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(libT) make the the speed measurements a little more accurate

This commit is contained in:
Charles Kerr 2008-11-26 18:00:37 +00:00
parent 9de7ccf7da
commit 2690766076
1 changed files with 11 additions and 24 deletions
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35
libtransmission/bandwidth.c
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@ -29,7 +29,7 @@ enum
{ {
HISTORY_MSEC = 2000, HISTORY_MSEC = 2000,
INTERVAL_MSEC = HISTORY_MSEC, INTERVAL_MSEC = HISTORY_MSEC,
GRANULARITY_MSEC = 250, GRANULARITY_MSEC = 40,
HISTORY_SIZE = ( INTERVAL_MSEC / GRANULARITY_MSEC ), HISTORY_SIZE = ( INTERVAL_MSEC / GRANULARITY_MSEC ),
MAGIC_NUMBER = 43143 MAGIC_NUMBER = 43143
}; };
@ -41,9 +41,8 @@ struct bratecontrol
}; };
static float static float
getSpeed( const struct bratecontrol * r ) getSpeed( const struct bratecontrol * r, int interval_msec )
{ {
const uint64_t interval_msec = HISTORY_MSEC;
uint64_t bytes = 0; uint64_t bytes = 0;
const uint64_t cutoff = tr_date ( ) - interval_msec; const uint64_t cutoff = tr_date ( ) - interval_msec;
int i = r->newest; int i = r->newest;
@ -240,7 +239,7 @@ tr_bandwidthIsLimited( const tr_bandwidth * b,
return b->band[dir].isLimited != 0; return b->band[dir].isLimited != 0;
} }
#if 0 #if 1
#define DEBUG_DIRECTION TR_UP #define DEBUG_DIRECTION TR_UP
#endif #endif
@ -258,32 +257,20 @@ tr_bandwidthAllocate( tr_bandwidth * b,
{ {
const double currentSpeed = tr_bandwidthGetPieceSpeed( b, dir ); /* KiB/s */ const double currentSpeed = tr_bandwidthGetPieceSpeed( b, dir ); /* KiB/s */
const double desiredSpeed = b->band[dir].desiredSpeed; /* KiB/s */ const double desiredSpeed = b->band[dir].desiredSpeed; /* KiB/s */
const double seconds_per_pulse = period_msec / 1000.0; const double pulseCount = HISTORY_MSEC / (double)period_msec;
const double current_bytes_per_pulse = currentSpeed * 1024.0 * seconds_per_pulse; const double nextPulseSpeed = desiredSpeed * ( pulseCount + 1 ) - ( currentSpeed * pulseCount );
const double desired_bytes_per_pulse = desiredSpeed * 1024.0 * seconds_per_pulse; b->band[dir].bytesLeft = nextPulseSpeed * 1024.0 * period_msec / 1000.0;
const double pulses_per_history = (double)HISTORY_MSEC / period_msec;
const double min = desired_bytes_per_pulse * 0.85;
const double max = desired_bytes_per_pulse * 1.15;
const double next_pulse_bytes = desired_bytes_per_pulse * ( pulses_per_history + 1 )
- ( current_bytes_per_pulse * pulses_per_history );
/* clamp the return value to lessen oscillation */
clamped = next_pulse_bytes;
clamped = MAX( clamped, min );
clamped = MIN( clamped, max );
b->band[dir].bytesLeft = clamped;
#ifdef DEBUG_DIRECTION #ifdef DEBUG_DIRECTION
if( dir == DEBUG_DIRECTION ) if( dir == DEBUG_DIRECTION )
fprintf( stderr, "bandwidth %p currentPieceSpeed(%5.2f of %5.2f) desiredSpeed(%5.2f), allocating %5.2f (unclamped: %5.2f)\n", fprintf( stderr, "bandwidth %p currentPieceSpeed(%5.2f of %5.2f) desiredSpeed(%5.2f), allocating %5.2f\n",
b, currentSpeed, tr_bandwidthGetRawSpeed( b, dir ), desiredSpeed, b, currentSpeed, tr_bandwidthGetRawSpeed( b, dir ), desiredSpeed,
clamped/1024.0, next_pulse_bytes/1024.0 ); b->band[dir].bytesLeft/1024.0 );
#endif #endif
} }
/* notify the io buffers that there's more bandwidth available */ /* notify the io buffers that there's more bandwidth available */
if( !b->band[dir].isLimited || ( clamped > 0.001 ) ) if( !b->band[dir].isLimited || ( b->band[dir].bytesLeft > 0 ) )
{ {
int i, n=0; int i, n=0;
short what = dir==TR_UP ? EV_WRITE : EV_READ; short what = dir==TR_UP ? EV_WRITE : EV_READ;
@ -359,7 +346,7 @@ tr_bandwidthGetRawSpeed( const tr_bandwidth * b, tr_direction dir )
assert( isBandwidth( b ) ); assert( isBandwidth( b ) );
assert( isDirection( dir ) ); assert( isDirection( dir ) );
return getSpeed( &b->band[dir].raw ); return getSpeed( &b->band[dir].raw, HISTORY_MSEC );
} }
double double
@ -368,7 +355,7 @@ tr_bandwidthGetPieceSpeed( const tr_bandwidth * b, tr_direction dir )
assert( isBandwidth( b ) ); assert( isBandwidth( b ) );
assert( isDirection( dir ) ); assert( isDirection( dir ) );
return getSpeed( &b->band[dir].piece ); return getSpeed( &b->band[dir].piece, HISTORY_MSEC );
} }
void void