+++ /dev/null
-// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*-
-// vim: ts=8 sw=2 smarttab
-/*
- * Ceph - scalable distributed file system
- *
- * Copyright (C) 2013 Inktank Storage, Inc.
- *
- * This is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License version 2.1, as published by the Free Software
- * Foundation. See file COPYING.
- *
- */
-
-#ifndef SNAPMAPPER_H
-#define SNAPMAPPER_H
-
-#include <string>
-#include <set>
-#include <utility>
-#include <string.h>
-
-#include "common/map_cacher.hpp"
-#include "common/hobject.h"
-#include "include/buffer.h"
-#include "include/encoding.h"
-#include "include/object.h"
-#include "os/ObjectStore.h"
-
-class OSDriver : public MapCacher::StoreDriver<std::string, bufferlist> {
- ObjectStore *os;
- coll_t cid;
- ghobject_t hoid;
-
-public:
- class OSTransaction : public MapCacher::Transaction<std::string, bufferlist> {
- friend class OSDriver;
- coll_t cid;
- ghobject_t hoid;
- ObjectStore::Transaction *t;
- OSTransaction(
- coll_t cid,
- const ghobject_t &hoid,
- ObjectStore::Transaction *t)
- : cid(cid), hoid(hoid), t(t) {}
- public:
- void set_keys(
- const std::map<std::string, bufferlist> &to_set) override {
- t->omap_setkeys(cid, hoid, to_set);
- }
- void remove_keys(
- const std::set<std::string> &to_remove) override {
- t->omap_rmkeys(cid, hoid, to_remove);
- }
- void add_callback(
- Context *c) override {
- t->register_on_applied(c);
- }
- };
-
- OSTransaction get_transaction(
- ObjectStore::Transaction *t) {
- return OSTransaction(cid, hoid, t);
- }
-
- OSDriver(ObjectStore *os, coll_t cid, const ghobject_t &hoid) :
- os(os), cid(cid), hoid(hoid) {}
- int get_keys(
- const std::set<std::string> &keys,
- std::map<std::string, bufferlist> *out) override;
- int get_next(
- const std::string &key,
- pair<std::string, bufferlist> *next) override;
-};
-
-/**
- * SnapMapper
- *
- * Manages two mappings:
- * 1) hobject_t -> {snapid}
- * 2) snapid -> {hobject_t}
- *
- * We accomplish this using two sets of keys:
- * 1) OBJECT_PREFIX + obj.str() -> encoding of object_snaps
- * 2) MAPPING_PREFIX + snapid_t + obj.str() -> encoding of pair<snapid_t, obj>
- *
- * The on disk strings and encodings are implemented in to_raw, to_raw_key,
- * from_raw, to_object_key.
- *
- * The object -> {snapid} mapping is primarily included so that the
- * SnapMapper state can be verified against the external PG state during
- * scrub etc.
- *
- * The 2) mapping is arranged such that all objects in a particular
- * snap will sort together, and so that all objects in a pg for a
- * particular snap will group under up to 8 prefixes.
- */
-class SnapMapper {
-public:
- CephContext* cct;
- struct object_snaps {
- hobject_t oid;
- std::set<snapid_t> snaps;
- object_snaps(hobject_t oid, const std::set<snapid_t> &snaps)
- : oid(oid), snaps(snaps) {}
- object_snaps() {}
- void encode(bufferlist &bl) const;
- void decode(bufferlist::iterator &bp);
- };
-
-private:
- MapCacher::MapCacher<std::string, bufferlist> backend;
-
- static const std::string MAPPING_PREFIX;
- static const std::string OBJECT_PREFIX;
-
- static std::string get_prefix(snapid_t snap);
-
- std::string to_raw_key(
- const std::pair<snapid_t, hobject_t> &to_map);
-
- std::pair<std::string, bufferlist> to_raw(
- const std::pair<snapid_t, hobject_t> &to_map);
-
- static bool is_mapping(const std::string &to_test);
-
- std::pair<snapid_t, hobject_t> from_raw(
- const std::pair<std::string, bufferlist> &image);
-
- std::string to_object_key(const hobject_t &hoid);
-
- int get_snaps(const hobject_t &oid, object_snaps *out);
-
- void set_snaps(
- const hobject_t &oid,
- const object_snaps &out,
- MapCacher::Transaction<std::string, bufferlist> *t);
-
- void clear_snaps(
- const hobject_t &oid,
- MapCacher::Transaction<std::string, bufferlist> *t);
-
- // True if hoid belongs in this mapping based on mask_bits and match
- bool check(const hobject_t &hoid) const {
- return hoid.match(mask_bits, match);
- }
-
- int _remove_oid(
- const hobject_t &oid, ///< [in] oid to remove
- MapCacher::Transaction<std::string, bufferlist> *t ///< [out] transaction
- );
-
-public:
- static string make_shard_prefix(shard_id_t shard) {
- if (shard == shard_id_t::NO_SHARD)
- return string();
- char buf[20];
- int r = snprintf(buf, sizeof(buf), ".%x", (int)shard);
- assert(r < (int)sizeof(buf));
- return string(buf, r) + '_';
- }
- uint32_t mask_bits;
- const uint32_t match;
- string last_key_checked;
- const int64_t pool;
- const shard_id_t shard;
- const string shard_prefix;
- SnapMapper(
- CephContext* cct,
- MapCacher::StoreDriver<std::string, bufferlist> *driver,
- uint32_t match, ///< [in] pgid
- uint32_t bits, ///< [in] current split bits
- int64_t pool, ///< [in] pool
- shard_id_t shard ///< [in] shard
- )
- : cct(cct), backend(driver), mask_bits(bits), match(match), pool(pool),
- shard(shard), shard_prefix(make_shard_prefix(shard)) {
- update_bits(mask_bits);
- }
-
- set<string> prefixes;
- /// Update bits in case of pg split
- void update_bits(
- uint32_t new_bits ///< [in] new split bits
- ) {
- assert(new_bits >= mask_bits);
- mask_bits = new_bits;
- set<string> _prefixes = hobject_t::get_prefixes(
- mask_bits,
- match,
- pool);
- prefixes.clear();
- for (set<string>::iterator i = _prefixes.begin();
- i != _prefixes.end();
- ++i) {
- prefixes.insert(shard_prefix + *i);
- }
- }
-
- /// Update snaps for oid, empty new_snaps removes the mapping
- int update_snaps(
- const hobject_t &oid, ///< [in] oid to update
- const std::set<snapid_t> &new_snaps, ///< [in] new snap set
- const std::set<snapid_t> *old_snaps, ///< [in] old snaps (for debugging)
- MapCacher::Transaction<std::string, bufferlist> *t ///< [out] transaction
- ); ///@ return error, 0 on success
-
- /// Add mapping for oid, must not already be mapped
- void add_oid(
- const hobject_t &oid, ///< [in] oid to add
- const std::set<snapid_t>& new_snaps, ///< [in] snaps
- MapCacher::Transaction<std::string, bufferlist> *t ///< [out] transaction
- );
-
- /// Returns first object with snap as a snap
- int get_next_objects_to_trim(
- snapid_t snap, ///< [in] snap to check
- unsigned max, ///< [in] max to get
- vector<hobject_t> *out ///< [out] next objects to trim (must be empty)
- ); ///< @return error, -ENOENT if no more objects
-
- /// Remove mapping for oid
- int remove_oid(
- const hobject_t &oid, ///< [in] oid to remove
- MapCacher::Transaction<std::string, bufferlist> *t ///< [out] transaction
- ); ///< @return error, -ENOENT if the object is not mapped
-
- /// Get snaps for oid
- int get_snaps(
- const hobject_t &oid, ///< [in] oid to get snaps for
- std::set<snapid_t> *snaps ///< [out] snaps
- ); ///< @return error, -ENOENT if oid is not recorded
-};
-WRITE_CLASS_ENCODER(SnapMapper::object_snaps)
-
-#endif
Code Review / stor4nfv.git / blobdiff