Here is my test unit I'm playing with. It's crude but can anyone suggest what other things I could test?
I'm playing with a string pointer also to see how ref counting/finalization plays in. Making your own managed typed using management operators is not tested but I'm sure it will be terrible compared to everything else.
* test_short_string time: 143ms
* test_ansi_string time: 115ms
* test_mem_string time: 115ms
* test_short_string_record time: 165ms
* test_ansi_string_record time: 75ms
* test_mem_string_record time: 47ms
* test_short_string_mutate time: 203ms
* test_ansi_string_mutate time: 181ms
=======================================================================================
{$mode objfpc}
program string_test;
uses
SysUtils, DateUtils;
const
ITERATIONS = 1000 * 1000;
TEST_STRING = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit';
type
TTestProc = procedure;
procedure test_mem_string;
procedure do_pass(const s: PString; len: Integer);
var
c: Char;
i: Integer;
begin
for i := 0 to len - 1 do
c := s^[i];
end;
var
s: PString;
i, len: Integer;
begin
for i := 0 to ITERATIONS - 1 do
begin
len := Length(TEST_STRING);
s := GetMem(len);
s^ := TEST_STRING;
do_pass(s, len);
FreeMem(s);
end;
end;
procedure test_short_string;
procedure do_pass(const s: ShortString);
var
c: Char;
i: Integer;
begin
for i := 0 to length(s) - 1 do
c := s[i];
end;
var
s: Shortstring;
i: Integer;
begin
for i := 0 to ITERATIONS - 1 do
begin
s := TEST_STRING;
do_pass(s);
end;
end;
procedure test_ansi_string;
procedure ansi_string_pass(const s: AnsiString);
var
c: Char;
i: Integer;
begin
for i := 0 to length(s) - 1 do
c := s[i];
end;
var
s: AnsiString;
i: Integer;
begin
for i := 0 to ITERATIONS - 1 do
begin
s := TEST_STRING;
ansi_string_pass(s);
end;
end;
procedure test_ansi_string_mutate;
var
i, j: Integer;
s1, s2: AnsiString;
begin
for i := 0 to ITERATIONS - 1 do
begin
s1 := TEST_STRING;
s2 := s1 + IntToStr(i);
for j := 1 to length(s2) - 1 do
s2[j] := 'x';
end;
end;
procedure test_short_string_mutate;
var
i, j: Integer;
s1, s2: ShortString;
begin
for i := 0 to ITERATIONS - 1 do
begin
s1 := TEST_STRING;
s2 := s1 + IntToStr(i);
for j := 1 to length(s2) - 1 do
s2[j] := 'x';
end;
end;
procedure test_short_string_record;
type
TMyRecord = record
a: ShortString;
b: ShortString;
c: ShortString;
end;
function do_pass(rec: TMyRecord): TMyRecord;
begin
result := rec;
end;
var
i: Integer;
r: TMyRecord;
begin
for i := 0 to ITERATIONS - 1 do
begin
r.a := TEST_STRING;
r.b := TEST_STRING;
r.c := TEST_STRING;
do_pass(r);
end;
end;
procedure test_ansi_string_record;
type
TMyRecord = record
a: AnsiString;
b: AnsiString;
c: AnsiString;
end;
function do_pass(rec: TMyRecord): TMyRecord;
begin
result := rec;
end;
var
i: Integer;
r: TMyRecord;
begin
for i := 0 to ITERATIONS - 1 do
begin
r.a := TEST_STRING;
r.b := TEST_STRING;
r.c := TEST_STRING;
do_pass(r);
end;
end;
procedure test_mem_string_record;
type
TMyRecord = record
a: PString;
b: PString;
c: PString;
end;
function do_pass(rec: TMyRecord): TMyRecord;
begin
result := rec;
end;
var
i: Integer;
r: TMyRecord;
len: Integer;
begin
len := Length(TEST_STRING);
for i := 0 to ITERATIONS - 1 do
begin
r.a := GetMem(len);
r.b := GetMem(len);
r.c := GetMem(len);
r.a^ := TEST_STRING;
r.b^ := TEST_STRING;
r.c^ := TEST_STRING;
do_pass(r);
end;
end;
procedure run_test(name: String; test: TTestProc);
var
startTime: Double;
begin
startTime := Now;
test;
writeln('* ', name,' time: ', MilliSecondsBetween(Now, StartTime), 'ms');
end;
begin
run_test('test_short_string', @test_short_string);
run_test('test_ansi_string', @test_ansi_string);
run_test('test_mem_string', @test_ansi_string);
run_test('test_short_string_record', @test_short_string_record);
run_test('test_ansi_string_record', @test_ansi_string_record);
run_test('test_mem_string_record', @test_mem_string_record);
run_test('test_short_string_mutate', @test_short_string_mutate);
run_test('test_ansi_string_mutate', @test_ansi_string_mutate);
end.
Regards,
Ryan Joseph
