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use fnv1a in fcl-stl

This commit is contained in:
Basile Burg 2016-07-04 09:25:44 +02:00
parent d92390471d
commit 4ea80a8ac4
1 changed files with 21 additions and 14 deletions
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35
src/ce_common.pas
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@ -33,15 +33,15 @@ type
// function used as string hasher in fcl-stl
TStringHash = class
class function hash(const key: string; maxBucketsPow2: longint): longint;
class function hash(const key: string; maxBucketsPow2: longword): longword;
end;
// HashMap for TValue by string
generic TStringHashMap<TValue> = class(specialize THashmap<string, TValue, TStringHash>);
// function used as objects haser in fcl-stl
// function used as object ptr hasher in fcl-stl
TObjectHash = class
class function hash(key: TObject; maxBucketsPow2: longint): longint;
class function hash(key: TObject; maxBucketsPow2: longword): longword;
end;
// HashSet for any object
@ -305,30 +305,37 @@ implementation
uses
ce_main;
class function TStringHash.hash(const key: string; maxBucketsPow2: longint): longint;
class function TStringHash.hash(const key: string; maxBucketsPow2: longword): longword;
var
i: integer;
begin
{$PUSH}{$R-}
result := 5381;
result := 2166136261;
for i:= 1 to key.length do
begin
result := ((result shl 5) + result) + Byte(key[i]);
result := result xor Byte(key[i]);
result *= 16777619;
end;
result := result and (maxBucketsPow2-1);
{$POP}
end;
class function TObjectHash.hash(key: TObject; maxBucketsPow2: longint): longint;
class function TObjectHash.hash(key: TObject; maxBucketsPow2: longword): longword;
var
ptr: PByte;
i: integer;
begin
{$PUSH}{$R-}{$WARNINGS OFF}{$HINTS OFF}
ptr := PByte(key);
result := 2166136261;
{$IFDEF CPU32}
Result := longint(Pointer(key)) and (maxBucketsPow2 -1);
for i:= 0 to 3 do
{$ELSE}
Result := longInt(Pointer(key)){ xor PlongInt(PInteger(&key) + 4)^)} and (maxBucketsPow2 -1);
for i:= 0 to 7 do
{$ENDIF}
{$POP}
begin
result := result xor ptr^;
result *= 16777619;
ptr += 1;
end;
result := result and (maxBucketsPow2-1);
end;
procedure TCEPersistentShortcut.assign(aValue: TPersistent);