2 * $Id: ad_write.c,v 1.3 2001-06-29 14:14:46 rufustfirefly Exp $
4 * Copyright (c) 1990,1995 Regents of The University of Michigan.
5 * All Rights Reserved. See COPYRIGHT.
10 #endif /* HAVE_CONFIG_H */
13 #include <sys/types.h>
14 #include <sys/param.h>
18 #endif /* HAVE_UNISTD_H */
21 #endif /* HAVE_FCNTL_H */
24 #include <atalk/adouble.h>
27 #define MIN(a,b) ((a)<(b)?(a):(b))
30 /* XXX: this would benefit from pwrite.
31 * locking has to be checked before each stream of consecutive
32 * ad_writes to prevent a lock in the middle from causing problems.
34 ssize_t ad_write( ad, eid, off, end, buf, buflen )
45 if ( eid == ADEID_DFORK ) {
47 if ( fstat( ad->ad_df.adf_fd, &st ) < 0 ) {
50 off = st.st_size - off;
53 if ( ad->ad_df.adf_off != off ) {
54 if ( lseek( ad->ad_df.adf_fd, (off_t) off, SEEK_SET ) < 0 ) {
57 ad->ad_df.adf_off = off;
59 cc = write( ad->ad_df.adf_fd, buf, buflen );
63 ad->ad_df.adf_off += cc;
66 off = ad->ad_eid[ eid ].ade_len - off;
68 cc = ad->ad_eid[eid].ade_off + off;
70 #ifdef USE_MMAPPED_HEADERS
71 if (eid != ADEID_RFORK) {
72 memcpy(ad->ad_data + cc, buf, buflen);
76 #endif /* ! USE_MMAPPED_HEADERS */
78 if ( ad->ad_hf.adf_off != cc ) {
79 if ( lseek( ad->ad_hf.adf_fd, (off_t) cc, SEEK_SET ) < 0 ) {
82 ad->ad_hf.adf_off = cc;
85 if ((cc = write( ad->ad_hf.adf_fd, buf, buflen )) < 0)
87 ad->ad_hf.adf_off += cc;
89 #ifndef USE_MMAPPED_HEADERS
90 /* sync up our internal buffer */
91 if (ad->ad_hf.adf_off < ad_getentryoff(ad, ADEID_RFORK))
92 memcpy(ad->ad_data + ad->ad_hf.adf_off, buf,
93 MIN(sizeof(ad->ad_data) - ad->ad_hf.adf_off, cc));
94 #else /* ! USE_MMAPPED_HEADERS */
96 #endif /* ! USE_MMAPPED_HEADERS */
97 if ( ad->ad_eid[ eid ].ade_len < off + cc ) {
98 ad->ad_eid[ eid ].ade_len = off + cc;
106 int ad_rtruncate( ad, size )
112 if (ad_tmplock(ad, ADEID_RFORK, ADLOCK_WR, 0, 0) < 0)
115 if ( ftruncate( ad->ad_hf.adf_fd,
116 size + ad->ad_eid[ ADEID_RFORK ].ade_off ) < 0 ) {
118 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
123 ad->ad_eid[ ADEID_RFORK ].ade_len = size;
124 if ( lseek( ad->ad_hf.adf_fd, ad->ad_eid[ADEID_RFORK].ade_off,
127 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
132 ad->ad_hf.adf_off = ad->ad_eid[ADEID_RFORK].ade_off;
133 ad_tmplock(ad, ADEID_RFORK, ADLOCK_CLR, 0, 0);
137 int ad_dtruncate(ad, size)
143 if (ad_tmplock(ad, ADEID_DFORK, ADLOCK_WR, 0, 0) < 0)
146 if (ftruncate(ad->ad_df.adf_fd, size) < 0) {
148 ad_tmplock(ad, ADEID_DFORK, ADLOCK_CLR, 0, 0);
151 ad_tmplock(ad, ADEID_DFORK, ADLOCK_CLR, 0, 0);