this category section
                                XmlNodeList elements = category.SelectNodes("*");
                                SettingScope scope;

                                if ((object)elements != null)
                                {
                                    foreach (XmlNode element in elements)
                                    {
                                        CategorizedSettingsElement categorySetting = new CategorizedSettingsElement(settingsCategory);

                                        categorySetting.Name = element.GetAttributeValue("name");
                                        categorySetting.Value = element.GetAttributeValue("value");
                                        categorySetting.Description = element.GetAttributeValue("description") ?? "";
                                        categorySetting.Encrypted = element.GetAttributeValue("encrypted").ToNonNullNorWhiteSpace("false").ParseBoolean();

                                        if (Enum.TryParse(element.GetAttributeValue("scope").ToNonNullNorWhiteSpace("Application"), out scope))
                                            categorySetting.Scope = scope;
                                        else
                                            categorySetting.Scope = SettingScope.Application;

                                        settingsCategory.Add(categorySetting);
                                    }
                                }
                            }
                        }
                    }
                }

                m_sectionLoaded = true;

                if ((object)m_sections == null)
                {
                    configSectionStream.Seek(0, SeekOrigin.Begin);
                    base.DeserializeSection(XmlReader.Create(configSectionStream));
                }
            }
        }