/* ** 2001 September 15 ** ** 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. ** ************************************************************************* ** Utility functions used throughout sqlite. ** ** This file contains functions for allocating memory, comparing ** strings, and stuff like that. ** */ #include "sqliteInt.h" #include #ifndef SQLITE_OMIT_FLOATING_POINT #include #endif /* ** Calls to sqlite3FaultSim() are used to simulate a failure during testing, ** or to bypass normal error detection during testing in order to let ** execute proceed further downstream. ** ** In deployment, sqlite3FaultSim() *always* return SQLITE_OK (0). The ** sqlite3FaultSim() function only returns non-zero during testing. ** ** During testing, if the test harness has set a fault-sim callback using ** a call to sqlite3_test_control(SQLITE_TESTCTRL_FAULT_INSTALL), then ** each call to sqlite3FaultSim() is relayed to that application-supplied ** callback and the integer return value form the application-supplied ** callback is returned by sqlite3FaultSim(). ** ** The integer argument to sqlite3FaultSim() is a code to identify which ** sqlite3FaultSim() instance is being invoked. Each call to sqlite3FaultSim() ** should have a unique code. To prevent legacy testing applications from ** breaking, the codes should not be changed or reused. */ #ifndef SQLITE_UNTESTABLE int sqlite3FaultSim(int iTest){ int (*xCallback)(int) = sqlite3GlobalConfig.xTestCallback; return xCallback ? xCallback(iTest) : SQLITE_OK; } #endif #ifndef SQLITE_OMIT_FLOATING_POINT /* ** Return true if the floating point value is Not a Number (NaN). ** ** Use the math library isnan() function if compiled with SQLITE_HAVE_ISNAN. ** Otherwise, we have our own implementation that works on most systems. */ int sqlite3IsNaN(double x){ int rc; /* The value return */ #if !SQLITE_HAVE_ISNAN && !HAVE_ISNAN u64 y; memcpy(&y,&x,sizeof(y)); rc = IsNaN(y); #else rc = isnan(x); #endif /* HAVE_ISNAN */ testcase( rc ); return rc; } #endif /* SQLITE_OMIT_FLOATING_POINT */ #ifndef SQLITE_OMIT_FLOATING_POINT /* ** Return true if the floating point value is NaN or +Inf or -Inf. */ int sqlite3IsOverflow(double x){ int rc; /* The value return */ u64 y; memcpy(&y,&x,sizeof(y)); rc = IsOvfl(y); return rc; } #endif /* SQLITE_OMIT_FLOATING_POINT */ /* ** Compute a string length that is limited to what can be stored in ** lower 30 bits of a 32-bit signed integer. ** ** The value returned will never be negative. Nor will it ever be greater ** than the actual length of the string. For very long strings (greater ** than 1GiB) the value returned might be less than the true string length. */ int sqlite3Strlen30(const char *z){ if( z==0 ) return 0; return 0x3fffffff & (int)strlen(z); } /* ** Return the declared type of a column. Or return zDflt if the column ** has no declared type. ** ** The column type is an extra string stored after the zero-terminator on ** the column name if and only if the COLFLAG_HASTYPE flag is set. */ char *sqlite3ColumnType(Column *pCol, char *zDflt){ if( pCol->colFlags & COLFLAG_HASTYPE ){ return pCol->zCnName + strlen(pCol->zCnName) + 1; }else if( pCol->eCType ){ assert( pCol->eCType<=SQLITE_N_STDTYPE ); return (char*)sqlite3StdType[pCol->eCType-1]; }else{ return zDflt; } } /* ** Helper function for sqlite3Error() - called rarely. Broken out into ** a separate routine to avoid unnecessary register saves on entry to ** sqlite3Error(). */ static SQLITE_NOINLINE void sqlite3ErrorFinish(sqlite3 *db, int err_code){ if( db->pErr ) sqlite3ValueSetNull(db->pErr); sqlite3SystemError(db, err_code); } /* ** Set the current error code to err_code and clear any prior error message. ** Also set iSysErrno (by calling sqlite3System) if the err_code indicates ** that would be appropriate. */ void sqlite3Error(sqlite3 *db, int err_code){ assert( db!=0 ); db->errCode = err_code; if( err_code || db->pErr ){ sqlite3ErrorFinish(db, err_code); }else{ db->errByteOffset = -1; } } /* ** The equivalent of sqlite3Error(db, SQLITE_OK). Clear the error state ** and error message. */ void sqlite3ErrorClear(sqlite3 *db){ assert( db!=0 ); db->errCode = SQLITE_OK; db->errByteOffset = -1; if( db->pErr ) sqlite3ValueSetNull(db->pErr); } /* ** Load the sqlite3.iSysErrno field if that is an appropriate thing ** to do based on the SQLite error code in rc. */ void sqlite3SystemError(sqlite3 *db, int rc){ if( rc==SQLITE_IOERR_NOMEM ) return; #if defined(SQLITE_USE_SEH) && !defined(SQLITE_OMIT_WAL) if( rc==SQLITE_IOERR_IN_PAGE ){ int ii; int iErr; sqlite3BtreeEnterAll(db); for(ii=0; iinDb; ii++){ if( db->aDb[ii].pBt ){ iErr = sqlite3PagerWalSystemErrno(sqlite3BtreePager(db->aDb[ii].pBt)); if( iErr ){ db->iSysErrno = iErr; } } } sqlite3BtreeLeaveAll(db); return; } #endif rc &= 0xff; if( rc==SQLITE_CANTOPEN || rc==SQLITE_IOERR ){ db->iSysErrno = sqlite3OsGetLastError(db->pVfs); } } /* ** Set the most recent error code and error string for the sqlite ** handle "db". The error code is set to "err_code". ** ** If it is not NULL, string zFormat specifies the format of the ** error string. zFormat and any string tokens that follow it are ** assumed to be encoded in UTF-8. ** ** To clear the most recent error for sqlite handle "db", sqlite3Error ** should be called with err_code set to SQLITE_OK and zFormat set ** to NULL. */ void sqlite3ErrorWithMsg(sqlite3 *db, int err_code, const char *zFormat, ...){ assert( db!=0 ); db->errCode = err_code; sqlite3SystemError(db, err_code); if( zFormat==0 ){ sqlite3Error(db, err_code); }else if( db->pErr || (db->pErr = sqlite3ValueNew(db))!=0 ){ char *z; va_list ap; va_start(ap, zFormat); z = sqlite3VMPrintf(db, zFormat, ap); va_end(ap); sqlite3ValueSetStr(db->pErr, -1, z, SQLITE_UTF8, SQLITE_DYNAMIC); } } /* ** Check for interrupts and invoke progress callback. */ void sqlite3ProgressCheck(Parse *p){ sqlite3 *db = p->db; if( AtomicLoad(&db->u1.isInterrupted) ){ p->nErr++; p->rc = SQLITE_INTERRUPT; } #ifndef SQLITE_OMIT_PROGRESS_CALLBACK if( db->xProgress ){ if( p->rc==SQLITE_INTERRUPT ){ p->nProgressSteps = 0; }else if( (++p->nProgressSteps)>=db->nProgressOps ){ if( db->xProgress(db->pProgressArg) ){ p->nErr++; p->rc = SQLITE_INTERRUPT; } p->nProgressSteps = 0; } } #endif } /* ** Add an error message to pParse->zErrMsg and increment pParse->nErr. ** ** This function should be used to report any error that occurs while ** compiling an SQL statement (i.e. within sqlite3_prepare()). The ** last thing the sqlite3_prepare() function does is copy the error ** stored by this function into the database handle using sqlite3Error(). ** Functions sqlite3Error() or sqlite3ErrorWithMsg() should be used ** during statement execution (sqlite3_step() etc.). */ void sqlite3ErrorMsg(Parse *pParse, const char *zFormat, ...){ char *zMsg; va_list ap; sqlite3 *db = pParse->db; assert( db!=0 ); assert( db->pParse==pParse || db->pParse->pToplevel==pParse ); db->errByteOffset = -2; va_start(ap, zFormat); zMsg = sqlite3VMPrintf(db, zFormat, ap); va_end(ap); if( db->errByteOffset<-1 ) db->errByteOffset = -1; if( db->suppressErr ){ sqlite3DbFree(db, zMsg); if( db->mallocFailed ){ pParse->nErr++; pParse->rc = SQLITE_NOMEM; } }else{ pParse->nErr++; sqlite3DbFree(db, pParse->zErrMsg); pParse->zErrMsg = zMsg; pParse->rc = SQLITE_ERROR; pParse->pWith = 0; } } /* ** If database connection db is currently parsing SQL, then transfer ** error code errCode to that parser if the parser has not already ** encountered some other kind of error. */ int sqlite3ErrorToParser(sqlite3 *db, int errCode){ Parse *pParse; if( db==0 || (pParse = db->pParse)==0 ) return errCode; pParse->rc = errCode; pParse->nErr++; return errCode; } /* ** Convert an SQL-style quoted string into a normal string by removing ** the quote characters. The conversion is done in-place. If the ** input does not begin with a quote character, then this routine ** is a no-op. ** ** The input string must be zero-terminated. A new zero-terminator ** is added to the dequoted string. ** ** The return value is -1 if no dequoting occurs or the length of the ** dequoted string, exclusive of the zero terminator, if dequoting does ** occur. ** ** 2002-02-14: This routine is extended to remove MS-Access style ** brackets from around identifiers. For example: "[a-b-c]" becomes ** "a-b-c". */ void sqlite3Dequote(char *z){ char quote; int i, j; if( z==0 ) return; quote = z[0]; if( !sqlite3Isquote(quote) ) return; if( quote=='[' ) quote = ']'; for(i=1, j=0;; i++){ assert( z[i] ); if( z[i]==quote ){ if( z[i+1]==quote ){ z[j++] = quote; i++; }else{ break; } }else{ z[j++] = z[i]; } } z[j] = 0; } void sqlite3DequoteExpr(Expr *p){ assert( !ExprHasProperty(p, EP_IntValue) ); assert( sqlite3Isquote(p->u.zToken[0]) ); p->flags |= p->u.zToken[0]=='"' ? EP_Quoted|EP_DblQuoted : EP_Quoted; sqlite3Dequote(p->u.zToken); } /* ** Expression p is a QNUMBER (quoted number). Dequote the value in p->u.zToken ** and set the type to INTEGER or FLOAT. "Quoted" integers or floats are those ** that contain '_' characters that must be removed before further processing. */ void sqlite3DequoteNumber(Parse *pParse, Expr *p){ assert( p!=0 || pParse->db->mallocFailed ); if( p ){ const char *pIn = p->u.zToken; char *pOut = p->u.zToken; int bHex = (pIn[0]=='0' && (pIn[1]=='x' || pIn[1]=='X')); int iValue; assert( p->op==TK_QNUMBER ); p->op = TK_INTEGER; do { if( *pIn!=SQLITE_DIGIT_SEPARATOR ){ *pOut++ = *pIn; if( *pIn=='e' || *pIn=='E' || *pIn=='.' ) p->op = TK_FLOAT; }else{ if( (bHex==0 && (!sqlite3Isdigit(pIn[-1]) || !sqlite3Isdigit(pIn[1]))) || (bHex==1 && (!sqlite3Isxdigit(pIn[-1]) || !sqlite3Isxdigit(pIn[1]))) ){ sqlite3ErrorMsg(pParse, "unrecognized token: \"%s\"", p->u.zToken); } } }while( *pIn++ ); if( bHex ) p->op = TK_INTEGER; /* tag-20240227-a: If after dequoting, the number is an integer that ** fits in 32 bits, then it must be converted into EP_IntValue. Other ** parts of the code expect this. See also tag-20240227-b. */ if( p->op==TK_INTEGER && sqlite3GetInt32(p->u.zToken, &iValue) ){ p->u.iValue = iValue; p->flags |= EP_IntValue; } } } /* ** If the input token p is quoted, try to adjust the token to remove ** the quotes. This is not always possible: ** ** "abc" -> abc ** "ab""cd" -> (not possible because of the interior "") ** ** Remove the quotes if possible. This is a optimization. The overall ** system should still return the correct answer even if this routine ** is always a no-op. */ void sqlite3DequoteToken(Token *p){ unsigned int i; if( p->n<2 ) return; if( !sqlite3Isquote(p->z[0]) ) return; for(i=1; in-1; i++){ if( sqlite3Isquote(p->z[i]) ) return; } p->n -= 2; p->z++; } /* ** Generate a Token object from a string */ void sqlite3TokenInit(Token *p, char *z){ p->z = z; p->n = sqlite3Strlen30(z); } /* Convenient short-hand */ #define UpperToLower sqlite3UpperToLower /* ** Some systems have stricmp(). Others have strcasecmp(). Because ** there is no consistency, we will define our own. ** ** IMPLEMENTATION-OF: R-30243-02494 The sqlite3_stricmp() and ** sqlite3_strnicmp() APIs allow applications and extensions to compare ** the contents of two buffers containing UTF-8 strings in a ** case-independent fashion, using the same definition of "case ** independence" that SQLite uses internally when comparing identifiers. */ int sqlite3_stricmp(const char *zLeft, const char *zRight){ if( zLeft==0 ){ return zRight ? -1 : 0; }else if( zRight==0 ){ return 1; } return sqlite3StrICmp(zLeft, zRight); } int sqlite3StrICmp(const char *zLeft, const char *zRight){ unsigned char *a, *b; int c, x; a = (unsigned char *)zLeft; b = (unsigned char *)zRight; for(;;){ c = *a; x = *b; if( c==x ){ if( c==0 ) break; }else{ c = (int)UpperToLower[c] - (int)UpperToLower[x]; if( c ) break; } a++; b++; } return c; } int sqlite3_strnicmp(const char *zLeft, const char *zRight, int N){ register unsigned char *a, *b; if( zLeft==0 ){ return zRight ? -1 : 0; }else if( zRight==0 ){ return 1; } a = (unsigned char *)zLeft; b = (unsigned char *)zRight; while( N-- > 0 && *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; } return N<0 ? 0 : UpperToLower[*a] - UpperToLower[*b]; } /* ** Compute an 8-bit hash on a string that is insensitive to case differences */ u8 sqlite3StrIHash(const char *z){ u8 h = 0; if( z==0 ) return 0; while( z[0] ){ h += UpperToLower[(unsigned char)z[0]]; z++; } return h; } /* Double-Double multiplication. (x[0],x[1]) *= (y,yy) ** ** Reference: ** T. J. Dekker, "A Floating-Point Technique for Extending the ** Available Precision". 1971-07-26. */ static void dekkerMul2(volatile double *x, double y, double yy){ /* ** The "volatile" keywords on parameter x[] and on local variables ** below are needed force intermediate results to be truncated to ** binary64 rather than be carried around in an extended-precision ** format. The truncation is necessary for the Dekker algorithm to ** work. Intel x86 floating point might omit the truncation without ** the use of volatile. */ volatile double tx, ty, p, q, c, cc; double hx, hy; u64 m; memcpy(&m, (void*)&x[0], 8); m &= 0xfffffffffc000000LL; memcpy(&hx, &m, 8); tx = x[0] - hx; memcpy(&m, &y, 8); m &= 0xfffffffffc000000LL; memcpy(&hy, &m, 8); ty = y - hy; p = hx*hy; q = hx*ty + tx*hy; c = p+q; cc = p - c + q + tx*ty; cc = x[0]*yy + x[1]*y + cc; x[0] = c + cc; x[1] = c - x[0]; x[1] += cc; } /* ** The string z[] is an text representation of a real number. ** Convert this string to a double and write it into *pResult. ** ** The string z[] is length bytes in length (bytes, not characters) and ** uses the encoding enc. 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. More specifically ** return ** 1 => The input string is a pure integer ** 2 or more => The input has a decimal point or eNNN clause ** 0 or less => The input string is not a valid number ** -1 => Not a valid number, but has a valid prefix which ** includes a decimal point and/or an eNNN clause ** ** 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. */ #if defined(_MSC_VER) #pragma warning(disable : 4756) #endif int sqlite3AtoF(const char *z, double *pResult, int length, u8 enc){ #ifndef SQLITE_OMIT_FLOATING_POINT int incr; const char *zEnd; /* sign * significand * (10 ^ (esign * exponent)) */ int sign = 1; /* sign of significand */ u64 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 */ int nDigit = 0; /* Number of digits processed */ int eType = 1; /* 1: pure integer, 2+: fractional -1 or less: bad UTF16 */ u64 s2; /* round-tripped significand */ double rr[2]; assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE ); *pResult = 0.0; /* Default return value, in case of an error */ if( length==0 ) return 0; if( enc==SQLITE_UTF8 ){ incr = 1; zEnd = z + length; }else{ int i; incr = 2; length &= ~1; assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 ); testcase( enc==SQLITE_UTF16LE ); testcase( enc==SQLITE_UTF16BE ); for(i=3-enc; i=zEnd ) return 0; /* get sign of significand */ if( *z=='-' ){ sign = -1; z+=incr; }else if( *z=='+' ){ z+=incr; } /* copy max significant digits to significand */ while( z=((LARGEST_UINT64-9)/10) ){ /* skip non-significant significand digits ** (increase exponent by d to shift decimal left) */ while( z=zEnd ) goto do_atof_calc; /* if decimal point is present */ if( *z=='.' ){ z+=incr; eType++; /* copy digits from after decimal to significand ** (decrease exponent by d to shift decimal right) */ while( z=zEnd ) goto do_atof_calc; /* if exponent is present */ if( *z=='e' || *z=='E' ){ z+=incr; eValid = 0; eType++; /* This branch is needed to avoid a (harmless) buffer overread. The ** special comment alerts the mutation tester that the correct answer ** is obtained even if the branch is omitted */ if( z>=zEnd ) goto do_atof_calc; /*PREVENTS-HARMLESS-OVERREAD*/ /* get sign of exponent */ if( *z=='-' ){ esign = -1; z+=incr; }else if( *z=='+' ){ z+=incr; } /* copy digits to exponent */ while( z0 && s<((LARGEST_UINT64-0x7ff)/10) ){ s *= 10; e--; } while( e<0 && (s%10)==0 ){ s /= 10; e++; } rr[0] = (double)s; assert( sizeof(s2)==sizeof(rr[0]) ); #ifdef SQLITE_DEBUG rr[1] = 18446744073709549568.0; memcpy(&s2, &rr[1], sizeof(s2)); assert( s2==0x43efffffffffffffLL ); #endif /* Largest double that can be safely converted to u64 ** vvvvvvvvvvvvvvvvvvvvvv */ if( rr[0]<=18446744073709549568.0 ){ s2 = (u64)rr[0]; rr[1] = s>=s2 ? (double)(s - s2) : -(double)(s2 - s); }else{ rr[1] = 0.0; } assert( rr[1]<=1.0e-10*rr[0] ); /* Equal only when rr[0]==0.0 */ if( e>0 ){ while( e>=100 ){ e -= 100; dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83); } while( e>=10 ){ e -= 10; dekkerMul2(rr, 1.0e+10, 0.0); } while( e>=1 ){ e -= 1; dekkerMul2(rr, 1.0e+01, 0.0); } }else{ while( e<=-100 ){ e += 100; dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117); } while( e<=-10 ){ e += 10; dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27); } while( e<=-1 ){ e += 1; dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18); } } *pResult = rr[0]+rr[1]; if( sqlite3IsNaN(*pResult) ) *pResult = 1e300*1e300; if( sign<0 ) *pResult = -*pResult; assert( !sqlite3IsNaN(*pResult) ); atof_return: /* return true if number and no extra non-whitespace characters after */ if( z==zEnd && nDigit>0 && eValid && eType>0 ){ return eType; }else if( eType>=2 && (eType==3 || eValid) && nDigit>0 ){ return -1; }else{ return 0; } #else return !sqlite3Atoi64(z, pResult, length, enc); #endif /* SQLITE_OMIT_FLOATING_POINT */ } #if defined(_MSC_VER) #pragma warning(default : 4756) #endif /* ** Render an signed 64-bit integer as text. Store the result in zOut[] and ** return the length of the string that was stored, in bytes. The value ** returned does not include the zero terminator at the end of the output ** string. ** ** The caller must ensure that zOut[] is at least 21 bytes in size. */ int sqlite3Int64ToText(i64 v, char *zOut){ int i; u64 x; char zTemp[22]; if( v<0 ){ x = (v==SMALLEST_INT64) ? ((u64)1)<<63 : (u64)-v; }else{ x = v; } i = sizeof(zTemp)-2; zTemp[sizeof(zTemp)-1] = 0; while( 1 /*exit-by-break*/ ){ zTemp[i] = (x%10) + '0'; x = x/10; if( x==0 ) break; i--; }; if( v<0 ) zTemp[--i] = '-'; memcpy(zOut, &zTemp[i], sizeof(zTemp)-i); return sizeof(zTemp)-1-i; } /* ** 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, ** ** compare2pow63("9223372036854775800", 1) ** ** will return -8. */ static int compare2pow63(const char *zNum, int incr){ int c = 0; int i; /* 012345678901234567 */ const char *pow63 = "922337203685477580"; for(i=0; c==0 && i<18; i++){ c = (zNum[i*incr]-pow63[i])*10; } if( c==0 ){ c = zNum[18*incr] - '8'; testcase( c==(-1) ); testcase( c==0 ); testcase( c==(+1) ); } return c; } /* ** Convert zNum to a 64-bit signed integer. zNum must be decimal. This ** routine does *not* accept hexadecimal notation. ** ** Returns: ** ** -1 Not even a prefix of the input text looks like an integer ** 0 Successful transformation. Fits in a 64-bit signed integer. ** 1 Excess non-space text after the integer value ** 2 Integer too large for a 64-bit signed integer or is malformed ** 3 Special case of 9223372036854775808 ** ** length is the number of bytes in the string (bytes, not characters). ** The string is not necessarily zero-terminated. The encoding is ** given by enc. */ int sqlite3Atoi64(const char *zNum, i64 *pNum, int length, u8 enc){ int incr; u64 u = 0; int neg = 0; /* assume positive */ int i; int c = 0; int nonNum = 0; /* True if input contains UTF16 with high byte non-zero */ int rc; /* Baseline return code */ const char *zStart; const char *zEnd = zNum + length; assert( enc==SQLITE_UTF8 || enc==SQLITE_UTF16LE || enc==SQLITE_UTF16BE ); if( enc==SQLITE_UTF8 ){ incr = 1; }else{ incr = 2; length &= ~1; assert( SQLITE_UTF16LE==2 && SQLITE_UTF16BE==3 ); for(i=3-enc; i='0' && c<='9'; i+=incr){ u = u*10 + c - '0'; } testcase( i==18*incr ); testcase( i==19*incr ); testcase( i==20*incr ); if( u>LARGEST_INT64 ){ /* This test and assignment is needed only to suppress UB warnings ** from clang and -fsanitize=undefined. This test and assignment make ** the code a little larger and slower, and no harm comes from omitting ** them, but we must appease the undefined-behavior pharisees. */ *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64; }else if( neg ){ *pNum = -(i64)u; }else{ *pNum = (i64)u; } rc = 0; if( i==0 && zStart==zNum ){ /* No digits */ rc = -1; }else if( nonNum ){ /* UTF16 with high-order bytes non-zero */ rc = 1; }else if( &zNum[i]19*incr ? 1 : compare2pow63(zNum, incr); if( c<0 ){ /* zNum is less than 9223372036854775808 so it fits */ assert( u<=LARGEST_INT64 ); return rc; }else{ *pNum = neg ? SMALLEST_INT64 : LARGEST_INT64; if( c>0 ){ /* zNum is greater than 9223372036854775808 so it overflows */ return 2; }else{ /* zNum is exactly 9223372036854775808. Fits if negative. The ** special case 2 overflow if positive */ assert( u-1==LARGEST_INT64 ); return neg ? rc : 3; } } } } /* ** Transform a UTF-8 integer literal, in either decimal or hexadecimal, ** into a 64-bit signed integer. This routine accepts hexadecimal literals, ** whereas sqlite3Atoi64() does not. ** ** Returns: ** ** 0 Successful transformation. Fits in a 64-bit signed integer. ** 1 Excess text after the integer value ** 2 Integer too large for a 64-bit signed integer or is malformed ** 3 Special case of 9223372036854775808 */ int sqlite3DecOrHexToI64(const char *z, i64 *pOut){ #ifndef SQLITE_OMIT_HEX_INTEGER if( z[0]=='0' && (z[1]=='x' || z[1]=='X') ){ u64 u = 0; int i, k; for(i=2; z[i]=='0'; i++){} for(k=i; sqlite3Isxdigit(z[k]); k++){ u = u*16 + sqlite3HexToInt(z[k]); } memcpy(pOut, &u, 8); if( k-i>16 ) return 2; if( z[k]!=0 ) return 1; return 0; }else #endif /* SQLITE_OMIT_HEX_INTEGER */ { int n = (int)(0x3fffffff&strspn(z,"+- \n\t0123456789")); if( z[n] ) n++; return sqlite3Atoi64(z, pOut, n, SQLITE_UTF8); } } /* ** If zNum represents an integer that will fit in 32-bits, then set ** *pValue to that integer and return true. Otherwise return false. ** ** This routine accepts both decimal and hexadecimal notation for integers. ** ** Any non-numeric characters that following zNum are ignored. ** This is different from sqlite3Atoi64() which requires the ** input number to be zero-terminated. */ int sqlite3GetInt32(const char *zNum, int *pValue){ sqlite_int64 v = 0; int i, c; int neg = 0; if( zNum[0]=='-' ){ neg = 1; zNum++; }else if( zNum[0]=='+' ){ zNum++; } #ifndef SQLITE_OMIT_HEX_INTEGER else if( zNum[0]=='0' && (zNum[1]=='x' || zNum[1]=='X') && sqlite3Isxdigit(zNum[2]) ){ u32 u = 0; zNum += 2; while( zNum[0]=='0' ) zNum++; for(i=0; i<8 && sqlite3Isxdigit(zNum[i]); i++){ u = u*16 + sqlite3HexToInt(zNum[i]); } if( (u&0x80000000)==0 && sqlite3Isxdigit(zNum[i])==0 ){ memcpy(pValue, &u, 4); return 1; }else{ return 0; } } #endif if( !sqlite3Isdigit(zNum[0]) ) return 0; while( zNum[0]=='0' ) zNum++; for(i=0; i<11 && (c = zNum[i] - '0')>=0 && c<=9; i++){ v = v*10 + c; } /* The longest decimal representation of a 32 bit integer is 10 digits: ** ** 1234567890 ** 2^31 -> 2147483648 */ testcase( i==10 ); if( i>10 ){ return 0; } testcase( v-neg==2147483647 ); if( v-neg>2147483647 ){ return 0; } if( neg ){ v = -v; } *pValue = (int)v; return 1; } /* ** Return a 32-bit integer value extracted from a string. If the ** string is not an integer, just return 0. */ int sqlite3Atoi(const char *z){ int x = 0; sqlite3GetInt32(z, &x); return x; } /* ** Decode a floating-point value into an approximate decimal ** representation. ** ** If iRound<=0 then round to -iRound significant digits to the ** the left of the decimal point, or to a maximum of mxRound total ** significant digits. ** ** If iRound>0 round to min(iRound,mxRound) significant digits total. ** ** mxRound must be positive. ** ** The significant digits of the decimal representation are ** stored in p->z[] which is a often (but not always) a pointer ** into the middle of p->zBuf[]. There are p->n significant digits. ** The p->z[] array is *not* zero-terminated. */ void sqlite3FpDecode(FpDecode *p, double r, int iRound, int mxRound){ int i; u64 v; int e, exp = 0; double rr[2]; p->isSpecial = 0; p->z = p->zBuf; assert( mxRound>0 ); /* Convert negative numbers to positive. Deal with Infinity, 0.0, and ** NaN. */ if( r<0.0 ){ p->sign = '-'; r = -r; }else if( r==0.0 ){ p->sign = '+'; p->n = 1; p->iDP = 1; p->z = "0"; return; }else{ p->sign = '+'; } memcpy(&v,&r,8); e = v>>52; if( (e&0x7ff)==0x7ff ){ p->isSpecial = 1 + (v!=0x7ff0000000000000LL); p->n = 0; p->iDP = 0; return; } /* Multiply r by powers of ten until it lands somewhere in between ** 1.0e+19 and 1.0e+17. ** ** Use Dekker-style double-double computation to increase the ** precision. ** ** The error terms on constants like 1.0e+100 computed using the ** decimal extension, for example as follows: ** ** SELECT decimal_exp(decimal_sub('1.0e+100',decimal(1.0e+100))); */ rr[0] = r; rr[1] = 0.0; if( rr[0]>9.223372036854774784e+18 ){ while( rr[0]>9.223372036854774784e+118 ){ exp += 100; dekkerMul2(rr, 1.0e-100, -1.99918998026028836196e-117); } while( rr[0]>9.223372036854774784e+28 ){ exp += 10; dekkerMul2(rr, 1.0e-10, -3.6432197315497741579e-27); } while( rr[0]>9.223372036854774784e+18 ){ exp += 1; dekkerMul2(rr, 1.0e-01, -5.5511151231257827021e-18); } }else{ while( rr[0]<9.223372036854774784e-83 ){ exp -= 100; dekkerMul2(rr, 1.0e+100, -1.5902891109759918046e+83); } while( rr[0]<9.223372036854774784e+07 ){ exp -= 10; dekkerMul2(rr, 1.0e+10, 0.0); } while( rr[0]<9.22337203685477478e+17 ){ exp -= 1; dekkerMul2(rr, 1.0e+01, 0.0); } } v = rr[1]<0.0 ? (u64)rr[0]-(u64)(-rr[1]) : (u64)rr[0]+(u64)rr[1]; /* Extract significant digits. */ i = sizeof(p->zBuf)-1; assert( v>0 ); while( v ){ p->zBuf[i--] = (v%10) + '0'; v /= 10; } assert( i>=0 && izBuf)-1 ); p->n = sizeof(p->zBuf) - 1 - i; assert( p->n>0 ); assert( p->nzBuf) ); p->iDP = p->n + exp; if( iRound<=0 ){ iRound = p->iDP - iRound; if( iRound==0 && p->zBuf[i+1]>='5' ){ iRound = 1; p->zBuf[i--] = '0'; p->n++; p->iDP++; } } if( iRound>0 && (iRoundn || p->n>mxRound) ){ char *z = &p->zBuf[i+1]; if( iRound>mxRound ) iRound = mxRound; p->n = iRound; if( z[iRound]>='5' ){ int j = iRound-1; while( 1 /*exit-by-break*/ ){ z[j]++; if( z[j]<='9' ) break; z[j] = '0'; if( j==0 ){ p->z[i--] = '1'; p->n++; p->iDP++; break; }else{ j--; } } } } p->z = &p->zBuf[i+1]; assert( i+p->n < sizeof(p->zBuf) ); while( ALWAYS(p->n>0) && p->z[p->n-1]=='0' ){ p->n--; } } /* ** Try to convert z into an unsigned 32-bit integer. Return true on ** success and false if there is an error. ** ** Only decimal notation is accepted. */ int sqlite3GetUInt32(const char *z, u32 *pI){ u64 v = 0; int i; for(i=0; sqlite3Isdigit(z[i]); i++){ v = v*10 + z[i] - '0'; if( v>4294967296LL ){ *pI = 0; return 0; } } if( i==0 || z[i]!=0 ){ *pI = 0; return 0; } *pI = (u32)v; return 1; } /* ** The variable-length integer encoding is as follows: ** ** KEY: ** A = 0xxxxxxx 7 bits of data and one flag bit ** B = 1xxxxxxx 7 bits of data and one flag bit ** C = xxxxxxxx 8 bits of data ** ** 7 bits - A ** 14 bits - BA ** 21 bits - BBA ** 28 bits - BBBA ** 35 bits - BBBBA ** 42 bits - BBBBBA ** 49 bits - BBBBBBA ** 56 bits - BBBBBBBA ** 64 bits - BBBBBBBBC */ /* ** Write a 64-bit variable-length integer to memory starting at p[0]. ** The length of data write will be between 1 and 9 bytes. The number ** of bytes written is returned. ** ** A variable-length integer consists of the lower 7 bits of each byte ** for all bytes that have the 8th bit set and one byte with the 8th ** bit clear. Except, if we get to the 9th byte, it stores the full ** 8 bits and is the last byte. */ static int SQLITE_NOINLINE putVarint64(unsigned char *p, u64 v){ int i, j, n; u8 buf[10]; if( v & (((u64)0xff000000)<<32) ){ p[8] = (u8)v; v >>= 8; for(i=7; i>=0; i--){ p[i] = (u8)((v & 0x7f) | 0x80); v >>= 7; } return 9; } n = 0; do{ buf[n++] = (u8)((v & 0x7f) | 0x80); v >>= 7; }while( v!=0 ); buf[0] &= 0x7f; assert( n<=9 ); for(i=0, j=n-1; j>=0; j--, i++){ p[i] = buf[j]; } return n; } int sqlite3PutVarint(unsigned char *p, u64 v){ if( v<=0x7f ){ p[0] = v&0x7f; return 1; } if( v<=0x3fff ){ p[0] = ((v>>7)&0x7f)|0x80; p[1] = v&0x7f; return 2; } return putVarint64(p,v); } /* ** Bitmasks used by sqlite3GetVarint(). These precomputed constants ** are defined here rather than simply putting the constant expressions ** inline in order to work around bugs in the RVT compiler. ** ** SLOT_2_0 A mask for (0x7f<<14) | 0x7f ** ** SLOT_4_2_0 A mask for (0x7f<<28) | SLOT_2_0 */ #define SLOT_2_0 0x001fc07f #define SLOT_4_2_0 0xf01fc07f /* ** Read a 64-bit variable-length integer from memory starting at p[0]. ** Return the number of bytes read. The value is stored in *v. */ u8 sqlite3GetVarint(const unsigned char *p, u64 *v){ u32 a,b,s; if( ((signed char*)p)[0]>=0 ){ *v = *p; return 1; } if( ((signed char*)p)[1]>=0 ){ *v = ((u32)(p[0]&0x7f)<<7) | p[1]; return 2; } /* Verify that constants are precomputed correctly */ assert( SLOT_2_0 == ((0x7f<<14) | (0x7f)) ); assert( SLOT_4_2_0 == ((0xfU<<28) | (0x7f<<14) | (0x7f)) ); a = ((u32)p[0])<<14; b = p[1]; p += 2; a |= *p; /* a: p0<<14 | p2 (unmasked) */ if (!(a&0x80)) { a &= SLOT_2_0; b &= 0x7f; b = b<<7; a |= b; *v = a; return 3; } /* CSE1 from below */ a &= SLOT_2_0; p++; b = b<<14; b |= *p; /* b: p1<<14 | p3 (unmasked) */ if (!(b&0x80)) { b &= SLOT_2_0; /* moved CSE1 up */ /* a &= (0x7f<<14)|(0x7f); */ a = a<<7; a |= b; *v = a; return 4; } /* a: p0<<14 | p2 (masked) */ /* b: p1<<14 | p3 (unmasked) */ /* 1:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ /* moved CSE1 up */ /* a &= (0x7f<<14)|(0x7f); */ b &= SLOT_2_0; s = a; /* s: p0<<14 | p2 (masked) */ p++; a = a<<14; a |= *p; /* a: p0<<28 | p2<<14 | p4 (unmasked) */ if (!(a&0x80)) { /* we can skip these cause they were (effectively) done above ** while calculating s */ /* a &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ /* b &= (0x7f<<14)|(0x7f); */ b = b<<7; a |= b; s = s>>18; *v = ((u64)s)<<32 | a; return 5; } /* 2:save off p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ s = s<<7; s |= b; /* s: p0<<21 | p1<<14 | p2<<7 | p3 (masked) */ p++; b = b<<14; b |= *p; /* b: p1<<28 | p3<<14 | p5 (unmasked) */ if (!(b&0x80)) { /* we can skip this cause it was (effectively) done above in calc'ing s */ /* b &= (0x7f<<28)|(0x7f<<14)|(0x7f); */ a &= SLOT_2_0; a = a<<7; a |= b; s = s>>18; *v = ((u64)s)<<32 | a; return 6; } p++; a = a<<14; a |= *p; /* a: p2<<28 | p4<<14 | p6 (unmasked) */ if (!(a&0x80)) { a &= SLOT_4_2_0; b &= SLOT_2_0; b = b<<7; a |= b; s = s>>11; *v = ((u64)s)<<32 | a; return 7; } /* CSE2 from below */ a &= SLOT_2_0; p++; b = b<<14; b |= *p; /* b: p3<<28 | p5<<14 | p7 (unmasked) */ if (!(b&0x80)) { b &= SLOT_4_2_0; /* moved CSE2 up */ /* a &= (0x7f<<14)|(0x7f); */ a = a<<7; a |= b; s = s>>4; *v = ((u64)s)<<32 | a; return 8; } p++; a = a<<15; a |= *p; /* a: p4<<29 | p6<<15 | p8 (unmasked) */ /* moved CSE2 up */ /* a &= (0x7f<<29)|(0x7f<<15)|(0xff); */ b &= SLOT_2_0; b = b<<8; a |= b; s = s<<4; b = p[-4]; b &= 0x7f; b = b>>3; s |= b; *v = ((u64)s)<<32 | a; return 9; } /* ** Read a 32-bit variable-length integer from memory starting at p[0]. ** Return the number of bytes read. The value is stored in *v. ** ** If the varint stored in p[0] is larger than can fit in a 32-bit unsigned ** integer, then set *v to 0xffffffff. ** ** A MACRO version, getVarint32, is provided which inlines the ** single-byte case. All code should use the MACRO version as ** this function assumes the single-byte case has already been handled. */ u8 sqlite3GetVarint32(const unsigned char *p, u32 *v){ u64 v64; u8 n; /* Assume that the single-byte case has already been handled by ** the getVarint32() macro */ assert( (p[0] & 0x80)!=0 ); if( (p[1] & 0x80)==0 ){ /* This is the two-byte case */ *v = ((p[0]&0x7f)<<7) | p[1]; return 2; } if( (p[2] & 0x80)==0 ){ /* This is the three-byte case */ *v = ((p[0]&0x7f)<<14) | ((p[1]&0x7f)<<7) | p[2]; return 3; } /* four or more bytes */ n = sqlite3GetVarint(p, &v64); assert( n>3 && n<=9 ); if( (v64 & SQLITE_MAX_U32)!=v64 ){ *v = 0xffffffff; }else{ *v = (u32)v64; } return n; } /* ** Return the number of bytes that will be needed to store the given ** 64-bit integer. */ int sqlite3VarintLen(u64 v){ int i; for(i=1; (v >>= 7)!=0; i++){ assert( i<10 ); } return i; } /* ** Read or write a four-byte big-endian integer value. */ u32 sqlite3Get4byte(const u8 *p){ #if SQLITE_BYTEORDER==4321 u32 x; memcpy(&x,p,4); return x; #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000 u32 x; memcpy(&x,p,4); return __builtin_bswap32(x); #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300 u32 x; memcpy(&x,p,4); return _byteswap_ulong(x); #else testcase( p[0]&0x80 ); return ((unsigned)p[0]<<24) | (p[1]<<16) | (p[2]<<8) | p[3]; #endif } void sqlite3Put4byte(unsigned char *p, u32 v){ #if SQLITE_BYTEORDER==4321 memcpy(p,&v,4); #elif SQLITE_BYTEORDER==1234 && GCC_VERSION>=4003000 u32 x = __builtin_bswap32(v); memcpy(p,&x,4); #elif SQLITE_BYTEORDER==1234 && MSVC_VERSION>=1300 u32 x = _byteswap_ulong(v); memcpy(p,&x,4); #else p[0] = (u8)(v>>24); p[1] = (u8)(v>>16); p[2] = (u8)(v>>8); p[3] = (u8)v; #endif } /* ** Translate a single byte of Hex into an integer. ** This routine only works if h really is a valid hexadecimal ** character: 0..9a..fA..F */ u8 sqlite3HexToInt(int h){ assert( (h>='0' && h<='9') || (h>='a' && h<='f') || (h>='A' && h<='F') ); #ifdef SQLITE_ASCII h += 9*(1&(h>>6)); #endif #ifdef SQLITE_EBCDIC h += 9*(1&~(h>>4)); #endif return (u8)(h & 0xf); } #if !defined(SQLITE_OMIT_BLOB_LITERAL) /* ** Convert a BLOB literal of the form "x'hhhhhh'" into its binary ** value. Return a pointer to its binary value. Space to hold the ** binary value has been obtained from malloc and must be freed by ** the calling routine. */ void *sqlite3HexToBlob(sqlite3 *db, const char *z, int n){ char *zBlob; int i; zBlob = (char *)sqlite3DbMallocRawNN(db, n/2 + 1); n--; if( zBlob ){ for(i=0; ieOpenState; if( eOpenState!=SQLITE_STATE_OPEN ){ if( sqlite3SafetyCheckSickOrOk(db) ){ testcase( sqlite3GlobalConfig.xLog!=0 ); logBadConnection("unopened"); } return 0; }else{ return 1; } } int sqlite3SafetyCheckSickOrOk(sqlite3 *db){ u8 eOpenState; eOpenState = db->eOpenState; if( eOpenState!=SQLITE_STATE_SICK && eOpenState!=SQLITE_STATE_OPEN && eOpenState!=SQLITE_STATE_BUSY ){ testcase( sqlite3GlobalConfig.xLog!=0 ); logBadConnection("invalid"); return 0; }else{ return 1; } } /* ** Attempt to add, subtract, or multiply the 64-bit signed value iB against ** the other 64-bit signed integer at *pA and store the result in *pA. ** Return 0 on success. Or if the operation would have resulted in an ** overflow, leave *pA unchanged and return 1. */ int sqlite3AddInt64(i64 *pA, i64 iB){ #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER) return __builtin_add_overflow(*pA, iB, pA); #else i64 iA = *pA; testcase( iA==0 ); testcase( iA==1 ); testcase( iB==-1 ); testcase( iB==0 ); if( iB>=0 ){ testcase( iA>0 && LARGEST_INT64 - iA == iB ); testcase( iA>0 && LARGEST_INT64 - iA == iB - 1 ); if( iA>0 && LARGEST_INT64 - iA < iB ) return 1; }else{ testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 1 ); testcase( iA<0 && -(iA + LARGEST_INT64) == iB + 2 ); if( iA<0 && -(iA + LARGEST_INT64) > iB + 1 ) return 1; } *pA += iB; return 0; #endif } int sqlite3SubInt64(i64 *pA, i64 iB){ #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER) return __builtin_sub_overflow(*pA, iB, pA); #else testcase( iB==SMALLEST_INT64+1 ); if( iB==SMALLEST_INT64 ){ testcase( (*pA)==(-1) ); testcase( (*pA)==0 ); if( (*pA)>=0 ) return 1; *pA -= iB; return 0; }else{ return sqlite3AddInt64(pA, -iB); } #endif } int sqlite3MulInt64(i64 *pA, i64 iB){ #if GCC_VERSION>=5004000 && !defined(__INTEL_COMPILER) return __builtin_mul_overflow(*pA, iB, pA); #else i64 iA = *pA; if( iB>0 ){ if( iA>LARGEST_INT64/iB ) return 1; if( iA0 ){ if( iBLARGEST_INT64/-iB ) return 1; } } *pA = iA*iB; return 0; #endif } /* ** Compute the absolute value of a 32-bit signed integer, of possible. Or ** if the integer has a value of -2147483648, return +2147483647 */ int sqlite3AbsInt32(int x){ if( x>=0 ) return x; if( x==(int)0x80000000 ) return 0x7fffffff; return -x; } #ifdef SQLITE_ENABLE_8_3_NAMES /* ** If SQLITE_ENABLE_8_3_NAMES is set at compile-time and if the database ** filename in zBaseFilename is a URI with the "8_3_names=1" parameter and ** if filename in z[] has a suffix (a.k.a. "extension") that is longer than ** three characters, then shorten the suffix on z[] to be the last three ** characters of the original suffix. ** ** If SQLITE_ENABLE_8_3_NAMES is set to 2 at compile-time, then always ** do the suffix shortening regardless of URI parameter. ** ** Examples: ** ** test.db-journal => test.nal ** test.db-wal => test.wal ** test.db-shm => test.shm ** test.db-mj7f3319fa => test.9fa */ void sqlite3FileSuffix3(const char *zBaseFilename, char *z){ #if SQLITE_ENABLE_8_3_NAMES<2 if( sqlite3_uri_boolean(zBaseFilename, "8_3_names", 0) ) #endif { int i, sz; sz = sqlite3Strlen30(z); for(i=sz-1; i>0 && z[i]!='/' && z[i]!='.'; i--){} if( z[i]=='.' && ALWAYS(sz>i+4) ) memmove(&z[i+1], &z[sz-3], 4); } } #endif /* ** Find (an approximate) sum of two LogEst values. This computation is ** not a simple "+" operator because LogEst is stored as a logarithmic ** value. ** */ LogEst sqlite3LogEstAdd(LogEst a, LogEst b){ static const unsigned char x[] = { 10, 10, /* 0,1 */ 9, 9, /* 2,3 */ 8, 8, /* 4,5 */ 7, 7, 7, /* 6,7,8 */ 6, 6, 6, /* 9,10,11 */ 5, 5, 5, /* 12-14 */ 4, 4, 4, 4, /* 15-18 */ 3, 3, 3, 3, 3, 3, /* 19-24 */ 2, 2, 2, 2, 2, 2, 2, /* 25-31 */ }; if( a>=b ){ if( a>b+49 ) return a; if( a>b+31 ) return a+1; return a+x[a-b]; }else{ if( b>a+49 ) return b; if( b>a+31 ) return b+1; return b+x[b-a]; } } /* ** Convert an integer into a LogEst. In other words, compute an ** approximation for 10*log2(x). */ LogEst sqlite3LogEst(u64 x){ static LogEst a[] = { 0, 2, 3, 5, 6, 7, 8, 9 }; LogEst y = 40; if( x<8 ){ if( x<2 ) return 0; while( x<8 ){ y -= 10; x <<= 1; } }else{ #if GCC_VERSION>=5004000 int i = 60 - __builtin_clzll(x); y += i*10; x >>= i; #else while( x>255 ){ y += 40; x >>= 4; } /*OPTIMIZATION-IF-TRUE*/ while( x>15 ){ y += 10; x >>= 1; } #endif } return a[x&7] + y - 10; } /* ** Convert a double into a LogEst ** In other words, compute an approximation for 10*log2(x). */ LogEst sqlite3LogEstFromDouble(double x){ u64 a; LogEst e; assert( sizeof(x)==8 && sizeof(a)==8 ); if( x<=1 ) return 0; if( x<=2000000000 ) return sqlite3LogEst((u64)x); memcpy(&a, &x, 8); e = (a>>52) - 1022; return e*10; } /* ** Convert a LogEst into an integer. */ u64 sqlite3LogEstToInt(LogEst x){ u64 n; n = x%10; x /= 10; if( n>=5 ) n -= 2; else if( n>=1 ) n -= 1; if( x>60 ) return (u64)LARGEST_INT64; return x>=3 ? (n+8)<<(x-3) : (n+8)>>(3-x); } /* ** Add a new name/number pair to a VList. This might require that the ** VList object be reallocated, so return the new VList. If an OOM ** error occurs, the original VList returned and the ** db->mallocFailed flag is set. ** ** A VList is really just an array of integers. To destroy a VList, ** simply pass it to sqlite3DbFree(). ** ** The first integer is the number of integers allocated for the whole ** VList. The second integer is the number of integers actually used. ** Each name/number pair is encoded by subsequent groups of 3 or more ** integers. ** ** Each name/number pair starts with two integers which are the numeric ** value for the pair and the size of the name/number pair, respectively. ** The text name overlays one or more following integers. The text name ** is always zero-terminated. ** ** Conceptually: ** ** struct VList { ** int nAlloc; // Number of allocated slots ** int nUsed; // Number of used slots ** struct VListEntry { ** int iValue; // Value for this entry ** int nSlot; // Slots used by this entry ** // ... variable name goes here ** } a[0]; ** } ** ** During code generation, pointers to the variable names within the ** VList are taken. When that happens, nAlloc is set to zero as an ** indication that the VList may never again be enlarged, since the ** accompanying realloc() would invalidate the pointers. */ VList *sqlite3VListAdd( sqlite3 *db, /* The database connection used for malloc() */ VList *pIn, /* The input VList. Might be NULL */ const char *zName, /* Name of symbol to add */ int nName, /* Bytes of text in zName */ int iVal /* Value to associate with zName */ ){ int nInt; /* number of sizeof(int) objects needed for zName */ char *z; /* Pointer to where zName will be stored */ int i; /* Index in pIn[] where zName is stored */ nInt = nName/4 + 3; assert( pIn==0 || pIn[0]>=3 ); /* Verify ok to add new elements */ if( pIn==0 || pIn[1]+nInt > pIn[0] ){ /* Enlarge the allocation */ sqlite3_int64 nAlloc = (pIn ? 2*(sqlite3_int64)pIn[0] : 10) + nInt; VList *pOut = sqlite3DbRealloc(db, pIn, nAlloc*sizeof(int)); if( pOut==0 ) return pIn; if( pIn==0 ) pOut[1] = 2; pIn = pOut; pIn[0] = nAlloc; } i = pIn[1]; pIn[i] = iVal; pIn[i+1] = nInt; z = (char*)&pIn[i+2]; pIn[1] = i+nInt; assert( pIn[1]<=pIn[0] ); memcpy(z, zName, nName); z[nName] = 0; return pIn; } /* ** Return a pointer to the name of a variable in the given VList that ** has the value iVal. Or return a NULL if there is no such variable in ** the list */ const char *sqlite3VListNumToName(VList *pIn, int iVal){ int i, mx; if( pIn==0 ) return 0; mx = pIn[1]; i = 2; do{ if( pIn[i]==iVal ) return (char*)&pIn[i+2]; i += pIn[i+1]; }while( i