ref: 8d51e7fa1a1dbcbde513c2b756d504c879598907
dir: /sys/src/cmd/venti/srv/zblock.c/
#include "stdinc.h" #include "dat.h" #include "fns.h" void fmtzbinit(Fmt *f, ZBlock *b) { memset(f, 0, sizeof *f); #ifdef PLAN9PORT fmtlocaleinit(f, nil, nil, nil); #endif f->start = b->data; f->to = f->start; f->stop = (char*)f->start + b->len; } #define ROUNDUP(p, n) ((void*)(((uintptr)(p)+(n)-1)&~(uintptr)((n)-1))) enum { OverflowCheck = 32 }; static char zmagic[] = "1234567890abcdefghijklmnopqrstuvxyz"; ZBlock * alloczblock(u32int size, int zeroed, uint blocksize) { uchar *p, *data; ZBlock *b; static ZBlock z; int n; if(blocksize == 0) blocksize = 32; /* try for cache line alignment */ n = size+OverflowCheck+sizeof(ZBlock)+blocksize+8; p = malloc(n); if(p == nil){ seterr(EOk, "out of memory"); return nil; } data = ROUNDUP(p, blocksize); b = ROUNDUP(data+size+OverflowCheck, 8); if(0) fprint(2, "alloc %p-%p data %p-%p b %p-%p\n", p, p+n, data, data+size, b, b+1); *b = z; b->data = data; b->free = p; b->len = size; b->_size = size; if(zeroed) memset(b->data, 0, size); memmove(b->data+size, zmagic, OverflowCheck); return b; } void freezblock(ZBlock *b) { if(b){ if(memcmp(b->data+b->_size, zmagic, OverflowCheck) != 0) abort(); memset(b->data+b->_size, 0, OverflowCheck); free(b->free); } } ZBlock* packet2zblock(Packet *p, u32int size) { ZBlock *b; if(p == nil) return nil; b = alloczblock(size, 0, 0); if(b == nil) return nil; if(packetcopy(p, b->data, 0, size) < 0){ freezblock(b); return nil; } return b; } Packet* zblock2packet(ZBlock *zb, u32int size) { Packet *p; if(zb == nil) return nil; p = packetalloc(); packetappend(p, zb->data, size); return p; }