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attempt better flushing

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rsc 2004-06-17 21:13:51 +00:00
parent eacc220a04
commit 59a9682013
1 changed files with 32 additions and 19 deletions
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51
src/libventi/file.c
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@ -664,7 +664,7 @@ mkindices(VtEntry *e, u32int bn, int *index)
{
int i, np;
memset(index, 0, VtPointerDepth*sizeof(int));
memset(index, 0, (VtPointerDepth+1)*sizeof(int));
np = e->psize/VtScoreSize;
for(i=0; bn > 0; i++){
@ -1168,8 +1168,8 @@ vtfileflushbefore(VtFile *r, u64int offset)
{
VtBlock *b, *bb;
VtEntry e;
int i, base, depth, ppb, epb, ok;
int index[VtPointerDepth+1], index1[VtPointerDepth+1], j, ret;
int i, base, depth, ppb, epb, doflush;
int index[VtPointerDepth+1], j, ret;
VtBlock *bi[VtPointerDepth+2];
uchar *score;
@ -1181,6 +1181,9 @@ vtfileflushbefore(VtFile *r, u64int offset)
if(b == nil)
return -1;
/*
* compute path through tree for the last written byte and the next one.
*/
ret = -1;
memset(bi, 0, sizeof bi);
depth = DEPTH(e.type);
@ -1190,10 +1193,12 @@ vtfileflushbefore(VtFile *r, u64int offset)
goto Err;
if(i > depth)
goto Err;
mkindices(&e, offset/e.dsize, index1);
ppb = e.psize / VtScoreSize;
epb = e.dsize / VtEntrySize;
/*
* load the blocks along the last written byte
*/
index[depth] = r->offset % r->epb;
for(i=depth; i>=0; i--){
bb = blockwalk(b, index[i], r->c, VtORDWR, &e);
@ -1204,33 +1209,41 @@ vtfileflushbefore(VtFile *r, u64int offset)
}
ret = 0;
/*
* walk up the path from leaf to root, flushing anything that
* has been finished.
*/
base = e.type&~VtTypeDepthMask;
for(i=0; i<depth; i++){
doflush = 0;
if(i == 0){
/* bottom: data or dir block */
ok = offset%e.dsize == 0;
/* leaf: data or dir block */
if(offset%e.dsize == 0)
doflush = 1;
}else{
/* middle: pointer blocks */
b = bi[i];
/*
* flush everything up to the break
* interior node: pointer blocks.
* specifically, b = bi[i] is a block whose index[i-1]'th entry
* points at bi[i-1].
*/
b = bi[i];
/*
* the index entries up to but not including index[i-1] point at
* finished blocks, so flush them for sure.
*/
for(j=0; j<index[i-1]; j++)
if(flushblock(r->c, nil, b->data+j*VtScoreSize, ppb, epb, base+i-1) < 0)
goto Err;
/*
* if the rest of the block is already flushed,
* we can flush the whole block.
* if index[i-1] is the last entry in the block and is global
* (i.e. the kid is flushed), then we can flush this block.
*/
ok = 0;
if(index[i] != index1[i]){
ok = 1;
for(; j<ppb; j++)
if(vtglobaltolocal(b->data+j*VtScoreSize) != NilBlock)
ok = 0;
}
if(j==ppb-1 && vtglobaltolocal(b->data+j*VtScoreSize)==NilBlock)
doflush = 1;
}
if(ok){
if(doflush){
if(i == depth)
score = e.score;
else