imapext-2007
view src/osdep/nt/fdstring.c @ 0:ada5e610ab86
imap-2007e
| author | yuuji@gentei.org |
|---|---|
| date | Mon, 14 Sep 2009 15:17:45 +0900 |
| parents | |
| children |
line source
1 /* ========================================================================
2 * Copyright 1988-2007 University of Washington
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 *
11 * ========================================================================
12 */
14 /*
15 * Program: File descriptor string routines
16 *
17 * Author: Mark Crispin
18 * Networks and Distributed Computing
19 * Computing & Communications
20 * University of Washington
21 * Administration Building, AG-44
22 * Seattle, WA 98195
23 * Internet: MRC@CAC.Washington.EDU
24 *
25 * Date: 15 April 1997
26 * Last Edited: 4 April 2007
27 */
29 #include "mail.h"
30 #include "osdep.h"
31 #include "misc.h"
32 #include "fdstring.h"
34 /* String driver for fd stringstructs */
36 static void fd_string_init (STRING *s,void *data,unsigned long size);
37 static char fd_string_next (STRING *s);
38 static void fd_string_setpos (STRING *s,unsigned long i);
40 STRINGDRIVER fd_string = {
41 fd_string_init, /* initialize string structure */
42 fd_string_next, /* get next byte in string structure */
43 fd_string_setpos /* set position in string structure */
44 };
47 /* Initialize string structure for fd stringstruct
48 * Accepts: string structure
49 * pointer to string
50 * size of string
51 */
53 static void fd_string_init (STRING *s,void *data,unsigned long size)
54 {
55 FDDATA *d = (FDDATA *) data;
56 /* note fd */
57 s->data = (void *) (unsigned long) d->fd;
58 s->data1 = d->pos; /* note file offset */
59 s->size = size; /* note size */
60 s->curpos = s->chunk = d->chunk;
61 s->chunksize = (unsigned long) d->chunksize;
62 s->offset = 0; /* initial position */
63 /* and size of data */
64 s->cursize = min (s->chunksize,size);
65 /* move to that position in the file */
66 lseek (d->fd,d->pos,L_SET);
67 read (d->fd,s->chunk,(size_t) s->cursize);
68 }
70 /* Get next character from fd stringstruct
71 * Accepts: string structure
72 * Returns: character, string structure chunk refreshed
73 */
75 static char fd_string_next (STRING *s)
76 {
77 char c = *s->curpos++; /* get next byte */
78 SETPOS (s,GETPOS (s)); /* move to next chunk */
79 return c; /* return the byte */
80 }
83 /* Set string pointer position for fd stringstruct
84 * Accepts: string structure
85 * new position
86 */
88 static void fd_string_setpos (STRING *s,unsigned long i)
89 {
90 if (i > s->size) i = s->size; /* don't permit setting beyond EOF */
91 s->offset = i; /* set new offset */
92 s->curpos = s->chunk; /* reset position */
93 /* set size of data */
94 if (s->cursize = min (s->chunksize,SIZE (s))) {
95 /* move to that position in the file */
96 lseek ((long) s->data,s->data1 + s->offset,L_SET);
97 read ((long) s->data,s->curpos,(size_t) s->cursize);
98 }
99 }