1 .TH VENTI-ZERO 3
2 .SH NAME
3 vtzerotruncate, vtzeroextend, vtzeroscore \- Venti block truncation
4 .SH SYNOPSIS
5 .ft L
6 #include <u.h>
7 .br
8 #include <libc.h>
9 .br
10 #include <venti.h>
11 .ta +\w'\fLuint 'u
12 .PP
13 .B
14 uint	vtzerotruncate(int type, uchar *buf, uint size)
15 .PP
16 .B
17 void	vtzeroextend(int type, uchar *buf, uint size, uint newsize)
18 .PP
19 .B
20 extern uchar vtzeroscore[VtScoreSize];
21 .SH DESCRIPTION
22 These utility functions compute how to truncate or replace
23 trailing zeros (for data blocks) or trailing zero scores
24 (for pointer blocks) to canonicalize the blocks before
25 storing them to Venti.
26 .PP
27 .I Vtzerotruncate
28 returns the size of the 
29 .IR size -byte
30 buffer pointed to by
31 .I buf
32 ignoring trailing zeros or zero scores,
33 according to the given
34 .IR type .
35 .PP
36 .I Vtzeroextend
37 pads
38 .I buf
39 with zeros or zero scores,
40 according to the given
41 .IR type ,
42 to grow it from
43 .I size
44 bytes to
45 .I newsize
46 bytes.
47 .PP
48 .I Vtzeroscore
49 is the score of the zero-length block.
50 .SH SOURCE
51 .B \*9/src/libventi/zero.c
52 .br
53 .B \*9/src/libventi/zeroscore.c
54 .SH SEE ALSO
55 .MR venti (3) ,
56 .MR venti (7)