/// <summary>
/// Reads a file filtering its content through the filter chain.
/// </summary>
/// <param name="fileName">The file to read.</param>
/// <param name="filterChain">Chain of filters to apply when reading, or <see langword="null" /> is no filters should be applied.</param>
/// <param name="inputEncoding">The encoding used to read the file.</param>
/// <remarks>
/// If <paramref name="inputEncoding" /> is <see langword="null" />,
/// then the system's ANSI code page will be used to read the file.
/// </remarks>
public static string ReadFile(string fileName, FilterChain filterChain, Encoding inputEncoding)
{
string content = null;
// determine character encoding to use
Encoding encoding = (inputEncoding != null) ? inputEncoding : Encoding.Default;
// read file
using (StreamReader sr = new StreamReader(fileName, encoding, true)) {
if (filterChain == null || filterChain.Filters.Count == 0)
{
content = sr.ReadToEnd();
}
else
{
Filter baseFilter = filterChain.GetBaseFilter(
new PhysicalTextReader(sr));
StringWriter sw = new StringWriter();
while (true)
{
int character = baseFilter.Read();
if (character == -1)
{
break;
}
sw.Write((char)character);
}
content = sw.ToString();
}
}
return(content);
}
/// <summary>
/// Copies a file filtering its content through the filter chain.
/// </summary>
/// <param name="sourceFileName">The file to copy</param>
/// <param name="destFileName">The file to copy to</param>
/// <param name="filterChain">Chain of filters to apply when copying, or <see langword="null" /> is no filters should be applied.</param>
/// <param name="inputEncoding">The encoding used to read the soure file.</param>
/// <param name="outputEncoding">The encoding used to write the destination file.</param>
public static void CopyFile(string sourceFileName, string destFileName, FilterChain filterChain, Encoding inputEncoding, Encoding outputEncoding)
{
// determine if filters are available
bool filtersAvailable = filterChain != null && filterChain.Filters.Count > 0;
// if no filters have been defined, and no input or output encoding
// is set, we can just use the File.Copy method
if (!filtersAvailable && inputEncoding == null && outputEncoding == null)
{
File.Copy(sourceFileName, destFileName, true);
}
else
{
// determine actual input encoding to use. if no explicit input
// encoding is specified, we'll use the system's current ANSI
// code page
Encoding actualInputEncoding = (inputEncoding != null) ?
inputEncoding : Encoding.Default;
// get base filter built on the file's reader. Use a 8k buffer.
using (StreamReader sourceFileReader = new StreamReader(sourceFileName, actualInputEncoding, true, 8192)) {
Encoding actualOutputEncoding = outputEncoding;
if (actualOutputEncoding == null)
{
// if no explicit output encoding is specified, we'll
// just use the encoding of the input file as determined
// by the runtime
//
// Note : the input encoding as specified on the filterchain
// might not match the current encoding of the streamreader
//
// eg. when specifing an ANSI encoding, the runtime might
// still detect the file is using UTF-8 encoding, because
// we use BOM detection
actualOutputEncoding = sourceFileReader.CurrentEncoding;
}
// writer for destination file
using (StreamWriter destFileWriter = new StreamWriter(destFileName, false, actualOutputEncoding, 8192)) {
if (filtersAvailable)
{
Filter baseFilter = filterChain.GetBaseFilter(new PhysicalTextReader(sourceFileReader));
bool atEnd = false;
int character;
while (!atEnd)
{
character = baseFilter.Read();
if (character > -1)
{
destFileWriter.Write((char)character);
}
else
{
atEnd = true;
}
}
}
else
{
char[] buffer = new char[8192];
while (true)
{
int charsRead = sourceFileReader.Read(buffer, 0, buffer.Length);
if (charsRead == 0)
{
break;
}
destFileWriter.Write(buffer, 0, charsRead);
}
}
}
}
}
}
