tzblock.c - plan9port - [fork] Plan 9 from user space
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tzblock.c (1658B)
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1 #include "stdinc.h"
2 #include "dat.h"
3 #include "fns.h"
4
5 void
6 fmtzbinit(Fmt *f, ZBlock *b)
7 {
8 memset(f, 0, sizeof *f);
9 #ifdef PLAN9PORT
10 fmtlocaleinit(f, nil, nil, nil);
11 #endif
12 f->start = b->data;
13 f->to = f->start;
14 f->stop = (char*)f->start + b->len;
15 }
16
17 #define ROUNDUP(p, n) ((void*)(((uintptr)(p)+(n)-1)&~(uintptr)((n)-1)))
18
19 enum {
20 OverflowCheck = 32
21 };
22 static char zmagic[] = "1234567890abcdefghijklmnopqrstuvxyz";
23
24 ZBlock *
25 alloczblock(u32int size, int zeroed, uint blocksize)
26 {
27 uchar *p, *data;
28 ZBlock *b;
29 static ZBlock z;
30 int n;
31
32 if(blocksize == 0)
33 blocksize = 32; /* try for cache line alignment */
34
35 n = size+OverflowCheck+sizeof(ZBlock)+blocksize+8;
36 p = malloc(n);
37 if(p == nil){
38 seterr(EOk, "out of memory");
39 return nil;
40 }
41
42 data = ROUNDUP(p, blocksize);
43 b = ROUNDUP(data+size+OverflowCheck, 8);
44 if(0) fprint(2, "alloc %p-%p data %p-%p b %p-%p\n",
45 p, p+n, data, data+size, b, b+1);
46 *b = z;
47 b->data = data;
48 b->free = p;
49 b->len = size;
50 b->_size = size;
51 if(zeroed)
52 memset(b->data, 0, size);
53 memmove(b->data+size, zmagic, OverflowCheck);
54 return b;
55 }
56
57 void
58 freezblock(ZBlock *b)
59 {
60 if(b){
61 if(memcmp(b->data+b->_size, zmagic, OverflowCheck) != 0)
62 abort();
63 memset(b->data+b->_size, 0, OverflowCheck);
64 free(b->free);
65 }
66 }
67
68 ZBlock*
69 packet2zblock(Packet *p, u32int size)
70 {
71 ZBlock *b;
72
73 if(p == nil)
74 return nil;
75 b = alloczblock(size, 0, 0);
76 if(b == nil)
77 return nil;
78 if(packetcopy(p, b->data, 0, size) < 0){
79 freezblock(b);
80 return nil;
81 }
82 return b;
83 }
84
85 Packet*
86 zblock2packet(ZBlock *zb, u32int size)
87 {
88 Packet *p;
89
90 if(zb == nil)
91 return nil;
92 p = packetalloc();
93 packetappend(p, zb->data, size);
94 return p;
95 }