2 * $Id: ad_write.c,v 1.4 2002-10-11 14:18:39 didg Exp $
4 * Copyright (c) 1990,1995 Regents of The University of Michigan.
5 * All Rights Reserved. See COPYRIGHT.
10 #endif /* HAVE_CONFIG_H */
12 #include <atalk/adouble.h>
15 #include <sys/param.h>
20 #define MIN(a,b) ((a)<(b)?(a):(b))
23 /* XXX: locking has to be checked before each stream of consecutive
24 * ad_writes to prevent a lock in the middle from causing problems.
27 ssize_t adf_pwrite(struct ad_fd *ad_fd, const void *buf, size_t count, off_t offset)
32 if ( ad_fd->adf_off != off ) {
33 if ( lseek( ad_fd->adf_fd, offset, SEEK_SET ) < 0 ) {
36 ad_fd->adf_off = offset;
38 cc = write( ad_fd->adf_fd, buf, count );
44 cc = pwrite(ad_fd->adf_fd, buf, count, offset );
50 ssize_t ad_write( ad, eid, off, end, buf, buflen )
61 if ( eid == ADEID_DFORK ) {
63 if ( fstat( ad->ad_df.adf_fd, &st ) < 0 ) {
66 off = st.st_size - off;
68 cc = adf_pwrite(&ad->ad_df, buf, buflen, off);
69 } else if ( eid == ADEID_RFORK ) {
73 if ( fstat( ad->ad_df.adf_fd, &st ) < 0 ) {
76 off = st.st_size - off -ad_getentryoff(ad, eid);
78 r_off = ad_getentryoff(ad, eid) + off;
79 cc = adf_pwrite(&ad->ad_hf, buf, buflen, r_off);
81 /* sync up our internal buffer FIXME always false? */
82 if (r_off < ad_getentryoff(ad, ADEID_RFORK)) {
83 memcpy(ad->ad_data + r_off, buf, MIN(sizeof(ad->ad_data) -r_off, cc));
85 if ( ad->ad_rlen < r_off + cc ) {
86 ad->ad_rlen = r_off + cc;
90 return -1; /* we don't know how to write if it's not a ressource or data fork */
96 int ad_rtruncate( ad, size )
102 if (ad_tmplock(ad, ADEID_RFORK, ADLOCK_WR, 0, 0) < 0)
105 if ( ftruncate( ad->ad_hf.adf_fd,
106 size + ad->ad_eid[ ADEID_RFORK ].ade_off ) < 0 ) {
108 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
115 ad->ad_eid[ ADEID_RFORK ].ade_len = size;
116 if ( lseek( ad->ad_hf.adf_fd, ad->ad_eid[ADEID_RFORK].ade_off,
119 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
124 ad->ad_hf.adf_off = ad->ad_eid[ADEID_RFORK].ade_off;
126 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
130 int ad_dtruncate(ad, size)
136 if (ad_tmplock(ad, ADEID_DFORK, ADLOCK_WR, 0, 0) < 0)
139 if (ftruncate(ad->ad_df.adf_fd, size) < 0) {
141 ad_tmplock(ad, ADEID_DFORK, ADLOCK_CLR, 0, 0);
145 ad_tmplock(ad, ADEID_DFORK, ADLOCK_CLR, 0, 0);