Write RNTuple data blocks in a TFile or a bare file container.
The writer can create a new TFile container for an RNTuple or add an RNTuple to an existing TFile. Creating a single RNTuple in a new TFile container can be done with a C file stream without a TFile class. Updating an existing TFile requires a proper TFile object. Also, writing a remote file requires a proper TFile object. A stand-alone version of RNTuple can remove the TFile based writer.
Definition at line 110 of file RMiniFile.hxx.
Classes | |
struct | RFileProper |
struct | RFileSimple |
Public Types | |
enum class | EContainerFormat { kTFile , kBare } |
For testing purposes, RNTuple data can be written into a bare file container instead of a ROOT file. More... | |
Public Member Functions | |
RNTupleFileWriter (const RNTupleFileWriter &other)=delete | |
RNTupleFileWriter (RNTupleFileWriter &&other)=delete | |
~RNTupleFileWriter () | |
void | Commit (int compression=RCompressionSetting::EDefaults::kUseGeneralPurpose) |
Writes the RNTuple key to the file so that the header and footer keys can be found. | |
RNTupleFileWriter & | operator= (const RNTupleFileWriter &other)=delete |
RNTupleFileWriter & | operator= (RNTupleFileWriter &&other)=delete |
std::uint64_t | ReserveBlob (size_t nbytes, size_t len, unsigned char keyBuffer[kBlobKeyLen]=nullptr) |
Reserves a new record as an RBlob key in the file. | |
void | Seek (std::uint64_t offset) |
Seek a simple writer to offset. | |
void | UpdateStreamerInfos (const RNTupleSerializer::StreamerInfoMap_t &streamerInfos) |
Ensures that the streamer info records passed as argument are written to the file. | |
std::uint64_t | WriteBlob (const void *data, size_t nbytes, size_t len) |
Writes a new record as an RBlob key into the file. | |
void | WriteIntoReservedBlob (const void *buffer, size_t nbytes, std::int64_t offset) |
Write into a reserved record; the caller is responsible for making sure that the written byte range is in the previously reserved key. | |
std::uint64_t | WriteNTupleFooter (const void *data, size_t nbytes, size_t lenFooter) |
Writes the compressed footer and registeres its location; lenFooter is the size of the uncompressed footer. | |
std::uint64_t | WriteNTupleHeader (const void *data, size_t nbytes, size_t lenHeader) |
Writes the compressed header and registeres its location; lenHeader is the size of the uncompressed header. | |
Static Public Member Functions | |
static std::unique_ptr< RNTupleFileWriter > | Append (std::string_view ntupleName, TDirectory &fileOrDirectory, std::uint64_t maxKeySize) |
The directory parameter can also be a TFile object (TFile inherits from TDirectory). | |
static void | PrepareBlobKey (std::int64_t offset, size_t nbytes, size_t len, unsigned char buffer[kBlobKeyLen]) |
Prepares buffer for a new record as an RBlob key at offset. | |
static std::unique_ptr< RNTupleFileWriter > | Recreate (std::string_view ntupleName, std::string_view path, EContainerFormat containerFormat, const ROOT::RNTupleWriteOptions &options) |
Create or truncate the local file given by path with the new empty RNTuple identified by ntupleName. | |
Static Public Attributes | |
static constexpr std::size_t | kBlobKeyLen = 42 |
The key length of a blob. It is always a big key (version > 1000) with class name RBlob. | |
Private Member Functions | |
RNTupleFileWriter (std::string_view name, std::uint64_t maxKeySize) | |
void | WriteBareFileSkeleton (int defaultCompression) |
For a bare file, which is necessarily written by a C file stream, write file header. | |
void | WriteTFileFreeList () |
Last record in the file. | |
void | WriteTFileKeysList (std::uint64_t anchorSize) |
Write the TList with the RNTuple key. | |
std::uint64_t | WriteTFileNTupleKey (int compression) |
The only key that will be visible in file->ls() Returns the size on disk of the anchor object. | |
void | WriteTFileSkeleton (int defaultCompression) |
For a TFile container written by a C file stream, write the header and TFile object. | |
void | WriteTFileStreamerInfo (int compression) |
Write the compressed streamer info record with the description of the RNTuple class. | |
Private Attributes | |
std::string | fFileName |
The file name without parent directory; only required when writing with a C file stream. | |
RFileProper | fFileProper |
For updating existing files and for storing more than just an RNTuple in the file. | |
RFileSimple | fFileSimple |
For simple use cases, survives without libRIO dependency. | |
bool | fIsBare = false |
A simple file can either be written as TFile container or as NTuple bare file. | |
RNTuple | fNTupleAnchor |
Header and footer location of the ntuple, written on Commit() | |
std::string | fNTupleName |
The identifier of the RNTuple; A single writer object can only write a single RNTuple but multiple writers can operate on the same file if (and only if) they use a proper TFile object for writing. | |
RNTupleSerializer::StreamerInfoMap_t | fStreamerInfoMap |
Set of streamer info records that should be written to the file. | |
#include <ROOT/RMiniFile.hxx>
For testing purposes, RNTuple data can be written into a bare file container instead of a ROOT file.
Enumerator | |
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kTFile | |
kBare |
Definition at line 215 of file RMiniFile.hxx.
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explicitprivate |
Definition at line 1117 of file RMiniFile.cxx.
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ROOT::Experimental::Internal::RNTupleFileWriter::~RNTupleFileWriter | ( | ) |
Definition at line 1126 of file RMiniFile.cxx.
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The directory parameter can also be a TFile object (TFile inherits from TDirectory).
Definition at line 1180 of file RMiniFile.cxx.
void ROOT::Experimental::Internal::RNTupleFileWriter::Commit | ( | int | compression = RCompressionSetting::EDefaults::kUseGeneralPurpose | ) |
Writes the RNTuple key to the file so that the header and footer keys can be found.
Definition at line 1209 of file RMiniFile.cxx.
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delete |
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delete |
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Prepares buffer for a new record as an RBlob key at offset.
Prepare a blob key in the provided buffer, which must provide space for kBlobKeyLen bytes.
(Note that the array type is purely documentation, the argument is actually just a pointer.)
Note that the array type is purely documentation, the argument is actually just a pointer.
Definition at line 875 of file RMiniFile.cxx.
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static |
Create or truncate the local file given by path with the new empty RNTuple identified by ntupleName.
Uses a C stream for writing
Definition at line 1129 of file RMiniFile.cxx.
std::uint64_t ROOT::Experimental::Internal::RNTupleFileWriter::ReserveBlob | ( | size_t | nbytes, |
size_t | len, | ||
unsigned char | keyBuffer[kBlobKeyLen] = nullptr ) |
Reserves a new record as an RBlob key in the file.
If keyBuffer is specified, it must be written before the returned offset. (Note that the array type is purely documentation, the argument is actually just a pointer.)
Definition at line 1319 of file RMiniFile.cxx.
void ROOT::Experimental::Internal::RNTupleFileWriter::Seek | ( | std::uint64_t | offset | ) |
Seek a simple writer to offset.
Note that previous data is not flushed immediately, but only by the next write (if necessary).
Definition at line 1193 of file RMiniFile.cxx.
void ROOT::Experimental::Internal::RNTupleFileWriter::UpdateStreamerInfos | ( | const RNTupleSerializer::StreamerInfoMap_t & | streamerInfos | ) |
Ensures that the streamer info records passed as argument are written to the file.
Definition at line 1203 of file RMiniFile.cxx.
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private |
For a bare file, which is necessarily written by a C file stream, write file header.
Definition at line 1369 of file RMiniFile.cxx.
std::uint64_t ROOT::Experimental::Internal::RNTupleFileWriter::WriteBlob | ( | const void * | data, |
size_t | nbytes, | ||
size_t | len ) |
Writes a new record as an RBlob key into the file.
Definition at line 1254 of file RMiniFile.cxx.
void ROOT::Experimental::Internal::RNTupleFileWriter::WriteIntoReservedBlob | ( | const void * | buffer, |
size_t | nbytes, | ||
std::int64_t | offset ) |
Write into a reserved record; the caller is responsible for making sure that the written byte range is in the previously reserved key.
Definition at line 1339 of file RMiniFile.cxx.
std::uint64_t ROOT::Experimental::Internal::RNTupleFileWriter::WriteNTupleFooter | ( | const void * | data, |
size_t | nbytes, | ||
size_t | lenFooter ) |
Writes the compressed footer and registeres its location; lenFooter is the size of the uncompressed footer.
Definition at line 1360 of file RMiniFile.cxx.
std::uint64_t ROOT::Experimental::Internal::RNTupleFileWriter::WriteNTupleHeader | ( | const void * | data, |
size_t | nbytes, | ||
size_t | lenHeader ) |
Writes the compressed header and registeres its location; lenHeader is the size of the uncompressed header.
Definition at line 1350 of file RMiniFile.cxx.
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Last record in the file.
Definition at line 1458 of file RMiniFile.cxx.
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Write the TList with the RNTuple key.
Definition at line 1429 of file RMiniFile.cxx.
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The only key that will be visible in file->ls() Returns the size on disk of the anchor object.
Definition at line 1475 of file RMiniFile.cxx.
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For a TFile container written by a C file stream, write the header and TFile object.
Definition at line 1500 of file RMiniFile.cxx.
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Write the compressed streamer info record with the description of the RNTuple class.
Definition at line 1386 of file RMiniFile.cxx.
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The file name without parent directory; only required when writing with a C file stream.
Definition at line 190 of file RMiniFile.hxx.
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For updating existing files and for storing more than just an RNTuple in the file.
Definition at line 181 of file RMiniFile.hxx.
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private |
For simple use cases, survives without libRIO dependency.
Definition at line 183 of file RMiniFile.hxx.
A simple file can either be written as TFile container or as NTuple bare file.
Definition at line 185 of file RMiniFile.hxx.
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Header and footer location of the ntuple, written on Commit()
Definition at line 192 of file RMiniFile.hxx.
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The identifier of the RNTuple; A single writer object can only write a single RNTuple but multiple writers can operate on the same file if (and only if) they use a proper TFile object for writing.
Definition at line 188 of file RMiniFile.hxx.
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Set of streamer info records that should be written to the file.
The RNTuple class description is always present.
Definition at line 195 of file RMiniFile.hxx.
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staticconstexpr |
The key length of a blob. It is always a big key (version > 1000) with class name RBlob.
Definition at line 113 of file RMiniFile.hxx.