//========= Copyright Valve Corporation, All rights reserved. ============// // // Purpose: // // $NoKeywords: $ //============================================================================= #ifndef THASH_H #define THASH_H #ifdef _WIN32 #pragma once #endif #include //#define DBGFLAG_THASH // Perform extra sanity checks on the THash // THash // This is a heavyweight, templatized version of DHash. // It differs from DHash in the following ways: // - It's templetized, and automatically constructs and destructs its records as appropriate // - It provides a scheduling service, which can be used to touch every record in the table // at a specified interval. The scheduler is low-overhead, and provides a very smooth // distribution of touches across frames. // Template arguments: // Data: the class to be stored in the hash table // I: the type of the primary key (uint32 by default) template class CTHash { private: // RecHdr // We insert one of these at the beginning of every record. It's used for // keeping the records in a linked list. typedef struct RecHdr_t { RecHdr_t *m_pRecHdrNext; // Next item in our linked list RecHdr_t *m_pRecHdrPrev; // Previous item in our linked list I m_unKey; // Key of this item int m_iBucket; // The bucket we're in int m_nRunRatio; // We want to run 1 cycle out of every m_nRunRatio // cycles (not at all if 0). #ifdef DBGFLAG_THASH uint m_iCycleLast; // Last cycle we were visited (whether or not we ran) #endif } RecHdr_t; // Bucket // Each hash bucket is represented by a Bucket structure, which points to the // first record with the bucket's hash. typedef struct Bucket_t { RecHdr_t *m_pRecHdrFirst; // First record in our list } Bucket_t; public: // Constructors & destructors CTHash( int cFramesPerCycle ); ~CTHash(); // Initializer void Init( int cRecordInit, int cBuckets ); // Insert a record into the table Data *PvRecordInsert( I unKey ); // Insert a record into the table and set the allocated object's pointer as the hash key Data *PvRecordInsertAutoKey(); // Changes the key for a previously inserted item void ChangeKey( Data * pvRecord, I unOldKey, I unNewKey ); // Remove a record void Remove( I unKey ); // Remove a record void Remove( Data * pvRecord ); // Remove all records void RemoveAll(); // Find a record Data *PvRecordFind( I unKey ) const; // How many records do we have int Count() const { return m_cRecordInUse; } // Iterate through our members Data *PvRecordFirst() const; Data *PvRecordNext( Data *pvRecordCur ) const; // We provide a scheduling service. Call StartFrameSchedule when you want to start running // records in a given frame, and repeatedly call PvRecordRun until it returns NULL (or you // run our of time). void SetRunRatio( Data *pvRecord, int nRunRatio ); void SetMicroSecPerCycle( int cMicroSecPerCycle, int cMicroSecPerFrame ) { m_cFramesPerCycle = cMicroSecPerCycle / cMicroSecPerFrame; } void StartFrameSchedule( bool bNewFrame ); Data *PvRecordRun(); bool BCompletedPass(); #ifdef DBGFLAG_VALIDATE virtual void Validate( CValidator &validator, const char *pchName ); #endif // DBGFLAG_VALIDATE private: // Insert a record into the table Data *PvRecordInsertInternal( RecHdr_t *pRecHdr, I unKey ); // Get the record associated with a THashHdr Data *PvRecordFromPRecHdr( RecHdr_t *pRecHdr ) const { return ( Data * ) ( ( ( uint8 * ) pRecHdr + sizeof( RecHdr_t ) ) ); } // Get the RecHdr preceding a PvRecord RecHdr_t *PRecHdrFromPvRecord( Data *pvRecord ) const { return ( ( ( RecHdr_t * ) pvRecord ) - 1 ); } // Get the hash bucket corresponding to a key int IBucket( I unKey ) const; void InsertIntoHash( RecHdr_t *pRecHdr, I unKey ); void RemoveFromHash( Data * pvRecord ); int m_cBucket; // # of hash buckets we have Bucket_t *m_pBucket; // Big array of hash buckets CUtlMemoryPool *m_pMemoryPoolRecord; // All our data records int m_cRecordInUse; // # of records in use RecHdr_t m_RecHdrHead; // Head of our linked list RecHdr_t m_RecHdrTail; // Tail of our linked list int m_cFramesPerCycle; // Run each of our records once every m_cFramesPerCycle frames RecHdr_t *m_pRecHdrRunNext; // Next record to run (be careful-- this is more complicated than it sounds) int m_iBucketRunMax; // Stop running when we get to this bucket uint m_iCycleCur; // Current cycle (ie, how many times we've made a complete scheduler pass) uint m_iCycleLast; // Our previous cycle uint m_iFrameCur; // Our current frame (incremented once each StartFrameSchedule) uint m_iCycleLastReported; // Last cycle checked by BCompletedPass() }; //----------------------------------------------------------------------------- // Purpose: Constructor // Input: cMicroSecRunInterval - How often we want the scheduler to run each of our records //----------------------------------------------------------------------------- template CTHash::CTHash( int cFramesPerCycle ) { m_cBucket = 0; m_pBucket = NULL; m_pMemoryPoolRecord = NULL; m_cRecordInUse = 0; m_cFramesPerCycle = cFramesPerCycle; m_pRecHdrRunNext = &m_RecHdrTail; // This will make us start at the beginning on our first frame m_iBucketRunMax = 0; m_iCycleCur = 0; m_iCycleLast = 0; m_iFrameCur = 0; m_iCycleLastReported = 0; m_RecHdrHead.m_pRecHdrPrev = NULL; m_RecHdrHead.m_pRecHdrNext = &m_RecHdrTail; m_RecHdrHead.m_iBucket = -1; m_RecHdrTail.m_pRecHdrPrev = &m_RecHdrHead; m_RecHdrTail.m_pRecHdrNext = NULL; } //----------------------------------------------------------------------------- // Purpose: Destructor //----------------------------------------------------------------------------- template CTHash::~CTHash() { RemoveAll(); if ( NULL != m_pBucket ) FreePv( m_pBucket ); m_pBucket = NULL; if ( NULL != m_pMemoryPoolRecord ) delete( m_pMemoryPoolRecord ); m_pMemoryPoolRecord = NULL; } //----------------------------------------------------------------------------- // Purpose: Initializer. Allocate our various arrays, and set up the free // list. // Input: cRecordInit - Initial # of data records we can contain // cBucket - # of hash buckets we should use //----------------------------------------------------------------------------- template void CTHash::Init( int cRecordInit, int cBucket ) { Assert( cRecordInit > 0 ); // need to init with non-zero value or memory pool will never grow // Copy our parameters m_cBucket = cBucket; // Alloc our arrays m_pBucket = ( Bucket_t * ) PvAlloc( sizeof( Bucket_t ) * m_cBucket ); m_pMemoryPoolRecord = new CUtlMemoryPool( sizeof( Data ) + sizeof( RecHdr_t ), cRecordInit, CUtlMemoryPool::GROW_SLOW ); // Init the hash buckets for ( int iBucket = 0; iBucket < m_cBucket; iBucket++ ) m_pBucket[iBucket].m_pRecHdrFirst = NULL; // Make the tail have an illegally large bucket m_RecHdrTail.m_iBucket = m_cBucket + 1; } //----------------------------------------------------------------------------- // Purpose: Inserts a new record into the table // Input: unKey - Primary key of the new record // Output: Pointer to the new record //----------------------------------------------------------------------------- template Data *CTHash::PvRecordInsert( I unKey ) { Assert( PvRecordFind( unKey ) == NULL ); // keys are unique; no record with this key may exist // Find a free record RecHdr_t *pRecHdr = ( RecHdr_t * ) m_pMemoryPoolRecord->Alloc(); return PvRecordInsertInternal( pRecHdr, unKey ); } //----------------------------------------------------------------------------- // Purpose: Inserts a new record into the table and sets its key to the pointer // value of the record // Output: Pointer to the new record //----------------------------------------------------------------------------- template Data *CTHash::PvRecordInsertAutoKey() { // Find a free record RecHdr_t *pRecHdr = ( RecHdr_t * ) m_pMemoryPoolRecord->Alloc(); return PvRecordInsertInternal( pRecHdr, (I) PvRecordFromPRecHdr( pRecHdr ) ); } //----------------------------------------------------------------------------- // Purpose: Inserts an allocated record into the hash table with specified key // and calls the constructor of the allocated object // Input: pRecHdr - record to insert // unKey - hash key to use for record // Output: Pointer to the new record //----------------------------------------------------------------------------- template Data *CTHash::PvRecordInsertInternal( RecHdr_t *pRecHdr, I unKey ) { InsertIntoHash( pRecHdr, unKey ); // assert that we don't have too many items per bucket static bool s_bPerfWarning = false; if ( !s_bPerfWarning && Count() >= ( 5 * m_cBucket ) ) { s_bPerfWarning = true; AssertMsg( false, "Performance warning: too many items, not enough buckets" ); Msg( "not enough buckets in thash class %s (%d records, %d buckets)\n", #ifdef _WIN32 typeid(*this).raw_name(), #else typeid(*this).name(), #endif Count(), m_cBucket ); } // Construct ourselves Data *pData = PvRecordFromPRecHdr( pRecHdr ); Construct( pData ); return pData; } //----------------------------------------------------------------------------- // Purpose: Changes key on previously inserted item // Input: pvRecord - record to change key for // unOldKey - old key (not strictly needed, but helpful consistency check) // unNewKey - new key to use //----------------------------------------------------------------------------- template void CTHash::ChangeKey( Data * pvRecord, I unOldKey, I unNewKey ) { Data * pvRecordFound = PvRecordFind( unOldKey ); Assert( pvRecordFound == pvRecord ); if ( pvRecordFound == pvRecord ) { RemoveFromHash( pvRecord ); InsertIntoHash( PRecHdrFromPvRecord( pvRecord), unNewKey ); } } //----------------------------------------------------------------------------- // Purpose: Removes the entry with a specified key from the table // Input: unKey - Key of the entry to remove //----------------------------------------------------------------------------- template void CTHash::Remove( I unKey ) { Data *pvRemove = ( Data * ) PvRecordFind( unKey ); Assert( pvRemove ); if ( !pvRemove ) return; Remove( pvRemove ); } //----------------------------------------------------------------------------- // Purpose: Removes the specified entry from the table // Input: pvRemove - Pointer to the entry to remove //----------------------------------------------------------------------------- template void CTHash::Remove( Data * pvRemove ) { // Destruct the record we're removing Destruct( pvRemove ); RemoveFromHash( pvRemove ); m_pMemoryPoolRecord->Free( PRecHdrFromPvRecord( pvRemove ) ); } //----------------------------------------------------------------------------- // Purpose: Removes all entries from the table //----------------------------------------------------------------------------- template void CTHash::RemoveAll() { Data * pvRecord = PvRecordFirst(); while ( pvRecord ) { Data *pvRecordNext = PvRecordNext( pvRecord ); Remove( pvRecord ); pvRecord = pvRecordNext; } } //----------------------------------------------------------------------------- // Purpose: Finds the entry with a specified key // Input: unKey - Key to find //----------------------------------------------------------------------------- template Data *CTHash::PvRecordFind( I unKey ) const { // Find our hash bucket int iBucket = IBucket( unKey ); // Walk the bucket's list looking for an exact match for ( RecHdr_t *pRecHdr = m_pBucket[iBucket].m_pRecHdrFirst; NULL != pRecHdr && pRecHdr->m_iBucket == iBucket; pRecHdr = pRecHdr->m_pRecHdrNext ) { if ( unKey == pRecHdr->m_unKey ) return PvRecordFromPRecHdr( pRecHdr ); } // Didn't find a match return NULL; } //----------------------------------------------------------------------------- // Purpose: Finds our first record // Output: Pointer to our first record //----------------------------------------------------------------------------- template Data *CTHash::PvRecordFirst() const { if ( &m_RecHdrTail != m_RecHdrHead.m_pRecHdrNext ) return PvRecordFromPRecHdr( m_RecHdrHead.m_pRecHdrNext ); else return NULL; } //----------------------------------------------------------------------------- // Purpose: Iterates to the record after a given record // Input: Pointer to a current record // Output: Pointer to the next record //----------------------------------------------------------------------------- template Data *CTHash::PvRecordNext( Data *pvRecordCur ) const { RecHdr_t *pRecHdr = PRecHdrFromPvRecord( pvRecordCur ); if ( &m_RecHdrTail == pRecHdr->m_pRecHdrNext ) return NULL; return PvRecordFromPRecHdr( pRecHdr->m_pRecHdrNext ); } //----------------------------------------------------------------------------- // Purpose: Sets the run ratio of a particular record in the hash table. // The record will be run 1 cycle out of every nRunRatio cycles. // Input: pvRecord - The record we're setting // nRunRatio - The run ratio for this record //----------------------------------------------------------------------------- template void CTHash::SetRunRatio( Data *pvRecord, int nRunRatio ) { PRecHdrFromPvRecord( pvRecord )->m_nRunRatio = nRunRatio; } //----------------------------------------------------------------------------- // Purpose: Prepares us to run all records that are due to be run this frame. // Records are run at a particular time dependent on their hash bucket, // regardless of when they were last run. // Input: bNewFrame - True if this is a new frame. If false, we've run // off the end of the list and are checking whether // we need to keep going at the beginning. //----------------------------------------------------------------------------- template void CTHash::StartFrameSchedule( bool bNewFrame ) { // Calculate our current frame and cycle cycle if ( bNewFrame ) { m_iCycleLast = m_iCycleCur; m_iFrameCur++; m_iCycleCur = m_iFrameCur / m_cFramesPerCycle; } // Calculate the last bucket to run int iFrameInCycle = m_iFrameCur % m_cFramesPerCycle; m_iBucketRunMax = ( int ) ( ( ( int64 ) ( iFrameInCycle + 1 ) * ( int64 ) m_cBucket ) / ( int64 ) m_cFramesPerCycle ); AssertFatal( m_iBucketRunMax >= 0 && m_iBucketRunMax <= m_cBucket ); // Are we starting a new cycle? if ( m_iCycleCur > m_iCycleLast ) { #ifdef DBGFLAG_THASH Assert( m_iCycleCur == m_iCycleLast + 1 ); #endif // Did we finish the last cycle? if ( &m_RecHdrTail == m_pRecHdrRunNext ) { m_pRecHdrRunNext = m_RecHdrHead.m_pRecHdrNext; } // No-- finish it up before moving on else { m_iBucketRunMax = m_cBucket + 1; } } } //----------------------------------------------------------------------------- // Purpose: Returns the next record to run, if any // Output: Pointer to the next record that needs to run (NULL if we're done) //----------------------------------------------------------------------------- template Data *CTHash::PvRecordRun() { // Loop until we find a record to run, or until we pass m_iBucketRunMax for ( ; ; ) { // Are we past our stopping point? if ( m_pRecHdrRunNext->m_iBucket >= m_iBucketRunMax ) { // If this cycle ran to the very end, see if we need to start over if ( m_iBucketRunMax > m_cBucket ) { StartFrameSchedule( false ); continue; } return NULL; } #ifdef DBGFLAG_THASH Assert( m_pRecHdrRunNext->m_iBucket >= m_iBucketRunFirst ); if ( 0 != m_pRecHdrRunNext->m_iCycleLast ) { if ( m_pRecHdrRunNext->m_iCycleLast == m_iCycleCur ) { DMsg( SPEW_CONSOLE, 1, "Double cycle: hdr = 0x%x, last frame = %d, curFrame = %d, first = %d, last = %d, bucket = %d\n", m_pRecHdrRunNext, m_pRecHdrRunNext->m_iFrameLast, m_iFrame, m_iBucketRunFirst, m_iBucketRunMax, m_pRecHdrRunNext->m_iBucket ); } else if ( m_pRecHdrRunNext->m_iCycleLast != m_iCycleCur - 1 ) { DMsg( SPEW_CONSOLE, 1, "Skipped cycle: hdr = 0x%x, cycleLast = %u, cycleCur = %u (missed %u cycles)\n", m_pRecHdrRunNext, m_pRecHdrRunNext->m_iCycleLast, m_iCycleCur, m_iCycleCur - m_pRecHdrRunNext->m_iCycleLast ); Assert( false ); } } m_pRecHdrRunNext->m_iCycleLast = m_iCycleCur; m_pRecHdrRunNext->m_iFrameLast = m_iFrame; #endif // Set up the record to run next time RecHdr_t *pRecHdrCur = m_pRecHdrRunNext; m_pRecHdrRunNext = m_pRecHdrRunNext->m_pRecHdrNext; // Does this record need to run? if ( 0 == pRecHdrCur->m_nRunRatio ) continue; if ( 0 == m_iCycleCur % pRecHdrCur->m_nRunRatio ) return PvRecordFromPRecHdr( pRecHdrCur ); } } //----------------------------------------------------------------------------- // Purpose: Return true if we've completed a scheduler pass since last called //----------------------------------------------------------------------------- template bool CTHash::BCompletedPass() { if ( m_iCycleCur != m_iCycleLastReported ) { m_iCycleLastReported = m_iCycleCur; return true; } return false; } extern const unsigned char g_CTHashRandomValues[256]; // definition lives in globals.cpp //----------------------------------------------------------------------------- // Purpose: Returns the index of the hash bucket corresponding to a particular key // Input: unKey - Key to find // Output: Index of the hash bucket corresponding to unKey //----------------------------------------------------------------------------- template int CTHash::IBucket( I unKey ) const { AssertFatal( m_cBucket > 0 ); // This is a pearsons hash variant that returns a maximum of 32 bits size_t size = sizeof(I); const uint8 * k = (const uint8 *) &unKey; uint32 byte_one = 0, byte_two = 0, byte_three = 0, byte_four = 0, n; while (size) { --size; n = *k++; byte_one = g_CTHashRandomValues[byte_one ^ n]; if (size) { --size; n = *k++; byte_two = g_CTHashRandomValues[byte_two ^ n]; } else break; if (size) { --size; n = *k++; byte_three = g_CTHashRandomValues[byte_three ^ n]; } else break; if (size) { --size; n = *k++; byte_four = g_CTHashRandomValues[byte_four ^ n]; } else break; } uint32 idx = ( byte_four << 24 ) | ( byte_three << 16 ) | ( byte_two << 8 ) | byte_one; idx = idx % m_cBucket; return ( (int) idx ); } #ifdef DBGFLAG_VALIDATE //----------------------------------------------------------------------------- // Purpose: Run a global validation pass on all of our data structures and memory // allocations. // Input: validator - Our global validator object // pchName - Our name (typically a member var in our container) //----------------------------------------------------------------------------- template void CTHash::Validate( CValidator &validator, const char *pchName ) { VALIDATE_SCOPE(); validator.ClaimMemory( m_pBucket ); ValidatePtr( m_pMemoryPoolRecord ); #if defined( _DEBUG ) // first verify m_cRecordInUse Data * pvRecord = PvRecordFirst(); int cItems = 0; while ( pvRecord ) { Data *pvRecordNext = PvRecordNext( pvRecord ); cItems++; pvRecord = pvRecordNext; } Assert( m_cRecordInUse == cItems ); // then ask the mempool to verify this if ( m_pMemoryPoolRecord ) m_pMemoryPoolRecord->LeakCheck( cItems ); #endif // _DEBUG } #endif // DBGFLAG_VALIDATE //----------------------------------------------------------------------------- // Purpose: Inserts a new record into the table // Input: unKey - Primary key of the new record // Output: Pointer to the new record //----------------------------------------------------------------------------- template void CTHash::InsertIntoHash( RecHdr_t *pRecHdr, I unKey ) { m_cRecordInUse++; // Init the RecHdr pRecHdr->m_unKey = unKey; pRecHdr->m_nRunRatio = 1; // Find our hash bucket int iBucket = IBucket( unKey ); pRecHdr->m_iBucket = iBucket; #ifdef DBGFLAG_THASH pRecHdr->m_iCycleLast = 0; #endif // Find where to insert ourselves in the linked list RecHdr_t *pRecHdrInsertBefore = &m_RecHdrTail; // Find the first bucket with anything in it that's at or after our bucket for ( int iBucketT = iBucket; iBucketT < m_cBucket; iBucketT++ ) { if ( NULL != m_pBucket[iBucketT].m_pRecHdrFirst ) { pRecHdrInsertBefore = m_pBucket[iBucketT].m_pRecHdrFirst; break; } } // Insert ourselves pRecHdr->m_pRecHdrNext = pRecHdrInsertBefore; pRecHdr->m_pRecHdrPrev = pRecHdrInsertBefore->m_pRecHdrPrev; pRecHdrInsertBefore->m_pRecHdrPrev = pRecHdr; pRecHdr->m_pRecHdrPrev->m_pRecHdrNext = pRecHdr; // Our bucket should point to us m_pBucket[iBucket].m_pRecHdrFirst = pRecHdr; } //----------------------------------------------------------------------------- // Purpose: Removes the specified entry from the table // Input: pvRemove - Pointer to the entry to remove //----------------------------------------------------------------------------- template void CTHash::RemoveFromHash( Data * pvRemove ) { // Find our RecHdr RecHdr_t *pRecHdr = PRecHdrFromPvRecord( pvRemove ); // If our bucket points to us, point it to the next record (or else NULL) int iBucket = IBucket( pRecHdr->m_unKey ); if ( pRecHdr == m_pBucket[iBucket].m_pRecHdrFirst ) { if ( pRecHdr->m_pRecHdrNext->m_iBucket == iBucket ) m_pBucket[iBucket].m_pRecHdrFirst = pRecHdr->m_pRecHdrNext; else m_pBucket[iBucket].m_pRecHdrFirst = NULL; } // Remove us from the linked list pRecHdr->m_pRecHdrPrev->m_pRecHdrNext = pRecHdr->m_pRecHdrNext; pRecHdr->m_pRecHdrNext->m_pRecHdrPrev = pRecHdr->m_pRecHdrPrev; // Are we the next record to run? if ( pRecHdr == m_pRecHdrRunNext ) m_pRecHdrRunNext = pRecHdr->m_pRecHdrNext; m_cRecordInUse--; } #endif // THASH_H