SQLite

#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 */
  char 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->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 ){
      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 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);

**      EOF on end-of-file.
**
** Return "" at EOF.  Return 0 on an OOM error.
*/
static char *csv_read_one_field(CsvReader *p){
  int c;
  p->n = 0;
  c = csv_getc(p);
  if( c==EOF ){
    p->cTerm = EOF;
    return "";
  }
  if( c=='"' ){
    int pc, ppc;
    int startLine = p->nLine;
    int cQuote = c;
    pc = ppc = 0;
    while( 1 ){
      c = csv_getc(p);
      if( c=='\n' ) p->nLine++;
      if( c==cQuote ){
        if( pc==cQuote ){
          pc = 0;
          continue;
        }
      }

      if( csv_append(p, (char)c) ) return 0;
      ppc = pc;
      pc = c;
    }
  }else{
    while( 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 = c;
  }

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*/

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,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

  }
  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.
**    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 */


  int tstFlags = 0;          /* Value for testflags=N parameter */
  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;
      }

      }
    }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{
      const char *z = csv_read_one_field(&sRdr);
      if( z==0 ) goto csvtab_connect_oom;
      pNew->nCol++;
    }while( sRdr.cTerm==',' );
  }
  pNew->zFilename = CSV_FILENAME;  CSV_FILENAME = 0;
  pNew->zData = CSV_DATA;          CSV_DATA = 0;
  pNew->tstFlags = tstFlags;

  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;

  CsvTable *pTab = (CsvTable*)p;
  CsvCursor *pCur;
  pCur = sqlite3_malloc( sizeof(*pCur) * sizeof(char*)*pTab->nCol );
  if( pCur==0 ) return SQLITE_NOMEM;
  memset(pCur, 0, sizeof(*pCur) + sizeof(char*)*pTab->nCol );
  pCur->azVal = (char**)&pCur[1];
  *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;
}

  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<=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
){
  CsvTable *pTab = (CsvTable*)tab;
  int i;
  int nConst = 0;
  pIdxInfo->estimatedCost = 1000000;
  if( (pTab->tstFlags & CSVTEST_FIDX)==0 ){
    return SQLITE_OK;
  }
  /* The usual (and sensible) case is to take the "return SQLITE_OK" above.
  ** The code below only runs when testflags=1.  The code below
  ** generates an artifical and unrealistic plan which is useful
  ** for testing virtual table logic but is not helpfulto 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.
  */
  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