fs_ptable *fs_ptable_open_filename(const char *fname, int flags)
{
fs_ptable *pt = calloc(1, sizeof(fs_ptable));
if (sizeof(struct ptable_header) != 512) {
fs_error(LOG_CRIT, "ptable header size not 512 bytes");
return NULL;
}
pt->fd = open(fname, FS_O_NOATIME | flags, FS_FILE_MODE);
if (pt->fd == -1) {
fs_error(LOG_CRIT, "failed to open ptable %s: %s", fname, strerror(errno));
return NULL;
}
pt->filename = g_strdup(fname);
pt->flags = flags;
struct ptable_header header;
lseek(pt->fd, 0, SEEK_SET);
if (flags & O_TRUNC || read(pt->fd, &header, sizeof(header)) <= 0) {
header.id = PTABLE_ID;
header.size = 1024;
header.length = 0;
header.revision = PTABLE_REVISION;
}
if (header.id != PTABLE_ID) {
fs_error(LOG_CRIT, "%s does not look like a ptable file", pt->filename);
return NULL;
}
if (header.revision != PTABLE_REVISION) {
fs_error(LOG_CRIT, "%s is wrong revision of ptable file", pt->filename);
return NULL;
}
if (map_pt(pt, header.length, header.size)) {
return NULL;
}
return pt;
}
fs_row_id fs_ptable_new_row(fs_ptable *pt)
{
if (!pt->ptr) {
fs_error(LOG_CRIT, "attempted to get row from unmapped ptable");
return 0;
}
if (pt->header->length == 0) {
pt->header->length = 1;
}
/* we can reuse a free'd row */
if (pt->header->free_list) {
fs_row_id newr = pt->header->free_list;
row *r = &pt->data[newr];
pt->header->free_list = r->cont;
r->cont = 0;
r->data[0] = 0;
r->data[1] = 0;
return newr;
}
if (pt->header->length >= pt->header->size) {
int length = pt->header->length;
int size = pt->header->size;
unmap_pt(pt);
map_pt(pt, length, size * 2);
}
row *r = &pt->data[pt->header->length];
r->cont = 0;
r->data[0] = 0;
r->data[1] = 0;
return (pt->header->length)++;
}
fs_ptable *fs_ptable_open_filename(const char *fname, int flags)
{
fs_ptable *pt = calloc(1, sizeof(fs_ptable));
if (sizeof(struct ptable_header) != 512) {
fs_error(LOG_CRIT, "ptable header size not 512 bytes");
free(pt);
return NULL;
}
pt->fd = open(fname, FS_O_NOATIME | flags, FS_FILE_MODE);
if (pt->fd == -1) {
fs_error(LOG_CRIT, "failed to open ptable %s: %s", fname, strerror(errno));
free(pt);
return NULL;
}
pt->filename = g_strdup(fname);
pt->flags = flags;
if (flags & O_TRUNC && ftruncate(pt->fd, sizeof(struct ptable_header)))
fs_error(LOG_CRIT, "ftruncate failed: %s", strerror(errno));
int mflags = PROT_READ;
if (flags & (O_RDWR | O_WRONLY)) mflags |= PROT_WRITE;
if (flags & (O_TRUNC)) mflags |= PROT_WRITE;
struct ptable_header *header = mmap(NULL, sizeof(struct ptable_header), mflags, MAP_FILE | MAP_SHARED, pt->fd, 0);
if (header == MAP_FAILED || header == NULL) {
fs_error(LOG_CRIT, "failed to mmap: %s", strerror(errno));
return NULL;
}
if (flags & O_TRUNC) {
header->id = PTABLE_ID;
header->size = 1024;
header->length = 0;
header->revision = PTABLE_REVISION;
if (msync(header, sizeof(*header), MS_SYNC)) {
fs_error(LOG_CRIT, "could not msync %s: %s", pt->filename, strerror(errno));
munmap(header, sizeof(*header));
return NULL;
}
}
if (header->id != PTABLE_ID) {
fs_error(LOG_CRIT, "%s does not look like a ptable file", pt->filename);
munmap(header, sizeof(*header));
return NULL;
}
if (header->revision != PTABLE_REVISION) {
fs_error(LOG_CRIT, "%s is wrong revision of ptable file", pt->filename);
munmap(header, sizeof(*header));
return NULL;
}
if (map_pt(pt, header->length, header->size))
return NULL;
if (munmap(header, sizeof(*header)))
fs_error(LOG_ERR, "could not unmap %s: %s", pt->filename, strerror(errno));
return pt;
}
