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Removed the need for all the tiny mallocs in ratecontrol by using a fixed sized, circular history

This commit is contained in:
Eric Petit 2007-01-22 22:58:51 +00:00
parent 40d8abb68f
commit 2bad2cae4b
1 changed files with 96 additions and 69 deletions
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157
libtransmission/ratecontrol.c
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@ -24,60 +24,51 @@
#include "transmission.h"
#define MAX_HISTORY 30
/* Maximum number of packets we keep track of. Since most packets are
* 1 KB, it means we remember the last 2 MB transferred */
#define HISTORY_SIZE 2048
/* How far back we go to calculate rates to be displayed in the
* interface */
#define LONG_INTERVAL 30000 /* 30 secs */
/* How far back we go to calculate pseudo-instantaneous transfer rates,
* for the actual rate control */
#define SHORT_INTERVAL 1000 /* 1 sec */
/***********************************************************************
* Structures
**********************************************************************/
typedef struct tr_transfer_s
{
uint64_t date;
int size;
}
tr_transfer_t;
typedef struct tr_transfer_s tr_transfer_t;
struct tr_ratecontrol_s
{
tr_lock_t lock;
int limit;
tr_transfer_t * first;
tr_transfer_t * last;
};
struct tr_transfer_s
{
uint64_t date;
int size;
tr_transfer_t * next;
tr_transfer_t * prev;
/* Circular history: it's empty if transferStop == transferStart,
* full if ( transferStop + 1 ) % HISTORY_SIZE == transferStart */
tr_transfer_t transfers[HISTORY_SIZE];
int transferStart;
int transferStop;
};
/***********************************************************************
* rateForInterval
***********************************************************************
* Returns the transfer rate on the last 'interval' milliseconds
* Local prototypes
**********************************************************************/
static inline float rateForInterval( tr_ratecontrol_t * r, int interval )
{
tr_transfer_t * t;
uint64_t start = tr_date() - interval;
int total = 0;
static float rateForInterval( tr_ratecontrol_t * r, int interval );
for( t = r->first; t && t->date > start; t = t->next )
{
total += t->size;
}
return ( 1000.0 / 1024.0 ) * total / interval;
}
static inline void cleanOldTransfers( tr_ratecontrol_t * r )
{
tr_transfer_t * t, * prev;
uint64_t old = tr_date() - MAX_HISTORY * 1000;
for( t = r->last; t && t->date < old; )
{
prev = t->prev;
if( prev )
prev->next = NULL;
else
r->first = NULL;
free( t );
t = prev;
r->last = prev;
}
}
/***********************************************************************
* Exported functions
**********************************************************************/
tr_ratecontrol_t * tr_rcInit()
{
@ -111,7 +102,7 @@ int tr_rcCanGlobalTransfer( tr_handle_t * h, int isUpload )
r = isUpload ? tor->upload : tor->download;
tr_lockLock( &r->lock );
rate += rateForInterval( r, 1000 );
rate += rateForInterval( r, SHORT_INTERVAL );
tr_lockUnlock( &r->lock );
if( rate >= (float)limit )
@ -135,7 +126,8 @@ int tr_rcCanTransfer( tr_ratecontrol_t * r )
int ret;
tr_lockLock( &r->lock );
ret = ( r->limit <= 0 ) ? ( r->limit < 0 ) : ( rateForInterval( r, 1000 ) < r->limit );
ret = ( r->limit <= 0 ) ? ( r->limit < 0 ) :
( rateForInterval( r, SHORT_INTERVAL ) < r->limit );
tr_lockUnlock( &r->lock );
return ret;
@ -147,24 +139,21 @@ void tr_rcTransferred( tr_ratecontrol_t * r, int size )
if( size < 100 )
{
/* Don't count small messages */
return;
}
tr_lockLock( &r->lock );
t = malloc( sizeof( tr_transfer_t ) );
if( r->first )
r->first->prev = t;
if( !r->last )
r->last = t;
t->next = r->first;
t->prev = NULL;
r->first = t;
r->transferStop = ( r->transferStop + 1 ) % HISTORY_SIZE;
if( r->transferStop == r->transferStart )
/* History is full, forget about the first (oldest) item */
r->transferStart = ( r->transferStart + 1 ) % HISTORY_SIZE;
t = &r->transfers[r->transferStop];
t->date = tr_date();
t->size = size;
cleanOldTransfers( r );
tr_lockUnlock( &r->lock );
}
@ -173,7 +162,7 @@ float tr_rcRate( tr_ratecontrol_t * r )
float ret;
tr_lockLock( &r->lock );
ret = rateForInterval( r, MAX_HISTORY * 1000 );
ret = rateForInterval( r, LONG_INTERVAL );
tr_lockUnlock( &r->lock );
return ret;
@ -181,17 +170,9 @@ float tr_rcRate( tr_ratecontrol_t * r )
void tr_rcReset( tr_ratecontrol_t * r )
{
tr_transfer_t * t, * next;
tr_lockLock( &r->lock );
for( t = r->first; t; )
{
next = t->next;
free( t );
t = next;
}
r->first = NULL;
r->last = NULL;
r->transferStart = 0;
r->transferStop = 0;
tr_lockUnlock( &r->lock );
}
@ -201,3 +182,49 @@ void tr_rcClose( tr_ratecontrol_t * r )
tr_lockClose( &r->lock );
free( r );
}
/***********************************************************************
* Local functions
**********************************************************************/
/***********************************************************************
* rateForInterval
***********************************************************************
* Returns the transfer rate in KB/s on the last 'interval'
* milliseconds
**********************************************************************/
static float rateForInterval( tr_ratecontrol_t * r, int interval )
{
tr_transfer_t * t = NULL;
uint64_t now, start;
int i, total;
now = tr_date();
start = now - interval;
/* Browse the history back in time */
total = 0;
for( i = r->transferStop; i != r->transferStart; i-- )
{
t = &r->transfers[i];
if( t->date < start )
break;
total += t->size;
if( !i )
i = HISTORY_SIZE; /* Loop */
}
if( ( r->transferStop + 1 ) % HISTORY_SIZE == r->transferStart
&& i == r->transferStart )
{
/* High bandwidth -> the history isn't big enough to remember
* everything transferred since 'interval' ms ago. Correct the
* interval so that we return the correct rate */
interval = now - t->date;
}
return ( 1000.0f / 1024.0f ) * total / interval;
}