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Add lseek() function to IsoFileSource.

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This commit is contained in:
Vreixo Formoso
2008-03-08 18:34:41 +01:00
parent 69fe1d6074
commit bad03a9a2b
4 changed files with 146 additions and 0 deletions
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55
libisofs/fs_image.c
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@ -632,6 +632,60 @@ int ifs_read(IsoFileSource *src, void *buf, size_t count)
return read;
}
static
off_t ifs_lseek(IsoFileSource *src, off_t offset, int flag)
{
ImageFileSourceData *data;
if (src == NULL) {
return (off_t)ISO_NULL_POINTER;
}
if (offset < (off_t)0) {
return (off_t)ISO_WRONG_ARG_VALUE;
}
data = src->data;
if (!data->opened) {
return (off_t)ISO_FILE_NOT_OPENED;
} else if (data->opened != 1) {
return (off_t)ISO_FILE_IS_DIR;
}
switch (flag) {
case 0: /* SEEK_SET */
data->data.offset = offset;
break;
case 1: /* SEEK_CUR */
data->data.offset += offset;
break;
case 2: /* SEEK_END */
/* do this make sense? */
data->data.offset = data->info.st_size + offset;
break;
default:
return (off_t)ISO_WRONG_ARG_VALUE;
}
if (data->data.offset % BLOCK_SIZE != 0) {
/* we need to buffer the block */
uint32_t block;
_ImageFsData *fsdata;
if (data->data.offset < data->info.st_size) {
int ret;
fsdata = data->fs->data;
block = data->block + (data->data.offset / BLOCK_SIZE);
ret = fsdata->src->read_block(fsdata->src, block,
data->data.content);
if (ret < 0) {
return (off_t)ret;
}
}
}
return data->data.offset;
}
static
int ifs_readdir(IsoFileSource *src, IsoFileSource **child)
{
@ -771,6 +825,7 @@ IsoFileSourceIface ifs_class = {
ifs_open,
ifs_close,
ifs_read,
ifs_lseek,
ifs_readdir,
ifs_readlink,
ifs_get_filesystem,