public CachePage(int size, long pageNum)
{
Buffer = new byte[size];
Dirty = false;
NextPage = null;
PageNumber = pageNum;
}
public CachePage(int size, long pageNum)
{
this.Buffer = new byte[size];
this.Dirty = false;
this.NextPage = null;
this.PageNumber = pageNum;
}
public override int ReadByte()
{
CachePage page = GetPage(m_position);
int num = CalcOffsetWithinPage(m_position);
UpdatePosition(1L);
return(page.Buffer[num]);
}
private void FlushPage(CachePage page, long pageNum)
{
if (page.Dirty)
{
long offset = CalcPageOffset(pageNum);
m_stream.Seek(offset, SeekOrigin.Begin);
page.Write(m_stream);
}
}
public override void WriteByte(byte value)
{
CachePage page = GetPage(m_position);
int num = CalcOffsetWithinPage(m_position);
UpdatePosition(1L);
page.Buffer[num] = value;
page.Dirty = true;
}
private void ActivateBlock(int bi)
{
if (cache[bi] == null)
{
byte[] arr = new byte[_block_length];
fs.Position = bi * BlockSize;
fs.Read(arr, 0, arr.Length);
cache[bi] = new CachePage()
{
array = arr
};
}
}
public override void Write(byte[] buffer, int offset, int count)
{
long num = m_position + count;
while (m_position < num)
{
CachePage page = GetPage(m_position);
int num2 = CalcOffsetWithinPage(m_position);
byte[] buffer2 = page.Buffer;
int num3 = Math.Min(buffer2.Length - num2, count);
Array.Copy(buffer, offset, buffer2, num2, num3);
UpdatePosition(num3);
count -= num3;
offset += num3;
page.Dirty = true;
}
}
private CachePage GetPage(long fileOffset)
{
long num = CalcPageNum(fileOffset);
CachePage value = null;
if (!m_pageCache.TryGetValue(num, out value))
{
bool flag = false;
if (m_pageCache.Count == m_pageCacheCapacity || (m_freezePageAllocations && m_pageCache.Count > 0))
{
value = m_firstPageToEvict;
long pageNumber = value.PageNumber;
m_firstPageToEvict = value.NextPage;
m_pageCache.Remove(pageNumber);
FlushPage(value, pageNumber);
value.PageNumber = num;
}
else
{
value = new CachePage(m_bytesPerPage, num);
flag = true;
}
long num2 = CalcPageOffset(num);
if (num2 < m_length)
{
m_stream.Seek(num2, SeekOrigin.Begin);
value.Read(m_stream);
}
else if (!flag)
{
value.InitBuffer();
}
m_pageCache[num] = value;
if (m_firstPageToEvict == null)
{
m_firstPageToEvict = value;
}
if (m_lastPageToEvict != null)
{
m_lastPageToEvict.NextPage = value;
}
m_lastPageToEvict = value;
}
return(value);
}
private CachePage GetPage(long fileOffset)
{
long num = this.CalcPageNum(fileOffset);
CachePage cachePage = null;
if (!this.m_pageCache.TryGetValue(num, out cachePage))
{
bool flag = false;
if (this.m_pageCache.Count == this.m_pageCacheCapacity || (this.m_freezePageAllocations && this.m_pageCache.Count > 0))
{
cachePage = this.m_firstPageToEvict;
long pageNumber = cachePage.PageNumber;
this.m_firstPageToEvict = cachePage.NextPage;
this.m_pageCache.Remove(pageNumber);
this.FlushPage(cachePage, pageNumber);
cachePage.PageNumber = num;
}
else
{
cachePage = new CachePage(this.m_bytesPerPage, num);
flag = true;
}
long num2 = this.CalcPageOffset(num);
if (num2 < this.m_length)
{
this.m_stream.Seek(num2, SeekOrigin.Begin);
cachePage.Read(this.m_stream);
}
else if (!flag)
{
cachePage.InitBuffer();
}
this.m_pageCache[num] = cachePage;
if (this.m_firstPageToEvict == null)
{
this.m_firstPageToEvict = cachePage;
}
if (this.m_lastPageToEvict != null)
{
this.m_lastPageToEvict.NextPage = cachePage;
}
this.m_lastPageToEvict = cachePage;
}
return(cachePage);
}
public override int Read(byte[] buffer, int offset, int count)
{
int result = count;
long num = m_position + count;
while (m_position < num)
{
CachePage page = GetPage(m_position);
int num2 = CalcOffsetWithinPage(m_position);
byte[] buffer2 = page.Buffer;
int num3 = Math.Min(buffer2.Length - num2, count);
Array.Copy(buffer2, num2, buffer, offset, num3);
UpdatePosition(num3);
count -= num3;
offset += num3;
}
return(result);
}
public void LoadCache()
{
if (cache == null)
{
ActivateCache();
}
byte[] buffer = new byte[BlockSize];
int bi = 0;
fs.Position = 0L;
for (long coord = 0L; coord < fs.Length; coord += BlockSize)
{
fs.Read(buffer, 0, (int)BlockSize);
cache[bi] = new CachePage()
{
array = new byte[BlockSize]
};
Array.Copy(buffer, 0, cache[bi].array, 0, (int)BlockSize);
bi++;
}
}
public void BigFlush()
{
if (false && cache != null)
{
int cnt = 0;
for (int pi = 0; pi < cache.Count; pi++)
{
CachePage cp = cache[pi];
if (cp == null || !cp.changed)
{
continue;
}
fs.Position = (long)pi * BlockSize;
fs.Write(cp.array, 0, (int)BlockSize);
cp.changed = false;
cnt++;
}
Console.WriteLine("Flush cnt = {0}", cnt);
}
this.Flush();
}
private async Task Cache(HttpContext context)
{
//bool useMinification = _options.EnableMinification && _minificationManagers.Count > 0;
//bool useCompression = _options.EnableCompression && _compressionManager != null;
var useMinification = _options.EnableMinification;
var useCompression = _options.EnableCompression;
var cacheSetting = _options.Setting;
var currentUrl = context.Request.Path.Value;
var accept = $"{context.Request.Headers["Accept"]}";
var isHtml = context.Request.Method == "GET" && !string.IsNullOrEmpty(accept) && accept.Contains("text/html") && context.Request.Headers["X-Requested-With"] != "XMLHttpRequest";
#region 做缓存处理
if (!isHtml || (!useMinification && !useCompression) || !_options.EnableCache || !cacheSetting.IgnorePages.Contains(currentUrl))
{
await _next.Invoke(context);
return;
}
#endregion
var cachePage = cacheSetting.CachePages.FirstOrDefault(a => a.Url == currentUrl);
if (cachePage == null)
{
cachePage = new CachePage()
{
Url = currentUrl
}
}
;
if (cachePage.CacheTime == 0)
{
cachePage.CacheTime = cacheSetting.CacheTime;
}
var cacheKey = GetKey(context.Request, cachePage.VaryByParams);
#region 判断缓存是否存在
var cacheContent = _cacheService.Get <CacheContent>(cacheKey);
if (cacheContent != null)
{
context.Response.Headers.Add("C-Cache", "Hit");
if (cacheContent.Headers != null && cacheContent.Headers.Count > 0)
{
foreach (var ch in cacheContent.Headers)
{
context.Response.Headers.Add(ch.Key, ch.Value);
}
}
await context.Response.Body.WriteAsync(cacheContent.Content, 0, cacheContent.Content.Length);
return;
}
#endregion
HttpRequest request = context.Request;
HttpResponse response = context.Response;
using (var cachedStream = new MemoryStream())
{
Stream originalStream = response.Body;
response.Body = cachedStream;
try
{
await _next.Invoke(context);
}
catch (Exception)
{
response.Body = originalStream;
cachedStream.Clear();
throw;
}
byte[] cachedBytes = cachedStream.ToArray();
int cachedByteCount = cachedBytes.Length;
bool isProcessed = false;
response.Body = originalStream;
cachedStream.Clear();
if (cachedByteCount == 0)
{
return;
}
if (response.StatusCode == 200)
{
string httpMethod = request.Method;
string contentType = response.ContentType;
string mediaType = null;
Encoding encoding = null;
if (contentType != null)
{
MediaTypeHeaderValue mediaTypeHeader;
if (MediaTypeHeaderValue.TryParse(contentType, out mediaTypeHeader))
{
mediaType = mediaTypeHeader.MediaType.Value;
encoding = mediaTypeHeader.Encoding;
}
}
encoding = encoding ?? Encoding.GetEncoding(0);
string content = encoding.GetString(cachedBytes);
string processedContent = content;
IHeaderDictionary responseHeaders = response.Headers;
bool isEncodedContent = responseHeaders.IsEncodedContent();
Action <string, string> appendHttpHeader = (key, value) =>
{
responseHeaders.Append(key, new StringValues(value));
};
#region Html压缩
if (useMinification && _options.IsAllowableResponseSize(cachedByteCount))
{
var htmlMinifier = new HtmlMinifier();
var result = htmlMinifier.Minify(processedContent);
if (result.Errors.Count == 0)
{
processedContent = result.MinifiedContent;
isProcessed = true;
}
//foreach (IMarkupMinificationManager minificationManager in _minificationManagers)
//{
// if (minificationManager.IsSupportedHttpMethod(httpMethod)
// && mediaType != null && minificationManager.IsSupportedMediaType(mediaType)
// && minificationManager.IsProcessablePage(currentUrl))
// {
// if (isEncodedContent)
// {
// throw new InvalidOperationException(
// string.Format(
// AspNetCommonStrings.MarkupMinificationIsNotApplicableToEncodedContent,
// responseHeaders["Content-Encoding"]
// )
// );
// }
// IMarkupMinifier minifier = minificationManager.CreateMinifier();
// MarkupMinificationResult minificationResult = minifier.Minify(processedContent,
// currentUrl, encoding, minificationManager.GenerateStatistics);
// if (minificationResult.Errors.Count == 0)
// {
// processedContent = minificationResult.MinifiedContent;
// isProcessed = true;
// }
// }
// if (isProcessed)
// {
// break;
// }
//}
}
#endregion
byte[] processedBytes;
if (isProcessed)
{
processedBytes = encoding.GetBytes(processedContent);
}
else
{
processedBytes = cachedBytes;
}
#region GZip压缩
if (useCompression && !isEncodedContent)
{
string acceptEncoding = request.Headers["Accept-Encoding"];
string[] encodingTokens = acceptEncoding
.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries)
.Select(e => e.Trim().ToLowerInvariant())
.ToArray();
ICompressor compressor = null;
foreach (var et in encodingTokens)
{
if (et == EncodingTokenConstants.Deflate)
{
compressor = new DeflateCompressor(new DeflateCompressionSettings()
{
Level = System.IO.Compression.CompressionLevel.Fastest
});
break;
}
else if (et == EncodingTokenConstants.GZip)
{
compressor = new GZipCompressor(new GZipCompressionSettings()
{
Level = System.IO.Compression.CompressionLevel.Fastest
});
}
}
if (compressor != null)
{
using (var inputStream = new MemoryStream(processedBytes))
using (var outputStream = new MemoryStream())
{
using (Stream compressedStream = compressor.Compress(outputStream))
{
await inputStream.CopyToAsync(compressedStream);
}
byte[] compressedBytes = outputStream.ToArray();
processedBytes = compressedBytes;
outputStream.Clear();
inputStream.Clear();
responseHeaders["Content-Length"] = compressedBytes.Length.ToString();
compressor.AppendHttpHeaders(appendHttpHeader);
await originalStream.WriteAsync(compressedBytes, 0, compressedBytes.Length);
}
}
//using (var inputStream = new MemoryStream(processedBytes))
//using (var outputStream = new MemoryStream())
//{
// string acceptEncoding = request.Headers["Accept-Encoding"];
// ICompressor compressor = _compressionManager.CreateCompressor(acceptEncoding);
// using (Stream compressedStream = compressor.Compress(outputStream))
// {
// await inputStream.CopyToAsync(compressedStream);
// }
// byte[] compressedBytes = outputStream.ToArray();
// processedBytes = compressedBytes;
// int compressedByteCount = compressedBytes.Length;
// outputStream.Clear();
// inputStream.Clear();
// responseHeaders["Content-Length"] = compressedByteCount.ToString();
// compressor.AppendHttpHeaders(appendHttpHeader);
// await originalStream.WriteAsync(compressedBytes, 0, compressedByteCount);
//}
isProcessed = true;
}
#endregion
else
{
if (isProcessed)
{
int processedByteCount = processedBytes.Length;
responseHeaders["Content-Length"] = processedByteCount.ToString();
await originalStream.WriteAsync(processedBytes, 0, processedByteCount);
}
}
#region 保存到缓存中
cacheContent = new CacheContent()
{
Content = processedBytes,
ContentType = contentType,
Headers = new Dictionary <string, string>()
};
foreach (var rh in responseHeaders)
{
cacheContent.Headers.Add(rh.Key, rh.Value);
}
await _cacheService.SetAsync(cacheKey, cacheContent, TimeSpan.FromSeconds(cachePage.CacheTime));
context.Response.Headers.Add("C-Cache", "Cached");
//Task.Factory.StartNew(obj =>
//{
// var cc = (CacheContent)obj;
//}, cacheContent);
#endregion
}
if (!isProcessed)
{
await originalStream.WriteAsync(cachedBytes, 0, cachedByteCount);
}
}
}
