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RSqliteDS.cxx
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1// Author: Jakob Blomer CERN 07/2018
2
3/*************************************************************************
4 * Copyright (C) 1995-2017, Rene Brun and Fons Rademakers. *
5 * All rights reserved. *
6 * *
7 * For the licensing terms see $ROOTSYS/LICENSE. *
8 * For the list of contributors see $ROOTSYS/README/CREDITS. *
9 *************************************************************************/
10
11// clang-format off
12/** \class ROOT::RDF::RSqliteDS
13 \ingroup dataframe
14 \brief RDataFrame data source class for reading SQlite files.
15*/
16
17// clang-format on
18
19#include <ROOT/RSqliteDS.hxx>
20#include <ROOT/RConfig.hxx>
21#include <ROOT/RDF/Utils.hxx>
22#include <ROOT/RMakeUnique.hxx>
23#include <ROOT/RRawFile.hxx>
24
25#include "TError.h"
26#include "TRandom.h"
27#include "TSystem.h"
28
29#include <algorithm>
30#include <cctype>
31#include <cerrno>
32#include <cstring> // for memcpy
33#include <ctime>
34#include <memory> // for placement new
35#include <stdexcept>
36#include <utility>
37
38#include <sqlite3.h>
39
40namespace {
41
42// In order to provide direct access to remote sqlite files through HTTP and HTTPS, this datasource provides a custom
43// "SQlite VFS module" that uses Davix for data access. The SQlite VFS modules are roughly what TSystem is
44// for ROOT -- an abstraction of the operating system interface.
45//
46// SQlite allows for registering custom VFS modules, which are a set of C callback functions that SQlite invokes when
47// it needs to read from a file, write to a file, etc. More information is available under https://sqlite.org/vfs.html
48//
49// In the context of a data source, SQlite will only ever call reading functions from the VFS module, the sqlite
50// files are not modified. Therefore, only a subset of the callback functions provide a non-trivial implementation.
51// The custom VFS module uses a RRawFile for the byte access, thereby it can access local and remote files.
52
53////////////////////////////////////////////////////////////////////////////
54/// SQlite VFS modules are identified by string names. The name has to be unique for the entire application.
55constexpr char const *gSQliteVfsName = "ROOT-Davix-readonly";
56
57////////////////////////////////////////////////////////////////////////////
58/// Holds the state of an open sqlite database. Objects of this struct are created in VfsRdOnlyOpen()
59/// and then passed by sqlite to the file I/O callbacks (read, close, etc.). This uses C style inheritance
60/// where the struct starts with a sqlite3_file member (base class) which is extended by members related to
61/// this particular VFS module. Every callback here thus casts the sqlite3_file input parameter to its "derived"
62/// type VfsRootFile.
63struct VfsRootFile {
64 VfsRootFile() = default;
65
66 sqlite3_file pFile;
67 std::unique_ptr<ROOT::Internal::RRawFile> fRawFile;
68};
69
70// The following callbacks implement the I/O operations of an open database
71
72////////////////////////////////////////////////////////////////////////////
73/// Releases the resources associated to a file opened with davix
74int VfsRdOnlyClose(sqlite3_file *pFile)
75{
76 VfsRootFile *p = reinterpret_cast<VfsRootFile *>(pFile);
77 // We can't use delete because the storage for p is managed by sqlite
78 p->~VfsRootFile();
79 return SQLITE_OK;
80}
81
82////////////////////////////////////////////////////////////////////////////
83/// Issues a byte range request for a chunk to the raw file
84int VfsRdOnlyRead(sqlite3_file *pFile, void *zBuf, int count, sqlite_int64 offset)
85{
86 VfsRootFile *p = reinterpret_cast<VfsRootFile *>(pFile);
87 auto nbytes = p->fRawFile->ReadAt(zBuf, count, offset);
88 return (nbytes != static_cast<unsigned int>(count)) ? SQLITE_IOERR : SQLITE_OK;
89}
90
91////////////////////////////////////////////////////////////////////////////
92/// We do not write to a database in the RDataSource and therefore can simply return an error for this callback
93int VfsRdOnlyWrite(sqlite3_file * /*pFile*/, const void * /*zBuf*/, int /*iAmt*/, sqlite_int64 /*iOfst*/)
94{
95 return SQLITE_OPEN_READONLY;
96}
97
98////////////////////////////////////////////////////////////////////////////
99/// We do not write to a database in the RDataSource and therefore can simply return an error for this callback
100int VfsRdOnlyTruncate(sqlite3_file * /*pFile*/, sqlite_int64 /*size*/)
101{
102 return SQLITE_OPEN_READONLY;
103}
104
105////////////////////////////////////////////////////////////////////////////
106/// As the database is read-only, syncing data to disc is a no-op and always succeeds
107int VfsRdOnlySync(sqlite3_file * /*pFile*/, int /*flags*/)
108{
109 return SQLITE_OK;
110}
111
112////////////////////////////////////////////////////////////////////////////
113/// Returns the cached file size
114int VfsRdOnlyFileSize(sqlite3_file *pFile, sqlite_int64 *pSize)
115{
116 VfsRootFile *p = reinterpret_cast<VfsRootFile *>(pFile);
117 *pSize = p->fRawFile->GetSize();
118 return SQLITE_OK;
119}
120
121////////////////////////////////////////////////////////////////////////////
122/// As the database is read-only, locks for concurrent access are no-ops and always succeeds
123int VfsRdOnlyLock(sqlite3_file * /*pFile*/, int /*level*/)
124{
125 return SQLITE_OK;
126}
127
128////////////////////////////////////////////////////////////////////////////
129/// As the database is read-only, locks for concurrent access are no-ops and always succeeds
130int VfsRdOnlyUnlock(sqlite3_file * /*pFile*/, int /*level*/)
131{
132 return SQLITE_OK;
133}
134
135////////////////////////////////////////////////////////////////////////////
136/// As the database is read-only, locks for concurrent access are no-ops and always succeeds
137int VfsRdOnlyCheckReservedLock(sqlite3_file * /*pFile*/, int *pResOut)
138{
139 *pResOut = 0;
140 return SQLITE_OK;
141}
142
143////////////////////////////////////////////////////////////////////////////
144/// As the database is read-only, we know there are no additional control files such as a database journal
145int VfsRdOnlyFileControl(sqlite3_file * /*p*/, int /*op*/, void * /*pArg*/)
146{
147 return SQLITE_NOTFOUND;
148}
149
150////////////////////////////////////////////////////////////////////////////
151/// The database device's sector size is only needed for writing
152int VfsRdOnlySectorSize(sqlite3_file * /*pFile*/)
153{
154 return SQLITE_OPEN_READONLY;
155}
156
157////////////////////////////////////////////////////////////////////////////
158/// The database device's properties are only needed for writing
159int VfsRdOnlyDeviceCharacteristics(sqlite3_file * /*pFile*/)
160{
161 return SQLITE_OPEN_READONLY;
162}
163
164////////////////////////////////////////////////////////////////////////////
165/// Fills a new VfsRootFile struct enclosing a Davix file
166int VfsRdOnlyOpen(sqlite3_vfs * /*vfs*/, const char *zName, sqlite3_file *pFile, int flags, int * /*pOutFlags*/)
167{
168 // Storage for the VfsRootFile structure has been already allocated by sqlite, so we use placement new
169 VfsRootFile *p = new (pFile) VfsRootFile();
170 p->pFile.pMethods = nullptr;
171
172 // This global struct contains the function pointers to all the callback operations that act on an open database.
173 // It is passed via the pFile struct back to sqlite so that it can call back to the functions provided above.
174 static const sqlite3_io_methods io_methods = {
175 1, // version
176 VfsRdOnlyClose,
177 VfsRdOnlyRead,
178 VfsRdOnlyWrite,
179 VfsRdOnlyTruncate,
180 VfsRdOnlySync,
181 VfsRdOnlyFileSize,
182 VfsRdOnlyLock,
183 VfsRdOnlyUnlock,
184 VfsRdOnlyCheckReservedLock,
185 VfsRdOnlyFileControl,
186 VfsRdOnlySectorSize,
187 VfsRdOnlyDeviceCharacteristics,
188 // Version 2 and later callbacks
189 nullptr, // xShmMap
190 nullptr, // xShmLock
191 nullptr, // xShmBarrier
192 nullptr, // xShmUnmap
193 nullptr, // xFetch
194 nullptr // xUnfetch
195 };
196
197 if (flags & (SQLITE_OPEN_READWRITE | SQLITE_OPEN_DELETEONCLOSE | SQLITE_OPEN_EXCLUSIVE))
198 return SQLITE_IOERR;
199
200 p->fRawFile = ROOT::Internal::RRawFile::Create(zName);
201 if (!p->fRawFile) {
202 ::Error("VfsRdOnlyOpen", "Cannot open %s\n", zName);
203 return SQLITE_IOERR;
204 }
205
206 if (!(p->fRawFile->GetFeatures() & ROOT::Internal::RRawFile::kFeatureHasSize)) {
207 ::Error("VfsRdOnlyOpen", "cannot determine file size of %s\n", zName);
208 return SQLITE_IOERR;
209 }
210
211 p->pFile.pMethods = &io_methods;
212 return SQLITE_OK;
213}
214
215// The following callbacks implement operating system specific functionality. In contrast to the previous callbacks,
216// there is no need to implement any customized logic for the following ones. An implementation has to be
217// provided nevertheless to have a fully functional VFS module.
218
219////////////////////////////////////////////////////////////////////////////
220/// This VFS module cannot remove files
221int VfsRdOnlyDelete(sqlite3_vfs * /*vfs*/, const char * /*zName*/, int /*syncDir*/)
222{
223 return SQLITE_IOERR_DELETE;
224}
225
226////////////////////////////////////////////////////////////////////////////
227/// Access control always allows read-only access to databases
228int VfsRdOnlyAccess(sqlite3_vfs * /*vfs*/, const char * /*zPath*/, int flags, int *pResOut)
229{
230 *pResOut = 0;
231 if (flags == SQLITE_ACCESS_READWRITE) {
232 return SQLITE_OPEN_READONLY;
233 }
234 return SQLITE_OK;
235}
236
237////////////////////////////////////////////////////////////////////////////
238/// No distinction between relative and full paths for URLs, returns the input path name
239int VfsRdOnlyFullPathname(sqlite3_vfs * /*vfs*/, const char *zPath, int nOut, char *zOut)
240{
241 zOut[nOut - 1] = '\0';
242 sqlite3_snprintf(nOut, zOut, "%s", zPath);
243 return SQLITE_OK;
244}
245
246////////////////////////////////////////////////////////////////////////////
247/// Let TRandom fill the buffer with random bytes
248int VfsRdOnlyRandomness(sqlite3_vfs * /*vfs*/, int nBuf, char *zBuf)
249{
250 for (int i = 0; i < nBuf; ++i) {
251 zBuf[i] = (char)gRandom->Integer(256);
252 }
253 return nBuf;
254}
255
256////////////////////////////////////////////////////////////////////////////
257/// Use ROOT's platform independent sleep wrapper
258int VfsRdOnlySleep(sqlite3_vfs * /*vfs*/, int microseconds)
259{
260 // Millisecond precision but sleep at least number of given microseconds as requested
261 gSystem->Sleep((microseconds + 1000 - 1) / 1000);
262 return microseconds;
263}
264
265////////////////////////////////////////////////////////////////////////////
266/// Use sqlite default implementation
267int VfsRdOnlyGetLastError(sqlite3_vfs * /*vfs*/, int /*not_used1*/, char * /*not_used2*/)
268{
269 return errno;
270}
271
272////////////////////////////////////////////////////////////////////////////
273/// Return UTC as being done in the sqlite unix VFS without gettimeofday()
274int VfsRdOnlyCurrentTimeInt64(sqlite3_vfs * /*vfs*/, sqlite3_int64 *piNow)
275{
276 static constexpr sqlite3_int64 unixEpoch = 24405875 * (sqlite3_int64)8640000;
277 time_t t;
278 time(&t);
279 *piNow = ((sqlite3_int64)t) * 1000 + unixEpoch;
280 return SQLITE_OK;
281}
282
283////////////////////////////////////////////////////////////////////////////
284/// Wrapper around VfsRdOnlyCurrentTimeInt64
285int VfsRdOnlyCurrentTime(sqlite3_vfs *vfs, double *prNow)
286{
287 sqlite3_int64 i = 0;
288 int rc = VfsRdOnlyCurrentTimeInt64(vfs, &i);
289 *prNow = i / 86400000.0;
290 return rc;
291}
292
293////////////////////////////////////////////////////////////////////////////
294/// A global struct of function pointers and details on the VfsRootFile class that together constitue a VFS module
295static struct sqlite3_vfs kSqlite3Vfs = {
296 1, // version of the struct
297 sizeof(VfsRootFile),
298 2000, // maximum URL length
299 nullptr, // pNext, maintained by sqlite
300 gSQliteVfsName,
301 nullptr, // pAppData
302 VfsRdOnlyOpen,
303 VfsRdOnlyDelete,
304 VfsRdOnlyAccess,
305 VfsRdOnlyFullPathname,
306 nullptr, // xDlOpen
307 nullptr, // xDlError
308 nullptr, // xDlSym
309 nullptr, // xDlClose
310 VfsRdOnlyRandomness,
311 VfsRdOnlySleep,
312 VfsRdOnlyCurrentTime,
313 VfsRdOnlyGetLastError,
314 VfsRdOnlyCurrentTimeInt64,
315 // Version 3 and later callbacks
316 nullptr, // xSetSystemCall
317 nullptr, // xGetSystemCall
318 nullptr, // xNextSystemCall
319};
320
321static bool RegisterSqliteVfs()
322{
323 int retval;
324 retval = sqlite3_vfs_register(&kSqlite3Vfs, false);
325 return (retval == SQLITE_OK);
326}
327
328} // anonymous namespace
329
330namespace ROOT {
331
332namespace RDF {
333
334namespace Internal {
335////////////////////////////////////////////////////////////////////////////
336/// The state of an open dataset in terms of the sqlite3 C library.
337struct RSqliteDSDataSet {
338 sqlite3 *fDb = nullptr;
339 sqlite3_stmt *fQuery = nullptr;
340};
341}
342
344 : fType(type), fIsActive(false), fInteger(0), fReal(0.0), fText(), fBlob(), fNull(nullptr)
345{
346 switch (type) {
347 case ETypes::kInteger: fPtr = &fInteger; break;
348 case ETypes::kReal: fPtr = &fReal; break;
349 case ETypes::kText: fPtr = &fText; break;
350 case ETypes::kBlob: fPtr = &fBlob; break;
351 case ETypes::kNull: fPtr = &fNull; break;
352 default: throw std::runtime_error("Internal error");
353 }
354}
355
356constexpr char const *RSqliteDS::fgTypeNames[];
357
358////////////////////////////////////////////////////////////////////////////
359/// \brief Build the dataframe
360/// \param[in] fileName The path to an sqlite3 file, will be opened read-only
361/// \param[in] query A valid sqlite3 SELECT query
362///
363/// The constructor opens the sqlite file, prepares the query engine and determines the column names and types.
364RSqliteDS::RSqliteDS(const std::string &fileName, const std::string &query)
365 : fDataSet(std::make_unique<Internal::RSqliteDSDataSet>()), fNSlots(0), fNRow(0)
366{
367 static bool hasSqliteVfs = RegisterSqliteVfs();
368 if (!hasSqliteVfs)
369 throw std::runtime_error("Cannot register SQlite VFS in RSqliteDS");
370
371 int retval;
372
373 retval = sqlite3_open_v2(fileName.c_str(), &fDataSet->fDb, SQLITE_OPEN_READONLY | SQLITE_OPEN_NOMUTEX,
374 gSQliteVfsName);
375 if (retval != SQLITE_OK)
376 SqliteError(retval);
377
378 retval = sqlite3_prepare_v2(fDataSet->fDb, query.c_str(), -1, &fDataSet->fQuery, nullptr);
379 if (retval != SQLITE_OK)
380 SqliteError(retval);
381
382 int colCount = sqlite3_column_count(fDataSet->fQuery);
383 retval = sqlite3_step(fDataSet->fQuery);
384 if ((retval != SQLITE_ROW) && (retval != SQLITE_DONE))
385 SqliteError(retval);
386
387 fValues.reserve(colCount);
388 for (int i = 0; i < colCount; ++i) {
389 fColumnNames.emplace_back(sqlite3_column_name(fDataSet->fQuery, i));
390 int type = SQLITE_NULL;
391 // Try first with the declared column type and then with the dynamic type
392 // for expressions
393 const char *declTypeCstr = sqlite3_column_decltype(fDataSet->fQuery, i);
394 if (declTypeCstr == nullptr) {
395 if (retval == SQLITE_ROW)
396 type = sqlite3_column_type(fDataSet->fQuery, i);
397 } else {
398 std::string declType(declTypeCstr);
399 std::transform(declType.begin(), declType.end(), declType.begin(), ::toupper);
400 if (declType == "INTEGER")
401 type = SQLITE_INTEGER;
402 else if (declType == "FLOAT")
403 type = SQLITE_FLOAT;
404 else if (declType == "TEXT")
405 type = SQLITE_TEXT;
406 else if (declType == "BLOB")
407 type = SQLITE_BLOB;
408 else
409 throw std::runtime_error("Unexpected column decl type");
410 }
411
412 switch (type) {
413 case SQLITE_INTEGER:
415 fValues.emplace_back(ETypes::kInteger);
416 break;
417 case SQLITE_FLOAT:
418 fColumnTypes.push_back(ETypes::kReal);
419 fValues.emplace_back(ETypes::kReal);
420 break;
421 case SQLITE_TEXT:
422 fColumnTypes.push_back(ETypes::kText);
423 fValues.emplace_back(ETypes::kText);
424 break;
425 case SQLITE_BLOB:
426 fColumnTypes.push_back(ETypes::kBlob);
427 fValues.emplace_back(ETypes::kBlob);
428 break;
429 case SQLITE_NULL:
430 // TODO: Null values in first rows are not well handled
431 fColumnTypes.push_back(ETypes::kNull);
432 fValues.emplace_back(ETypes::kNull);
433 break;
434 default: throw std::runtime_error("Unhandled data type");
435 }
436 }
437}
438
439////////////////////////////////////////////////////////////////////////////
440/// Frees the sqlite resources and closes the file.
442{
443 // sqlite3_finalize returns the error code of the most recent operation on fQuery.
444 sqlite3_finalize(fDataSet->fQuery);
445 // Closing can possibly fail with SQLITE_BUSY, in which case resources are leaked. This should not happen
446 // the way it is used in this class because we cleanup the prepared statement before.
447 sqlite3_close_v2(fDataSet->fDb);
448}
449
450////////////////////////////////////////////////////////////////////////////
451/// Returns the SELECT queries names. The column names have been cached in the constructor.
452/// For expressions, the column name is the string of the expression unless the query defines a column name with as
453/// like in "SELECT 1 + 1 as mycolumn FROM table"
454const std::vector<std::string> &RSqliteDS::GetColumnNames() const
455{
456 return fColumnNames;
457}
458
459////////////////////////////////////////////////////////////////////////////
460/// Activates the given column's result value.
462{
463 const auto index = std::distance(fColumnNames.begin(), std::find(fColumnNames.begin(), fColumnNames.end(), name));
464 const auto type = fColumnTypes[index];
465
466 if ((type == ETypes::kInteger && typeid(Long64_t) != ti) || (type == ETypes::kReal && typeid(double) != ti) ||
467 (type == ETypes::kText && typeid(std::string) != ti) ||
468 (type == ETypes::kBlob && typeid(std::vector<unsigned char>) != ti) ||
469 (type == ETypes::kNull && typeid(void *) != ti)) {
470 std::string errmsg = "The type selected for column \"";
471 errmsg += name;
472 errmsg += "\" does not correspond to column type, which is ";
473 errmsg += GetTypeName(name);
474 throw std::runtime_error(errmsg);
475 }
476
477 fValues[index].fIsActive = true;
478 return std::vector<void *>{fNSlots, &fValues[index].fPtr};
479}
480
481////////////////////////////////////////////////////////////////////////////
482/// Returns a range of size 1 as long as more rows are available in the SQL result set.
483/// This inherently serialized the RDF independent of the number of slots.
484std::vector<std::pair<ULong64_t, ULong64_t>> RSqliteDS::GetEntryRanges()
485{
486 std::vector<std::pair<ULong64_t, ULong64_t>> entryRanges;
487 int retval = sqlite3_step(fDataSet->fQuery);
488 switch (retval) {
489 case SQLITE_DONE: return entryRanges;
490 case SQLITE_ROW:
491 entryRanges.emplace_back(fNRow, fNRow + 1);
492 fNRow++;
493 return entryRanges;
494 default:
495 SqliteError(retval);
496 // Never here
497 abort();
498 }
499}
500
501////////////////////////////////////////////////////////////////////////////
502/// Returns the C++ type for a given column name, implemented as a linear search through all the columns.
503std::string RSqliteDS::GetTypeName(std::string_view colName) const
504{
505 unsigned N = fColumnNames.size();
506
507 for (unsigned i = 0; i < N; ++i) {
508 if (colName == fColumnNames[i]) {
509 return fgTypeNames[static_cast<int>(fColumnTypes[i])];
510 }
511 }
512 throw std::runtime_error("Unknown column: " + std::string(colName));
513}
514
515////////////////////////////////////////////////////////////////////////////
516/// A linear search through the columns for the given name
518{
519 return std::find(fColumnNames.begin(), fColumnNames.end(), colName) != fColumnNames.end();
520}
521
522////////////////////////////////////////////////////////////////////////////
523/// Resets the SQlite query engine at the beginning of the event loop.
525{
526 fNRow = 0;
527 int retval = sqlite3_reset(fDataSet->fQuery);
528 if (retval != SQLITE_OK)
529 throw std::runtime_error("SQlite error, reset");
530}
531
533{
534 return "RSqliteDS";
535}
536
537////////////////////////////////////////////////////////////////////////////////////////////////
538/// \brief Factory method to create a SQlite RDataFrame.
539/// \param[in] fileName Path of the sqlite file.
540/// \param[in] query SQL query that defines the data set.
542{
543 ROOT::RDataFrame rdf(std::make_unique<RSqliteDS>(std::string(fileName), std::string(query)));
544 return rdf;
545}
546
547////////////////////////////////////////////////////////////////////////////
548/// Stores the result of the current active sqlite query row as a C++ value.
549bool RSqliteDS::SetEntry(unsigned int /* slot */, ULong64_t entry)
550{
551 R__ASSERT(entry + 1 == fNRow);
552 unsigned N = fValues.size();
553 for (unsigned i = 0; i < N; ++i) {
554 if (!fValues[i].fIsActive)
555 continue;
556
557 int nbytes;
558 switch (fValues[i].fType) {
559 case ETypes::kInteger: fValues[i].fInteger = sqlite3_column_int64(fDataSet->fQuery, i); break;
560 case ETypes::kReal: fValues[i].fReal = sqlite3_column_double(fDataSet->fQuery, i); break;
561 case ETypes::kText:
562 nbytes = sqlite3_column_bytes(fDataSet->fQuery, i);
563 if (nbytes == 0) {
564 fValues[i].fText = "";
565 } else {
566 fValues[i].fText = reinterpret_cast<const char *>(sqlite3_column_text(fDataSet->fQuery, i));
567 }
568 break;
569 case ETypes::kBlob:
570 nbytes = sqlite3_column_bytes(fDataSet->fQuery, i);
571 fValues[i].fBlob.resize(nbytes);
572 if (nbytes > 0) {
573 std::memcpy(fValues[i].fBlob.data(), sqlite3_column_blob(fDataSet->fQuery, i), nbytes);
574 }
575 break;
576 case ETypes::kNull: break;
577 default: throw std::runtime_error("Unhandled column type");
578 }
579 }
580 return true;
581}
582
583////////////////////////////////////////////////////////////////////////////////////////////////
584/// Almost a no-op, many slots can in fact reduce the performance due to thread synchronization.
585void RSqliteDS::SetNSlots(unsigned int nSlots)
586{
587 if (nSlots > 1) {
588 ::Warning("SetNSlots", "Currently the SQlite data source faces performance degradation in multi-threaded mode. "
589 "Consider turning off IMT.");
590 }
591 fNSlots = nSlots;
592}
593
594////////////////////////////////////////////////////////////////////////////////////////////////
595/// Helper function to throw an exception if there is a fatal sqlite error, e.g. an I/O error.
596void RSqliteDS::SqliteError(int errcode)
597{
598 std::string errmsg = "SQlite error: ";
599 errmsg += sqlite3_errstr(errcode);
600 throw std::runtime_error(errmsg);
601}
602
603} // namespace RDF
604
605} // namespace ROOT
long long Long64_t
Definition: RtypesCore.h:71
unsigned long long ULong64_t
Definition: RtypesCore.h:72
#define R__ASSERT(e)
Definition: TError.h:96
void Error(const char *location, const char *msgfmt,...)
void Warning(const char *location, const char *msgfmt,...)
#define N
char name[80]
Definition: TGX11.cxx:109
int type
Definition: TGX11.cxx:120
R__EXTERN TRandom * gRandom
Definition: TRandom.h:62
R__EXTERN TSystem * gSystem
Definition: TSystem.h:556
static std::unique_ptr< RRawFile > Create(std::string_view url, ROptions options=ROptions())
Factory method that returns a suitable concrete implementation according to the transport in the url.
Definition: RRawFile.cxx:73
static constexpr int kFeatureHasSize
GetSize() does not return kUnknownFileSize.
Definition: RRawFile.hxx:49
std::vector< void * > Record_t
void SetNSlots(unsigned int nSlots) final
Almost a no-op, many slots can in fact reduce the performance due to thread synchronization.
Definition: RSqliteDS.cxx:585
static constexpr char const * fgTypeNames[]
Corresponds to the types defined in ETypes.
Definition: RSqliteDS.hxx:91
std::string GetLabel() final
Return a string representation of the datasource type.
Definition: RSqliteDS.cxx:532
void Initialise() final
Resets the SQlite query engine at the beginning of the event loop.
Definition: RSqliteDS.cxx:524
unsigned int fNSlots
Definition: RSqliteDS.hxx:82
std::vector< std::string > fColumnNames
Definition: RSqliteDS.hxx:84
~RSqliteDS()
Frees the sqlite resources and closes the file.
Definition: RSqliteDS.cxx:441
bool HasColumn(std::string_view colName) const final
A linear search through the columns for the given name.
Definition: RSqliteDS.cxx:517
std::vector< ETypes > fColumnTypes
Definition: RSqliteDS.hxx:85
std::string GetTypeName(std::string_view colName) const final
Returns the C++ type for a given column name, implemented as a linear search through all the columns.
Definition: RSqliteDS.cxx:503
ETypes
All the types known to SQlite. Changes require changing fgTypeNames, too.
Definition: RSqliteDS.hxx:56
Record_t GetColumnReadersImpl(std::string_view name, const std::type_info &) final
Activates the given column's result value.
Definition: RSqliteDS.cxx:461
RSqliteDS(const std::string &fileName, const std::string &query)
Build the dataframe.
Definition: RSqliteDS.cxx:364
std::unique_ptr< Internal::RSqliteDSDataSet > fDataSet
Definition: RSqliteDS.hxx:81
std::vector< std::pair< ULong64_t, ULong64_t > > GetEntryRanges() final
Returns a range of size 1 as long as more rows are available in the SQL result set.
Definition: RSqliteDS.cxx:484
const std::vector< std::string > & GetColumnNames() const final
Returns the SELECT queries names.
Definition: RSqliteDS.cxx:454
bool SetEntry(unsigned int slot, ULong64_t entry) final
Stores the result of the current active sqlite query row as a C++ value.
Definition: RSqliteDS.cxx:549
void SqliteError(int errcode)
Helper function to throw an exception if there is a fatal sqlite error, e.g. an I/O error.
Definition: RSqliteDS.cxx:596
std::vector< Value_t > fValues
The data source is inherently single-threaded and returns only one row at a time. This vector holds t...
Definition: RSqliteDS.hxx:87
ROOT's RDataFrame offers a high level interface for analyses of data stored in TTrees,...
Definition: RDataFrame.hxx:42
virtual UInt_t Integer(UInt_t imax)
Returns a random integer uniformly distributed on the interval [ 0, imax-1 ].
Definition: TRandom.cxx:349
virtual void Sleep(UInt_t milliSec)
Sleep milliSec milli seconds.
Definition: TSystem.cxx:435
basic_string_view< char > string_view
RDataFrame MakeSqliteDataFrame(std::string_view fileName, std::string_view query)
Factory method to create a SQlite RDataFrame.
Definition: RSqliteDS.cxx:541
tbb::task_arena is an alias of tbb::interface7::task_arena, which doesn't allow to forward declare tb...
Definition: StringConv.hxx:21
void * fPtr
Points to one of the values; an address to this pointer is returned by GetColumnReadersImpl.
Definition: RSqliteDS.hxx:76
std::vector< unsigned char > fBlob
Definition: RSqliteDS.hxx:74