Changeset 10 for ProtocolBuffers/UProtocolBuffers.pas

Timestamp:

Oct 12, 2009, 12:52:28 PM (15 years ago)

Author:

george

Message:

• Modified: Enhanced handling of submessage and string wire types.

File:

• ProtocolBuffers/UProtocolBuffers.pas (modified) (9 diffs)

ProtocolBuffers/UProtocolBuffers.pas

@@ -25 +25 @@
     procedure SaveVariantToStream(Stream: TStream; Value: Integer);
     function LoadVariantFromStream(Stream: TStream): Integer;
+    procedure SaveLengthDelimitedToStream(Stream: TStream; Block: TStream);
+    procedure LoadLengthDelimitedFromStream(Stream: TStream; Block: TStream);
     procedure SaveHeadToStream(Stream: TStream);
     procedure LoadHeadFromStream(Stream: TStream);
@@ -51 +53 @@
   { TPBMessageItem }
   TPBMessageItem = class(TPBItem)
+    GenerateHead: Boolean;
     Items: TList; // TList<TPBItem>;
     function SearchItemByTag(Tag: Integer): TPBItem;
@@ -78 +81 @@
 procedure TProtocolBuffer.LoadFromStream(Stream: TStream);
 begin
-  BaseMessage.LoadHeadFromStream(Stream);
+  BaseMessage.GenerateHead := False;
   BaseMessage.LoadFromStream(Stream);
 end;
@@ -84 +87 @@
 procedure TProtocolBuffer.SaveToStream(Stream: TStream);
 begin
+  BaseMessage.GenerateHead := False;
   BaseMessage.SaveToStream(Stream);
 end;
@@ -118 +122 @@
 var
   I: Integer;
-begin
-  inherited;
-  SaveHeadToStream(Stream);
+  TempStream: TMemoryStream;
+begin
+  inherited;
+  // Generate message content to temporary stream
+  TempStream := TMemoryStream.Create;
   for I := 0 to Items.Count - 1 do
-    TPBItem(Items[I]).SaveToStream(Stream);
+    TPBItem(Items[I]).SaveToStream(TempStream);
+  // if head is used than write lenght-delimited head type with block byte length
+  if GenerateHead then begin
+    SaveHeadToStream(Stream);
+    SaveVariantToStream(Stream, TempStream.Size);
+  end;
+  TempStream.Position := 0;
+  TempStream.SaveToStream(Stream);
+  TempStream.Free;
 end;
 
@@ -130 +144 @@
   TempItem: TPBItem;
   SearchItem: TPBItem;
-begin
-  inherited;
+  EndIndex: Integer;
+  TempStream: TMemoryStream;
+begin
+  inherited;
+  TempStream := TMemoryStream.Create;
+
+  if GenerateHead then begin
+    I := LoadVariantFromStream(Stream);
+    EndIndex := Stream.Position + I;
+  end else EndIndex := Stream.Size;
+
   TempItem := TPBItem.Create;
-  for I := 0 to Items.Count - 1 do begin
+  while Stream.Position < EndIndex do begin
     TempItem.LoadHeadFromStream(Stream);
     SearchItem := SearchItemByTag(TempItem.Tag);
@@ -146 +169 @@
       else if SearchItem is TPBMessageItem then
         TPBMessageItem(SearchItem).LoadFromStream(Stream);
+    end else begin
+      if TempItem.ItemType = itVariant then
+        TempItem.LoadVariantFromStream(Stream)
+      else if TempItem.ItemType = itLengthDelimited then
+        TempItem.LoadLengthDelimitedFromStream(Stream, TempStream);
     end;
   end;
+  TempStream.Free;
 end;
 
@@ -154 +183 @@
   ItemType := itLengthDelimited;
   Items := TList.Create;
+  GenerateHead := True;
 end;
 
@@ -243 +273 @@
 end;
 
+procedure TPBItem.SaveLengthDelimitedToStream(Stream: TStream; Block: TStream);
+begin
+  SaveVariantToStream(Stream, Block.Size);
+  Block.Position := 0;
+  TMemoryStreamEx(Block).ReadStream(Stream, Block.Size);
+end;
+
+procedure TPBItem.LoadLengthDelimitedFromStream(Stream: TStream; Block: TStream
+  );
+var
+  Size: Integer;
+begin
+  Size := LoadVariantFromStream(Stream);
+  TMemoryStreamEx(Stream).ReadStream(Block, Size);
+end;
+
 { TPBIntegerItem }