Many hyperlinks are disabled.
Use anonymous login
to enable hyperlinks.
Overview
Comment: | In vdbesort.c, rename vdbeSorterDoCompare() to vdbeMergeEngineCompare() and move it closer to the one place where it is called. Other minor comment changes. |
---|---|
Downloads: | Tarball | ZIP archive |
Timelines: | family | ancestors | descendants | both | threads |
Files: | files | file ages | folders |
SHA1: |
09d50d9f0fe7df26dadb0a332731683a |
User & Date: | drh 2014-07-28 18:57:40.217 |
Context
2014-07-28
| ||
19:58 | Rename vdbeIncrMergerInit() to vdbeMergeEngineInit() - a much more accurate name. (check-in: 5b084a2dd5 user: drh tags: threads) | |
18:57 | In vdbesort.c, rename vdbeSorterDoCompare() to vdbeMergeEngineCompare() and move it closer to the one place where it is called. Other minor comment changes. (check-in: 09d50d9f0f user: drh tags: threads) | |
17:18 | In vdbesort.c, rename all pointers to sqlite3_file objects "pFd" and use the name "pFile" only for pointers to SortFile objects. Other comment enhancements. (check-in: 518290a7fc user: drh tags: threads) | |
Changes
Changes to src/vdbesort.c.
︙ | ︙ | |||
605 606 607 608 609 610 611 | rc = sqlite3OsFetch(pFile->pFd, 0, (int)pFile->iEof, (void**)pp); testcase( rc!=SQLITE_OK ); } return rc; } /* | > | | 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 | rc = sqlite3OsFetch(pFile->pFd, 0, (int)pFile->iEof, (void**)pp); testcase( rc!=SQLITE_OK ); } return rc; } /* ** Attach PmaReader pReadr to file pFile (if it is not already attached to ** that file) and seek it to offset iOff within the file. Return SQLITE_OK ** if successful, or an SQLite error code if an error occurs. */ static int vdbePmaReaderSeek( SortSubtask *pTask, /* Task context */ PmaReader *pReadr, /* Reader whose cursor is to be moved */ SorterFile *pFile, /* Sorter file to read from */ i64 iOff /* Offset in pFile */ |
︙ | ︙ | |||
755 756 757 758 759 760 761 | UnpackedRecord *r2 = pTask->pUnpacked; if( pKey2 ){ sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2); } return sqlite3VdbeRecordCompare(nKey1, pKey1, r2, 0); } | < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < < | 756 757 758 759 760 761 762 763 764 765 766 767 768 769 | UnpackedRecord *r2 = pTask->pUnpacked; if( pKey2 ){ sqlite3VdbeRecordUnpack(pTask->pSorter->pKeyInfo, nKey2, pKey2, r2); } return sqlite3VdbeRecordCompare(nKey1, pKey1, r2, 0); } /* ** Initialize the temporary index cursor just opened as a sorter cursor. ** ** Usually, the sorter module uses the value of (pCsr->pKeyInfo->nField) ** to determine the number of fields that should be compared from the ** records being sorted. However, if the value passed as argument nField ** is non-zero and the sorter is able to guarantee a stable sort, nField |
︙ | ︙ | |||
1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 | */ static void vdbeIncrSetThreads(IncrMerger *pIncr){ pIncr->bUseThread = 1; pIncr->pTask->file2.iEof -= pIncr->mxSz; } #endif /* SQLITE_MAX_WORKER_THREADS>0 */ #define INCRINIT_NORMAL 0 #define INCRINIT_TASK 1 #define INCRINIT_ROOT 2 | > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > | | | | | > | | < | > > | 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 | */ static void vdbeIncrSetThreads(IncrMerger *pIncr){ pIncr->bUseThread = 1; pIncr->pTask->file2.iEof -= pIncr->mxSz; } #endif /* SQLITE_MAX_WORKER_THREADS>0 */ /* ** Recompute pMerger->aTree[iOut] by comparing the next keys on the ** two PmaReaders that feed that entry. Neither of the PmaReaders ** are advanced. This routine merely does the comparison. */ static void vdbeMergeEngineCompare( MergeEngine *pMerger, /* Merge engine containing PmaReaders to compare */ int iOut /* Store the result in pMerger->aTree[iOut] */ ){ int i1; int i2; int iRes; PmaReader *p1; PmaReader *p2; assert( iOut<pMerger->nTree && iOut>0 ); if( iOut>=(pMerger->nTree/2) ){ i1 = (iOut - pMerger->nTree/2) * 2; i2 = i1 + 1; }else{ i1 = pMerger->aTree[iOut*2]; i2 = pMerger->aTree[iOut*2+1]; } p1 = &pMerger->aReadr[i1]; p2 = &pMerger->aReadr[i2]; if( p1->pFd==0 ){ iRes = i2; }else if( p2->pFd==0 ){ iRes = i1; }else{ int res; assert( pMerger->pTask->pUnpacked!=0 ); /* from vdbeSortSubtaskMain() */ res = vdbeSorterCompare( pMerger->pTask, p1->aKey, p1->nKey, p2->aKey, p2->nKey ); if( res<=0 ){ iRes = i1; }else{ iRes = i2; } } pMerger->aTree[iOut] = iRes; } /* ** Allowed values for the eMode parameter to vdbeIncrMergerInit() ** and vdbePmaReaderIncrMergeInit(). */ #define INCRINIT_NORMAL 0 #define INCRINIT_TASK 1 #define INCRINIT_ROOT 2 /* Forward reference. ** The vdbeIncrMergeInit() and vdbePmaReaderIncrMergeInit() routines call each ** other (when building a merge tree). */ static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode); /* ** Initialize the MergeEngine object passed as the second argument. Once this ** function returns, the first key of merged data may be read from the ** MergeEngine object in the usual fashion. ** ** If argument eMode is INCRINIT_ROOT, then it is assumed that any IncrMerge ** objects attached to the PmaReader objects that the merger reads from have ** already been populated, but that they have not yet populated aFile[0] and ** set the PmaReader objects up to read from it. In this case all that is ** required is to call vdbePmaReaderNext() on each PmaReader to point it at ** its first key. ** ** Otherwise, if eMode is any value other than INCRINIT_ROOT, then use ** vdbePmaReaderIncrMergeInit() to initialize each PmaReader that feeds data ** to pMerger. ** ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. */ static int vdbeIncrMergerInit( SortSubtask *pTask, /* Thread that will run pMerger */ MergeEngine *pMerger, /* MergeEngine to initialize */ int eMode /* One of the INCRINIT_XXX constants */ ){ int rc = SQLITE_OK; /* Return code */ int i; /* For looping over PmaReader objects */ int nTree = pMerger->nTree; /* Verify that the MergeEngine is assigned to a single thread */ assert( pMerger->pTask==0 || pMerger->pTask==pTask ); pMerger->pTask = pTask; for(i=0; i<nTree; i++){ if( eMode==INCRINIT_ROOT ){ /* PmaReaders should be normally initialized in order, as if they are ** reading from the same temp file this makes for more linear file IO. ** However, in the INCRINIT_ROOT case, if PmaReader aReadr[nTask-1] is ** in use it will block the vdbePmaReaderNext() call while it uses ** the main thread to fill its buffer. So calling PmaReaderNext() ** on this PmaReader before any of the multi-threaded PmaReaders takes ** better advantage of multi-processor hardware. */ rc = vdbePmaReaderNext(&pMerger->aReadr[nTree-i-1]); }else{ rc = vdbePmaReaderIncrMergeInit(&pMerger->aReadr[i], INCRINIT_NORMAL); } if( rc!=SQLITE_OK ) return rc; } for(i=pMerger->nTree-1; i>0; i--){ vdbeMergeEngineCompare(pMerger, i); } return pTask->pUnpacked->errCode; } /* ** Initialize the IncrMerge field of a PmaReader. ** ** If the PmaReader passed as the first argument is not an incremental-reader ** (if pReadr->pIncr==0), then this function is a no-op. Otherwise, it serves ** to open and/or initialize the temp file related fields of the IncrMerge ** object at (pReadr->pIncr). ** ** If argument eMode is set to INCRINIT_NORMAL, then all PmaReaders ** in the sub-tree headed by pReadr are also initialized. Data is then loaded |
︙ | ︙ | |||
1946 1947 1948 1949 1950 1951 1952 | ** that pReadr->pIncr is a multi-threaded IncrMerge objects, and that all ** child-trees have already been initialized using IncrInit(INCRINIT_TASK). ** In this case vdbePmaReaderNext() is called on all child PmaReaders and ** the current PmaReader set to point to the first key in its range. ** ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. */ | | | | 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 | ** that pReadr->pIncr is a multi-threaded IncrMerge objects, and that all ** child-trees have already been initialized using IncrInit(INCRINIT_TASK). ** In this case vdbePmaReaderNext() is called on all child PmaReaders and ** the current PmaReader set to point to the first key in its range. ** ** SQLITE_OK is returned if successful, or an SQLite error code otherwise. */ static int vdbePmaReaderIncrMergeInit(PmaReader *pReadr, int eMode){ int rc = SQLITE_OK; IncrMerger *pIncr = pReadr->pIncr; if( pIncr ){ SortSubtask *pTask = pIncr->pTask; sqlite3 *db = pTask->pSorter->db; rc = vdbeIncrMergerInit(pTask, pIncr->pMerger, eMode); /* Set up the required files for pIncr. A multi-theaded IncrMerge object ** requires two temp files to itself, whereas a single-threaded object ** only requires a region of pTask->file2. */ if( rc==SQLITE_OK ){ int mxSz = pIncr->mxSz; #if SQLITE_MAX_WORKER_THREADS>0 |
︙ | ︙ | |||
2001 2002 2003 2004 2005 2006 2007 | } } return rc; } #if SQLITE_MAX_WORKER_THREADS>0 /* | | | > > | | 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 | } } return rc; } #if SQLITE_MAX_WORKER_THREADS>0 /* ** The main routine for vdbePmaReaderIncrMergeInit() operations run in ** background threads. */ static void *vdbePmaReaderBgInit(void *pCtx){ PmaReader *pReader = (PmaReader*)pCtx; void *pRet = SQLITE_INT_TO_PTR( vdbePmaReaderIncrMergeInit(pReader,INCRINIT_TASK) ); pReader->pIncr->pTask->bDone = 1; return pRet; } /* ** Use a background thread to invoke vdbePmaReaderIncrMergeInit(INCRINIT_TASK) ** on the the PmaReader object passed as the first argument. ** ** This call will initialize the various fields of the pReadr->pIncr ** structure and, if it is a multi-threaded IncrMerger, launch a ** background thread to populate aFile[1]. */ static int vdbePmaReaderBgIncrInit(PmaReader *pReadr){ |
︙ | ︙ | |||
2266 2267 2268 2269 2270 2271 2272 | } } for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){ PmaReader *p = &pMain->aReadr[iTask]; assert( p->pIncr==0 || p->pIncr->pTask==&pSorter->aTask[iTask] ); if( p->pIncr ){ if( iTask==pSorter->nTask-1 ){ | | | | | 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 | } } for(iTask=0; rc==SQLITE_OK && iTask<pSorter->nTask; iTask++){ PmaReader *p = &pMain->aReadr[iTask]; assert( p->pIncr==0 || p->pIncr->pTask==&pSorter->aTask[iTask] ); if( p->pIncr ){ if( iTask==pSorter->nTask-1 ){ rc = vdbePmaReaderIncrMergeInit(p, INCRINIT_TASK); }else{ rc = vdbePmaReaderBgIncrInit(p); } } } } pMain = 0; } if( rc==SQLITE_OK ){ rc = vdbePmaReaderIncrMergeInit(pReadr, INCRINIT_ROOT); } }else #endif { rc = vdbeIncrMergerInit(pTask0, pMain, INCRINIT_NORMAL); pSorter->pMerger = pMain; pMain = 0; } } if( rc!=SQLITE_OK ){ vdbeMergeEngineFree(pMain); |
︙ | ︙ |