Added parameter and test for growth increments and rounding

Co-Authored-By: Claude <noreply@anthropic.com>

Includes/_Allocators.pbi

@@ -28,20 +28,25 @@ XIncludeFile "./_Commons.pbi"
 
 ;-> Thingies
 
-Procedure.i MsgPackCreate(InitialSize.i)
+Procedure.i MsgPackCreate(InitialSize.i, GrowthIncrement.i = 1)
 	Protected *ReturnedValue.MsgPackData = #Null
-	
+
 	If InitialSize <= 0
 		DebuggerWarning("Returning #Null, requested size was zero or negative")
 		ProcedureReturn #Null
 	EndIf
+
+	If GrowthIncrement <= 0
+		DebuggerWarning("Returning #Null, growth increment was zero or negative")
+		ProcedureReturn #Null
+	EndIf
 	
 	*ReturnedValue = AllocateStructure(MsgPackData)
 	
 	If *ReturnedValue <> #Null
 		*ReturnedValue\BufferOffset = 0
 		*ReturnedValue\BufferSize = InitialSize
-		*ReturnedValue\BufferGrowthIncrement = InitialSize
+		*ReturnedValue\BufferGrowthIncrement = GrowthIncrement
 		*ReturnedValue\DataFlags = 0
 		
 		*ReturnedValue\Buffer = AllocateMemory(InitialSize)
@@ -60,12 +65,17 @@ EndProcedure
 ;  be grown or freed by this include, and the caller must free it themselves.
 ; If `GiveOwnership` is `#True`, `*Buffer` MUST come from `AllocateMemory()`, since it
 ;  may be reallocated when growing, and it can be freed through `MsgPackFree()`.
-Procedure.i MsgPackWrapMsgBuffer(*Buffer, BufferSize.i, GiveOwnership.b = #False)
+Procedure.i MsgPackWrapMsgBuffer(*Buffer, BufferSize.i, GiveOwnership.b = #False, GrowthIncrement.i = 1)
 	Protected *ReturnedValue.MsgPackData = #Null
-	
+
 	If *Buffer = #Null Or BufferSize <= 0
 		ProcedureReturn #Null
 	EndIf
+
+	If GrowthIncrement <= 0
+		DebuggerWarning("Returning #Null, growth increment was zero or negative")
+		ProcedureReturn #Null
+	EndIf
 	
 	*ReturnedValue = AllocateStructure(MsgPackData)
 	If *ReturnedValue = #Null
@@ -74,7 +84,7 @@ Procedure.i MsgPackWrapMsgBuffer(*Buffer, BufferSize.i, GiveOwnership.b = #False
 	
 	*ReturnedValue\BufferOffset = 0
 	*ReturnedValue\BufferSize = BufferSize
-	*ReturnedValue\BufferGrowthIncrement = 0
+	*ReturnedValue\BufferGrowthIncrement = GrowthIncrement
 	*ReturnedValue\DataFlags = 0
 	*ReturnedValue\Buffer = *Buffer
 

UnitTests/01_Allocators/TestGrowthRounding.pb

@@ -0,0 +1,80 @@
+EnableExplicit
+
+XIncludeFile "../_UnitTesting.pbi"
+XIncludeFile "../../Includes/MessagePack.pbi"
+
+
+; Default growth increment is 1, no rounding
+Define *BufferHolder.MsgPackData = MsgPackCreate(16)
+
+AssertEquals(*BufferHolder\BufferGrowthIncrement, 1, "Default growth increment is 1.")
+AssertEquals(MsgPackGrow(*BufferHolder, 3), #MsgPack_Error_Success, "Growing 16 by 3 with the default increment.")
+AssertEquals(*BufferHolder\BufferSize, 19, "Size is exactly 19.")
+
+MsgPackFree(*BufferHolder, #True)
+
+
+; Rounding up to the next multiple of the growth increment
+*BufferHolder = MsgPackCreate(16, 16)
+
+AssertEquals(MsgPackGrow(*BufferHolder, 2), #MsgPack_Error_Success, "Growing 16 by 2 with an increment of 16.")
+AssertEquals(*BufferHolder\BufferSize, 32, "Size was rounded up to 32. (1)")
+AssertEquals(MemorySize(*BufferHolder\Buffer), 32, "Size was rounded up to 32. (2)")
+
+AssertEquals(MsgPackGrow(*BufferHolder, 17), #MsgPack_Error_Success, "Growing 32 by 17 with an increment of 16.")
+AssertEquals(*BufferHolder\BufferSize, 64, "Size was rounded up to 64.")
+
+AssertEquals(MsgPackGrow(*BufferHolder, 16), #MsgPack_Error_Success, "Growing 64 by an exact multiple.")
+AssertEquals(*BufferHolder\BufferSize, 80, "Size is exactly 80.")
+
+*BufferHolder\BufferGrowthIncrement = 1
+AssertEquals(MsgPackGrow(*BufferHolder, 3), #MsgPack_Error_Success, "Growing 80 by 3 without increment.")
+AssertEquals(*BufferHolder\BufferSize, 83, "Size is exactly 83.")
+
+MsgPackFree(*BufferHolder, #True)
+
+
+; Writers only grow by the missing amount
+*BufferHolder = MsgPackCreate(4)
+*BufferHolder\BufferOffset = 3
+
+AssertEquals(MsgPackWriteUInt16(*BufferHolder, $1234), #MsgPack_Error_Success, "Writing 3 bytes at offset 3 of a 4 bytes buffer.")
+AssertEquals(*BufferHolder\BufferSize, 6, "Buffer grew by the 2 missing bytes only.")
+AssertEquals(*BufferHolder\BufferOffset, 6, "Offset is now at the end.")
+
+MsgPackFree(*BufferHolder, #True)
+
+
+; Wrapped buffer that stays owned by the caller
+Define *RawBuffer = AllocateMemory(2)
+*BufferHolder = MsgPackWrapMsgBuffer(*RawBuffer, 2)
+
+AssertIsTrue(Bool(_MsgPackHasFlag(*BufferHolder, #MsgPack_DataFlags_CannotGrow)), "Non-owned wrap cannot grow.")
+AssertIsTrue(Bool(_MsgPackHasFlag(*BufferHolder, #MsgPack_DataFlags_NoBufferFree)), "Non-owned wrap cannot be freed.")
+AssertEquals(MsgPackWriteUInt16(*BufferHolder, $1234), #MsgPack_Error_CannotGrowBufferDueToConfig, "Writing past a non-owned wrap is refused.")
+AssertEquals(*BufferHolder\Buffer, *RawBuffer, "Buffer pointer is untouched.")
+AssertEquals(*BufferHolder\BufferSize, 2, "Buffer size is untouched.")
+
+AssertIsTrue(MsgPackFree(*BufferHolder, #False), "Non-owned wrap is freed without its buffer.")
+FreeMemory(*RawBuffer)
+
+
+; Wrapped buffer whose ownership is given
+*RawBuffer = AllocateMemory(2)
+*BufferHolder = MsgPackWrapMsgBuffer(*RawBuffer, 2, #True)
+
+AssertIsFalse(Bool(_MsgPackHasFlag(*BufferHolder, #MsgPack_DataFlags_CannotGrow)), "Owned wrap can grow.")
+AssertIsFalse(Bool(_MsgPackHasFlag(*BufferHolder, #MsgPack_DataFlags_NoBufferFree)), "Owned wrap can be freed.")
+AssertEquals(MsgPackWriteUInt16(*BufferHolder, $1234), #MsgPack_Error_Success, "Writing past an owned wrap grows it.")
+AssertEquals(*BufferHolder\BufferSize, 3, "Buffer grew by the missing byte.")
+
+AssertIsTrue(MsgPackFree(*BufferHolder, #True), "Owned wrap is freed with its buffer.")
+
+
+If FailedUnitTests
+	End 1
+EndIf
+
+Debug "Done !"
+
+End 0