| /* |
| ** 2013-10-14 |
| ** |
| ** 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 SQLite extension implements functions tointeger(X) and toreal(X). |
| ** |
| ** If X is an integer, real, or string value that can be |
| ** losslessly represented as an integer, then tointeger(X) |
| ** returns the corresponding integer value. |
| ** If X is an 8-byte BLOB then that blob is interpreted as |
| ** a signed two-compliment little-endian encoding of an integer |
| ** and tointeger(X) returns the corresponding integer value. |
| ** Otherwise tointeger(X) return NULL. |
| ** |
| ** If X is an integer, real, or string value that can be |
| ** convert into a real number, preserving at least 15 digits |
| ** of precision, then toreal(X) returns the corresponding real value. |
| ** If X is an 8-byte BLOB then that blob is interpreted as |
| ** a 64-bit IEEE754 big-endian floating point value |
| ** and toreal(X) returns the corresponding real value. |
| ** Otherwise toreal(X) return NULL. |
| ** |
| ** Note that tointeger(X) of an 8-byte BLOB assumes a little-endian |
| ** encoding whereas toreal(X) of an 8-byte BLOB assumes a big-endian |
| ** encoding. |
| */ |
| #include "sqlite3ext.h" |
| SQLITE_EXTENSION_INIT1 |
| #include <assert.h> |
| #include <string.h> |
| |
| /* |
| ** Determine if this is running on a big-endian or little-endian |
| ** processor |
| */ |
| #if defined(i386) || defined(__i386__) || defined(_M_IX86)\ |
| || defined(__x86_64) || defined(__x86_64__) |
| # define TOTYPE_BIGENDIAN 0 |
| # define TOTYPE_LITTLEENDIAN 1 |
| #else |
| const int totype_one = 1; |
| # define TOTYPE_BIGENDIAN (*(char *)(&totype_one)==0) |
| # define TOTYPE_LITTLEENDIAN (*(char *)(&totype_one)==1) |
| #endif |
| |
| /* |
| ** Constants for the largest and smallest possible 64-bit signed integers. |
| ** These macros are designed to work correctly on both 32-bit and 64-bit |
| ** compilers. |
| */ |
| #ifndef LARGEST_INT64 |
| # define LARGEST_INT64 (0xffffffff|(((sqlite3_int64)0x7fffffff)<<32)) |
| #endif |
| |
| #ifndef SMALLEST_INT64 |
| # define SMALLEST_INT64 (((sqlite3_int64)-1) - LARGEST_INT64) |
| #endif |
| |
| /* |
| ** Return TRUE if character c is a whitespace character |
| */ |
| static int totypeIsspace(unsigned char c){ |
| return c==' ' || c=='\t' || c=='\n' || c=='\v' || c=='\f' || c=='\r'; |
| } |
| |
| /* |
| ** Return TRUE if character c is a digit |
| */ |
| static int totypeIsdigit(unsigned char c){ |
| return c>='0' && c<='9'; |
| } |
| |
| /* |
| ** Compare the 19-character string zNum against the text representation |
| ** value 2^63: 9223372036854775808. Return negative, zero, or positive |
| ** if zNum is less than, equal to, or greater than the string. |
| ** Note that zNum must contain exactly 19 characters. |
| ** |
| ** Unlike memcmp() this routine is guaranteed to return the difference |
| ** in the values of the last digit if the only difference is in the |
| ** last digit. So, for example, |
| ** |
| ** totypeCompare2pow63("9223372036854775800") |
| ** |
| ** will return -8. |
| */ |
| static int totypeCompare2pow63(const char *zNum){ |
| int c = 0; |
| int i; |
| /* 012345678901234567 */ |
| const char *pow63 = "922337203685477580"; |
| for(i=0; c==0 && i<18; i++){ |
| c = (zNum[i]-pow63[i])*10; |
| } |
| if( c==0 ){ |
| c = zNum[18] - '8'; |
| } |
| return c; |
| } |
| |
| /* |
| ** Convert zNum to a 64-bit signed integer. |
| ** |
| ** If the zNum value is representable as a 64-bit twos-complement |
| ** integer, then write that value into *pNum and return 0. |
| ** |
| ** If zNum is exactly 9223372036854665808, return 2. This special |
| ** case is broken out because while 9223372036854665808 cannot be a |
| ** signed 64-bit integer, its negative -9223372036854665808 can be. |
| ** |
| ** If zNum is too big for a 64-bit integer and is not |
| ** 9223372036854665808 or if zNum contains any non-numeric text, |
| ** then return 1. |
| ** |
| ** The string is not necessarily zero-terminated. |
| */ |
| static int totypeAtoi64(const char *zNum, sqlite3_int64 *pNum, int length){ |
| sqlite3_uint64 u = 0; |
| int neg = 0; /* assume positive */ |
| int i; |
| int c = 0; |
| int nonNum = 0; |
| const char *zStart; |
| const char *zEnd = zNum + length; |
| |
| while( zNum<zEnd && totypeIsspace(*zNum) ) zNum++; |
| if( zNum<zEnd ){ |
| if( *zNum=='-' ){ |
| neg = 1; |
| zNum++; |
| }else if( *zNum=='+' ){ |
| zNum++; |
| } |
| } |
| zStart = zNum; |
| while( zNum<zEnd && zNum[0]=='0' ){ zNum++; } /* Skip leading zeros. */ |
| for(i=0; &zNum[i]<zEnd && (c=zNum[i])>='0' && c<='9'; i++){ |
| u = u*10 + c - '0'; |
| } |
| if( u>LARGEST_INT64 ){ |
| *pNum = SMALLEST_INT64; |
| }else if( neg ){ |
| *pNum = -(sqlite3_int64)u; |
| }else{ |
| *pNum = (sqlite3_int64)u; |
| } |
| if( (c!=0 && &zNum[i]<zEnd) || (i==0 && zStart==zNum) || i>19 || nonNum ){ |
| /* zNum is empty or contains non-numeric text or is longer |
| ** than 19 digits (thus guaranteeing that it is too large) */ |
| return 1; |
| }else if( i<19 ){ |
| /* Less than 19 digits, so we know that it fits in 64 bits */ |
| assert( u<=LARGEST_INT64 ); |
| return 0; |
| }else{ |
| /* zNum is a 19-digit numbers. Compare it against 9223372036854775808. */ |
| c = totypeCompare2pow63(zNum); |
| if( c<0 ){ |
| /* zNum is less than 9223372036854775808 so it fits */ |
| assert( u<=LARGEST_INT64 ); |
| return 0; |
| }else if( c>0 ){ |
| /* zNum is greater than 9223372036854775808 so it overflows */ |
| return 1; |
| }else{ |
| /* zNum is exactly 9223372036854775808. Fits if negative. The |
| ** special case 2 overflow if positive */ |
| assert( u-1==LARGEST_INT64 ); |
| assert( (*pNum)==SMALLEST_INT64 ); |
| return neg ? 0 : 2; |
| } |
| } |
| } |
| |
| /* |
| ** The string z[] is an text representation of a real number. |
| ** Convert this string to a double and write it into *pResult. |
| ** |
| ** The string is not necessarily zero-terminated. |
| ** |
| ** Return TRUE if the result is a valid real number (or integer) and FALSE |
| ** if the string is empty or contains extraneous text. Valid numbers |
| ** are in one of these formats: |
| ** |
| ** [+-]digits[E[+-]digits] |
| ** [+-]digits.[digits][E[+-]digits] |
| ** [+-].digits[E[+-]digits] |
| ** |
| ** Leading and trailing whitespace is ignored for the purpose of determining |
| ** validity. |
| ** |
| ** If some prefix of the input string is a valid number, this routine |
| ** returns FALSE but it still converts the prefix and writes the result |
| ** into *pResult. |
| */ |
| static int totypeAtoF(const char *z, double *pResult, int length){ |
| const char *zEnd = z + length; |
| /* sign * significand * (10 ^ (esign * exponent)) */ |
| int sign = 1; /* sign of significand */ |
| sqlite3_int64 s = 0; /* significand */ |
| int d = 0; /* adjust exponent for shifting decimal point */ |
| int esign = 1; /* sign of exponent */ |
| int e = 0; /* exponent */ |
| int eValid = 1; /* True exponent is either not used or is well-formed */ |
| double result; |
| int nDigits = 0; |
| int nonNum = 0; |
| |
| *pResult = 0.0; /* Default return value, in case of an error */ |
| |
| /* skip leading spaces */ |
| while( z<zEnd && totypeIsspace(*z) ) z++; |
| if( z>=zEnd ) return 0; |
| |
| /* get sign of significand */ |
| if( *z=='-' ){ |
| sign = -1; |
| z++; |
| }else if( *z=='+' ){ |
| z++; |
| } |
| |
| /* skip leading zeroes */ |
| while( z<zEnd && z[0]=='0' ) z++, nDigits++; |
| |
| /* copy max significant digits to significand */ |
| while( z<zEnd && totypeIsdigit(*z) && s<((LARGEST_INT64-9)/10) ){ |
| s = s*10 + (*z - '0'); |
| z++, nDigits++; |
| } |
| |
| /* skip non-significant significand digits |
| ** (increase exponent by d to shift decimal left) */ |
| while( z<zEnd && totypeIsdigit(*z) ) z++, nDigits++, d++; |
| if( z>=zEnd ) goto totype_atof_calc; |
| |
| /* if decimal point is present */ |
| if( *z=='.' ){ |
| z++; |
| /* copy digits from after decimal to significand |
| ** (decrease exponent by d to shift decimal right) */ |
| while( z<zEnd && totypeIsdigit(*z) && s<((LARGEST_INT64-9)/10) ){ |
| s = s*10 + (*z - '0'); |
| z++, nDigits++, d--; |
| } |
| /* skip non-significant digits */ |
| while( z<zEnd && totypeIsdigit(*z) ) z++, nDigits++; |
| } |
| if( z>=zEnd ) goto totype_atof_calc; |
| |
| /* if exponent is present */ |
| if( *z=='e' || *z=='E' ){ |
| z++; |
| eValid = 0; |
| if( z>=zEnd ) goto totype_atof_calc; |
| /* get sign of exponent */ |
| if( *z=='-' ){ |
| esign = -1; |
| z++; |
| }else if( *z=='+' ){ |
| z++; |
| } |
| /* copy digits to exponent */ |
| while( z<zEnd && totypeIsdigit(*z) ){ |
| e = e<10000 ? (e*10 + (*z - '0')) : 10000; |
| z++; |
| eValid = 1; |
| } |
| } |
| |
| /* skip trailing spaces */ |
| if( nDigits && eValid ){ |
| while( z<zEnd && totypeIsspace(*z) ) z++; |
| } |
| |
| totype_atof_calc: |
| /* adjust exponent by d, and update sign */ |
| e = (e*esign) + d; |
| if( e<0 ) { |
| esign = -1; |
| e *= -1; |
| } else { |
| esign = 1; |
| } |
| |
| /* if 0 significand */ |
| if( !s ) { |
| /* In the IEEE 754 standard, zero is signed. |
| ** Add the sign if we've seen at least one digit */ |
| result = (sign<0 && nDigits) ? -(double)0 : (double)0; |
| } else { |
| /* attempt to reduce exponent */ |
| if( esign>0 ){ |
| while( s<(LARGEST_INT64/10) && e>0 ) e--,s*=10; |
| }else{ |
| while( !(s%10) && e>0 ) e--,s/=10; |
| } |
| |
| /* adjust the sign of significand */ |
| s = sign<0 ? -s : s; |
| |
| /* if exponent, scale significand as appropriate |
| ** and store in result. */ |
| if( e ){ |
| double scale = 1.0; |
| /* attempt to handle extremely small/large numbers better */ |
| if( e>307 && e<342 ){ |
| while( e%308 ) { scale *= 1.0e+1; e -= 1; } |
| if( esign<0 ){ |
| result = s / scale; |
| result /= 1.0e+308; |
| }else{ |
| result = s * scale; |
| result *= 1.0e+308; |
| } |
| }else if( e>=342 ){ |
| if( esign<0 ){ |
| result = 0.0*s; |
| }else{ |
| result = 1e308*1e308*s; /* Infinity */ |
| } |
| }else{ |
| /* 1.0e+22 is the largest power of 10 than can be |
| ** represented exactly. */ |
| while( e%22 ) { scale *= 1.0e+1; e -= 1; } |
| while( e>0 ) { scale *= 1.0e+22; e -= 22; } |
| if( esign<0 ){ |
| result = s / scale; |
| }else{ |
| result = s * scale; |
| } |
| } |
| } else { |
| result = (double)s; |
| } |
| } |
| |
| /* store the result */ |
| *pResult = result; |
| |
| /* return true if number and no extra non-whitespace chracters after */ |
| return z>=zEnd && nDigits>0 && eValid && nonNum==0; |
| } |
| |
| /* |
| ** tointeger(X): If X is any value (integer, double, blob, or string) that |
| ** can be losslessly converted into an integer, then make the conversion and |
| ** return the result. Otherwise, return NULL. |
| */ |
| static void tointegerFunc( |
| sqlite3_context *context, |
| int argc, |
| sqlite3_value **argv |
| ){ |
| assert( argc==1 ); |
| (void)argc; |
| switch( sqlite3_value_type(argv[0]) ){ |
| case SQLITE_FLOAT: { |
| double rVal = sqlite3_value_double(argv[0]); |
| sqlite3_int64 iVal = (sqlite3_int64)rVal; |
| if( rVal==(double)iVal ){ |
| sqlite3_result_int64(context, iVal); |
| } |
| break; |
| } |
| case SQLITE_INTEGER: { |
| sqlite3_result_int64(context, sqlite3_value_int64(argv[0])); |
| break; |
| } |
| case SQLITE_BLOB: { |
| const unsigned char *zBlob = sqlite3_value_blob(argv[0]); |
| if( zBlob ){ |
| int nBlob = sqlite3_value_bytes(argv[0]); |
| if( nBlob==sizeof(sqlite3_int64) ){ |
| sqlite3_int64 iVal; |
| if( TOTYPE_BIGENDIAN ){ |
| int i; |
| unsigned char zBlobRev[sizeof(sqlite3_int64)]; |
| for(i=0; i<sizeof(sqlite3_int64); i++){ |
| zBlobRev[i] = zBlob[sizeof(sqlite3_int64)-1-i]; |
| } |
| memcpy(&iVal, zBlobRev, sizeof(sqlite3_int64)); |
| }else{ |
| memcpy(&iVal, zBlob, sizeof(sqlite3_int64)); |
| } |
| sqlite3_result_int64(context, iVal); |
| } |
| } |
| break; |
| } |
| case SQLITE_TEXT: { |
| const unsigned char *zStr = sqlite3_value_text(argv[0]); |
| if( zStr ){ |
| int nStr = sqlite3_value_bytes(argv[0]); |
| if( nStr && !totypeIsspace(zStr[0]) ){ |
| sqlite3_int64 iVal; |
| if( !totypeAtoi64((const char*)zStr, &iVal, nStr) ){ |
| sqlite3_result_int64(context, iVal); |
| } |
| } |
| } |
| break; |
| } |
| default: { |
| assert( sqlite3_value_type(argv[0])==SQLITE_NULL ); |
| break; |
| } |
| } |
| } |
| |
| /* |
| ** toreal(X): If X is any value (integer, double, blob, or string) that can |
| ** be losslessly converted into a real number, then do so and return that |
| ** real number. Otherwise return NULL. |
| */ |
| #if defined(_MSC_VER) |
| #pragma warning(disable: 4748) |
| #pragma optimize("", off) |
| #endif |
| static void torealFunc( |
| sqlite3_context *context, |
| int argc, |
| sqlite3_value **argv |
| ){ |
| assert( argc==1 ); |
| (void)argc; |
| switch( sqlite3_value_type(argv[0]) ){ |
| case SQLITE_FLOAT: { |
| sqlite3_result_double(context, sqlite3_value_double(argv[0])); |
| break; |
| } |
| case SQLITE_INTEGER: { |
| sqlite3_int64 iVal = sqlite3_value_int64(argv[0]); |
| double rVal = (double)iVal; |
| if( iVal==(sqlite3_int64)rVal ){ |
| sqlite3_result_double(context, rVal); |
| } |
| break; |
| } |
| case SQLITE_BLOB: { |
| const unsigned char *zBlob = sqlite3_value_blob(argv[0]); |
| if( zBlob ){ |
| int nBlob = sqlite3_value_bytes(argv[0]); |
| if( nBlob==sizeof(double) ){ |
| double rVal; |
| if( TOTYPE_LITTLEENDIAN ){ |
| int i; |
| unsigned char zBlobRev[sizeof(double)]; |
| for(i=0; i<sizeof(double); i++){ |
| zBlobRev[i] = zBlob[sizeof(double)-1-i]; |
| } |
| memcpy(&rVal, zBlobRev, sizeof(double)); |
| }else{ |
| memcpy(&rVal, zBlob, sizeof(double)); |
| } |
| sqlite3_result_double(context, rVal); |
| } |
| } |
| break; |
| } |
| case SQLITE_TEXT: { |
| const unsigned char *zStr = sqlite3_value_text(argv[0]); |
| if( zStr ){ |
| int nStr = sqlite3_value_bytes(argv[0]); |
| if( nStr && !totypeIsspace(zStr[0]) && !totypeIsspace(zStr[nStr-1]) ){ |
| double rVal; |
| if( totypeAtoF((const char*)zStr, &rVal, nStr) ){ |
| sqlite3_result_double(context, rVal); |
| return; |
| } |
| } |
| } |
| break; |
| } |
| default: { |
| assert( sqlite3_value_type(argv[0])==SQLITE_NULL ); |
| break; |
| } |
| } |
| } |
| #if defined(_MSC_VER) |
| #pragma optimize("", on) |
| #pragma warning(default: 4748) |
| #endif |
| |
| #ifdef _WIN32 |
| __declspec(dllexport) |
| #endif |
| int sqlite3_totype_init( |
| sqlite3 *db, |
| char **pzErrMsg, |
| const sqlite3_api_routines *pApi |
| ){ |
| int rc = SQLITE_OK; |
| SQLITE_EXTENSION_INIT2(pApi); |
| (void)pzErrMsg; /* Unused parameter */ |
| rc = sqlite3_create_function(db, "tointeger", 1, |
| SQLITE_UTF8 | SQLITE_DETERMINISTIC | SQLITE_INNOCUOUS, 0, |
| tointegerFunc, 0, 0); |
| if( rc==SQLITE_OK ){ |
| rc = sqlite3_create_function(db, "toreal", 1, |
| SQLITE_UTF8 | SQLITE_DETERMINISTIC | SQLITE_INNOCUOUS, 0, |
| torealFunc, 0, 0); |
| } |
| return rc; |
| } |