protected async Task <TemplateFactoryResult> CompileAsync(IGeneratedRazorTemplate razorTemplate)
{
CompiledTemplateDescriptor templateDescriptor = await templateCompiler.CompileAsync(razorTemplate);
templateDescriptor.ExpirationToken = razorTemplate.ProjectItem.ExpirationToken;
string templateKey = templateDescriptor.TemplateKey;
if (templateDescriptor.TemplateAttribute != null)
{
Type compiledType = templateDescriptor.TemplateAttribute.TemplateType;
var newExpression = Expression.New(compiledType);
var keyProperty = compiledType.GetTypeInfo().GetProperty(nameof(ITemplatePage.Key));
var propertyBindExpression = Expression.Bind(keyProperty, Expression.Constant(templateKey));
var objectInitializeExpression = Expression.MemberInit(newExpression, propertyBindExpression);
var pageFactory = Expression
.Lambda <Func <ITemplatePage> >(objectInitializeExpression)
.Compile();
return(new TemplateFactoryResult(templateDescriptor, pageFactory));
}
else
{
throw new RazorLightException($"Template {templateKey} is corrupted or invalid");
}
}
/// <summary>
/// Initializes a new instance of <see cref="TemplateFactoryResult"/> with the
/// specified <see cref="ITemplatePage"/> factory.
/// </summary>
/// <param name="templatePageFactory">The <see cref="ITemplatePage"/> factory.</param>
/// <param name="viewDescriptor">The <see cref="CompiledTemplateDescriptor"/>.</param>
public TemplateFactoryResult(
CompiledTemplateDescriptor viewDescriptor,
Func <ITemplatePage> templatePageFactory)
{
TemplateDescriptor = viewDescriptor ?? throw new ArgumentNullException(nameof(viewDescriptor));
TemplatePageFactory = templatePageFactory;
}
protected CompiledTemplateDescriptor CompileAndEmit(IGeneratedRazorTemplate razorTemplate)
{
if (razorTemplate == null)
{
throw new ArgumentNullException(nameof(razorTemplate));
}
string assemblyName = Path.GetRandomFileName();
var compilation = CreateCompilation(razorTemplate.GeneratedCode, assemblyName);
using (var assemblyStream = new MemoryStream())
using (var pdbStream = new MemoryStream())
{
var result = compilation.Emit(
assemblyStream,
pdbStream,
options: EmitOptions);
if (!result.Success)
{
List <Diagnostic> errorsDiagnostics = result.Diagnostics
.Where(d => d.IsWarningAsError || d.Severity == DiagnosticSeverity.Error)
.ToList();
StringBuilder builder = new StringBuilder();
builder.AppendLine("Failed to compile generated Razor template:");
var errorMessages = new List <string>();
foreach (Diagnostic diagnostic in errorsDiagnostics)
{
FileLinePositionSpan lineSpan = diagnostic.Location.SourceTree.GetMappedLineSpan(diagnostic.Location.SourceSpan);
string errorMessage = diagnostic.GetMessage();
string formattedMessage = $"- ({lineSpan.StartLinePosition.Line}:{lineSpan.StartLinePosition.Character}) {errorMessage}";
errorMessages.Add(formattedMessage);
builder.AppendLine(formattedMessage);
}
builder.AppendLine("\nSee CompilationErrors for detailed information");
throw new TemplateCompilationException(builder.ToString(), errorMessages);
}
assemblyStream.Seek(0, SeekOrigin.Begin);
pdbStream.Seek(0, SeekOrigin.Begin);
var assembly = Assembly.Load(assemblyStream.ToArray(), pdbStream.ToArray());
var templateDescriptor = new CompiledTemplateDescriptor()
{
TemplateKey = razorTemplate.TemplateKey,
TemplateAttribute = assembly.GetCustomAttribute <RazorLightTemplateAttribute>(),
};
return(templateDescriptor);
}
}
public Func <ITemplatePage> CreateFactory(CompiledTemplateDescriptor templateDescriptor)
{
string templateKey = templateDescriptor.TemplateKey;
if (templateDescriptor.TemplateAttribute != null)
{
Type compiledType = templateDescriptor.TemplateAttribute.TemplateType;
var newExpression = Expression.New(compiledType);
var keyProperty = compiledType.GetTypeInfo().GetProperty(nameof(ITemplatePage.Key));
var propertyBindExpression = Expression.Bind(keyProperty, Expression.Constant(templateKey));
var objectInitializeExpression = Expression.MemberInit(newExpression, propertyBindExpression);
var pageFactory = Expression
.Lambda <Func <ITemplatePage> >(objectInitializeExpression)
.Compile();
return(pageFactory);
}
else
{
throw new RazorLightException($"Template {templateKey} is corrupted or invalid");
}
}
private Task <CompiledTemplateDescriptor> OnCacheMissAsync(string templateKey)
{
ViewCompilerWorkItem item;
TaskCompletionSource <CompiledTemplateDescriptor> taskSource;
MemoryCacheEntryOptions cacheEntryOptions;
// Safe races cannot be allowed when compiling Razor pages. To ensure only one compilation request succeeds
// per file, we'll lock the creation of a cache entry. Creating the cache entry should be very quick. The
// actual work for compiling files happens outside the critical section.
lock (_cacheLock)
{
string normalizedKey = GetNormalizedKey(templateKey);
// Double-checked locking to handle a possible race.
if (_cache.TryGetValue(normalizedKey, out Task <CompiledTemplateDescriptor> result))
{
return(result);
}
if (_precompiledViews.TryGetValue(normalizedKey, out var precompiledView))
{
item = null;
//item = CreatePrecompiledWorkItem(normalizedKey, precompiledView);
}
else
{
item = CreateRuntimeCompilationWorkItem(templateKey).GetAwaiter().GetResult();
}
// At this point, we've decided what to do - but we should create the cache entry and
// release the lock first.
cacheEntryOptions = new MemoryCacheEntryOptions();
if (item.ExpirationToken != null)
{
cacheEntryOptions.ExpirationTokens.Add(item.ExpirationToken);
}
taskSource = new TaskCompletionSource <CompiledTemplateDescriptor>();
if (item.SupportsCompilation)
{
// We'll compile in just a sec, be patient.
}
else
{
// If we can't compile, we should have already created the descriptor
Debug.Assert(item.Descriptor != null);
taskSource.SetResult(item.Descriptor);
}
_cache.Set(item.NormalizedKey, taskSource.Task, cacheEntryOptions);
}
// Now the lock has been released so we can do more expensive processing.
if (item.SupportsCompilation)
{
Debug.Assert(taskSource != null);
//if (item.Descriptor?.Item != null &&
// ChecksumValidator.IsItemValid(_projectEngine, item.Descriptor.Item))
//{
// // If the item has checksums to validate, we should also have a precompiled view.
// Debug.Assert(item.Descriptor != null);
// taskSource.SetResult(item.Descriptor);
// return taskSource.Task;
//}
try
{
CompiledTemplateDescriptor descriptor = CompileAndEmit(item.ProjectItem);
descriptor.ExpirationToken = cacheEntryOptions.ExpirationTokens.FirstOrDefault();
taskSource.SetResult(descriptor);
}
catch (Exception ex)
{
taskSource.SetException(ex);
}
}
return(taskSource.Task);
}
