static bool
S_obtain_deletion_lock(PolyReader *self) {
PolyReaderIVARS *const ivars = PolyReader_IVARS(self);
ivars->deletion_lock = IxManager_Make_Deletion_Lock(ivars->manager);
Lock_Clear_Stale(ivars->deletion_lock);
if (!Lock_Obtain(ivars->deletion_lock)) {
DECREF(ivars->deletion_lock);
ivars->deletion_lock = NULL;
return false;
}
return true;
}
static void
S_obtain_write_lock(BackgroundMerger *self) {
BackgroundMergerIVARS *const ivars = BGMerger_IVARS(self);
Lock *write_lock = IxManager_Make_Write_Lock(ivars->manager);
Lock_Clear_Stale(write_lock);
if (Lock_Obtain(write_lock)) {
// Only assign if successful, otherwise DESTROY unlocks -- bad!
ivars->write_lock = write_lock;
}
else {
DECREF(write_lock);
}
}
static bool
S_obtain_read_lock(PolyReader *self, const CharBuf *snapshot_file_name) {
PolyReaderIVARS *const ivars = PolyReader_IVARS(self);
ivars->read_lock = IxManager_Make_Snapshot_Read_Lock(ivars->manager,
snapshot_file_name);
Lock_Clear_Stale(ivars->read_lock);
if (!Lock_Obtain(ivars->read_lock)) {
DECREF(ivars->read_lock);
ivars->read_lock = NULL;
return false;
}
return true;
}
static void
S_obtain_merge_lock(BackgroundMerger *self) {
BackgroundMergerIVARS *const ivars = BGMerger_IVARS(self);
Lock *merge_lock = IxManager_Make_Merge_Lock(ivars->manager);
Lock_Clear_Stale(merge_lock);
if (Lock_Obtain(merge_lock)) {
// Only assign if successful, same rationale as above.
ivars->merge_lock = merge_lock;
}
else {
// We can't get the merge lock, so it seems there must be another
// BackgroundMerger running.
DECREF(merge_lock);
}
}
static void
S_zap_dead_merge(FilePurger *self, Hash *candidates)
{
IndexManager *manager = self->manager;
Lock *merge_lock = IxManager_Make_Merge_Lock(manager);
Lock_Clear_Stale(merge_lock);
if (!Lock_Is_Locked(merge_lock)) {
Hash *merge_data = IxManager_Read_Merge_Data(manager);
Obj *cutoff = merge_data
? Hash_Fetch_Str(merge_data, "cutoff", 6)
: NULL;
if (cutoff) {
CharBuf *cutoff_seg = Seg_num_to_name(Obj_To_I64(cutoff));
if (Folder_Exists(self->folder, cutoff_seg)) {
ZombieCharBuf *merge_json = ZCB_WRAP_STR("merge.json", 10);
DirHandle *dh = Folder_Open_Dir(self->folder, cutoff_seg);
CharBuf *entry = dh ? DH_Get_Entry(dh) : NULL;
CharBuf *filepath = CB_new(32);
if (!dh) {
THROW(ERR, "Can't open segment dir '%o'", filepath);
}
Hash_Store(candidates, (Obj*)cutoff_seg, INCREF(&EMPTY));
Hash_Store(candidates, (Obj*)merge_json, INCREF(&EMPTY));
while (DH_Next(dh)) {
// TODO: recursively delete subdirs within seg dir.
CB_setf(filepath, "%o/%o", cutoff_seg, entry);
Hash_Store(candidates, (Obj*)filepath, INCREF(&EMPTY));
}
DECREF(filepath);
DECREF(dh);
}
DECREF(cutoff_seg);
}
DECREF(merge_data);
}
DECREF(merge_lock);
return;
}
static void
S_zap_dead_merge(FilePurger *self, Hash *candidates) {
FilePurgerIVARS *const ivars = FilePurger_IVARS(self);
IndexManager *manager = ivars->manager;
Lock *merge_lock = IxManager_Make_Merge_Lock(manager);
Lock_Clear_Stale(merge_lock);
if (!Lock_Is_Locked(merge_lock)) {
Hash *merge_data = IxManager_Read_Merge_Data(manager);
Obj *cutoff = merge_data
? Hash_Fetch_Utf8(merge_data, "cutoff", 6)
: NULL;
if (cutoff) {
String *cutoff_seg = Seg_num_to_name(Json_obj_to_i64(cutoff));
if (Folder_Exists(ivars->folder, cutoff_seg)) {
String *merge_json = SSTR_WRAP_UTF8("merge.json", 10);
DirHandle *dh = Folder_Open_Dir(ivars->folder, cutoff_seg);
if (!dh) {
THROW(ERR, "Can't open segment dir '%o'", cutoff_seg);
}
Hash_Store(candidates, cutoff_seg, (Obj*)CFISH_TRUE);
Hash_Store(candidates, merge_json, (Obj*)CFISH_TRUE);
while (DH_Next(dh)) {
// TODO: recursively delete subdirs within seg dir.
String *entry = DH_Get_Entry(dh);
String *filepath = Str_newf("%o/%o", cutoff_seg, entry);
Hash_Store(candidates, filepath, (Obj*)CFISH_TRUE);
DECREF(filepath);
DECREF(entry);
}
DECREF(dh);
}
DECREF(cutoff_seg);
}
DECREF(merge_data);
}
DECREF(merge_lock);
return;
}
void
FilePurger_purge(FilePurger *self)
{
Lock *deletion_lock = IxManager_Make_Deletion_Lock(self->manager);
// Obtain deletion lock, purge files, release deletion lock.
Lock_Clear_Stale(deletion_lock);
if (Lock_Obtain(deletion_lock)) {
Folder *folder = self->folder;
Hash *failures = Hash_new(0);
VArray *purgables;
VArray *snapshots;
S_discover_unused(self, &purgables, &snapshots);
// Attempt to delete entries -- if failure, no big deal, just try
// again later. Proceed in reverse lexical order so that directories
// get deleted after they've been emptied.
VA_Sort(purgables, NULL, NULL);
for (uint32_t i = VA_Get_Size(purgables); i--; ) {
CharBuf *entry = (CharBuf*)VA_fetch(purgables, i);
if (Hash_Fetch(self->disallowed, (Obj*)entry)) { continue; }
if (!Folder_Delete(folder, entry)) {
if (Folder_Exists(folder, entry)) {
Hash_Store(failures, (Obj*)entry, INCREF(&EMPTY));
}
}
}
for (uint32_t i = 0, max = VA_Get_Size(snapshots); i < max; i++) {
Snapshot *snapshot = (Snapshot*)VA_Fetch(snapshots, i);
bool_t snapshot_has_failures = false;
if (Hash_Get_Size(failures)) {
// Only delete snapshot files if all of their entries were
// successfully deleted.
VArray *entries = Snapshot_List(snapshot);
for (uint32_t j = VA_Get_Size(entries); j--; ) {
CharBuf *entry = (CharBuf*)VA_Fetch(entries, j);
if (Hash_Fetch(failures, (Obj*)entry)) {
snapshot_has_failures = true;
break;
}
}
DECREF(entries);
}
if (!snapshot_has_failures) {
CharBuf *snapfile = Snapshot_Get_Path(snapshot);
Folder_Delete(folder, snapfile);
}
}
DECREF(failures);
DECREF(purgables);
DECREF(snapshots);
Lock_Release(deletion_lock);
}
else {
WARN("Can't obtain deletion lock, skipping deletion of "
"obsolete files");
}
DECREF(deletion_lock);
}
static void
S_discover_unused(FilePurger *self, VArray **purgables_ptr,
VArray **snapshots_ptr)
{
Folder *folder = self->folder;
DirHandle *dh = Folder_Open_Dir(folder, NULL);
if (!dh) { RETHROW(INCREF(Err_get_error())); }
VArray *spared = VA_new(1);
VArray *snapshots = VA_new(1);
CharBuf *snapfile = NULL;
// Start off with the list of files in the current snapshot.
if (self->snapshot) {
VArray *entries = Snapshot_List(self->snapshot);
VArray *referenced = S_find_all_referenced(folder, entries);
VA_Push_VArray(spared, referenced);
DECREF(entries);
DECREF(referenced);
snapfile = Snapshot_Get_Path(self->snapshot);
if (snapfile) { VA_Push(spared, INCREF(snapfile)); }
}
CharBuf *entry = DH_Get_Entry(dh);
Hash *candidates = Hash_new(64);
while (DH_Next(dh)) {
if (!CB_Starts_With_Str(entry, "snapshot_", 9)) { continue; }
else if (!CB_Ends_With_Str(entry, ".json", 5)) { continue; }
else if (snapfile && CB_Equals(entry, (Obj*)snapfile)) { continue; }
else {
Snapshot *snapshot
= Snapshot_Read_File(Snapshot_new(), folder, entry);
Lock *lock
= IxManager_Make_Snapshot_Read_Lock(self->manager, entry);
VArray *snap_list = Snapshot_List(snapshot);
VArray *referenced = S_find_all_referenced(folder, snap_list);
// DON'T obtain the lock -- only see whether another
// entity holds a lock on the snapshot file.
if (lock) {
Lock_Clear_Stale(lock);
}
if (lock && Lock_Is_Locked(lock)) {
// The snapshot file is locked, which means someone's using
// that version of the index -- protect all of its entries.
uint32_t new_size = VA_Get_Size(spared)
+ VA_Get_Size(referenced) + 1;
VA_Grow(spared, new_size);
VA_Push(spared, (Obj*)CB_Clone(entry));
VA_Push_VArray(spared, referenced);
}
else {
// No one's using this snapshot, so all of its entries are
// candidates for deletion.
for (uint32_t i = 0, max = VA_Get_Size(referenced); i < max; i++) {
CharBuf *file = (CharBuf*)VA_Fetch(referenced, i);
Hash_Store(candidates, (Obj*)file, INCREF(&EMPTY));
}
VA_Push(snapshots, INCREF(snapshot));
}
DECREF(referenced);
DECREF(snap_list);
DECREF(snapshot);
DECREF(lock);
}
}
DECREF(dh);
// Clean up after a dead segment consolidation.
S_zap_dead_merge(self, candidates);
// Eliminate any current files from the list of files to be purged.
for (uint32_t i = 0, max = VA_Get_Size(spared); i < max; i++) {
CharBuf *filename = (CharBuf*)VA_Fetch(spared, i);
DECREF(Hash_Delete(candidates, (Obj*)filename));
}
// Pass back purgables and Snapshots.
*purgables_ptr = Hash_Keys(candidates);
*snapshots_ptr = snapshots;
DECREF(candidates);
DECREF(spared);
}
Indexer*
Indexer_init(Indexer *self, Schema *schema, Obj *index,
IndexManager *manager, int32_t flags)
{
bool_t create = (flags & Indexer_CREATE) ? true : false;
bool_t truncate = (flags & Indexer_TRUNCATE) ? true : false;
Folder *folder = S_init_folder(index, create);
Lock *write_lock;
CharBuf *latest_snapfile;
Snapshot *latest_snapshot = Snapshot_new();
// Init.
self->stock_doc = Doc_new(NULL, 0);
self->truncate = false;
self->optimize = false;
self->prepared = false;
self->needs_commit = false;
self->snapfile = NULL;
self->merge_lock = NULL;
// Assign.
self->folder = folder;
self->manager = manager
? (IndexManager*)INCREF(manager)
: IxManager_new(NULL, NULL);
IxManager_Set_Folder(self->manager, folder);
// Get a write lock for this folder.
write_lock = IxManager_Make_Write_Lock(self->manager);
Lock_Clear_Stale(write_lock);
if (Lock_Obtain(write_lock)) {
// Only assign if successful, otherwise DESTROY unlocks -- bad!
self->write_lock = write_lock;
}
else {
DECREF(write_lock);
DECREF(self);
RETHROW(INCREF(Err_get_error()));
}
// Find the latest snapshot or create a new one.
latest_snapfile = IxFileNames_latest_snapshot(folder);
if (latest_snapfile) {
Snapshot_Read_File(latest_snapshot, folder, latest_snapfile);
}
// Look for an existing Schema if one wasn't supplied.
if (schema) {
self->schema = (Schema*)INCREF(schema);
}
else {
if (!latest_snapfile) {
THROW(ERR, "No Schema supplied, and can't find one in the index");
}
else {
CharBuf *schema_file = S_find_schema_file(latest_snapshot);
Hash *dump = (Hash*)Json_slurp_json(folder, schema_file);
if (dump) { // read file successfully
self->schema = (Schema*)CERTIFY(
VTable_Load_Obj(SCHEMA, (Obj*)dump), SCHEMA);
schema = self->schema;
DECREF(dump);
schema_file = NULL;
}
else {
THROW(ERR, "Failed to parse %o", schema_file);
}
}
}
// If we're clobbering, start with an empty Snapshot and an empty
// PolyReader. Otherwise, start with the most recent Snapshot and an
// up-to-date PolyReader.
if (truncate) {
self->snapshot = Snapshot_new();
self->polyreader = PolyReader_new(schema, folder, NULL, NULL, NULL);
self->truncate = true;
}
else {
// TODO: clone most recent snapshot rather than read it twice.
self->snapshot = (Snapshot*)INCREF(latest_snapshot);
self->polyreader = latest_snapfile
? PolyReader_open((Obj*)folder, NULL, NULL)
: PolyReader_new(schema, folder, NULL, NULL, NULL);
if (latest_snapfile) {
// Make sure than any existing fields which may have been
// dynamically added during past indexing sessions get added.
Schema *old_schema = PolyReader_Get_Schema(self->polyreader);
Schema_Eat(schema, old_schema);
}
}
// Zap detritus from previous sessions.
{
// Note: we have to feed FilePurger with the most recent snapshot file
// now, but with the Indexer's snapshot later.
FilePurger *file_purger
= FilePurger_new(folder, latest_snapshot, self->manager);
FilePurger_Purge(file_purger);
DECREF(file_purger);
}
// Create a new segment.
{
int64_t new_seg_num
= IxManager_Highest_Seg_Num(self->manager, latest_snapshot) + 1;
Lock *merge_lock = IxManager_Make_Merge_Lock(self->manager);
uint32_t i, max;
if (Lock_Is_Locked(merge_lock)) {
// If there's a background merge process going on, stay out of its
// way.
Hash *merge_data = IxManager_Read_Merge_Data(self->manager);
Obj *cutoff_obj = merge_data
? Hash_Fetch_Str(merge_data, "cutoff", 6)
: NULL;
if (!cutoff_obj) {
DECREF(merge_lock);
DECREF(merge_data);
THROW(ERR, "Background merge detected, but can't read merge data");
}
else {
int64_t cutoff = Obj_To_I64(cutoff_obj);
if (cutoff >= new_seg_num) {
new_seg_num = cutoff + 1;
}
}
DECREF(merge_data);
}
self->segment = Seg_new(new_seg_num);
// Add all known fields to Segment.
{
VArray *fields = Schema_All_Fields(schema);
for (i = 0, max = VA_Get_Size(fields); i < max; i++) {
Seg_Add_Field(self->segment, (CharBuf*)VA_Fetch(fields, i));
}
DECREF(fields);
}
DECREF(merge_lock);
}
// Create new SegWriter and FilePurger.
self->file_purger
= FilePurger_new(folder, self->snapshot, self->manager);
self->seg_writer = SegWriter_new(self->schema, self->snapshot,
self->segment, self->polyreader);
SegWriter_Prep_Seg_Dir(self->seg_writer);
// Grab a local ref to the DeletionsWriter.
self->del_writer = (DeletionsWriter*)INCREF(
SegWriter_Get_Del_Writer(self->seg_writer));
DECREF(latest_snapfile);
DECREF(latest_snapshot);
return self;
}
