Mega Code Archive
Reallocmem - reallocate an existing block of storage system unit
<![CDATA[
procedure ReallocMem ( var StoragePointer : Pointer; StorageSize : Integer ) ;
Description
The ReallocMem procedure changes the storage size of an existing block of storage.
The size may be smaller or bigger.
If smaller, then the existing storage is effectively truncated, the remainder being released.
If larger, the storage is extended. Or a new block is allocated if necessary. In either case, the existing storage block data is preserved, and the new part is unitialised.
Notes
Warning : use with caution - excessive use can fragment storage.
Related commands
Dispose Dispose of storage used by a pointer type variable
FreeMem Free memory storage used by a variable
GetMem Get a specified number of storage bytes
New Create a new pointer type variable
Example code : Allocate using GetMem and then reallocate using ReallocMem
type
TRecord = Record
name : string[10];
age : Byte;
end;
var
recPointer : ^TRecord;
begin
// Allocate storage for 2 records
// Note : It is better to use New for this
// It is used here for illustration purposes only
GetMem(recPointer, 2 * SizeOf(TRecord));
// Fill out these 2 records with values
recPointer.name := 'Brian';
recPointer.age := 23;
Inc(recPointer);
recPointer.name := 'Jim';
recPointer.age := 55;
// Whoops - forgot to add Sally ...
Dec(recPointer);
ReallocMem(recPointer, 3 * SizeOf(TRecord));
// Now add a third record
Inc(recPointer,2);
recPointer.name := 'Sally';
recPointer.age := 38;
// Now display these values
Dec(recPointer, 2);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
Inc(recPointer);
ShowMessageFmt('%s is %d',[recPointer.name, recPointer.age]);
end;
Show full unit code
Brian is 23
Jim is 55
Sally is 38
]]>