Changeset 9 for ProtocolBuffers/UProtocolBuffers.pas

Timestamp:

Oct 12, 2009, 11:01:02 AM (15 years ago)

Author:

george

Message:

• Modified: Enhanced loading from stream.
• Added: Demo form is displaying original PB tree and target loaded PB tree.

File:

• ProtocolBuffers/UProtocolBuffers.pas (modified) (12 diffs)

ProtocolBuffers/UProtocolBuffers.pas

@@ -25 +25 @@
     procedure SaveVariantToStream(Stream: TStream; Value: Integer);
     function LoadVariantFromStream(Stream: TStream): Integer;
+    procedure SaveHeadToStream(Stream: TStream);
+    procedure LoadHeadFromStream(Stream: TStream);
     procedure SaveToStream(Stream: TStream); virtual;
     procedure LoadFromStream(Stream: TStream); virtual;
@@ -50 +52 @@
   TPBMessageItem = class(TPBItem)
     Items: TList; // TList<TPBItem>;
+    function SearchItemByTag(Tag: Integer): TPBItem;
     procedure SaveToStream(Stream: TStream); override;
     procedure LoadFromStream(Stream: TStream); override;
@@ -75 +78 @@
 procedure TProtocolBuffer.LoadFromStream(Stream: TStream);
 begin
+  BaseMessage.LoadHeadFromStream(Stream);
   BaseMessage.LoadFromStream(Stream);
 end;
@@ -101 +105 @@
 { TPBMessageItem }
 
+function TPBMessageItem.SearchItemByTag(Tag: Integer): TPBItem;
+var
+  I: Integer;
+begin
+  I := 0;
+  while (I < Items.Count) and (TPBItem(Items[I]).Tag <> Tag) do Inc(I);
+  if I < Items.Count then Result := Items[I]
+    else Result := nil;
+end;
+
 procedure TPBMessageItem.SaveToStream(Stream: TStream);
 var
   I: Integer;
 begin
-  inherited SaveToStream(Stream);
+  inherited;
+  SaveHeadToStream(Stream);
   for I := 0 to Items.Count - 1 do
     TPBItem(Items[I]).SaveToStream(Stream);
@@ -113 +128 @@
 var
   I: Integer;
-begin
-  inherited LoadFromStream(Stream);
-  for I := 0 to Items.Count - 1 do
-    TPBItem(Items[I]).LoadFromStream(Stream);
+  TempItem: TPBItem;
+  SearchItem: TPBItem;
+begin
+  inherited;
+  TempItem := TPBItem.Create;
+  for I := 0 to Items.Count - 1 do begin
+    TempItem.LoadHeadFromStream(Stream);
+    SearchItem := SearchItemByTag(TempItem.Tag);
+    if Assigned(SearchItem) then begin
+      if SearchItem.ItemType <> TempItem.ItemType then
+        raise Exception.Create('Bad type for item "' + SearchItem.Name +
+          '" with tag ' + IntToStr(SearchItem.Tag));
+      if SearchItem is TPBIntegerItem then
+        TPBIntegerItem(SearchItem).LoadFromStream(Stream)
+      else if SearchItem is TPBStringItem then
+        TPBStringItem(SearchItem).LoadFromStream(Stream)
+      else if SearchItem is TPBMessageItem then
+        TPBMessageItem(SearchItem).LoadFromStream(Stream);
+    end;
+  end;
 end;
 
@@ -154 +185 @@
 end;
 
-procedure TPBItem.SaveToStream(Stream: TStream);
+procedure TPBItem.SaveHeadToStream(Stream: TStream);
 var
   ByteIndex: Byte;
@@ -171 +202 @@
 end;
 
-procedure TPBItem.LoadFromStream(Stream: TStream);
+procedure TPBItem.LoadHeadFromStream(Stream: TStream);
 var
   Data: Byte;
@@ -187 +218 @@
 end;
 
+procedure TPBItem.SaveToStream(Stream: TStream);
+begin
+
+end;
+
+procedure TPBItem.LoadFromStream(Stream: TStream);
+begin
+
+end;
+
 function TPBItem.LoadVariantFromStream(Stream: TStream): Integer;
 var
@@ -206 +247 @@
 procedure TPBIntegerItem.SaveToStream(Stream: TStream);
 begin
-  inherited SaveToStream(Stream);
+  inherited;
+  SaveHeadToStream(Stream);
   SaveVariantToStream(Stream, Value);
 end;
@@ -212 +254 @@
 procedure TPBIntegerItem.LoadFromStream(Stream: TStream);
 begin
-  inherited LoadFromStream(Stream);
-  LoadVariantFromStream(Stream);
+  inherited;
+  Value := LoadVariantFromStream(Stream);
 end;
 
@@ -225 +267 @@
 procedure TPBStringItem.SaveToStream(Stream: TStream);
 begin
-  inherited SaveToStream(Stream);
+  inherited;
+  SaveHeadToStream(Stream);
   SaveVariantToStream(Stream, Length(Value));
   TMemoryStreamEx(Stream).Write(Value[1], Length(Value));
@@ -232 +275 @@
 procedure TPBStringItem.LoadFromStream(Stream: TStream);
 begin
-  inherited LoadFromStream(Stream);
+  inherited;
   SetLength(Value, LoadVariantFromStream(Stream));
   TMemoryStreamEx(Stream).Read(Value[1], Length(Value));