From: Ketmar Dark <ketmar@ketmar.no-ip.org>
Date: Fri, 25 Aug 2017 12:58:49 +0000 (+0300)
Subject: idpool: it is now possible to request the specified id
X-Git-Url: http://deadsoftware.ru/gitweb?a=commitdiff_plain;h=30f7ce6315b82400548455c6872a271dc1f00f50;p=d2df-sdl.git

idpool: it is now possible to request the specified id
---

diff --git a/src/shared/idpool.pas b/src/shared/idpool.pas
index efba5e6..7817cc1 100644
--- a/src/shared/idpool.pas
+++ b/src/shared/idpool.pas
@@ -14,7 +14,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  *)
 {$INCLUDE a_modes.inc}
-{.$DEFINE IDPOOL_CHECKS}
+{$DEFINE IDPOOL_CHECKS}
 unit idpool;
 
 interface
@@ -56,6 +56,9 @@ type
     // returns InvalidId if there are no more free ids (or throws)
     function alloc (dothrow: Boolean=true): LongWord;
 
+    // returns InvalidId if there are no more free ids (or throws)
+    function alloc (aid: LongWord; dothrow: Boolean=true): LongWord;
+
     // it is NOT ok to release already released id
     procedure release (aid: LongWord);
 
@@ -74,7 +77,6 @@ type
     property capacity: Integer read getCapacity;
   end;
 
-
 implementation
 
 uses
@@ -119,11 +121,11 @@ var
 begin
   for f := 0 to mRangeUsed-1 do
   begin
-    if (mRanges[f].first > mRanges[f].last) then raise Exception.Create('invalid range');
-    if (mRanges[f].first > mMaxId) then raise Exception.Create('invalid range');
-    if (mRanges[f].last > mMaxId) then raise Exception.Create('invalid range');
-    if (f > 0) and (mRanges[f-1].last >= mRanges[f].first) then raise Exception.Create('invalid range order');
-    if (f > 0) and (mRanges[f-1].last+1 = mRanges[f].first) then raise Exception.Create('unmerged ranges');
+    if (mRanges[f].first > mRanges[f].last) then begin dump(); raise Exception.Create('invalid range'); end;
+    if (mRanges[f].first > mMaxId) then begin dump(); raise Exception.Create('invalid range'); end;
+    if (mRanges[f].last > mMaxId) then begin dump(); raise Exception.Create('invalid range'); end;
+    if (f > 0) and (mRanges[f-1].last >= mRanges[f].first) then begin dump(); raise Exception.Create('invalid range order'); end;
+    if (f > 0) and (mRanges[f-1].last+1 = mRanges[f].first) then begin dump(); raise Exception.Create('unmerged ranges'); end;
   end;
 end;
 
@@ -220,6 +222,73 @@ begin
 end;
 
 
+// returns InvalidId if there are no more free ids (or throws)
+function TIdPool.alloc (aid: LongWord; dothrow: Boolean=true): LongWord;
+var
+  ii, c: Integer;
+begin
+  if (mRangeUsed = 0) then
+  begin
+    // no more ids
+    if dothrow then raise Exception.Create('TIdPool: no more free ids');
+    result := InvalidId;
+    exit;
+  end;
+  // invalid?
+  if (aid > mMaxId) then
+  begin
+    if dothrow then raise Exception.Create('TIdPool: cannot allocate invalid id');
+    result := InvalidId;
+    exit;
+  end;
+  // find range with this id
+  ii := findRangeWithId(aid);
+  if (ii < 0) or (aid < mRanges[ii].first) or (aid > mRanges[ii].last) then
+  begin
+    if dothrow then raise Exception.Create('TIdPool: cannot allocate already allocated id');
+    result := InvalidId;
+    exit;
+  end;
+  // always return requested id
+  result := aid;
+  // can we shrink range head?
+  if (aid = mRanges[ii].first) then
+  begin
+    // yep; range with the only id?
+    if (aid = mRanges[ii].last) then
+    begin
+      // delete this range
+      for c := ii+1 to mRangeUsed-1 do mRanges[c-1] := mRanges[c];
+      Dec(mRangeUsed);
+    end
+    else
+    begin
+      mRanges[ii].first := aid+1;
+    end;
+    Inc(mUsedIds);
+    {$IF DEFINED(IDPOOL_CHECKS)}check();{$ENDIF}
+    exit;
+  end;
+  // can we shrink range tail?
+  if (aid = mRanges[ii].last) then
+  begin
+    // yep; simply shrink, 'cause range with one id was processed in the previous `if`
+    mRanges[ii].last := aid-1;
+    Inc(mUsedIds);
+    {$IF DEFINED(IDPOOL_CHECKS)}check();{$ENDIF}
+    exit;
+  end;
+  // split this range to two
+  if (mRangeUsed+1 > Length(mRanges)) then SetLength(mRanges, Length(mRanges)+1024);
+  for c := mRangeUsed downto ii+1 do mRanges[c] := mRanges[c-1];
+  Inc(mRangeUsed);
+  mRanges[ii].last := aid-1;
+  mRanges[ii+1].first := aid+1;
+  Inc(mUsedIds);
+  {$IF DEFINED(IDPOOL_CHECKS)}check();{$ENDIF}
+end;
+
+
 // it is NOT ok to release already released id
 procedure TIdPool.release (aid: LongWord);
 var
@@ -250,7 +319,7 @@ begin
     else
     begin
       // nope, insert new first range
-      if (mRangeUsed+1 > Length(mRanges)) then SetLength(mRanges, Length(mRanges)*2);
+      if (mRangeUsed+1 > Length(mRanges)) then SetLength(mRanges, Length(mRanges)+1024);
       assert(mRangeUsed < Length(mRanges));
       for c := mRangeUsed downto 1 do mRanges[c] := mRanges[c-1];
       Inc(mRangeUsed);
@@ -273,7 +342,7 @@ begin
     else
     begin
       // nope, insert new last range
-      if (mRangeUsed+1 > Length(mRanges)) then SetLength(mRanges, Length(mRanges)*2);
+      if (mRangeUsed+1 > Length(mRanges)) then SetLength(mRanges, Length(mRanges)+1024);
       assert(mRangeUsed < Length(mRanges));
       mRanges[mRangeUsed].first := aid;
       mRanges[mRangeUsed].last := aid;
@@ -336,7 +405,7 @@ begin
     exit;
   end;
   // cannot grow anything, insert empty range after ii
-  if (mRangeUsed = Length(mRanges)) then SetLength(mRanges, Length(mRanges)*2);
+  if (mRangeUsed = Length(mRanges)) then SetLength(mRanges, Length(mRanges)+1024);
   for c := mRangeUsed downto ii do mRanges[c+1] := mRanges[c];
   Inc(ii);
   mRanges[ii].first := aid;
diff --git a/src/shared/ztest_idpool.dpr b/src/shared/ztest_idpool.dpr
index 393c43c..32d0fd0 100644
--- a/src/shared/ztest_idpool.dpr
+++ b/src/shared/ztest_idpool.dpr
@@ -48,11 +48,29 @@ var
   f, n: Integer;
   usedIds: Integer = 0;
 begin
-  ip := TIdPool.Create(65535*1024);
+  ip := TIdPool.Create(65535);
   SetLength(map, ip.maxId+1);
   for f := 0 to High(map) do map[f] := false;
   for f := 0 to High(map) div 2 do
   begin
+    while true do
+    begin
+      n := Random(ip.maxId+1);
+      if map[n] then
+      begin
+        if not ip.hasAlloced[n] then raise Exception.Create('invalid pool(0)');
+        if ip.hasFree[n] then raise Exception.Create('invalid pool(1)');
+        continue;
+      end;
+      break;
+    end;
+    if (ip.alloc(n) <> n) then raise Exception.Create('wutafuuuuu?!');
+    map[n] := true;
+    Inc(usedIds);
+    if not ip.hasAlloced[n] then raise Exception.Create('invalid pool(3)');
+    if ip.hasFree[n] then raise Exception.Create('invalid pool(4)');
+    //ip.dump();
+    {
     if ip.hasAlloced[f] then raise Exception.Create('invalid pool(0)');
     if not ip.hasFree[f] then raise Exception.Create('invalid pool(1)');
     if (ip.alloc <> f) then raise Exception.Create('invalid alloc(2)');
@@ -60,6 +78,7 @@ begin
     Inc(usedIds);
     if not ip.hasAlloced[f] then raise Exception.Create('invalid pool(3)');
     if ip.hasFree[f] then raise Exception.Create('invalid pool(4)');
+    }
   end;
   for f := 0 to 10000000 do
   begin
@@ -107,6 +126,7 @@ begin
       if not ip.hasFree[f] then raise Exception.Create('invalid pool(e)');
     end;
   end;
+  ip.Free();
 end;