// Filter the request data to get the file binary data.
// Here is an algorithm logic to filter the data. There
// will be a lot of words to say before we talk about
// the algorithm(Maybe a small book). So I just open the
// source here but omit the explanation in details.
private void FilterFileDataFromBodyEntity(byte[] data)
{
if (data == null)
{
return;
}
if (draft != null)
{
byte[] temp = BinaryHelper.Combine(draft,
BinaryHelper.Copy(data, 0, _boundary.Length));
int entity_st = BinaryHelper.SequenceIndexOf(temp, _boundary, 0);
int entity_ed = BinaryHelper.SequenceIndexOf(temp, _boundary,
entity_st + _boundary.Length + 2);
if (isFile && !isFinished)
{
if (entity_st == 0)
{
int header_st = entity_st + _boundary.Length + 2;
int header_ed = BinaryHelper.SequenceIndexOf(temp,
_doubleBackSpace, header_st);
int body_st = header_ed + 4;
if (entity_ed == -1)
{
AppendToLastEntity(BinaryHelper.SubData(draft, body_st));
draft = null;
}
else
{
AppendToLastEntity(BinaryHelper.SubData(draft,
body_st, entity_ed - body_st - 2));
isFinished = true;
isFile = false;
draft = BinaryHelper.SubData(draft, entity_ed);
}
}
else
{
AppendToLastEntity(draft);
draft = null;
}
}
// When need append new data, combine the two
// binary array into one.
data = BinaryHelper.Combine(draft, data);
draft = null;
}
while (true)
{
// find the boundary
int entity_st = BinaryHelper.SequenceIndexOf(data, _boundary, 0);
// if the current loaded data contain the boundary
if (entity_st > -1)
{
if (isFile && !isFinished)
{
AppendToLastEntity(BinaryHelper.SubData(data, 0,
entity_st - 2));
data = BinaryHelper.SubData(data, entity_st);
isFile = false;
isFinished = true;
continue;
}
int entity_ed = BinaryHelper.SequenceIndexOf(data, _boundary,
entity_st + _boundary.Length + 2);
int header_st = entity_st + _boundary.Length + 2;
int header_ed = BinaryHelper.SequenceIndexOf(data,
_doubleBackSpace, header_st);
int body_st = header_ed + 4;
if (body_st < 4)
{
// If the header in the entity is not complete, then
// set the draft as the data, and dump out the function
// to ask for more data.
draft = data;
return;
}
else
{
// If the header in the entity is complete
if (!isFile && isFinished)
{
// Encoding the data in the header of the entity
string headerInEntity = ASCIIEncoding.UTF8.GetString(
BinaryHelper.SubData(data, header_st, header_ed - header_st));
// If it is a file entity, the header contain the keyword:"filename".
if (headerInEntity.IndexOf("filename") > -1)
{
// Use Regular Expression to get the meta key values from
// the header of the entity.
Regex detailsReg =
new Regex("Content-Disposition: form-data; name=\"([^\"]*)\";" +
" filename=\"([^\"]*)\"Content-Type: ([^\"]*)");
Match regMatch =
detailsReg.Match(headerInEntity.Replace("\r\n", ""));
string controlName = regMatch.Groups[1].Value;
string clientPath = regMatch.Groups[2].Value;
string contentType = regMatch.Groups[3].Value;
if (string.IsNullOrEmpty(clientPath))
{
isFile = false;
}
else
{
isFile = true;
// Create a new instance for the file entity
UploadFile up = new UploadFile(clientPath, contentType);
FilterResult.Add(up);
isFinished = false;
}
}
else
{
isFile = false;
}
}
}
if (entity_ed > -1)
{
// If we can find another boundary after the first boundary,
// that means the entity block is ended there.
// Only if it is a file entity we need to get the data
// in the body of the entity
if (isFile)
{
AppendToLastEntity(BinaryHelper.SubData(data,
body_st, entity_ed - body_st - 2));
isFinished = true;
isFile = false;
}
// Remove the current processed entity data
// and loop for the next one.
data = BinaryHelper.SubData(data, entity_ed);
if (BinaryHelper.Equals(data, _endTag))
{
data = null;
draft = null;
return;
}
continue;
}
else
{
// If we can't find the end mark, we have to
// move the data to the draft and
// ask for new data to append.
draft = data;
return;
}
}
else
{
// If we can't find any mark of the boundary,
// we have to move the data to the draft and
// ask for new data to append.
draft = data;
return;
}
}
}
// 过滤请求数据来获取文件的二进制数据.
// 这里是过滤数据的算法逻辑.
// 在我们讲到算法之前将会有很多内容要
// 讲（可能要一本书）.所以我只在这里开
// 个头，但是忽略详细的解释.
private void FilterFileDataFromBodyEntity(byte[] data)
{
if (data == null)
{
return;
}
if (draft != null)
{
byte[] temp = BinaryHelper.Combine(draft,
BinaryHelper.Copy(data, 0, _boundary.Length));
int entity_st = BinaryHelper.SequenceIndexOf(temp, _boundary, 0);
int entity_ed = BinaryHelper.SequenceIndexOf(temp, _boundary,
entity_st + _boundary.Length + 2);
if (isFile && !isFinished)
{
if (entity_st == 0)
{
int header_st = entity_st + _boundary.Length + 2;
int header_ed = BinaryHelper.SequenceIndexOf(temp,
_doubleBackSpace, header_st);
int body_st = header_ed + 4;
if (entity_ed == -1)
{
AppendToLastEntity(BinaryHelper.SubData(draft, body_st));
draft = null;
}
else
{
AppendToLastEntity(BinaryHelper.SubData(draft,
body_st, entity_ed - body_st - 2));
isFinished = true;
isFile = false;
draft = BinaryHelper.SubData(draft, entity_ed);
}
}
else
{
AppendToLastEntity(draft);
draft = null;
}
}
// 当需要添加新数据时，
// 把这两个二进制数组合并成一个.
data = BinaryHelper.Combine(draft, data);
draft = null;
}
while (true)
{
// 找到边界
int entity_st = BinaryHelper.SequenceIndexOf(data, _boundary, 0);
// 如果当前加载的数据包含边界
if (entity_st > -1)
{
if (isFile && !isFinished)
{
AppendToLastEntity(BinaryHelper.SubData(data, 0,
entity_st - 2));
data = BinaryHelper.SubData(data, entity_st);
isFile = false;
isFinished = true;
continue;
}
int entity_ed = BinaryHelper.SequenceIndexOf(data, _boundary,
entity_st + _boundary.Length + 2);
int header_st = entity_st + _boundary.Length + 2;
int header_ed = BinaryHelper.SequenceIndexOf(data,
_doubleBackSpace, header_st);
int body_st = header_ed + 4;
if (body_st < 4)
{
// 如果实体的头部不完整，
// 设置这个实体作为数据，
// 卸载掉函数来请求更多的数据.
draft = data;
return;
}
else
{
// 如果实体的头部完整
if (!isFile && isFinished)
{
// 把实体头部的数据转换为UTF8编码
string headerInEntity = ASCIIEncoding.UTF8.GetString(
BinaryHelper.SubData(data, header_st, header_ed - header_st));
// 如果这是一个文件实体，头部包会含关键字："filename".
if (headerInEntity.IndexOf("filename") > -1)
{
// 在实体的头部使用正则表达式来
// 获取元数据的关键字值.
Regex detailsReg =
new Regex("Content-Disposition: form-data; name=\"([^\"]*)\";" +
" filename=\"([^\"]*)\"Content-Type: ([^\"]*)");
Match regMatch =
detailsReg.Match(headerInEntity.Replace("\r\n", ""));
string controlName = regMatch.Groups[1].Value;
string clientPath = regMatch.Groups[2].Value;
string contentType = regMatch.Groups[3].Value;
if (string.IsNullOrEmpty(clientPath))
{
isFile = false;
}
else
{
isFile = true;
// 为文件实体创建一个新的实例
UploadFile up = new UploadFile(clientPath, contentType);
FilterResult.Add(up);
isFinished = false;
}
}
else
{
isFile = false;
}
}
}
if (entity_ed > -1)
{
// 如果我们在第一个边界之后又发现另一边界，
// 那表示实体块在那里结束了.
// 只是文件实体的时候，我们才需要在实体的
// 主体里获取数据.
if (isFile)
{
AppendToLastEntity(BinaryHelper.SubData(data,
body_st, entity_ed - body_st - 2));
isFinished = true;
isFile = false;
}
// 移除当前的实体处理数据并且
// 循环到下一个数据.
data = BinaryHelper.SubData(data, entity_ed);
if (BinaryHelper.Equals(data, _endTag))
{
data = null;
draft = null;
return;
}
continue;
}
else
{
// 如果我们不能找到结束标记,我们
// 必须要把这些数据移到草稿并
// 请求添加新数据.
draft = data;
return;
}
}
else
{
// 如果我们不能找到结束标记,我们
// 必须要把这些数据移到草稿并
// 请求添加新数据.
draft = data;
return;
}
}
}