Represents the data in one snapshot metadata file. More...

Detailed Description

Represents the data in one snapshot metadata file.

One snapshot metadata file is written for each snapshotting as an xml file. It contains metadata of all storages and a few other global things.

We write it out as part of snapshotting. We read it at restart.

Definition at line 44 of file snapshot_metadata.hpp.

#include <snapshot_metadata.hpp>

Inheritance diagram for foedus::snapshot::SnapshotMetadata:

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Collaboration diagram for foedus::snapshot::SnapshotMetadata:

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Public Member Functions
void	clear ()

storage::Metadata *	get_metadata (storage::StorageId id)

ErrorStack	load (tinyxml2::XMLElement *element) override
	Reads the content of this object from the given XML element. More...

ErrorStack	save (tinyxml2::XMLElement *element) const override
	Writes the content of this object to the given XML element. More...

const char *	get_tag_name () const override
	Returns an XML tag name for this object as a root element. More...

void	assign (const foedus::externalize::Externalizable *other) override
	Polymorphic assign operator. More...

Public Member Functions inherited from foedus::externalize::Externalizable
ErrorStack	load_from_string (const std::string &xml)
	Load the content of this object from the given XML string. More...

void	save_to_stream (std::ostream *ptr) const
	Invokes save() and directs the resulting XML text to the given stream. More...

ErrorStack	load_from_file (const fs::Path &path)
	Load the content of this object from the specified XML file. More...

ErrorStack	save_to_file (const fs::Path &path) const
	Atomically and durably writes out this object to the specified XML file. More...

Public Attributes
SnapshotId	id_
	Equivalent to Snapshot::id_. More...

Epoch::EpochInteger	base_epoch_
	Equivalent to Snapshot::base_epoch_. More...

Epoch::EpochInteger	valid_until_epoch_
	Equivalent to Snapshot::valid_until_epoch_. More...

storage::StorageId	largest_storage_id_
	The largest StorageId we so far observed. More...

storage::StorageControlBlock *	storage_control_blocks_
	control block of all storages. More...

memory::AlignedMemory	storage_control_blocks_memory_
	Memory backing storage_control_blocks_. More...

Additional Inherited Members
Static Public Member Functions inherited from foedus::externalize::Externalizable
static ErrorStack	insert_comment (tinyxml2::XMLElement *element, const std::string &comment)

static ErrorStack	append_comment (tinyxml2::XMLElement *parent, const std::string &comment)

static ErrorStack	create_element (tinyxml2::XMLElement parent, const std::string &name, tinyxml2::XMLElement *out)

template<typename T >
static ErrorStack	add_element (tinyxml2::XMLElement *parent, const std::string &tag, const std::string &comment, T value)
	Only declaration in header. More...

template<uint MAXLEN, typename CHAR >
static ErrorStack	add_element (tinyxml2::XMLElement *parent, const std::string &tag, const std::string &comment, const assorted::FixedString< MAXLEN, CHAR > &value)

template<typename T >
static ErrorStack	add_element (tinyxml2::XMLElement *parent, const std::string &tag, const std::string &comment, const std::vector< T > &value)
	vector version More...

template<typename ENUM >
static ErrorStack	add_enum_element (tinyxml2::XMLElement *parent, const std::string &tag, const std::string &comment, ENUM value)
	enum version More...

static ErrorStack	add_child_element (tinyxml2::XMLElement *parent, const std::string &tag, const std::string &comment, const Externalizable &child)
	child Externalizable version More...

template<typename T >
static ErrorStack	get_element (tinyxml2::XMLElement parent, const std::string &tag, T out, bool optional=false, T value=0)
	Only declaration in header. More...

static ErrorStack	get_element (tinyxml2::XMLElement parent, const std::string &tag, std::string out, bool optional=false, const char *value="")
	string type is bit special. More...

template<uint MAXLEN, typename CHAR >
static ErrorStack	get_element (tinyxml2::XMLElement parent, const std::string &tag, assorted::FixedString< MAXLEN, CHAR > out, bool optional=false, const assorted::FixedString< MAXLEN, CHAR > &value=assorted::FixedString< MAXLEN, CHAR >())

template<typename ENUM >
static ErrorStack	get_enum_element (tinyxml2::XMLElement parent, const std::string &tag, ENUM out, bool optional=false, ENUM default_value=static_cast< ENUM >(0))
	enum version More...

template<typename T >
static ErrorStack	get_element (tinyxml2::XMLElement parent, const std::string &tag, std::vector< T > out, bool optional=false)
	vector version. More...

static ErrorStack	get_child_element (tinyxml2::XMLElement parent, const std::string &tag, Externalizable child, bool optional=false)
	child Externalizable version More...

Member Function Documentation

void foedus::snapshot::SnapshotMetadata::assign ( const foedus::externalize::Externalizable * other )

overridevirtual

Polymorphic assign operator.

This should invoke operator= of the derived class.

Parameters

[in] other assigned value. It must be dynamic-castable to the assignee class.

Implements foedus::externalize::Externalizable.

Definition at line 100 of file snapshot_metadata.cpp.

References ASSERT_ND.

                                                                 {
   ASSERT_ND(false);  // should not be called
 }

void foedus::snapshot::SnapshotMetadata::clear ( )

Definition at line 33 of file snapshot_metadata.cpp.

References base_epoch_, id_, foedus::Epoch::kEpochInvalid, foedus::snapshot::kNullSnapshotId, largest_storage_id_, foedus::memory::AlignedMemory::release_block(), storage_control_blocks_, storage_control_blocks_memory_, and valid_until_epoch_.

Referenced by load().

                              {
   id_ = kNullSnapshotId;
   base_epoch_ = Epoch::kEpochInvalid;
   valid_until_epoch_ = Epoch::kEpochInvalid;
   largest_storage_id_ = 0;
   storage_control_blocks_ = nullptr;
   storage_control_blocks_memory_.release_block();
 }

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storage::Metadata* foedus::snapshot::SnapshotMetadata::get_metadata ( storage::StorageId id )

inline

Definition at line 46 of file snapshot_metadata.hpp.

References foedus::storage::StorageControlBlock::meta_, and storage_control_blocks_.

Referenced by foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

                                                      {
     return &storage_control_blocks_[id].meta_;
   }

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const char* foedus::snapshot::SnapshotMetadata::get_tag_name ( ) const

inlineoverridevirtual

Returns an XML tag name for this object as a root element.

We might want to give a different name for same externalizable objects, so this is used only when it is the root element of xml.

Implements foedus::externalize::Externalizable.

Definition at line 52 of file snapshot_metadata.hpp.

52 { return "SnapshotMetadata"; }

ErrorStack foedus::snapshot::SnapshotMetadata::load ( tinyxml2::XMLElement * element )

overridevirtual

Reads the content of this object from the given XML element.

Parameters

[in] element the XML element that represents this object

Expect errors due to missing-elements, out-of-range values, etc.

Implements foedus::externalize::Externalizable.

Definition at line 42 of file snapshot_metadata.cpp.

References foedus::memory::AlignedMemory::alloc(), base_epoch_, CHECK_ERROR, clear(), EXTERNALIZE_LOAD_ELEMENT, foedus::memory::AlignedMemory::get_block(), foedus::memory::AlignedMemory::get_size(), id_, foedus::memory::AlignedMemory::kNumaAllocOnnode, foedus::kRetOk, foedus::soc::GlobalMemoryAnchors::kStorageMemorySize, largest_storage_id_, foedus::storage::MetadataSerializer::load_all_storages_from_xml(), storage_control_blocks_, storage_control_blocks_memory_, and valid_until_epoch_.

                                                              {
   clear();
   EXTERNALIZE_LOAD_ELEMENT(element, id_);
   EXTERNALIZE_LOAD_ELEMENT(element, base_epoch_);
   EXTERNALIZE_LOAD_ELEMENT(element, valid_until_epoch_);
   EXTERNALIZE_LOAD_ELEMENT(element, largest_storage_id_);
 
   uint64_t memory_size
     = static_cast<uint64_t>(largest_storage_id_ + 1) * soc::GlobalMemoryAnchors::kStorageMemorySize;
   storage_control_blocks_memory_.alloc(
     memory_size,
     1 << 12,
     memory::AlignedMemory::kNumaAllocOnnode,
     0);
   storage_control_blocks_ = reinterpret_cast<storage::StorageControlBlock*>(
     storage_control_blocks_memory_.get_block());
   std::memset(storage_control_blocks_, 0, storage_control_blocks_memory_.get_size());
 
   // <storages>
   tinyxml2::XMLElement* storages = element->FirstChildElement(kStoragesTagName);
   if (!storages) {
     // <storages> tag is missing. treat it as no storages. but weird!
     LOG(ERROR) << "WAIT, the snapshot metadata file doesn't have " << kStoragesTagName
       << " element? that's weird. It'll be treated as empty, but this shouldn't happen!";
   } else {
     CHECK_ERROR(storage::MetadataSerializer::load_all_storages_from_xml(
       largest_storage_id_,
       storages,
       storage_control_blocks_));
   }
   // </storages>
   return kRetOk;
 }

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ErrorStack foedus::snapshot::SnapshotMetadata::save ( tinyxml2::XMLElement * element ) const

overridevirtual

Writes the content of this object to the given XML element.

Parameters

[in] element the XML element that represents this object

Expect only out-of-memory error. We receive the XML element this object will represent, so this method does not determine the XML element name of itself. The parent object determines children's tag names because one parent object might have multiple child objects of the same type with different XML element name.

Implements foedus::externalize::Externalizable.

Definition at line 76 of file snapshot_metadata.cpp.

References base_epoch_, CHECK_ERROR, CHECK_OUTOFMEMORY, EXTERNALIZE_SAVE_ELEMENT, id_, foedus::externalize::Externalizable::insert_comment(), foedus::kRetOk, largest_storage_id_, foedus::storage::MetadataSerializer::save_all_storages_to_xml(), storage_control_blocks_, and valid_until_epoch_.

                                                                    {
   CHECK_ERROR(insert_comment(element, "Metadata of a snapshot"));
 
   EXTERNALIZE_SAVE_ELEMENT(element, id_, "Unique ID of this snapshot");
   EXTERNALIZE_SAVE_ELEMENT(element, base_epoch_,
     "This snapshot was taken based on another snapshot that is valid_until this epoch."
     " If this is the first snapshot, this value is 0.");
   EXTERNALIZE_SAVE_ELEMENT(element, valid_until_epoch_,
     "This snapshot contains all the logs until this epoch.");
   EXTERNALIZE_SAVE_ELEMENT(element, largest_storage_id_,
     "The largest StorageId we so far observed.");
 
   // <storages>
   tinyxml2::XMLElement* storages = element->GetDocument()->NewElement(kStoragesTagName);
   CHECK_OUTOFMEMORY(storages);
   element->InsertEndChild(storages);
   CHECK_ERROR(insert_comment(storages, "Metadata of all storages"));
   CHECK_ERROR(storage::MetadataSerializer::save_all_storages_to_xml(
     largest_storage_id_,
     storages,
     storage_control_blocks_));
   // </storages>
   return kRetOk;
 }

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Member Data Documentation

Epoch::EpochInteger foedus::snapshot::SnapshotMetadata::base_epoch_

Equivalent to Snapshot::base_epoch_.

Definition at line 59 of file snapshot_metadata.hpp.

Referenced by clear(), load(), save(), and foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

SnapshotId foedus::snapshot::SnapshotMetadata::id_

Equivalent to Snapshot::id_.

Definition at line 56 of file snapshot_metadata.hpp.

Referenced by clear(), load(), foedus::snapshot::SnapshotManagerPimpl::read_snapshot_metadata(), save(), and foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

storage::StorageId foedus::snapshot::SnapshotMetadata::largest_storage_id_

The largest StorageId we so far observed.

Definition at line 65 of file snapshot_metadata.hpp.

Referenced by clear(), foedus::storage::StorageManagerPimpl::clone_all_storage_metadata(), foedus::storage::StorageManagerPimpl::initialize_read_latest_snapshot(), load(), save(), and foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

storage::StorageControlBlock* foedus::snapshot::SnapshotMetadata::storage_control_blocks_

control block of all storages.

This is a copy of the shared memory, so no need to delete.

Definition at line 72 of file snapshot_metadata.hpp.

Referenced by clear(), foedus::storage::StorageManagerPimpl::clone_all_storage_metadata(), get_metadata(), foedus::storage::StorageManagerPimpl::initialize_read_latest_snapshot(), load(), save(), and foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

memory::AlignedMemory foedus::snapshot::SnapshotMetadata::storage_control_blocks_memory_

Memory backing storage_control_blocks_.

Definition at line 75 of file snapshot_metadata.hpp.

Referenced by clear(), foedus::storage::StorageManagerPimpl::clone_all_storage_metadata(), and load().

Epoch::EpochInteger foedus::snapshot::SnapshotMetadata::valid_until_epoch_

Equivalent to Snapshot::valid_until_epoch_.

Definition at line 62 of file snapshot_metadata.hpp.

Referenced by clear(), load(), save(), and foedus::snapshot::SnapshotManagerPimpl::snapshot_metadata().

The documentation for this struct was generated from the following files:

/home/shino/foedus_code/foedus-core/include/foedus/snapshot/snapshot_metadata.hpp
/home/shino/foedus_code/foedus-core/src/foedus/snapshot/snapshot_metadata.cpp

Detailed Description

Public Member Functions

Public Attributes

Additional Inherited Members

Member Function Documentation

Member Data Documentation