Add CancellationToken support to async methods #9

Introduce support for `CancellationToken` across various methods to allow for task cancellation and improve responsiveness.
- Update `DecodeAsync` method in `DocxContentDecoder.cs`, `PdfContentDecoder.cs`, `TextContentDecoder.cs`, and `IContentDecoder.cs` to include an optional `CancellationToken` parameter.
- Modify endpoint handlers in `Program.cs` to accept and pass `CancellationToken` parameters.
- Update methods in `ChatService.cs` to include `CancellationToken` parameters.
- Update methods in `DocumentService.cs` to include `CancellationToken` parameters.
- Update methods in `VectorSearchService.cs` to include `CancellationToken` parameters.
These changes ensure that long-running operations can be canceled if needed, improving the application's ability to handle cancellation requests gracefully.

SqlDatabaseVectorSearch/ContentDecoders/DocxContentDecoder.cs

@@ -6,7 +6,7 @@ namespace SqlDatabaseVectorSearch.ContentDecoders;
 
 public class DocxContentDecoder : IContentDecoder
 {
-    public Task<string> DecodeAsync(Stream stream, string contentType)
+    public Task<string> DecodeAsync(Stream stream, string contentType, CancellationToken cancellationToken = default)
     {
         // Open a Word document for read-only access.
         using var document = WordprocessingDocument.Open(stream, false);

SqlDatabaseVectorSearch/ContentDecoders/IContentDecoder.cs

@@ -2,5 +2,5 @@
 
 public interface IContentDecoder
 {
-    Task<string> DecodeAsync(Stream stream, string contentType);
+    Task<string> DecodeAsync(Stream stream, string contentType, CancellationToken cancellationToken = default);
 }

SqlDatabaseVectorSearch/ContentDecoders/PdfContentDecoder.cs

@@ -6,7 +6,7 @@ namespace SqlDatabaseVectorSearch.ContentDecoders;
 
 public class PdfContentDecoder : IContentDecoder
 {
-    public Task<string> DecodeAsync(Stream stream, string contentType)
+    public Task<string> DecodeAsync(Stream stream, string contentType, CancellationToken cancellationToken = default)
     {
         var content = new StringBuilder();
 

SqlDatabaseVectorSearch/ContentDecoders/TextContentDecoder.cs

@@ -2,10 +2,10 @@
 
 public class TextContentDecoder : IContentDecoder
 {
-    public async Task<string> DecodeAsync(Stream stream, string contentType)
+    public async Task<string> DecodeAsync(Stream stream, string contentType, CancellationToken cancellationToken = default)
     {
         using var readStream = new StreamReader(stream);
-        var content = await readStream.ReadToEndAsync();
+        var content = await readStream.ReadToEndAsync(cancellationToken);
 
         return content;
     }