diff options
Diffstat (limited to 'chromium/third_party/sqlite/sqlite-src-3240000/ext/misc/csv.c')
| -rw-r--r-- | chromium/third_party/sqlite/sqlite-src-3240000/ext/misc/csv.c | 887 |
1 files changed, 0 insertions, 887 deletions
diff --git a/chromium/third_party/sqlite/sqlite-src-3240000/ext/misc/csv.c b/chromium/third_party/sqlite/sqlite-src-3240000/ext/misc/csv.c deleted file mode 100644 index ec90f96f28a..00000000000 --- a/chromium/third_party/sqlite/sqlite-src-3240000/ext/misc/csv.c +++ /dev/null @@ -1,887 +0,0 @@ -/* -** 2016-05-28 -** -** The author disclaims copyright to this source code. In place of -** a legal notice, here is a blessing: -** -** May you do good and not evil. -** May you find forgiveness for yourself and forgive others. -** May you share freely, never taking more than you give. -** -****************************************************************************** -** -** This file contains the implementation of an SQLite virtual table for -** reading CSV files. -** -** Usage: -** -** .load ./csv -** CREATE VIRTUAL TABLE temp.csv USING csv(filename=FILENAME); -** SELECT * FROM csv; -** -** The columns are named "c1", "c2", "c3", ... by default. But the -** application can define its own CREATE TABLE statement as an additional -** parameter. For example: -** -** CREATE VIRTUAL TABLE temp.csv2 USING csv( -** filename = "../http.log", -** schema = "CREATE TABLE x(date,ipaddr,url,referrer,userAgent)" -** ); -** -** Instead of specifying a file, the text of the CSV can be loaded using -** the data= parameter. -** -** If the columns=N parameter is supplied, then the CSV file is assumed to have -** N columns. If the columns parameter is omitted, the CSV file is opened -** as soon as the virtual table is constructed and the first row of the CSV -** is read in order to count the tables. -** -** Some extra debugging features (used for testing virtual tables) are available -** if this module is compiled with -DSQLITE_TEST. -*/ -#include <sqlite3ext.h> -SQLITE_EXTENSION_INIT1 -#include <string.h> -#include <stdlib.h> -#include <assert.h> -#include <stdarg.h> -#include <ctype.h> -#include <stdio.h> - -#ifndef SQLITE_OMIT_VIRTUALTABLE - -/* -** A macro to hint to the compiler that a function should not be -** inlined. -*/ -#if defined(__GNUC__) -# define CSV_NOINLINE __attribute__((noinline)) -#elif defined(_MSC_VER) && _MSC_VER>=1310 -# define CSV_NOINLINE __declspec(noinline) -#else -# define CSV_NOINLINE -#endif - - -/* Max size of the error message in a CsvReader */ -#define CSV_MXERR 200 - -/* Size of the CsvReader input buffer */ -#define CSV_INBUFSZ 1024 - -/* A context object used when read a CSV file. */ -typedef struct CsvReader CsvReader; -struct CsvReader { - FILE *in; /* Read the CSV text from this input stream */ - char *z; /* Accumulated text for a field */ - int n; /* Number of bytes in z */ - int nAlloc; /* Space allocated for z[] */ - int nLine; /* Current line number */ - int bNotFirst; /* True if prior text has been seen */ - int cTerm; /* Character that terminated the most recent field */ - size_t iIn; /* Next unread character in the input buffer */ - size_t nIn; /* Number of characters in the input buffer */ - char *zIn; /* The input buffer */ - char zErr[CSV_MXERR]; /* Error message */ -}; - -/* Initialize a CsvReader object */ -static void csv_reader_init(CsvReader *p){ - p->in = 0; - p->z = 0; - p->n = 0; - p->nAlloc = 0; - p->nLine = 0; - p->bNotFirst = 0; - p->nIn = 0; - p->zIn = 0; - p->zErr[0] = 0; -} - -/* Close and reset a CsvReader object */ -static void csv_reader_reset(CsvReader *p){ - if( p->in ){ - fclose(p->in); - sqlite3_free(p->zIn); - } - sqlite3_free(p->z); - csv_reader_init(p); -} - -/* Report an error on a CsvReader */ -static void csv_errmsg(CsvReader *p, const char *zFormat, ...){ - va_list ap; - va_start(ap, zFormat); - sqlite3_vsnprintf(CSV_MXERR, p->zErr, zFormat, ap); - va_end(ap); -} - -/* Open the file associated with a CsvReader -** Return the number of errors. -*/ -static int csv_reader_open( - CsvReader *p, /* The reader to open */ - const char *zFilename, /* Read from this filename */ - const char *zData /* ... or use this data */ -){ - if( zFilename ){ - p->zIn = sqlite3_malloc( CSV_INBUFSZ ); - if( p->zIn==0 ){ - csv_errmsg(p, "out of memory"); - return 1; - } - p->in = fopen(zFilename, "rb"); - if( p->in==0 ){ - sqlite3_free(p->zIn); - csv_reader_reset(p); - csv_errmsg(p, "cannot open '%s' for reading", zFilename); - return 1; - } - }else{ - assert( p->in==0 ); - p->zIn = (char*)zData; - p->nIn = strlen(zData); - } - return 0; -} - -/* The input buffer has overflowed. Refill the input buffer, then -** return the next character -*/ -static CSV_NOINLINE int csv_getc_refill(CsvReader *p){ - size_t got; - - assert( p->iIn>=p->nIn ); /* Only called on an empty input buffer */ - assert( p->in!=0 ); /* Only called if reading froma file */ - - got = fread(p->zIn, 1, CSV_INBUFSZ, p->in); - if( got==0 ) return EOF; - p->nIn = got; - p->iIn = 1; - return p->zIn[0]; -} - -/* Return the next character of input. Return EOF at end of input. */ -static int csv_getc(CsvReader *p){ - if( p->iIn >= p->nIn ){ - if( p->in!=0 ) return csv_getc_refill(p); - return EOF; - } - return ((unsigned char*)p->zIn)[p->iIn++]; -} - -/* Increase the size of p->z and append character c to the end. -** Return 0 on success and non-zero if there is an OOM error */ -static CSV_NOINLINE int csv_resize_and_append(CsvReader *p, char c){ - char *zNew; - int nNew = p->nAlloc*2 + 100; - zNew = sqlite3_realloc64(p->z, nNew); - if( zNew ){ - p->z = zNew; - p->nAlloc = nNew; - p->z[p->n++] = c; - return 0; - }else{ - csv_errmsg(p, "out of memory"); - return 1; - } -} - -/* Append a single character to the CsvReader.z[] array. -** Return 0 on success and non-zero if there is an OOM error */ -static int csv_append(CsvReader *p, char c){ - if( p->n>=p->nAlloc-1 ) return csv_resize_and_append(p, c); - p->z[p->n++] = c; - return 0; -} - -/* Read a single field of CSV text. Compatible with rfc4180 and extended -** with the option of having a separator other than ",". -** -** + Input comes from p->in. -** + Store results in p->z of length p->n. Space to hold p->z comes -** from sqlite3_malloc64(). -** + Keep track of the line number in p->nLine. -** + Store the character that terminates the field in p->cTerm. Store -** EOF on end-of-file. -** -** Return 0 at EOF or on OOM. On EOF, the p->cTerm character will have -** been set to EOF. -*/ -static char *csv_read_one_field(CsvReader *p){ - int c; - p->n = 0; - c = csv_getc(p); - if( c==EOF ){ - p->cTerm = EOF; - return 0; - } - if( c=='"' ){ - int pc, ppc; - int startLine = p->nLine; - pc = ppc = 0; - while( 1 ){ - c = csv_getc(p); - if( c<='"' || pc=='"' ){ - if( c=='\n' ) p->nLine++; - if( c=='"' ){ - if( pc=='"' ){ - pc = 0; - continue; - } - } - if( (c==',' && pc=='"') - || (c=='\n' && pc=='"') - || (c=='\n' && pc=='\r' && ppc=='"') - || (c==EOF && pc=='"') - ){ - do{ p->n--; }while( p->z[p->n]!='"' ); - p->cTerm = (char)c; - break; - } - if( pc=='"' && c!='\r' ){ - csv_errmsg(p, "line %d: unescaped %c character", p->nLine, '"'); - break; - } - if( c==EOF ){ - csv_errmsg(p, "line %d: unterminated %c-quoted field\n", - startLine, '"'); - p->cTerm = (char)c; - break; - } - } - if( csv_append(p, (char)c) ) return 0; - ppc = pc; - pc = c; - } - }else{ - /* If this is the first field being parsed and it begins with the - ** UTF-8 BOM (0xEF BB BF) then skip the BOM */ - if( (c&0xff)==0xef && p->bNotFirst==0 ){ - csv_append(p, (char)c); - c = csv_getc(p); - if( (c&0xff)==0xbb ){ - csv_append(p, (char)c); - c = csv_getc(p); - if( (c&0xff)==0xbf ){ - p->bNotFirst = 1; - p->n = 0; - return csv_read_one_field(p); - } - } - } - while( c>',' || (c!=EOF && c!=',' && c!='\n') ){ - if( csv_append(p, (char)c) ) return 0; - c = csv_getc(p); - } - if( c=='\n' ){ - p->nLine++; - if( p->n>0 && p->z[p->n-1]=='\r' ) p->n--; - } - p->cTerm = (char)c; - } - if( p->z ) p->z[p->n] = 0; - p->bNotFirst = 1; - return p->z; -} - - -/* Forward references to the various virtual table methods implemented -** in this file. */ -static int csvtabCreate(sqlite3*, void*, int, const char*const*, - sqlite3_vtab**,char**); -static int csvtabConnect(sqlite3*, void*, int, const char*const*, - sqlite3_vtab**,char**); -static int csvtabBestIndex(sqlite3_vtab*,sqlite3_index_info*); -static int csvtabDisconnect(sqlite3_vtab*); -static int csvtabOpen(sqlite3_vtab*, sqlite3_vtab_cursor**); -static int csvtabClose(sqlite3_vtab_cursor*); -static int csvtabFilter(sqlite3_vtab_cursor*, int idxNum, const char *idxStr, - int argc, sqlite3_value **argv); -static int csvtabNext(sqlite3_vtab_cursor*); -static int csvtabEof(sqlite3_vtab_cursor*); -static int csvtabColumn(sqlite3_vtab_cursor*,sqlite3_context*,int); -static int csvtabRowid(sqlite3_vtab_cursor*,sqlite3_int64*); - -/* An instance of the CSV virtual table */ -typedef struct CsvTable { - sqlite3_vtab base; /* Base class. Must be first */ - char *zFilename; /* Name of the CSV file */ - char *zData; /* Raw CSV data in lieu of zFilename */ - long iStart; /* Offset to start of data in zFilename */ - int nCol; /* Number of columns in the CSV file */ - unsigned int tstFlags; /* Bit values used for testing */ -} CsvTable; - -/* Allowed values for tstFlags */ -#define CSVTEST_FIDX 0x0001 /* Pretend that constrained searchs cost less*/ - -/* A cursor for the CSV virtual table */ -typedef struct CsvCursor { - sqlite3_vtab_cursor base; /* Base class. Must be first */ - CsvReader rdr; /* The CsvReader object */ - char **azVal; /* Value of the current row */ - int *aLen; /* Length of each entry */ - sqlite3_int64 iRowid; /* The current rowid. Negative for EOF */ -} CsvCursor; - -/* Transfer error message text from a reader into a CsvTable */ -static void csv_xfer_error(CsvTable *pTab, CsvReader *pRdr){ - sqlite3_free(pTab->base.zErrMsg); - pTab->base.zErrMsg = sqlite3_mprintf("%s", pRdr->zErr); -} - -/* -** This method is the destructor fo a CsvTable object. -*/ -static int csvtabDisconnect(sqlite3_vtab *pVtab){ - CsvTable *p = (CsvTable*)pVtab; - sqlite3_free(p->zFilename); - sqlite3_free(p->zData); - sqlite3_free(p); - return SQLITE_OK; -} - -/* Skip leading whitespace. Return a pointer to the first non-whitespace -** character, or to the zero terminator if the string has only whitespace */ -static const char *csv_skip_whitespace(const char *z){ - while( isspace((unsigned char)z[0]) ) z++; - return z; -} - -/* Remove trailing whitespace from the end of string z[] */ -static void csv_trim_whitespace(char *z){ - size_t n = strlen(z); - while( n>0 && isspace((unsigned char)z[n]) ) n--; - z[n] = 0; -} - -/* Dequote the string */ -static void csv_dequote(char *z){ - int j; - char cQuote = z[0]; - size_t i, n; - - if( cQuote!='\'' && cQuote!='"' ) return; - n = strlen(z); - if( n<2 || z[n-1]!=z[0] ) return; - for(i=1, j=0; i<n-1; i++){ - if( z[i]==cQuote && z[i+1]==cQuote ) i++; - z[j++] = z[i]; - } - z[j] = 0; -} - -/* Check to see if the string is of the form: "TAG = VALUE" with optional -** whitespace before and around tokens. If it is, return a pointer to the -** first character of VALUE. If it is not, return NULL. -*/ -static const char *csv_parameter(const char *zTag, int nTag, const char *z){ - z = csv_skip_whitespace(z); - if( strncmp(zTag, z, nTag)!=0 ) return 0; - z = csv_skip_whitespace(z+nTag); - if( z[0]!='=' ) return 0; - return csv_skip_whitespace(z+1); -} - -/* Decode a parameter that requires a dequoted string. -** -** Return 1 if the parameter is seen, or 0 if not. 1 is returned -** even if there is an error. If an error occurs, then an error message -** is left in p->zErr. If there are no errors, p->zErr[0]==0. -*/ -static int csv_string_parameter( - CsvReader *p, /* Leave the error message here, if there is one */ - const char *zParam, /* Parameter we are checking for */ - const char *zArg, /* Raw text of the virtual table argment */ - char **pzVal /* Write the dequoted string value here */ -){ - const char *zValue; - zValue = csv_parameter(zParam,(int)strlen(zParam),zArg); - if( zValue==0 ) return 0; - p->zErr[0] = 0; - if( *pzVal ){ - csv_errmsg(p, "more than one '%s' parameter", zParam); - return 1; - } - *pzVal = sqlite3_mprintf("%s", zValue); - if( *pzVal==0 ){ - csv_errmsg(p, "out of memory"); - return 1; - } - csv_trim_whitespace(*pzVal); - csv_dequote(*pzVal); - return 1; -} - - -/* Return 0 if the argument is false and 1 if it is true. Return -1 if -** we cannot really tell. -*/ -static int csv_boolean(const char *z){ - if( sqlite3_stricmp("yes",z)==0 - || sqlite3_stricmp("on",z)==0 - || sqlite3_stricmp("true",z)==0 - || (z[0]=='1' && z[1]==0) - ){ - return 1; - } - if( sqlite3_stricmp("no",z)==0 - || sqlite3_stricmp("off",z)==0 - || sqlite3_stricmp("false",z)==0 - || (z[0]=='0' && z[1]==0) - ){ - return 0; - } - return -1; -} - - -/* -** Parameters: -** filename=FILENAME Name of file containing CSV content -** data=TEXT Direct CSV content. -** schema=SCHEMA Alternative CSV schema. -** header=YES|NO First row of CSV defines the names of -** columns if "yes". Default "no". -** columns=N Assume the CSV file contains N columns. -** -** Only available if compiled with SQLITE_TEST: -** -** testflags=N Bitmask of test flags. Optional -** -** If schema= is omitted, then the columns are named "c0", "c1", "c2", -** and so forth. If columns=N is omitted, then the file is opened and -** the number of columns in the first row is counted to determine the -** column count. If header=YES, then the first row is skipped. -*/ -static int csvtabConnect( - sqlite3 *db, - void *pAux, - int argc, const char *const*argv, - sqlite3_vtab **ppVtab, - char **pzErr -){ - CsvTable *pNew = 0; /* The CsvTable object to construct */ - int bHeader = -1; /* header= flags. -1 means not seen yet */ - int rc = SQLITE_OK; /* Result code from this routine */ - int i, j; /* Loop counters */ -#ifdef SQLITE_TEST - int tstFlags = 0; /* Value for testflags=N parameter */ -#endif - int nCol = -99; /* Value of the columns= parameter */ - CsvReader sRdr; /* A CSV file reader used to store an error - ** message and/or to count the number of columns */ - static const char *azParam[] = { - "filename", "data", "schema", - }; - char *azPValue[3]; /* Parameter values */ -# define CSV_FILENAME (azPValue[0]) -# define CSV_DATA (azPValue[1]) -# define CSV_SCHEMA (azPValue[2]) - - - assert( sizeof(azPValue)==sizeof(azParam) ); - memset(&sRdr, 0, sizeof(sRdr)); - memset(azPValue, 0, sizeof(azPValue)); - for(i=3; i<argc; i++){ - const char *z = argv[i]; - const char *zValue; - for(j=0; j<sizeof(azParam)/sizeof(azParam[0]); j++){ - if( csv_string_parameter(&sRdr, azParam[j], z, &azPValue[j]) ) break; - } - if( j<sizeof(azParam)/sizeof(azParam[0]) ){ - if( sRdr.zErr[0] ) goto csvtab_connect_error; - }else - if( (zValue = csv_parameter("header",6,z))!=0 ){ - int x; - if( bHeader>=0 ){ - csv_errmsg(&sRdr, "more than one 'header' parameter"); - goto csvtab_connect_error; - } - x = csv_boolean(zValue); - if( x==1 ){ - bHeader = 1; - }else if( x==0 ){ - bHeader = 0; - }else{ - csv_errmsg(&sRdr, "unrecognized argument to 'header': %s", zValue); - goto csvtab_connect_error; - } - }else -#ifdef SQLITE_TEST - if( (zValue = csv_parameter("testflags",9,z))!=0 ){ - tstFlags = (unsigned int)atoi(zValue); - }else -#endif - if( (zValue = csv_parameter("columns",7,z))!=0 ){ - if( nCol>0 ){ - csv_errmsg(&sRdr, "more than one 'columns' parameter"); - goto csvtab_connect_error; - } - nCol = atoi(zValue); - if( nCol<=0 ){ - csv_errmsg(&sRdr, "must have at least one column"); - goto csvtab_connect_error; - } - }else - { - csv_errmsg(&sRdr, "unrecognized parameter '%s'", z); - goto csvtab_connect_error; - } - } - if( (CSV_FILENAME==0)==(CSV_DATA==0) ){ - csv_errmsg(&sRdr, "must either filename= or data= but not both"); - goto csvtab_connect_error; - } - if( nCol<=0 && csv_reader_open(&sRdr, CSV_FILENAME, CSV_DATA) ){ - goto csvtab_connect_error; - } - pNew = sqlite3_malloc( sizeof(*pNew) ); - *ppVtab = (sqlite3_vtab*)pNew; - if( pNew==0 ) goto csvtab_connect_oom; - memset(pNew, 0, sizeof(*pNew)); - if( nCol>0 ){ - pNew->nCol = nCol; - }else{ - do{ - csv_read_one_field(&sRdr); - pNew->nCol++; - }while( sRdr.cTerm==',' ); - } - pNew->zFilename = CSV_FILENAME; CSV_FILENAME = 0; - pNew->zData = CSV_DATA; CSV_DATA = 0; -#ifdef SQLITE_TEST - pNew->tstFlags = tstFlags; -#endif - pNew->iStart = bHeader==1 ? ftell(sRdr.in) : 0; - csv_reader_reset(&sRdr); - if( CSV_SCHEMA==0 ){ - char *zSep = ""; - CSV_SCHEMA = sqlite3_mprintf("CREATE TABLE x("); - if( CSV_SCHEMA==0 ) goto csvtab_connect_oom; - for(i=0; i<pNew->nCol; i++){ - CSV_SCHEMA = sqlite3_mprintf("%z%sc%d TEXT",CSV_SCHEMA, zSep, i); - zSep = ","; - } - CSV_SCHEMA = sqlite3_mprintf("%z);", CSV_SCHEMA); - } - rc = sqlite3_declare_vtab(db, CSV_SCHEMA); - if( rc ) goto csvtab_connect_error; - for(i=0; i<sizeof(azPValue)/sizeof(azPValue[0]); i++){ - sqlite3_free(azPValue[i]); - } - return SQLITE_OK; - -csvtab_connect_oom: - rc = SQLITE_NOMEM; - csv_errmsg(&sRdr, "out of memory"); - -csvtab_connect_error: - if( pNew ) csvtabDisconnect(&pNew->base); - for(i=0; i<sizeof(azPValue)/sizeof(azPValue[0]); i++){ - sqlite3_free(azPValue[i]); - } - if( sRdr.zErr[0] ){ - sqlite3_free(*pzErr); - *pzErr = sqlite3_mprintf("%s", sRdr.zErr); - } - csv_reader_reset(&sRdr); - if( rc==SQLITE_OK ) rc = SQLITE_ERROR; - return rc; -} - -/* -** Reset the current row content held by a CsvCursor. -*/ -static void csvtabCursorRowReset(CsvCursor *pCur){ - CsvTable *pTab = (CsvTable*)pCur->base.pVtab; - int i; - for(i=0; i<pTab->nCol; i++){ - sqlite3_free(pCur->azVal[i]); - pCur->azVal[i] = 0; - pCur->aLen[i] = 0; - } -} - -/* -** The xConnect and xCreate methods do the same thing, but they must be -** different so that the virtual table is not an eponymous virtual table. -*/ -static int csvtabCreate( - sqlite3 *db, - void *pAux, - int argc, const char *const*argv, - sqlite3_vtab **ppVtab, - char **pzErr -){ - return csvtabConnect(db, pAux, argc, argv, ppVtab, pzErr); -} - -/* -** Destructor for a CsvCursor. -*/ -static int csvtabClose(sqlite3_vtab_cursor *cur){ - CsvCursor *pCur = (CsvCursor*)cur; - csvtabCursorRowReset(pCur); - csv_reader_reset(&pCur->rdr); - sqlite3_free(cur); - return SQLITE_OK; -} - -/* -** Constructor for a new CsvTable cursor object. -*/ -static int csvtabOpen(sqlite3_vtab *p, sqlite3_vtab_cursor **ppCursor){ - CsvTable *pTab = (CsvTable*)p; - CsvCursor *pCur; - size_t nByte; - nByte = sizeof(*pCur) + (sizeof(char*)+sizeof(int))*pTab->nCol; - pCur = sqlite3_malloc64( nByte ); - if( pCur==0 ) return SQLITE_NOMEM; - memset(pCur, 0, nByte); - pCur->azVal = (char**)&pCur[1]; - pCur->aLen = (int*)&pCur->azVal[pTab->nCol]; - *ppCursor = &pCur->base; - if( csv_reader_open(&pCur->rdr, pTab->zFilename, pTab->zData) ){ - csv_xfer_error(pTab, &pCur->rdr); - return SQLITE_ERROR; - } - return SQLITE_OK; -} - - -/* -** Advance a CsvCursor to its next row of input. -** Set the EOF marker if we reach the end of input. -*/ -static int csvtabNext(sqlite3_vtab_cursor *cur){ - CsvCursor *pCur = (CsvCursor*)cur; - CsvTable *pTab = (CsvTable*)cur->pVtab; - int i = 0; - char *z; - do{ - z = csv_read_one_field(&pCur->rdr); - if( z==0 ){ - break; - } - if( i<pTab->nCol ){ - if( pCur->aLen[i] < pCur->rdr.n+1 ){ - char *zNew = sqlite3_realloc64(pCur->azVal[i], pCur->rdr.n+1); - if( zNew==0 ){ - csv_errmsg(&pCur->rdr, "out of memory"); - csv_xfer_error(pTab, &pCur->rdr); - break; - } - pCur->azVal[i] = zNew; - pCur->aLen[i] = pCur->rdr.n+1; - } - memcpy(pCur->azVal[i], z, pCur->rdr.n+1); - i++; - } - }while( pCur->rdr.cTerm==',' ); - if( z==0 || (pCur->rdr.cTerm==EOF && i<pTab->nCol) ){ - pCur->iRowid = -1; - }else{ - pCur->iRowid++; - while( i<pTab->nCol ){ - sqlite3_free(pCur->azVal[i]); - pCur->azVal[i] = 0; - pCur->aLen[i] = 0; - i++; - } - } - return SQLITE_OK; -} - -/* -** Return values of columns for the row at which the CsvCursor -** is currently pointing. -*/ -static int csvtabColumn( - sqlite3_vtab_cursor *cur, /* The cursor */ - sqlite3_context *ctx, /* First argument to sqlite3_result_...() */ - int i /* Which column to return */ -){ - CsvCursor *pCur = (CsvCursor*)cur; - CsvTable *pTab = (CsvTable*)cur->pVtab; - if( i>=0 && i<pTab->nCol && pCur->azVal[i]!=0 ){ - sqlite3_result_text(ctx, pCur->azVal[i], -1, SQLITE_STATIC); - } - return SQLITE_OK; -} - -/* -** Return the rowid for the current row. -*/ -static int csvtabRowid(sqlite3_vtab_cursor *cur, sqlite_int64 *pRowid){ - CsvCursor *pCur = (CsvCursor*)cur; - *pRowid = pCur->iRowid; - return SQLITE_OK; -} - -/* -** Return TRUE if the cursor has been moved off of the last -** row of output. -*/ -static int csvtabEof(sqlite3_vtab_cursor *cur){ - CsvCursor *pCur = (CsvCursor*)cur; - return pCur->iRowid<0; -} - -/* -** Only a full table scan is supported. So xFilter simply rewinds to -** the beginning. -*/ -static int csvtabFilter( - sqlite3_vtab_cursor *pVtabCursor, - int idxNum, const char *idxStr, - int argc, sqlite3_value **argv -){ - CsvCursor *pCur = (CsvCursor*)pVtabCursor; - CsvTable *pTab = (CsvTable*)pVtabCursor->pVtab; - pCur->iRowid = 0; - if( pCur->rdr.in==0 ){ - assert( pCur->rdr.zIn==pTab->zData ); - assert( pTab->iStart>=0 ); - assert( (size_t)pTab->iStart<=pCur->rdr.nIn ); - pCur->rdr.iIn = pTab->iStart; - }else{ - fseek(pCur->rdr.in, pTab->iStart, SEEK_SET); - pCur->rdr.iIn = 0; - pCur->rdr.nIn = 0; - } - return csvtabNext(pVtabCursor); -} - -/* -** Only a forward full table scan is supported. xBestIndex is mostly -** a no-op. If CSVTEST_FIDX is set, then the presence of equality -** constraints lowers the estimated cost, which is fiction, but is useful -** for testing certain kinds of virtual table behavior. -*/ -static int csvtabBestIndex( - sqlite3_vtab *tab, - sqlite3_index_info *pIdxInfo -){ - pIdxInfo->estimatedCost = 1000000; -#ifdef SQLITE_TEST - if( (((CsvTable*)tab)->tstFlags & CSVTEST_FIDX)!=0 ){ - /* The usual (and sensible) case is to always do a full table scan. - ** The code in this branch only runs when testflags=1. This code - ** generates an artifical and unrealistic plan which is useful - ** for testing virtual table logic but is not helpful to real applications. - ** - ** Any ==, LIKE, or GLOB constraint is marked as usable by the virtual - ** table (even though it is not) and the cost of running the virtual table - ** is reduced from 1 million to just 10. The constraints are *not* marked - ** as omittable, however, so the query planner should still generate a - ** plan that gives a correct answer, even if they plan is not optimal. - */ - int i; - int nConst = 0; - for(i=0; i<pIdxInfo->nConstraint; i++){ - unsigned char op; - if( pIdxInfo->aConstraint[i].usable==0 ) continue; - op = pIdxInfo->aConstraint[i].op; - if( op==SQLITE_INDEX_CONSTRAINT_EQ - || op==SQLITE_INDEX_CONSTRAINT_LIKE - || op==SQLITE_INDEX_CONSTRAINT_GLOB - ){ - pIdxInfo->estimatedCost = 10; - pIdxInfo->aConstraintUsage[nConst].argvIndex = nConst+1; - nConst++; - } - } - } -#endif - return SQLITE_OK; -} - - -static sqlite3_module CsvModule = { - 0, /* iVersion */ - csvtabCreate, /* xCreate */ - csvtabConnect, /* xConnect */ - csvtabBestIndex, /* xBestIndex */ - csvtabDisconnect, /* xDisconnect */ - csvtabDisconnect, /* xDestroy */ - csvtabOpen, /* xOpen - open a cursor */ - csvtabClose, /* xClose - close a cursor */ - csvtabFilter, /* xFilter - configure scan constraints */ - csvtabNext, /* xNext - advance a cursor */ - csvtabEof, /* xEof - check for end of scan */ - csvtabColumn, /* xColumn - read data */ - csvtabRowid, /* xRowid - read data */ - 0, /* xUpdate */ - 0, /* xBegin */ - 0, /* xSync */ - 0, /* xCommit */ - 0, /* xRollback */ - 0, /* xFindMethod */ - 0, /* xRename */ -}; - -#ifdef SQLITE_TEST -/* -** For virtual table testing, make a version of the CSV virtual table -** available that has an xUpdate function. But the xUpdate always returns -** SQLITE_READONLY since the CSV file is not really writable. -*/ -static int csvtabUpdate(sqlite3_vtab *p,int n,sqlite3_value**v,sqlite3_int64*x){ - return SQLITE_READONLY; -} -static sqlite3_module CsvModuleFauxWrite = { - 0, /* iVersion */ - csvtabCreate, /* xCreate */ - csvtabConnect, /* xConnect */ - csvtabBestIndex, /* xBestIndex */ - csvtabDisconnect, /* xDisconnect */ - csvtabDisconnect, /* xDestroy */ - csvtabOpen, /* xOpen - open a cursor */ - csvtabClose, /* xClose - close a cursor */ - csvtabFilter, /* xFilter - configure scan constraints */ - csvtabNext, /* xNext - advance a cursor */ - csvtabEof, /* xEof - check for end of scan */ - csvtabColumn, /* xColumn - read data */ - csvtabRowid, /* xRowid - read data */ - csvtabUpdate, /* xUpdate */ - 0, /* xBegin */ - 0, /* xSync */ - 0, /* xCommit */ - 0, /* xRollback */ - 0, /* xFindMethod */ - 0, /* xRename */ -}; -#endif /* SQLITE_TEST */ - -#endif /* !defined(SQLITE_OMIT_VIRTUALTABLE) */ - - -#ifdef _WIN32 -__declspec(dllexport) -#endif -/* -** This routine is called when the extension is loaded. The new -** CSV virtual table module is registered with the calling database -** connection. -*/ -int sqlite3_csv_init( - sqlite3 *db, - char **pzErrMsg, - const sqlite3_api_routines *pApi -){ -#ifndef SQLITE_OMIT_VIRTUALTABLE - int rc; - SQLITE_EXTENSION_INIT2(pApi); - rc = sqlite3_create_module(db, "csv", &CsvModule, 0); -#ifdef SQLITE_TEST - if( rc==SQLITE_OK ){ - rc = sqlite3_create_module(db, "csv_wr", &CsvModuleFauxWrite, 0); - } -#endif - return rc; -#else - return SQLITE_OK; -#endif -} |