// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddScoped <IBrowserOptimizeCssService, BrowserOptimizeCssService>();
services.AddScoped <ICustomOptimizeCssService, CustomOptimizeCssService>();
services.AddMvc(opt => opt.Filters.Add <GlobalExceptionFilter>());
services.AddSwaggerGen(c =>
{
c.SwaggerDoc("v1",
new Info
{
Title = ApiName,
Version = "v1"
});
// UseFullTypeNameInSchemaIds replacement for .NET Core
c.CustomSchemaIds(x => x.FullName);
});
//just use this to be sure that AngleSharp lib will be loaded
var initAngleSharp = AngleSharp.Configuration.Default.GetType();
//Register popular encoding providers (to be able parse response from http client)
Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);
//Register options
var chromeSessionPoolConfig = Configuration.GetSection(ConfigurationConstants.CHROME_SESSION_POOL_CONFIGURATION_SECTION);
services.Configure <CacheConfiguration>(Configuration.GetSection(ConfigurationConstants.CACHE_CONFIGURATION_SECTION));
services.Configure <ChromeSessionPoolConfiguration>(chromeSessionPoolConfig);
//Don't wait until chrome sessions pool will be initialize.
//In production probably will be better to wait.
var chromeSessionPoolConfigObject = chromeSessionPoolConfig.Get <ChromeSessionPoolConfiguration>();
if (chromeSessionPoolConfigObject.IsPreInitializeChromeSessionPool)
{
if (chromeSessionPoolConfigObject.WaitForInitializing)
{
Task.WaitAll(ChromeSessionPool.InitPool(chromeSessionPoolConfigObject));
}
else
{
ChromeSessionPool.InitPool(chromeSessionPoolConfigObject);
}
}
}
private async Task <string> GetMinCssForUrlAsync(string url)
{
//Take from cache if exists
if (_cache.Get <string>(url) != null)
{
return(_cache.Get <string>(url));
}
//Take available session from pool
var chromeSession = ChromeSessionPool.GetInstance();
try
{
//Navigate to page, enable and start rule usage tracking
await chromeSession.InternalSession.DOM.Enable(new DOM.EnableCommand());
await chromeSession.InternalSession.CSS.Enable(new CSS.EnableCommand());
await chromeSession.InternalSession.CSS.StartRuleUsageTracking(new CSS.StartRuleUsageTrackingCommand());
await chromeSession.InternalSession.Page.Navigate(new NavigateCommand { Url = url });
var rules = new List <RuleUsage>();
TakeCoverageDeltaCommandResponse coverageResponse;
//TODO: smart logic to wait report, currently just wait when delta == 0
var waitCount = 0;
do
{
//https://chromedevtools.github.io/devtools-protocol/tot/CSS#method-takeCoverageDelta
coverageResponse = await chromeSession.InternalSession.CSS.TakeCoverageDelta(new TakeCoverageDeltaCommand());
coverageResponse.Coverage = coverageResponse.Coverage ?? new RuleUsage[0];
//If no found.. sleep and try it again
if (coverageResponse.Coverage.Length == 0)
{
Thread.Sleep(++waitCount * 100);
//try again after sleep
//timeout 120 seconds
coverageResponse = await chromeSession.InternalSession.CSS.TakeCoverageDelta(new TakeCoverageDeltaCommand());
coverageResponse.Coverage = coverageResponse.Coverage ?? new RuleUsage[0];
rules.AddRange(coverageResponse.Coverage);
//if found, reset sleep count, because it means that chrome is processing css
if (coverageResponse.Coverage.Length > 0)
{
waitCount = 0;
}
}
}while (coverageResponse.Coverage.Length != 0 ||
waitCount <= 3);
//Stop tacking
await chromeSession.InternalSession.CSS.StopRuleUsageTracking(new CSS.StopRuleUsageTrackingCommand());
//Get stylesheets
var usedRules = rules.Where(r => r.Used).ToList();
var styleSheetIds = usedRules.Select(r => r.StyleSheetId).Distinct();
var styleSheets = styleSheetIds.Select(s => new
{
chromeSession.InternalSession.CSS.GetStyleSheetText(new GetStyleSheetTextCommand {
StyleSheetId = s
}).Result.Text,
StyleSheetId = s
}).ToList();
//Get only used css, and constrcut it
var usedCssStrb = new StringBuilder();
foreach (var rule in usedRules)
{
var styleSheetText = styleSheets.First(s => s.StyleSheetId.Equals(rule.StyleSheetId)).Text;
var ruleString = styleSheetText.Substring((int)rule.StartOffset, (int)rule.EndOffset - (int)rule.StartOffset);
usedCssStrb.Append(ruleString);
}
//minimize CSS
var minCss = Uglify.Css(usedCssStrb.ToString()).Code;
//Cache it for one hour
_cache.Set(url, minCss, TimeSpan.FromSeconds(_cacheConfiguration.UrlCacheTime));
return(minCss);
}
finally
{
//Free up resource
ChromeSessionPool.ReleaseInstance(chromeSession);
}
}
private void OnShutdown()
{
ChromeSessionPool.Dispose();
}
public Task <IEnumerable <ChromeSession> > GetActiveSessions()
{
return(ChromeSessionPool.GetActiveSessions());
}
