diff options
| -rw-r--r-- | sys/src/9/port/cache.c | 150 |
1 files changed, 72 insertions, 78 deletions
diff --git a/sys/src/9/port/cache.c b/sys/src/9/port/cache.c index 22ba52fbc..4391a026d 100644 --- a/sys/src/9/port/cache.c +++ b/sys/src/9/port/cache.c @@ -16,7 +16,7 @@ enum typedef struct Extent Extent; struct Extent { - int bid; + uintptr bid; ulong start; int len; Page *cache; @@ -40,7 +40,7 @@ typedef struct Cache Cache; struct Cache { Lock; - int pgno; + uintptr pgno; Mntcache *head; Mntcache *tail; Mntcache *hash[NHASH]; @@ -59,7 +59,7 @@ Image fscache; static Cache cache; static Ecache ecache; -static int maxcache = MAXCACHE; +static ulong maxcache = MAXCACHE; static void extentfree(Extent* e) @@ -89,16 +89,17 @@ extentalloc(void) ecache.head = e; e++; } - ecache.free += NEXTENT; ecache.total += NEXTENT; + ecache.free += NEXTENT; } e = ecache.head; ecache.head = e->next; - memset(e, 0, sizeof(Extent)); ecache.free--; unlock(&ecache); + memset(e, 0, sizeof(Extent)); + return e; } @@ -124,61 +125,61 @@ cinit(void) } cache.tail = m; - cache.tail->next = 0; - cache.head->prev = 0; + cache.tail->next = nil; + cache.head->prev = nil; fscache.notext = 1; } -Page* +static Page* cpage(Extent *e) { /* Easy consistency check */ if(e->cache->daddr != e->bid) - return 0; + return nil; return lookpage(&fscache, e->bid); } -void +static void cnodata(Mntcache *m) { Extent *e; /* * Invalidate all extent data - * Image lru will waste the pages + * pagereclaim() will waste the pages */ - while(e = m->list){ + while((e = m->list) != nil){ m->list = e->next; extentfree(e); } } -void +static void ctail(Mntcache *m) { /* Unlink and send to the tail */ - if(m->prev) + if(m->prev != nil) m->prev->next = m->next; else cache.head = m->next; - if(m->next) + if(m->next != nil) m->next->prev = m->prev; else cache.tail = m->prev; - if(cache.tail) { + if(cache.tail != nil) { m->prev = cache.tail; cache.tail->next = m; - m->next = 0; + m->next = nil; cache.tail = m; } else { cache.head = m; cache.tail = m; - m->prev = 0; - m->next = 0; + m->prev = nil; + m->next = nil; } } @@ -188,11 +189,11 @@ clookup(Chan *c, int skipvers) { Mntcache *m; - for(m = cache.hash[c->qid.path%NHASH]; m; m = m->hash) + for(m = cache.hash[c->qid.path%NHASH]; m != nil; m = m->hash) if(eqchantdqid(c, m->type, m->dev, m->qid, skipvers) && c->qid.type == m->qid.type) return m; - return 0; + return nil; } void @@ -202,13 +203,13 @@ copen(Chan *c) /* directories aren't cacheable and append-only files confuse us */ if(c->qid.type&(QTDIR|QTAPPEND)){ - c->mcp = 0; + c->mcp = nil; return; } lock(&cache); m = clookup(c, 1); - if(m == 0) + if(m == nil) m = cache.head; else if(m->qid.vers == c->qid.vers) { ctail(m); @@ -219,7 +220,7 @@ copen(Chan *c) ctail(m); l = &cache.hash[m->qid.path%NHASH]; - for(f = *l; f; f = f->hash) { + for(f = *l; f != nil; f = f->hash) { if(f == m) { *l = m->hash; break; @@ -232,7 +233,7 @@ copen(Chan *c) qlock(m); lock(&cache); f = clookup(c, 0); - if(f != 0) { + if(f != nil) { /* * someone got there first while cache lock * was released and added a updated Mntcache @@ -266,14 +267,14 @@ ccache(Chan *c) Mntcache *m; m = c->mcp; - if(m) { + if(m != nil) { qlock(m); if(eqchantdqid(c, m->type, m->dev, m->qid, 0) && c->qid.type == m->qid.type) return m; - c->mcp = 0; + c->mcp = nil; qunlock(m); } - return 0; + return nil; } int @@ -286,34 +287,33 @@ cread(Chan *c, uchar *buf, int len, vlong off) int o, l, total; ulong offset; - if(off+len > maxcache) + if(off >= maxcache || len <= 0) return 0; m = ccache(c); - if(m == 0) + if(m == nil) return 0; offset = off; t = &m->list; - for(e = *t; e; e = e->next) { + for(e = *t; e != nil; e = e->next) { if(offset >= e->start && offset < e->start+e->len) break; t = &e->next; } - if(e == 0) { + if(e == nil) { qunlock(m); return 0; } total = 0; - while(len) { + while(len > 0) { p = cpage(e); - if(p == 0) { + if(p == nil) { *t = e->next; extentfree(e); - qunlock(m); - return total; + break; } o = offset - e->start; @@ -342,7 +342,7 @@ cread(Chan *c, uchar *buf, int len, vlong off) total += l; t = &e->next; e = e->next; - if(e == 0 || e->start != offset) + if(e == nil || e->start != offset) break; } @@ -350,7 +350,7 @@ cread(Chan *c, uchar *buf, int len, vlong off) return total; } -Extent* +static Extent* cchain(uchar *buf, ulong offset, int len, Extent **tail) { int l; @@ -358,16 +358,16 @@ cchain(uchar *buf, ulong offset, int len, Extent **tail) KMap *k; Extent *e, *start, **t; - start = 0; - *tail = 0; + start = nil; + *tail = nil; t = &start; - while(len) { + while(len > 0) { e = extentalloc(); - if(e == 0) + if(e == nil) break; p = auxpage(); - if(p == 0) { + if(p == nil) { extentfree(e); break; } @@ -417,14 +417,14 @@ cchain(uchar *buf, ulong offset, int len, Extent **tail) return start; } -int +static int cpgmove(Extent *e, uchar *buf, int boff, int len) { Page *p; KMap *k; p = cpage(e); - if(p == 0) + if(p == nil) return 0; k = kmap(p); @@ -445,25 +445,25 @@ cpgmove(Extent *e, uchar *buf, int boff, int len) void cupdate(Chan *c, uchar *buf, int len, vlong off) { + int o; Mntcache *m; Extent *tail; Extent *e, *f, *p; - int o, ee, eblock; - ulong offset; + ulong offset, eblock, ee; - if(off > maxcache || len == 0) + if(off >= maxcache || len <= 0) return; m = ccache(c); - if(m == 0) + if(m == nil) return; /* * Find the insertion point */ offset = off; - p = 0; - for(f = m->list; f; f = f->next) { + p = nil; + for(f = m->list; f != nil; f = f->next) { if(f->start > offset) break; p = f; @@ -471,22 +471,19 @@ cupdate(Chan *c, uchar *buf, int len, vlong off) /* trim if there is a successor */ eblock = offset+len; - if(f != 0 && eblock > f->start) { + if(f != nil && eblock > f->start) { len -= (eblock - f->start); - if(len <= 0) { - qunlock(m); - return; - } + if(len <= 0) + goto out; } - if(p == 0) { /* at the head */ + if(p == nil) { /* at the head */ e = cchain(buf, offset, len, &tail); - if(e != 0) { + if(e != nil) { m->list = e; tail->next = f; } - qunlock(m); - return; + goto out; } /* trim to the predecessor */ @@ -494,10 +491,8 @@ cupdate(Chan *c, uchar *buf, int len, vlong off) if(offset < ee) { o = ee - offset; len -= o; - if(len <= 0) { - qunlock(m); - return; - } + if(len <= 0) + goto out; buf += o; offset += o; } @@ -513,20 +508,20 @@ cupdate(Chan *c, uchar *buf, int len, vlong off) len -= o; offset += o; if(len <= 0) { - if(f && p->start + p->len > f->start) + if(f != nil && p->start + p->len > f->start) print("CACHE: p->start=%uld p->len=%d f->start=%uld\n", p->start, p->len, f->start); - qunlock(m); - return; + goto out; } } } e = cchain(buf, offset, len, &tail); - if(e != 0) { + if(e != nil) { p->next = e; tail->next = f; } +out: qunlock(m); } @@ -535,29 +530,28 @@ cwrite(Chan* c, uchar *buf, int len, vlong off) { int o, eo; Mntcache *m; - ulong eblock, ee; Extent *p, *f, *e, *tail; - ulong offset; + ulong offset, eblock, ee; - if(off > maxcache || len == 0) + if(off >= maxcache || len <= 0) return; m = ccache(c); - if(m == 0) + if(m == nil) return; offset = off; m->qid.vers++; c->qid.vers++; - p = 0; - for(f = m->list; f; f = f->next) { + p = nil; + for(f = m->list; f != nil; f = f->next) { if(f->start >= offset) break; p = f; } - if(p != 0) { + if(p != nil) { ee = p->start+p->len; eo = offset - p->start; /* pack in predecessor if there is space */ @@ -577,7 +571,7 @@ cwrite(Chan* c, uchar *buf, int len, vlong off) /* free the overlap -- it's a rare case */ eblock = offset+len; - while(f && f->start < eblock) { + while(f != nil && f->start < eblock) { e = f->next; extentfree(f); f = e; @@ -585,12 +579,12 @@ cwrite(Chan* c, uchar *buf, int len, vlong off) /* link the block (if any) into the middle */ e = cchain(buf, offset, len, &tail); - if(e != 0) { + if(e != nil) { tail->next = f; f = e; } - if(p == 0) + if(p == nil) m->list = f; else p->next = f; |