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-rw-r--r--src/cmd/vac/cache.c876
1 files changed, 0 insertions, 876 deletions
diff --git a/src/cmd/vac/cache.c b/src/cmd/vac/cache.c
deleted file mode 100644
index fc34d688..00000000
--- a/src/cmd/vac/cache.c
+++ /dev/null
@@ -1,876 +0,0 @@
-#include "stdinc.h"
-#include "vac.h"
-#include "dat.h"
-#include "fns.h"
-
-typedef struct Label Label;
-
-enum {
- BadHeap = ~0,
-};
-
-/*
- * the plan is to store data to the cache in c->size blocks
- * with the block zero extended to fill it out. When writing to
- * venti, the block will be zero truncated. The walker will also check
- * that the block fits within psize or dsize as the case may be.
- */
-
-struct Cache
-{
- VtLock *lk;
- VtSession *z;
- u32int now; /* ticks for usage timestamps */
- int size; /* max. size of any block; allocated to each block */
- Lump **heads; /* hash table for finding address */
- int nheap; /* number of available victims */
- Lump **heap; /* heap for locating victims */
- long nblocks; /* number of blocks allocated */
- Lump *blocks; /* array of block descriptors */
- u8int *mem; /* memory for all block descriptors */
- Lump *free; /* free list of lumps */
-
- long hashSize;
-};
-
-/*
- * the tag for a block is hash(index, parent tag)
- */
-
-struct Label {
- uchar gen[4];
- uchar state;
- uchar type; /* top bit indicates it is part of a directory */
- uchar tag[4]; /* tag of file it is in */
-};
-
-
-static char ENoDir[] = "directory entry is not allocated";
-
-static void fixHeap(int si, Lump *b);
-static int upHeap(int i, Lump *b);
-static int downHeap(int i, Lump *b);
-static char *lumpState(int);
-static void lumpSetState(Lump *u, int state);
-
-Cache *
-cacheAlloc(VtSession *z, int blockSize, long nblocks)
-{
- int i;
- Cache *c;
- Lump *b;
-
- c = vtMemAllocZ(sizeof(Cache));
-
- c->lk = vtLockAlloc();
- c->z = z;
- c->size = blockSize;
- c->nblocks = nblocks;
- c->hashSize = nblocks;
- c->heads = vtMemAllocZ(c->hashSize*sizeof(Lump*));
- c->heap = vtMemAllocZ(nblocks*sizeof(Lump*));
- c->blocks = vtMemAllocZ(nblocks*sizeof(Lump));
- c->mem = vtMemAllocZ(nblocks * blockSize);
- for(i = 0; i < nblocks; i++){
- b = &c->blocks[i];
- b->lk = vtLockAlloc();
- b->c = c;
- b->data = &c->mem[i * blockSize];
- b->addr = i+1;
- b->state = LumpFree;
- b->heap = BadHeap;
- b->next = c->free;
- c->free = b;
- }
- c->nheap = 0;
-
- return c;
-}
-
-long
-cacheGetSize(Cache *c)
-{
- return c->nblocks;
-}
-
-int
-cacheGetBlockSize(Cache *c)
-{
- return c->size;
-}
-
-int
-cacheSetSize(Cache *c, long nblocks)
-{
- USED(c);
- USED(nblocks);
- return 0;
-}
-
-void
-cacheFree(Cache *c)
-{
- int i;
-
- for(i = 0; i < c->nblocks; i++){
- assert(c->blocks[i].ref == 0);
- vtLockFree(c->blocks[i].lk);
- }
- vtMemFree(c->heads);
- vtMemFree(c->blocks);
- vtMemFree(c->mem);
- vtMemFree(c);
-}
-
-static u32int
-hash(Cache *c, uchar score[VtScoreSize], int type)
-{
- u32int h;
- uchar *p = score + VtScoreSize-4;
-
- h = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
- h += type;
- return h % c->hashSize;
-}
-
-static void
-findLump(Cache *c, Lump *bb)
-{
- Lump *b, *last;
- int h;
-
- last = nil;
- h = hash(c, bb->score, bb->type);
- for(b = c->heads[h]; b != nil; b = b->next){
- if(last != b->prev)
- vtFatal("bad prev link");
- if(b == bb)
- return;
- last = b;
- }
- vtFatal("block missing from hash table");
-}
-
-void
-cacheCheck(Cache *c)
-{
- u32int size, now;
- int i, k, refed, free;
- static uchar zero[VtScoreSize];
- Lump *p;
-
- size = c->size;
- now = c->now;
-
- free = 0;
- for(p=c->free; p; p=p->next)
- free++;
- for(i = 0; i < c->nheap; i++){
- if(c->heap[i]->heap != i)
- vtFatal("mis-heaped at %d: %d", i, c->heap[i]->heap);
- if(i > 0 && c->heap[(i - 1) >> 1]->used2 - now > c->heap[i]->used2 - now)
- vtFatal("bad heap ordering");
- k = (i << 1) + 1;
- if(k < c->nheap && c->heap[i]->used2 - now > c->heap[k]->used2 - now)
- vtFatal("bad heap ordering");
- k++;
- if(k < c->nheap && c->heap[i]->used2 - now > c->heap[k]->used2 - now)
- vtFatal("bad heap ordering");
- }
-
- refed = 0;
- for(i = 0; i < c->nblocks; i++){
- if(c->blocks[i].data != &c->mem[i * size])
- vtFatal("mis-blocked at %d", i);
- if(c->blocks[i].ref && c->blocks[i].heap == BadHeap){
- refed++;
- }
- if(memcmp(zero, c->blocks[i].score, VtScoreSize))
- findLump(c, &c->blocks[i]);
- }
-if(refed > 0)fprint(2, "cacheCheck: nheap %d refed %d free %d\n", c->nheap, refed, free);
- assert(c->nheap + refed + free == c->nblocks);
- refed = 0;
- for(i = 0; i < c->nblocks; i++){
- if(c->blocks[i].ref) {
-if(1)fprint(2, "%d %V %d %s\n", c->blocks[i].type, c->blocks[i].score, c->blocks[i].ref, lumpState(c->blocks[i].state));
- refed++;
- }
- }
-if(refed > 0)fprint(2, "cacheCheck: in used %d\n", refed);
-}
-
-/*
- * delete an arbitrary block from the heap
- */
-static void
-delHeap(Lump *db)
-{
- fixHeap(db->heap, db->c->heap[--db->c->nheap]);
- db->heap = BadHeap;
-}
-
-static void
-fixHeap(int si, Lump *b)
-{
- int i;
-
- i = upHeap(si, b);
- if(i == si)
- downHeap(i, b);
-}
-
-static int
-upHeap(int i, Lump *b)
-{
- Lump *bb;
- u32int now;
- int p;
- Cache *c;
-
- c = b->c;
- now = c->now;
- for(; i != 0; i = p){
- p = (i - 1) >> 1;
- bb = c->heap[p];
- if(b->used2 - now >= bb->used2 - now)
- break;
- c->heap[i] = bb;
- bb->heap = i;
- }
- c->heap[i] = b;
- b->heap = i;
-
- return i;
-}
-
-static int
-downHeap(int i, Lump *b)
-{
- Lump *bb;
- u32int now;
- int k;
- Cache *c;
-
- c = b->c;
- now = c->now;
- for(; ; i = k){
- k = (i << 1) + 1;
- if(k >= c->nheap)
- break;
- if(k + 1 < c->nheap && c->heap[k]->used2 - now > c->heap[k + 1]->used2 - now)
- k++;
- bb = c->heap[k];
- if(b->used2 - now <= bb->used2 - now)
- break;
- c->heap[i] = bb;
- bb->heap = i;
- }
- c->heap[i] = b;
- b->heap = i;
- return i;
-}
-
-
-/* called with c->lk held */
-Lump *
-cacheBumpLump(Cache *c)
-{
- Lump *b;
-
- /*
- * missed: locate the block with the oldest second to last use.
- * remove it from the heap, and fix up the heap.
- */
- if(c->free) {
- b = c->free;
- c->free = b->next;
- } else {
- for(;;){
- if(c->nheap == 0) {
- cacheCheck(c);
- assert(0);
- return nil;
- }
- b = c->heap[0];
- delHeap(b);
- if(b->ref == 0)
- break;
- }
-
- /*
- * unchain the block from hash chain
- */
- if(b->prev == nil)
- c->heads[hash(c, b->score, b->type)] = b->next;
- else
- b->prev->next = b->next;
- if(b->next != nil)
- b->next->prev = b->prev;
-
- }
-
- /*
- * the new block has no last use, so assume it happens sometime in the middle
- */
- b->used = (b->used2 + c->now) / 2;
- b->asize = 0;
-
- return b;
-}
-
-Lump *
-cacheAllocLump(Cache *c, int type, int size, int dir)
-{
- Lump *b;
- ulong h;
-
- assert(size <= c->size);
-
-again:
- vtLock(c->lk);
- b = cacheBumpLump(c);
- if(b == nil) {
- vtUnlock(c->lk);
-fprint(2, "cache is full\n");
- /* XXX should be better */
- sleep(100);
- goto again;
- }
-
- vtLock(b->lk);
-
- assert(b->ref == 0);
- b->ref++;
- b->used2 = b->used;
- b->used = c->now++;
-
- /* convert addr into score */
- memset(b->score, 0, VtScoreSize-4);
- b->score[VtScoreSize-4] = b->addr>>24;
- b->score[VtScoreSize-3] = b->addr>>16;
- b->score[VtScoreSize-2] = b->addr>>8;
- b->score[VtScoreSize-1] = b->addr;
-
- b->dir = dir;
- b->type = type;
- b->gen = 0;
- b->asize = size;
- b->state = LumpFree;
-
- h = hash(c, b->score, b->type);
-
- /* chain onto correct hash */
- b->next = c->heads[h];
- c->heads[h] = b;
- if(b->next != nil)
- b->next->prev = b;
- b->prev = nil;
-
- vtUnlock(c->lk);
-
- vtZeroExtend(type, b->data, 0, size);
- lumpSetState(b, LumpActive);
-
- return b;
-}
-
-int
-scoreIsLocal(uchar score[VtScoreSize])
-{
- static uchar zero[VtScoreSize];
-
- return memcmp(score, zero, VtScoreSize-4) == 0;
-}
-
-Lump *
-cacheGetLump(Cache *c, uchar score[VtScoreSize], int type, int size)
-{
- Lump *b;
- ulong h;
- int n;
- static uchar zero[VtScoreSize];
-
- assert(size <= c->size);
-
- h = hash(c, score, type);
-
-again:
- /*
- * look for the block in the cache
- */
- vtLock(c->lk);
- for(b = c->heads[h]; b != nil; b = b->next){
- if(memcmp(b->score, score, VtScoreSize) == 0 && b->type == type)
- goto found;
- }
-
- /* should not be looking for a temp block */
- if(scoreIsLocal(score)) {
- if(memcmp(score, zero, VtScoreSize) == 0)
- vtSetError("looking for zero score");
- else
- vtSetError("missing local block");
- vtUnlock(c->lk);
- return nil;
- }
-
- b = cacheBumpLump(c);
- if(b == nil) {
- vtUnlock(c->lk);
- sleep(100);
- goto again;
- }
-
- /* chain onto correct hash */
- b->next = c->heads[h];
- c->heads[h] = b;
- if(b->next != nil)
- b->next->prev = b;
- b->prev = nil;
-
- memmove(b->score, score, VtScoreSize);
- b->type = type;
- b->state = LumpFree;
-
-found:
- b->ref++;
- b->used2 = b->used;
- b->used = c->now++;
- if(b->heap != BadHeap)
- fixHeap(b->heap, b);
-
- vtUnlock(c->lk);
-
- vtLock(b->lk);
- if(b->state != LumpFree)
- return b;
-
- n = vtRead(c->z, score, type, b->data, size);
- if(n < 0) {
- lumpDecRef(b, 1);
- return nil;
- }
- if(!vtSha1Check(score, b->data, n)) {
- vtSetError("vtSha1Check failed");
- lumpDecRef(b, 1);
- return nil;
- }
- vtZeroExtend(type, b->data, n, size);
- b->asize = size;
- lumpSetState(b, LumpVenti);
-
- return b;
-}
-
-static char *
-lumpState(int state)
-{
- switch(state) {
- default:
- return "Unknown!!";
- case LumpFree:
- return "Free";
- case LumpActive:
- return "Active";
- case LumpSnap:
- return "Snap";
- case LumpZombie:
- return "Zombie";
- case LumpVenti:
- return "Venti";
- }
-}
-
-static void
-lumpSetState(Lump *u, int state)
-{
-// if(u->state != LumpFree)
-// fprint(2, "%V: %s -> %s\n", u->score, lumpState(u->state), lumpState(state));
- u->state = state;
-}
-
-int
-lumpGetScore(Lump *u, int offset, uchar score[VtScoreSize])
-{
- uchar *sp;
- VtRoot root;
- VtEntry dir;
-
- vtLock(u->lk);
-
- switch(u->type) {
- default:
- vtSetError("bad type");
- goto Err;
- case VtPointerType0:
- case VtPointerType1:
- case VtPointerType2:
- case VtPointerType3:
- case VtPointerType4:
- case VtPointerType5:
- case VtPointerType6:
- if((offset+1)*VtScoreSize > u->asize)
- sp = nil;
- else
- sp = u->data + offset*VtScoreSize;
- break;
- case VtRootType:
- if(u->asize < VtRootSize) {
- vtSetError("runt root block");
- goto Err;
- }
- if(!vtRootUnpack(&root, u->data))
- goto Err;
- sp = root.score;
- break;
- case VtDirType:
- if((offset+1)*VtEntrySize > u->asize) {
- vtSetError(ENoDir);
- goto Err;
- }
- if(!vtEntryUnpack(&dir, u->data, offset))
- goto Err;
- if(!dir.flags & VtEntryActive) {
- vtSetError(ENoDir);
- goto Err;
- }
- sp = dir.score;
- break;
- }
-
- if(sp == nil)
- memmove(score, vtZeroScore, VtScoreSize);
- else
- memmove(score, sp, VtScoreSize);
-
- vtUnlock(u->lk);
- return !scoreIsLocal(score);
-Err:
- vtUnlock(u->lk);
- return 0;
-}
-
-Lump *
-lumpWalk(Lump *u, int offset, int type, int size, int readOnly, int lock)
-{
- Lump *v, *vv;
- Cache *c;
- uchar score[VtScoreSize], *sp;
- VtRoot root;
- VtEntry dir;
- int split, isdir;
-
- c = u->c;
- vtLock(u->lk);
-
-Again:
- v = nil;
- vv = nil;
-
- isdir = u->dir;
- switch(u->type) {
- default:
- vtSetError("bad type");
- goto Err;
- case VtPointerType0:
- case VtPointerType1:
- case VtPointerType2:
- case VtPointerType3:
- case VtPointerType4:
- case VtPointerType5:
- case VtPointerType6:
- if((offset+1)*VtScoreSize > u->asize)
- sp = nil;
- else
- sp = u->data + offset*VtScoreSize;
- break;
- case VtRootType:
- if(u->asize < VtRootSize) {
- vtSetError("runt root block");
- goto Err;
- }
- if(!vtRootUnpack(&root, u->data))
- goto Err;
- sp = root.score;
- break;
- case VtDirType:
- if((offset+1)*VtEntrySize > u->asize) {
- vtSetError(ENoDir);
- goto Err;
- }
- if(!vtEntryUnpack(&dir, u->data, offset))
- goto Err;
- if(!(dir.flags & VtEntryActive)) {
- vtSetError(ENoDir);
- goto Err;
- }
- isdir = (dir.flags & VtEntryDir) != 0;
-// sp = dir.score;
- sp = u->data + offset*VtEntrySize + 20;
- break;
- }
-
- if(sp == nil)
- memmove(score, vtZeroScore, VtScoreSize);
- else
- memmove(score, sp, VtScoreSize);
-
- vtUnlock(u->lk);
-
-
-if(0)fprint(2, "lumpWalk: %V:%s %d:%d-> %V:%d\n", u->score, lumpState(u->state), u->type, offset, score, type);
- v = cacheGetLump(c, score, type, size);
- if(v == nil)
- return nil;
-
- split = 1;
- if(readOnly)
- split = 0;
-
- switch(v->state) {
- default:
- assert(0);
- case LumpFree:
-fprint(2, "block is free %V!\n", v->score);
- vtSetError("phase error");
- goto Err2;
- case LumpActive:
- if(v->gen < u->gen) {
-print("LumpActive gen\n");
- lumpSetState(v, LumpSnap);
- v->gen = u->gen;
- } else
- split = 0;
- break;
- case LumpSnap:
- case LumpVenti:
- break;
- }
-
- /* easy case */
- if(!split) {
- if(!lock)
- vtUnlock(v->lk);
- return v;
- }
-
- if(sp == nil) {
- vtSetError("bad offset");
- goto Err2;
- }
-
- vv = cacheAllocLump(c, v->type, size, isdir);
- /* vv is locked */
- vv->gen = u->gen;
- memmove(vv->data, v->data, v->asize);
-if(0)fprint(2, "split %V into %V\n", v->score, vv->score);
-
- lumpDecRef(v, 1);
- v = nil;
-
- vtLock(u->lk);
- if(u->state != LumpActive) {
- vtSetError("bad parent state: can not happen");
- goto Err;
- }
-
- /* check that nothing changed underfoot */
- if(memcmp(sp, score, VtScoreSize) != 0) {
- lumpDecRef(vv, 1);
-fprint(2, "lumpWalk: parent changed under foot\n");
- goto Again;
- }
-
- /* XXX - hold Active blocks up - will go eventually */
- lumpIncRef(vv);
-
- /* change the parent */
- memmove(sp, vv->score, VtScoreSize);
-
- vtUnlock(u->lk);
-
- if(!lock)
- vtUnlock(vv->lk);
- return vv;
-Err:
- vtUnlock(u->lk);
- lumpDecRef(v, 0);
- lumpDecRef(vv, 1);
- return nil;
-Err2:
- lumpDecRef(v, 1);
- return nil;
-
-}
-
-void
-lumpFreeEntry(Lump *u, int entry)
-{
- uchar score[VtScoreSize];
- int type;
- ulong gen;
- VtEntry dir;
- Cache *c;
-
- c = u->c;
- vtLock(u->lk);
- if(u->state == LumpVenti)
- goto Exit;
-
- switch(u->type) {
- default:
- fprint(2, "freeing bad lump type: %d\n", u->type);
- return;
- case VtPointerType0:
- if((entry+1)*VtScoreSize > u->asize)
- goto Exit;
- memmove(score, u->data + entry*VtScoreSize, VtScoreSize);
- memmove(u->data + entry*VtScoreSize, vtZeroScore, VtScoreSize);
- type = u->dir?VtDirType:VtDataType;
- break;
- case VtPointerType1:
- case VtPointerType2:
- case VtPointerType3:
- case VtPointerType4:
- case VtPointerType5:
- case VtPointerType6:
- if((entry+1)*VtScoreSize > u->asize)
- goto Exit;
- memmove(score, u->data + entry*VtScoreSize, VtScoreSize);
- memmove(u->data + entry*VtScoreSize, vtZeroScore, VtScoreSize);
- type = u->type-1;
- break;
- case VtDirType:
- if((entry+1)*VtEntrySize > u->asize)
- goto Exit;
- if(!vtEntryUnpack(&dir, u->data, entry))
- goto Exit;
- if(!dir.flags & VtEntryActive)
- goto Exit;
- gen = dir.gen;
- if(gen != ~0)
- gen++;
- if(dir.depth == 0)
- type = (dir.flags&VtEntryDir)?VtDirType:VtDataType;
- else
- type = VtPointerType0 + dir.depth - 1;
- memmove(score, dir.score, VtScoreSize);
- memset(&dir, 0, sizeof(dir));
- dir.gen = gen;
- vtEntryPack(&dir, u->data, entry);
- break;
- case VtDataType:
- type = VtErrType;
- break;
- }
- vtUnlock(u->lk);
- if(type == VtErrType || !scoreIsLocal(score))
- return;
-
- u = cacheGetLump(c, score, type, c->size);
- if(u == nil)
- return;
- lumpDecRef(u, 1);
- /* XXX remove extra reference */
- lumpDecRef(u, 0);
- return;
-Exit:
- vtUnlock(u->lk);
- return;
-
-}
-
-void
-lumpCleanup(Lump *u)
-{
- int i, n;
-
- switch(u->type) {
- default:
- return;
- case VtPointerType0:
- case VtPointerType1:
- case VtPointerType2:
- case VtPointerType3:
- case VtPointerType4:
- case VtPointerType5:
- case VtPointerType6:
- n = u->asize/VtScoreSize;
- break;
- case VtDirType:
- n = u->asize/VtEntrySize;
- break;
- }
-
- for(i=0; i<n; i++)
- lumpFreeEntry(u, i);
-}
-
-
-void
-lumpDecRef(Lump *b, int unlock)
-{
- int i;
- Cache *c;
-
- if(b == nil)
- return;
-
- if(unlock)
- vtUnlock(b->lk);
-
- c = b->c;
- vtLock(c->lk);
- if(--b->ref > 0) {
- vtUnlock(c->lk);
- return;
- }
- assert(b->ref == 0);
-
- switch(b->state) {
- default:
- fprint(2, "bad state: %s\n", lumpState(b->state));
- assert(0);
- case LumpActive:
- /* hack - but will do for now */
- b->ref++;
- vtUnlock(c->lk);
- lumpCleanup(b);
- vtLock(c->lk);
- b->ref--;
- lumpSetState(b, LumpFree);
- break;
- case LumpZombie:
- lumpSetState(b, LumpFree);
- break;
- case LumpFree:
- case LumpVenti:
- break;
- }
-
- /*
- * reinsert in the free heap
- */
- if(b->heap == BadHeap) {
- i = upHeap(c->nheap++, b);
- c->heap[i] = b;
- b->heap = i;
- }
-
- vtUnlock(c->lk);
-}
-
-Lump *
-lumpIncRef(Lump *b)
-{
- Cache *c;
-
- c = b->c;
-
- vtLock(c->lk);
- assert(b->ref > 0);
- b->ref++;
- vtUnlock(c->lk);
- return b;
-}
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