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|
/**
* Copyright (C) 2018-present MongoDB, Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the Server Side Public License, version 1,
* as published by MongoDB, Inc.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* Server Side Public License for more details.
*
* You should have received a copy of the Server Side Public License
* along with this program. If not, see
* <http://www.mongodb.com/licensing/server-side-public-license>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the Server Side Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#include <algorithm>
#include <boost/optional.hpp>
#include <iosfwd>
#include <string>
#include "mongo/base/status_with.h"
#include "mongo/base/string_data.h"
#include "mongo/bson/util/builder.h"
#include "mongo/db/repl/optime.h"
#include "mongo/db/server_options.h"
#include "mongo/logv2/log_attr.h"
#include "mongo/util/assert_util.h"
#include "mongo/util/uuid.h"
namespace mongo {
class NamespaceString {
public:
constexpr static size_t MaxDatabaseNameLen =
128; // max str len for the db name, including null char
constexpr static size_t MaxNSCollectionLenFCV42 = 120U;
constexpr static size_t MaxNsCollectionLen = 255;
// Reserved system namespaces
// Namespace for the admin database
static constexpr StringData kAdminDb = "admin"_sd;
// Namespace for the local database
static constexpr StringData kLocalDb = "local"_sd;
// Namespace for the sharding config database
static constexpr StringData kConfigDb = "config"_sd;
// Name for the system views collection
static constexpr StringData kSystemDotViewsCollectionName = "system.views"_sd;
// Names of privilege document collections
static constexpr StringData kSystemUsers = "system.users"_sd;
static constexpr StringData kSystemRoles = "system.roles"_sd;
// Prefix for orphan collections
static constexpr StringData kOrphanCollectionPrefix = "orphan."_sd;
static constexpr StringData kOrphanCollectionDb = "local"_sd;
// Prefix for collections that store the local resharding oplog buffer.
static constexpr StringData kReshardingLocalOplogBufferPrefix =
"localReshardingOplogBuffer."_sd;
// Prefix for resharding conflict stash collections.
static constexpr StringData kReshardingConflictStashPrefix = "localReshardingConflictStash."_sd;
// Prefix for temporary resharding collection.
static constexpr StringData kTemporaryReshardingCollectionPrefix = "system.resharding."_sd;
// Prefix for time-series buckets collection.
static constexpr StringData kTimeseriesBucketsCollectionPrefix = "system.buckets."_sd;
// Namespace for storing configuration data, which needs to be replicated if the server is
// running as a replica set. Documents in this collection should represent some configuration
// state of the server, which needs to be recovered/consulted at startup. Each document in this
// namespace should have its _id set to some string, which meaningfully describes what it
// represents. For example, 'shardIdentity' and 'featureCompatibilityVersion'.
static const NamespaceString kServerConfigurationNamespace;
// Namespace for storing the logical sessions information
static const NamespaceString kLogicalSessionsNamespace;
// Namespace for storing the transaction information for each session
static const NamespaceString kSessionTransactionsTableNamespace;
// Name for a shard's collections metadata collection, each document of which indicates the
// state of a specific collection
static const NamespaceString kShardConfigCollectionsNamespace;
// Name for a shard's databases metadata collection, each document of which indicates the state
// of a specific database
static const NamespaceString kShardConfigDatabasesNamespace;
// Namespace for storing keys for signing and validating cluster times created by the cluster
// that this node is in.
static const NamespaceString kKeysCollectionNamespace;
// Namespace for storing keys for validating cluster times created by other clusters.
static const NamespaceString kExternalKeysCollectionNamespace;
// Namespace of the the oplog collection.
static const NamespaceString kRsOplogNamespace;
// Namespace for storing the persisted state of transaction coordinators.
static const NamespaceString kTransactionCoordinatorsNamespace;
// Namespace for storing the persisted state of migration coordinators.
static const NamespaceString kMigrationCoordinatorsNamespace;
// Namespace for storing the persisted state of tenant migration donors.
static const NamespaceString kTenantMigrationDonorsNamespace;
// Namespace for storing the persisted state of tenant migration recipient service instances.
static const NamespaceString kTenantMigrationRecipientsNamespace;
// Namespace for view on local.oplog.rs for tenant migrations.
static const NamespaceString kTenantMigrationOplogView;
// Namespace for replica set configuration settings.
static const NamespaceString kSystemReplSetNamespace;
// Namespace for index build entries.
static const NamespaceString kIndexBuildEntryNamespace;
// Namespace for pending range deletions.
static const NamespaceString kRangeDeletionNamespace;
// Namespace containing pending range deletions snapshots for rename operations.
static const NamespaceString kRangeDeletionForRenameNamespace;
// Namespace for the coordinator's resharding operation state.
static const NamespaceString kConfigReshardingOperationsNamespace;
// Namespace for the donor shard's local resharding operation state.
static const NamespaceString kDonorReshardingOperationsNamespace;
// Namespace for the recipient shard's local resharding operation state.
static const NamespaceString kRecipientReshardingOperationsNamespace;
// Namespace for persisting sharding DDL coordinators state documents
static const NamespaceString kShardingDDLCoordinatorsNamespace;
// Namespace for persisting sharding DDL rename participant state documents
static const NamespaceString kShardingRenameParticipantsNamespace;
// Namespace for balancer settings and default read and write concerns.
static const NamespaceString kConfigSettingsNamespace;
// Namespace for vector clock state.
static const NamespaceString kVectorClockNamespace;
// Namespace for storing oplog applier progress for resharding.
static const NamespaceString kReshardingApplierProgressNamespace;
// Namespace for storing config.transactions cloner progress for resharding.
static const NamespaceString kReshardingTxnClonerProgressNamespace;
// Namespace for storing config.collectionCriticalSections documents
static const NamespaceString kCollectionCriticalSectionsNamespace;
// Dummy namespace used for forcing secondaries to handle an oplog entry on its own batch.
static const NamespaceString kForceOplogBatchBoundaryNamespace;
/**
* Constructs an empty NamespaceString.
*/
NamespaceString() : _ns(), _dotIndex(std::string::npos) {}
/**
* Constructs a NamespaceString from the fully qualified namespace named in "ns".
*/
explicit NamespaceString(StringData ns) {
_ns = ns.toString(); // copy to our buffer
_dotIndex = _ns.find('.');
uassert(ErrorCodes::InvalidNamespace,
"namespaces cannot have embedded null characters",
_ns.find('\0') == std::string::npos);
}
/**
* Constructs a NamespaceString for the given database and collection names.
* "dbName" must not contain a ".", and "collectionName" must not start with one.
*/
NamespaceString(StringData dbName, StringData collectionName)
: _ns(dbName.size() + collectionName.size() + 1, '\0') {
uassert(ErrorCodes::InvalidNamespace,
"'.' is an invalid character in the database name: " + dbName,
dbName.find('.') == std::string::npos);
uassert(ErrorCodes::InvalidNamespace,
"Collection names cannot start with '.': " + collectionName,
collectionName.empty() || collectionName[0] != '.');
std::string::iterator it = std::copy(dbName.begin(), dbName.end(), _ns.begin());
*it = '.';
++it;
it = std::copy(collectionName.begin(), collectionName.end(), it);
_dotIndex = dbName.size();
dassert(it == _ns.end());
dassert(_ns[_dotIndex] == '.');
uassert(ErrorCodes::InvalidNamespace,
"namespaces cannot have embedded null characters",
_ns.find('\0') == std::string::npos);
}
/**
* Constructs the namespace '<dbName>.$cmd.aggregate', which we use as the namespace for
* aggregation commands with the format {aggregate: 1}.
*/
static NamespaceString makeCollectionlessAggregateNSS(StringData dbName);
/**
* Constructs a NamespaceString representing a listCollections namespace. The format for this
* namespace is "<dbName>.$cmd.listCollections".
*/
static NamespaceString makeListCollectionsNSS(StringData dbName);
/**
* NOTE: DollarInDbNameBehavior::allow is deprecated.
*
* Please use DollarInDbNameBehavior::disallow and check explicitly for any DB names that must
* contain a $.
*/
enum class DollarInDbNameBehavior {
Disallow,
Allow, // Deprecated
};
StringData db() const {
return _dotIndex == std::string::npos ? _ns : StringData(_ns.data(), _dotIndex);
}
StringData coll() const {
return _dotIndex == std::string::npos
? StringData()
: StringData(_ns.c_str() + _dotIndex + 1, _ns.size() - 1 - _dotIndex);
}
const std::string& ns() const {
return _ns;
}
const std::string& toString() const {
return ns();
}
size_t size() const {
return _ns.size();
}
bool isEmpty() const {
return _ns.empty();
}
//
// The following methods assume isValid() is true for this NamespaceString.
//
bool isHealthlog() const {
return isLocal() && coll() == "system.healthlog";
}
bool isSystem() const {
return coll().startsWith("system.");
}
bool isNormalCollection() const {
return !isSystem() && !(isLocal() && coll().startsWith("replset."));
}
bool isAdminDB() const {
return db() == kAdminDb;
}
bool isLocal() const {
return db() == kLocalDb;
}
bool isSystemDotProfile() const {
return coll() == "system.profile";
}
bool isSystemDotViews() const {
return coll() == kSystemDotViewsCollectionName;
}
bool isServerConfigurationCollection() const {
return (db() == kAdminDb) && (coll() == "system.version");
}
bool isPrivilegeCollection() const {
if (!isAdminDB()) {
return false;
}
return (coll() == kSystemUsers) || (coll() == kSystemRoles);
}
bool isConfigDB() const {
return db() == kConfigDb;
}
bool isCommand() const {
return coll() == "$cmd";
}
bool isOplog() const {
return oplog(_ns);
}
bool isOnInternalDb() const {
if (db() == kAdminDb)
return true;
if (db() == kLocalDb)
return true;
if (db() == kConfigDb)
return true;
return false;
}
bool isOrphanCollection() const {
return db() == kOrphanCollectionDb && coll().startsWith(kOrphanCollectionPrefix);
}
/**
* Returns whether the specified namespace is used for internal purposes only and can
* never be marked as anything other than UNSHARDED.
*/
bool isNamespaceAlwaysUnsharded() const;
/**
* Returns whether the specified namespace is config.cache.chunks.<>.
*/
bool isConfigDotCacheDotChunks() const;
/**
* Returns whether the specified namespace is config.localReshardingOplogBuffer.<>.
*/
bool isReshardingLocalOplogBufferCollection() const;
/**
* Returns whether the specified namespace is config.localReshardingConflictStash.<>.
*/
bool isReshardingConflictStashCollection() const;
/**
* Returns whether the specified namespace is <database>.system.resharding.<>.
*/
bool isTemporaryReshardingCollection() const;
/**
* Returns whether the specified namespace is <database>.system.buckets.<>.
*/
bool isTimeseriesBucketsCollection() const;
/**
* Returns the time-series buckets namespace for this view.
*/
NamespaceString makeTimeseriesBucketsNamespace() const;
/**
* Returns the time-series view namespace for this buckets namespace.
*/
NamespaceString getTimeseriesViewNamespace() const;
/**
* Returns whether a namespace is replicated, based only on its string value. One notable
* omission is that map reduce `tmp.mr` collections may or may not be replicated. Callers must
* decide how to handle that case separately.
*
* Note: This function considers "replicated" to be any namespace that should be timestamped.
* Not all collections that are timestamped are replicated explicitly through the oplog.
* Drop-pending collections are a notable example. Please use
* ReplicationCoordinator::isOplogDisabledForNS to determine if a namespace gets logged in the
* oplog.
*/
bool isReplicated() const;
/**
* The namespace associated with some ClientCursors does not correspond to a particular
* namespace. For example, this is true for listCollections cursors and $currentOp agg cursors.
* Returns true if the namespace string is for a "collectionless" cursor.
*/
bool isCollectionlessCursorNamespace() const {
return coll().startsWith("$cmd."_sd);
}
bool isCollectionlessAggregateNS() const;
bool isListCollectionsCursorNS() const;
/**
* Returns true if a client can modify this namespace even though it is under ".system."
* For example <dbname>.system.users is ok for regular clients to update.
*/
bool isLegalClientSystemNS(const ServerGlobalParams::FeatureCompatibility& currentFCV) const;
/**
* Returns true if this namespace refers to a drop-pending collection.
*/
bool isDropPendingNamespace() const;
/**
* Returns true if operations on this namespace must be applied in their own oplog batch.
*/
bool mustBeAppliedInOwnOplogBatch() const;
/**
* Returns the drop-pending namespace name for this namespace, provided the given optime.
*
* Example:
* test.foo -> test.system.drop.<timestamp seconds>i<timestamp increment>t<term>.foo
*/
NamespaceString makeDropPendingNamespace(const repl::OpTime& opTime) const;
/**
* Returns the optime used to generate the drop-pending namespace.
* Returns an error if this namespace is not drop-pending.
*/
StatusWith<repl::OpTime> getDropPendingNamespaceOpTime() const;
/**
* Returns true if the namespace is valid. Special namespaces for internal use are considered as
* valid.
*/
bool isValid(DollarInDbNameBehavior behavior = DollarInDbNameBehavior::Allow) const {
return validDBName(db(), behavior) && !coll().empty();
}
/**
* NamespaceString("foo.bar").getSisterNS("blah") returns "foo.blah".
*/
std::string getSisterNS(StringData local) const;
NamespaceString getCommandNS() const {
return {db(), "$cmd"};
}
void serializeCollectionName(BSONObjBuilder* builder, StringData fieldName) const;
/**
* @return true if the ns is an oplog one, otherwise false.
*/
static bool oplog(StringData ns) {
return ns.startsWith("local.oplog.");
}
/**
* samples:
* good
* foo
* bar
* foo-bar
* bad:
* foo bar
* foo.bar
* foo"bar
*
* @param db - a possible database name
* @param DollarInDbNameBehavior - please do not change the default value. DB names that must
* contain a $ should be checked explicitly.
* @return if db is an allowed database name
*/
static bool validDBName(StringData db,
DollarInDbNameBehavior behavior = DollarInDbNameBehavior::Disallow);
/**
* Takes a fully qualified namespace (ie dbname.collectionName), and returns true if
* the collection name component of the namespace is valid.
* samples:
* good:
* foo.bar
* bad:
* foo.
*
* @param ns - a full namespace (a.b)
* @return if db.coll is an allowed collection name
*/
static bool validCollectionComponent(StringData ns);
/**
* Takes a collection name and returns true if it is a valid collection name.
* samples:
* good:
* foo
* system.views
* bad:
* $foo
* @param coll - a collection name component of a namespace
* @return if the input is a valid collection name
*/
static bool validCollectionName(StringData coll);
// Relops among `NamespaceString`.
friend bool operator==(const NamespaceString& a, const NamespaceString& b) {
return a.ns() == b.ns();
}
friend bool operator!=(const NamespaceString& a, const NamespaceString& b) {
return a.ns() != b.ns();
}
friend bool operator<(const NamespaceString& a, const NamespaceString& b) {
return a.ns() < b.ns();
}
friend bool operator>(const NamespaceString& a, const NamespaceString& b) {
return a.ns() > b.ns();
}
friend bool operator<=(const NamespaceString& a, const NamespaceString& b) {
return a.ns() <= b.ns();
}
friend bool operator>=(const NamespaceString& a, const NamespaceString& b) {
return a.ns() >= b.ns();
}
template <typename H>
friend H AbslHashValue(H h, const NamespaceString& nss) {
return H::combine(std::move(h), nss._ns);
}
friend auto logAttrs(const NamespaceString& nss) {
return "namespace"_attr = nss;
}
private:
std::string _ns;
size_t _dotIndex = 0;
};
/**
* This class is intented to be used by commands which can accept either a collection name or
* database + collection UUID. It will never be initialized with both.
*/
class NamespaceStringOrUUID {
public:
NamespaceStringOrUUID(NamespaceString nss) : _nss(std::move(nss)) {}
NamespaceStringOrUUID(std::string dbname, UUID uuid)
: _uuid(std::move(uuid)), _dbname(std::move(dbname)) {}
const boost::optional<NamespaceString>& nss() const {
return _nss;
}
void setNss(const NamespaceString& nss) {
_nss = nss;
}
const boost::optional<UUID>& uuid() const {
return _uuid;
}
/**
* Returns database name if this object was initialized with a UUID.
*/
const std::string& dbname() const {
return _dbname;
}
void preferNssForSerialization() {
_preferNssForSerialization = true;
}
/**
* Returns database name derived from either '_nss' or '_dbname'.
*/
StringData db() const {
return _nss ? _nss->db() : StringData(_dbname);
}
std::string toString() const;
void serialize(BSONObjBuilder* builder, StringData fieldName) const;
private:
// At any given time exactly one of these optionals will be initialized.
boost::optional<NamespaceString> _nss;
boost::optional<UUID> _uuid;
// When seralizing, if both '_nss' and '_uuid' are present, use '_nss'.
bool _preferNssForSerialization = false;
// Empty string when '_nss' is non-none, and contains the database name when '_uuid' is
// non-none. Although the UUID specifies a collection uniquely, we must later verify that the
// collection belongs to the database named here.
std::string _dbname;
};
std::ostream& operator<<(std::ostream& stream, const NamespaceString& nss);
std::ostream& operator<<(std::ostream& stream, const NamespaceStringOrUUID& nsOrUUID);
StringBuilder& operator<<(StringBuilder& builder, const NamespaceString& nss);
StringBuilder& operator<<(StringBuilder& builder, const NamespaceStringOrUUID& nsOrUUID);
/**
* "database.a.b.c" -> "database"
*/
inline StringData nsToDatabaseSubstring(StringData ns) {
size_t i = ns.find('.');
if (i == std::string::npos) {
massert(
10078, "nsToDatabase: db too long", ns.size() < NamespaceString::MaxDatabaseNameLen);
return ns;
}
massert(10088,
"nsToDatabase: db too long",
i < static_cast<size_t>(NamespaceString::MaxDatabaseNameLen));
return ns.substr(0, i);
}
/**
* "database.a.b.c" -> "database"
*
* TODO: make this return a StringData
*/
inline std::string nsToDatabase(StringData ns) {
return nsToDatabaseSubstring(ns).toString();
}
/**
* "database.a.b.c" -> "a.b.c"
*/
inline StringData nsToCollectionSubstring(StringData ns) {
size_t i = ns.find('.');
massert(16886, "nsToCollectionSubstring: no .", i != std::string::npos);
return ns.substr(i + 1);
}
/**
* foo = false
* foo. = false
* foo.a = true
*/
inline bool nsIsFull(StringData ns) {
size_t i = ns.find('.');
if (i == std::string::npos)
return false;
if (i == ns.size() - 1)
return false;
return true;
}
/**
* foo = true
* foo. = false
* foo.a = false
*/
inline bool nsIsDbOnly(StringData ns) {
size_t i = ns.find('.');
if (i == std::string::npos)
return true;
return false;
}
inline bool NamespaceString::validDBName(StringData db, DollarInDbNameBehavior behavior) {
if (db.size() == 0 || db.size() >= 64)
return false;
for (StringData::const_iterator iter = db.begin(), end = db.end(); iter != end; ++iter) {
switch (*iter) {
case '\0':
case '/':
case '\\':
case '.':
case ' ':
case '"':
return false;
case '$':
if (behavior == DollarInDbNameBehavior::Disallow)
return false;
continue;
#ifdef _WIN32
// We prohibit all FAT32-disallowed characters on Windows
case '*':
case '<':
case '>':
case ':':
case '|':
case '?':
return false;
#endif
default:
continue;
}
}
return true;
}
inline bool NamespaceString::validCollectionComponent(StringData ns) {
size_t idx = ns.find('.');
if (idx == std::string::npos)
return false;
return validCollectionName(ns.substr(idx + 1)) || oplog(ns);
}
inline bool NamespaceString::validCollectionName(StringData coll) {
if (coll.empty())
return false;
if (coll[0] == '.')
return false;
for (StringData::const_iterator iter = coll.begin(), end = coll.end(); iter != end; ++iter) {
switch (*iter) {
case '\0':
case '$':
return false;
default:
continue;
}
}
return true;
}
} // namespace mongo
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