ddnet/src/engine/shared/snapshot.cpp

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2010-11-20 10:37:14 +00:00
/* (c) Magnus Auvinen. See licence.txt in the root of the distribution for more information. */
/* If you are missing that file, acquire a complete release at teeworlds.com. */
2010-05-29 07:25:38 +00:00
#include "snapshot.h"
#include "engine.h"
#include "compression.h"
// CSnapshot
CSnapshotItem *CSnapshot::GetItem(int Index)
{
return (CSnapshotItem *)(DataStart() + Offsets()[Index]);
}
int CSnapshot::GetItemSize(int Index)
{
if(Index == m_NumItems-1)
return (m_DataSize - Offsets()[Index]) - sizeof(CSnapshotItem);
return (Offsets()[Index+1] - Offsets()[Index]) - sizeof(CSnapshotItem);
}
int CSnapshot::GetItemIndex(int Key)
{
// TODO: OPT: this should not be a linear search. very bad
for(int i = 0; i < m_NumItems; i++)
{
if(GetItem(i)->Key() == Key)
return i;
}
return -1;
}
int CSnapshot::Crc()
{
int Crc = 0;
for(int i = 0; i < m_NumItems; i++)
{
CSnapshotItem *pItem = GetItem(i);
int Size = GetItemSize(i);
for(int b = 0; b < Size/4; b++)
Crc += pItem->Data()[b];
}
return Crc;
}
void CSnapshot::DebugDump()
{
dbg_msg("snapshot", "data_size=%d num_items=%d", m_DataSize, m_NumItems);
for(int i = 0; i < m_NumItems; i++)
{
CSnapshotItem *pItem = GetItem(i);
int Size = GetItemSize(i);
dbg_msg("snapshot", "\ttype=%d id=%d", pItem->Type(), pItem->ID());
for(int b = 0; b < Size/4; b++)
dbg_msg("snapshot", "\t\t%3d %12d\t%08x", b, pItem->Data()[b], pItem->Data()[b]);
}
}
// CSnapshotDelta
struct CItemList
{
int m_Num;
int m_aKeys[64];
int m_aIndex[64];
};
enum
{
HASHLIST_SIZE = 256,
};
static void GenerateHash(CItemList *pHashlist, CSnapshot *pSnapshot)
{
for(int i = 0; i < HASHLIST_SIZE; i++)
pHashlist[i].m_Num = 0;
for(int i = 0; i < pSnapshot->NumItems(); i++)
{
int Key = pSnapshot->GetItem(i)->Key();
int HashID = ((Key>>8)&0xf0) | (Key&0xf);
if(pHashlist[HashID].m_Num != 64)
{
pHashlist[HashID].m_aIndex[pHashlist[HashID].m_Num] = i;
pHashlist[HashID].m_aKeys[pHashlist[HashID].m_Num] = Key;
pHashlist[HashID].m_Num++;
}
}
}
static int GetItemIndexHashed(int Key, const CItemList *pHashlist)
{
int HashID = ((Key>>8)&0xf0) | (Key&0xf);
for(int i = 0; i < pHashlist[HashID].m_Num; i++)
{
if(pHashlist[HashID].m_aKeys[i] == Key)
return pHashlist[HashID].m_aIndex[i];
}
return -1;
}
static int DiffItem(int *pPast, int *pCurrent, int *pOut, int Size)
{
int Needed = 0;
while(Size)
{
*pOut = *pCurrent-*pPast;
Needed |= *pOut;
pOut++;
pPast++;
pCurrent++;
Size--;
}
return Needed;
}
void CSnapshotDelta::UndiffItem(int *pPast, int *pDiff, int *pOut, int Size)
{
while(Size)
{
*pOut = *pPast+*pDiff;
if(*pDiff == 0)
m_aSnapshotDataRate[m_SnapshotCurrent] += 1;
else
{
unsigned char aBuf[16];
unsigned char *pEnd = CVariableInt::Pack(aBuf, *pDiff);
m_aSnapshotDataRate[m_SnapshotCurrent] += (int)(pEnd - (unsigned char*)aBuf) * 8;
}
pOut++;
pPast++;
pDiff++;
Size--;
}
}
CSnapshotDelta::CSnapshotDelta()
{
mem_zero(m_aItemSizes, sizeof(m_aItemSizes));
mem_zero(m_aSnapshotDataRate, sizeof(m_aSnapshotDataRate));
mem_zero(m_aSnapshotDataUpdates, sizeof(m_aSnapshotDataUpdates));
m_SnapshotCurrent = 0;
mem_zero(&m_Empty, sizeof(m_Empty));
}
void CSnapshotDelta::SetStaticsize(int ItemType, int Size)
{
m_aItemSizes[ItemType] = Size;
}
CSnapshotDelta::CData *CSnapshotDelta::EmptyDelta()
{
return &m_Empty;
}
// TODO: OPT: this should be made much faster
int CSnapshotDelta::CreateDelta(CSnapshot *pFrom, CSnapshot *pTo, void *pDstData)
{
CData *pDelta = (CData *)pDstData;
int *pData = (int *)pDelta->m_pData;
int i, ItemSize, PastIndex;
CSnapshotItem *pFromItem;
CSnapshotItem *pCurItem;
CSnapshotItem *pPastItem;
int Count = 0;
int SizeCount = 0;
pDelta->m_NumDeletedItems = 0;
pDelta->m_NumUpdateItems = 0;
pDelta->m_NumTempItems = 0;
CItemList Hashlist[HASHLIST_SIZE];
GenerateHash(Hashlist, pTo);
// pack deleted stuff
for(i = 0; i < pFrom->NumItems(); i++)
{
pFromItem = pFrom->GetItem(i);
if(GetItemIndexHashed(pFromItem->Key(), Hashlist) == -1)
{
// deleted
pDelta->m_NumDeletedItems++;
*pData = pFromItem->Key();
pData++;
}
}
GenerateHash(Hashlist, pFrom);
int aPastIndecies[1024];
// fetch previous indices
// we do this as a separate pass because it helps the cache
for(i = 0; i < pTo->NumItems(); i++)
{
pCurItem = pTo->GetItem(i); // O(1) .. O(n)
aPastIndecies[i] = GetItemIndexHashed(pCurItem->Key(), Hashlist); // O(n) .. O(n^n)
}
for(i = 0; i < pTo->NumItems(); i++)
{
// do delta
ItemSize = pTo->GetItemSize(i); // O(1) .. O(n)
pCurItem = pTo->GetItem(i); // O(1) .. O(n)
PastIndex = aPastIndecies[i];
if(PastIndex != -1)
{
int *pItemDataDst = pData+3;
pPastItem = pFrom->GetItem(PastIndex);
if(m_aItemSizes[pCurItem->Type()])
pItemDataDst = pData+2;
if(DiffItem((int*)pPastItem->Data(), (int*)pCurItem->Data(), pItemDataDst, ItemSize/4))
{
*pData++ = pCurItem->Type();
*pData++ = pCurItem->ID();
if(!m_aItemSizes[pCurItem->Type()])
*pData++ = ItemSize/4;
pData += ItemSize/4;
pDelta->m_NumUpdateItems++;
}
}
else
{
*pData++ = pCurItem->Type();
*pData++ = pCurItem->ID();
if(!m_aItemSizes[pCurItem->Type()])
*pData++ = ItemSize/4;
mem_copy(pData, pCurItem->Data(), ItemSize);
SizeCount += ItemSize;
pData += ItemSize/4;
pDelta->m_NumUpdateItems++;
Count++;
}
}
if(0)
{
dbg_msg("snapshot", "%d %d %d",
pDelta->m_NumDeletedItems,
pDelta->m_NumUpdateItems,
pDelta->m_NumTempItems);
}
/*
// TODO: pack temp stuff
// finish
//mem_copy(pDelta->offsets, deleted, pDelta->num_deleted_items*sizeof(int));
//mem_copy(&(pDelta->offsets[pDelta->num_deleted_items]), update, pDelta->num_update_items*sizeof(int));
//mem_copy(&(pDelta->offsets[pDelta->num_deleted_items+pDelta->num_update_items]), temp, pDelta->num_temp_items*sizeof(int));
//mem_copy(pDelta->data_start(), data, data_size);
//pDelta->data_size = data_size;
* */
if(!pDelta->m_NumDeletedItems && !pDelta->m_NumUpdateItems && !pDelta->m_NumTempItems)
return 0;
return (int)((char*)pData-(char*)pDstData);
}
static int RangeCheck(void *pEnd, void *pPtr, int Size)
{
if((const char *)pPtr + Size > (const char *)pEnd)
return -1;
return 0;
}
int CSnapshotDelta::UnpackDelta(CSnapshot *pFrom, CSnapshot *pTo, void *pSrcData, int DataSize)
{
CSnapshotBuilder Builder;
CData *pDelta = (CData *)pSrcData;
int *pData = (int *)pDelta->m_pData;
int *pEnd = (int *)(((char *)pSrcData + DataSize));
CSnapshotItem *pFromItem;
int Keep, ItemSize;
int *pDeleted;
int Id, Type, Key;
int FromIndex;
int *pNewData;
Builder.Init();
// unpack deleted stuff
pDeleted = pData;
pData += pDelta->m_NumDeletedItems;
if(pData > pEnd)
return -1;
// copy all non deleted stuff
for(int i = 0; i < pFrom->NumItems(); i++)
{
// dbg_assert(0, "fail!");
pFromItem = pFrom->GetItem(i);
ItemSize = pFrom->GetItemSize(i);
Keep = 1;
for(int d = 0; d < pDelta->m_NumDeletedItems; d++)
{
if(pDeleted[d] == pFromItem->Key())
{
Keep = 0;
break;
}
}
if(Keep)
{
// keep it
mem_copy(
Builder.NewItem(pFromItem->Type(), pFromItem->ID(), ItemSize),
pFromItem->Data(), ItemSize);
}
}
// unpack updated stuff
for(int i = 0; i < pDelta->m_NumUpdateItems; i++)
{
if(pData+2 > pEnd)
return -1;
Type = *pData++;
Id = *pData++;
if(m_aItemSizes[Type])
ItemSize = m_aItemSizes[Type];
else
{
if(pData+1 > pEnd)
return -2;
ItemSize = (*pData++) * 4;
}
m_SnapshotCurrent = Type;
if(RangeCheck(pEnd, pData, ItemSize) || ItemSize < 0) return -3;
Key = (Type<<16)|Id;
// create the item if needed
pNewData = Builder.GetItemData(Key);
if(!pNewData)
pNewData = (int *)Builder.NewItem(Key>>16, Key&0xffff, ItemSize);
//if(range_check(pEnd, pNewData, ItemSize)) return -4;
FromIndex = pFrom->GetItemIndex(Key);
if(FromIndex != -1)
{
// we got an update so we need pTo apply the diff
UndiffItem((int *)pFrom->GetItem(FromIndex)->Data(), pData, pNewData, ItemSize/4);
m_aSnapshotDataUpdates[m_SnapshotCurrent]++;
}
else // no previous, just copy the pData
{
mem_copy(pNewData, pData, ItemSize);
m_aSnapshotDataRate[m_SnapshotCurrent] += ItemSize*8;
m_aSnapshotDataUpdates[m_SnapshotCurrent]++;
}
pData += ItemSize/4;
}
// finish up
return Builder.Finish(pTo);
}
// CSnapshotStorage
void CSnapshotStorage::Init()
{
m_pFirst = 0;
m_pLast = 0;
}
void CSnapshotStorage::PurgeAll()
{
CHolder *pHolder = m_pFirst;
CHolder *pNext;
while(pHolder)
{
pNext = pHolder->m_pNext;
mem_free(pHolder);
pHolder = pNext;
}
// no more snapshots in storage
m_pFirst = 0;
m_pLast = 0;
}
void CSnapshotStorage::PurgeUntil(int Tick)
{
CHolder *pHolder = m_pFirst;
CHolder *pNext;
while(pHolder)
{
pNext = pHolder->m_pNext;
if(pHolder->m_Tick >= Tick)
return; // no more to remove
mem_free(pHolder);
// did we come to the end of the list?
if (!pNext)
break;
m_pFirst = pNext;
pNext->m_pPrev = 0x0;
pHolder = pNext;
}
// no more snapshots in storage
m_pFirst = 0;
m_pLast = 0;
}
void CSnapshotStorage::Add(int Tick, int64 Tagtime, int DataSize, void *pData, int CreateAlt)
{
// allocate memory for holder + snapshot_data
int TotalSize = sizeof(CHolder)+DataSize;
if(CreateAlt)
TotalSize += DataSize;
CHolder *pHolder = (CHolder *)mem_alloc(TotalSize, 1);
// set data
pHolder->m_Tick = Tick;
pHolder->m_Tagtime = Tagtime;
pHolder->m_SnapSize = DataSize;
pHolder->m_pSnap = (CSnapshot*)(pHolder+1);
mem_copy(pHolder->m_pSnap, pData, DataSize);
if(CreateAlt) // create alternative if wanted
{
pHolder->m_pAltSnap = (CSnapshot*)(((char *)pHolder->m_pSnap) + DataSize);
mem_copy(pHolder->m_pAltSnap, pData, DataSize);
}
else
pHolder->m_pAltSnap = 0;
// link
pHolder->m_pNext = 0;
pHolder->m_pPrev = m_pLast;
if(m_pLast)
m_pLast->m_pNext = pHolder;
else
m_pFirst = pHolder;
m_pLast = pHolder;
}
int CSnapshotStorage::Get(int Tick, int64 *pTagtime, CSnapshot **ppData, CSnapshot **ppAltData)
{
CHolder *pHolder = m_pFirst;
while(pHolder)
{
if(pHolder->m_Tick == Tick)
{
if(pTagtime)
*pTagtime = pHolder->m_Tagtime;
if(ppData)
*ppData = pHolder->m_pSnap;
if(ppAltData)
*ppData = pHolder->m_pAltSnap;
return pHolder->m_SnapSize;
}
pHolder = pHolder->m_pNext;
}
return -1;
}
// CSnapshotBuilder
void CSnapshotBuilder::Init()
{
m_DataSize = 0;
m_NumItems = 0;
}
CSnapshotItem *CSnapshotBuilder::GetItem(int Index)
{
return (CSnapshotItem *)&(m_aData[m_aOffsets[Index]]);
}
int *CSnapshotBuilder::GetItemData(int Key)
{
int i;
for(i = 0; i < m_NumItems; i++)
{
if(GetItem(i)->Key() == Key)
return (int *)GetItem(i)->Data();
}
return 0;
}
int CSnapshotBuilder::Finish(void *SpnapData)
{
// flattern and make the snapshot
CSnapshot *pSnap = (CSnapshot *)SpnapData;
int OffsetSize = sizeof(int)*m_NumItems;
pSnap->m_DataSize = m_DataSize;
pSnap->m_NumItems = m_NumItems;
mem_copy(pSnap->Offsets(), m_aOffsets, OffsetSize);
mem_copy(pSnap->DataStart(), m_aData, m_DataSize);
return sizeof(CSnapshot) + OffsetSize + m_DataSize;
}
void *CSnapshotBuilder::NewItem(int Type, int ID, int Size)
{
CSnapshotItem *pObj = (CSnapshotItem *)(m_aData + m_DataSize);
mem_zero(pObj, sizeof(CSnapshotItem) + Size);
pObj->m_TypeAndID = (Type<<16)|ID;
m_aOffsets[m_NumItems] = m_DataSize;
m_DataSize += sizeof(CSnapshotItem) + Size;
m_NumItems++;
dbg_assert(m_DataSize < CSnapshot::MAX_SIZE, "too much data");
dbg_assert(m_NumItems < MAX_ITEMS, "too many items");
return pObj->Data();
}