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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:28:19 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-05 17:28:19 +0000 |
commit | 18657a960e125336f704ea058e25c27bd3900dcb (patch) | |
tree | 17b438b680ed45a996d7b59951e6aa34023783f2 /ext/misc/decimal.c | |
parent | Initial commit. (diff) | |
download | sqlite3-upstream.tar.xz sqlite3-upstream.zip |
Adding upstream version 3.40.1.upstream/3.40.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'ext/misc/decimal.c')
-rw-r--r-- | ext/misc/decimal.c | 635 |
1 files changed, 635 insertions, 0 deletions
diff --git a/ext/misc/decimal.c b/ext/misc/decimal.c new file mode 100644 index 0000000..37c6c2f --- /dev/null +++ b/ext/misc/decimal.c @@ -0,0 +1,635 @@ +/* +** 2020-06-22 +** +** 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. +** +****************************************************************************** +** +** Routines to implement arbitrary-precision decimal math. +** +** The focus here is on simplicity and correctness, not performance. +*/ +#include "sqlite3ext.h" +SQLITE_EXTENSION_INIT1 +#include <assert.h> +#include <string.h> +#include <ctype.h> +#include <stdlib.h> + +/* Mark a function parameter as unused, to suppress nuisance compiler +** warnings. */ +#ifndef UNUSED_PARAMETER +# define UNUSED_PARAMETER(X) (void)(X) +#endif + + +/* A decimal object */ +typedef struct Decimal Decimal; +struct Decimal { + char sign; /* 0 for positive, 1 for negative */ + char oom; /* True if an OOM is encountered */ + char isNull; /* True if holds a NULL rather than a number */ + char isInit; /* True upon initialization */ + int nDigit; /* Total number of digits */ + int nFrac; /* Number of digits to the right of the decimal point */ + signed char *a; /* Array of digits. Most significant first. */ +}; + +/* +** Release memory held by a Decimal, but do not free the object itself. +*/ +static void decimal_clear(Decimal *p){ + sqlite3_free(p->a); +} + +/* +** Destroy a Decimal object +*/ +static void decimal_free(Decimal *p){ + if( p ){ + decimal_clear(p); + sqlite3_free(p); + } +} + +/* +** Allocate a new Decimal object. Initialize it to the number given +** by the input string. +*/ +static Decimal *decimal_new( + sqlite3_context *pCtx, + sqlite3_value *pIn, + int nAlt, + const unsigned char *zAlt +){ + Decimal *p; + int n, i; + const unsigned char *zIn; + int iExp = 0; + p = sqlite3_malloc( sizeof(*p) ); + if( p==0 ) goto new_no_mem; + p->sign = 0; + p->oom = 0; + p->isInit = 1; + p->isNull = 0; + p->nDigit = 0; + p->nFrac = 0; + if( zAlt ){ + n = nAlt, + zIn = zAlt; + }else{ + if( sqlite3_value_type(pIn)==SQLITE_NULL ){ + p->a = 0; + p->isNull = 1; + return p; + } + n = sqlite3_value_bytes(pIn); + zIn = sqlite3_value_text(pIn); + } + p->a = sqlite3_malloc64( n+1 ); + if( p->a==0 ) goto new_no_mem; + for(i=0; isspace(zIn[i]); i++){} + if( zIn[i]=='-' ){ + p->sign = 1; + i++; + }else if( zIn[i]=='+' ){ + i++; + } + while( i<n && zIn[i]=='0' ) i++; + while( i<n ){ + char c = zIn[i]; + if( c>='0' && c<='9' ){ + p->a[p->nDigit++] = c - '0'; + }else if( c=='.' ){ + p->nFrac = p->nDigit + 1; + }else if( c=='e' || c=='E' ){ + int j = i+1; + int neg = 0; + if( j>=n ) break; + if( zIn[j]=='-' ){ + neg = 1; + j++; + }else if( zIn[j]=='+' ){ + j++; + } + while( j<n && iExp<1000000 ){ + if( zIn[j]>='0' && zIn[j]<='9' ){ + iExp = iExp*10 + zIn[j] - '0'; + } + j++; + } + if( neg ) iExp = -iExp; + break; + } + i++; + } + if( p->nFrac ){ + p->nFrac = p->nDigit - (p->nFrac - 1); + } + if( iExp>0 ){ + if( p->nFrac>0 ){ + if( iExp<=p->nFrac ){ + p->nFrac -= iExp; + iExp = 0; + }else{ + iExp -= p->nFrac; + p->nFrac = 0; + } + } + if( iExp>0 ){ + p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 ); + if( p->a==0 ) goto new_no_mem; + memset(p->a+p->nDigit, 0, iExp); + p->nDigit += iExp; + } + }else if( iExp<0 ){ + int nExtra; + iExp = -iExp; + nExtra = p->nDigit - p->nFrac - 1; + if( nExtra ){ + if( nExtra>=iExp ){ + p->nFrac += iExp; + iExp = 0; + }else{ + iExp -= nExtra; + p->nFrac = p->nDigit - 1; + } + } + if( iExp>0 ){ + p->a = sqlite3_realloc64(p->a, p->nDigit + iExp + 1 ); + if( p->a==0 ) goto new_no_mem; + memmove(p->a+iExp, p->a, p->nDigit); + memset(p->a, 0, iExp); + p->nDigit += iExp; + p->nFrac += iExp; + } + } + return p; + +new_no_mem: + if( pCtx ) sqlite3_result_error_nomem(pCtx); + sqlite3_free(p); + return 0; +} + +/* +** Make the given Decimal the result. +*/ +static void decimal_result(sqlite3_context *pCtx, Decimal *p){ + char *z; + int i, j; + int n; + if( p==0 || p->oom ){ + sqlite3_result_error_nomem(pCtx); + return; + } + if( p->isNull ){ + sqlite3_result_null(pCtx); + return; + } + z = sqlite3_malloc( p->nDigit+4 ); + if( z==0 ){ + sqlite3_result_error_nomem(pCtx); + return; + } + i = 0; + if( p->nDigit==0 || (p->nDigit==1 && p->a[0]==0) ){ + p->sign = 0; + } + if( p->sign ){ + z[0] = '-'; + i = 1; + } + n = p->nDigit - p->nFrac; + if( n<=0 ){ + z[i++] = '0'; + } + j = 0; + while( n>1 && p->a[j]==0 ){ + j++; + n--; + } + while( n>0 ){ + z[i++] = p->a[j] + '0'; + j++; + n--; + } + if( p->nFrac ){ + z[i++] = '.'; + do{ + z[i++] = p->a[j] + '0'; + j++; + }while( j<p->nDigit ); + } + z[i] = 0; + sqlite3_result_text(pCtx, z, i, sqlite3_free); +} + +/* +** SQL Function: decimal(X) +** +** Convert input X into decimal and then back into text +*/ +static void decimalFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *p = decimal_new(context, argv[0], 0, 0); + UNUSED_PARAMETER(argc); + decimal_result(context, p); + decimal_free(p); +} + +/* +** Compare to Decimal objects. Return negative, 0, or positive if the +** first object is less than, equal to, or greater than the second. +** +** Preconditions for this routine: +** +** pA!=0 +** pA->isNull==0 +** pB!=0 +** pB->isNull==0 +*/ +static int decimal_cmp(const Decimal *pA, const Decimal *pB){ + int nASig, nBSig, rc, n; + if( pA->sign!=pB->sign ){ + return pA->sign ? -1 : +1; + } + if( pA->sign ){ + const Decimal *pTemp = pA; + pA = pB; + pB = pTemp; + } + nASig = pA->nDigit - pA->nFrac; + nBSig = pB->nDigit - pB->nFrac; + if( nASig!=nBSig ){ + return nASig - nBSig; + } + n = pA->nDigit; + if( n>pB->nDigit ) n = pB->nDigit; + rc = memcmp(pA->a, pB->a, n); + if( rc==0 ){ + rc = pA->nDigit - pB->nDigit; + } + return rc; +} + +/* +** SQL Function: decimal_cmp(X, Y) +** +** Return negative, zero, or positive if X is less then, equal to, or +** greater than Y. +*/ +static void decimalCmpFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *pA = 0, *pB = 0; + int rc; + + UNUSED_PARAMETER(argc); + pA = decimal_new(context, argv[0], 0, 0); + if( pA==0 || pA->isNull ) goto cmp_done; + pB = decimal_new(context, argv[1], 0, 0); + if( pB==0 || pB->isNull ) goto cmp_done; + rc = decimal_cmp(pA, pB); + if( rc<0 ) rc = -1; + else if( rc>0 ) rc = +1; + sqlite3_result_int(context, rc); +cmp_done: + decimal_free(pA); + decimal_free(pB); +} + +/* +** Expand the Decimal so that it has a least nDigit digits and nFrac +** digits to the right of the decimal point. +*/ +static void decimal_expand(Decimal *p, int nDigit, int nFrac){ + int nAddSig; + int nAddFrac; + if( p==0 ) return; + nAddFrac = nFrac - p->nFrac; + nAddSig = (nDigit - p->nDigit) - nAddFrac; + if( nAddFrac==0 && nAddSig==0 ) return; + p->a = sqlite3_realloc64(p->a, nDigit+1); + if( p->a==0 ){ + p->oom = 1; + return; + } + if( nAddSig ){ + memmove(p->a+nAddSig, p->a, p->nDigit); + memset(p->a, 0, nAddSig); + p->nDigit += nAddSig; + } + if( nAddFrac ){ + memset(p->a+p->nDigit, 0, nAddFrac); + p->nDigit += nAddFrac; + p->nFrac += nAddFrac; + } +} + +/* +** Add the value pB into pA. +** +** Both pA and pB might become denormalized by this routine. +*/ +static void decimal_add(Decimal *pA, Decimal *pB){ + int nSig, nFrac, nDigit; + int i, rc; + if( pA==0 ){ + return; + } + if( pA->oom || pB==0 || pB->oom ){ + pA->oom = 1; + return; + } + if( pA->isNull || pB->isNull ){ + pA->isNull = 1; + return; + } + nSig = pA->nDigit - pA->nFrac; + if( nSig && pA->a[0]==0 ) nSig--; + if( nSig<pB->nDigit-pB->nFrac ){ + nSig = pB->nDigit - pB->nFrac; + } + nFrac = pA->nFrac; + if( nFrac<pB->nFrac ) nFrac = pB->nFrac; + nDigit = nSig + nFrac + 1; + decimal_expand(pA, nDigit, nFrac); + decimal_expand(pB, nDigit, nFrac); + if( pA->oom || pB->oom ){ + pA->oom = 1; + }else{ + if( pA->sign==pB->sign ){ + int carry = 0; + for(i=nDigit-1; i>=0; i--){ + int x = pA->a[i] + pB->a[i] + carry; + if( x>=10 ){ + carry = 1; + pA->a[i] = x - 10; + }else{ + carry = 0; + pA->a[i] = x; + } + } + }else{ + signed char *aA, *aB; + int borrow = 0; + rc = memcmp(pA->a, pB->a, nDigit); + if( rc<0 ){ + aA = pB->a; + aB = pA->a; + pA->sign = !pA->sign; + }else{ + aA = pA->a; + aB = pB->a; + } + for(i=nDigit-1; i>=0; i--){ + int x = aA[i] - aB[i] - borrow; + if( x<0 ){ + pA->a[i] = x+10; + borrow = 1; + }else{ + pA->a[i] = x; + borrow = 0; + } + } + } + } +} + +/* +** Compare text in decimal order. +*/ +static int decimalCollFunc( + void *notUsed, + int nKey1, const void *pKey1, + int nKey2, const void *pKey2 +){ + const unsigned char *zA = (const unsigned char*)pKey1; + const unsigned char *zB = (const unsigned char*)pKey2; + Decimal *pA = decimal_new(0, 0, nKey1, zA); + Decimal *pB = decimal_new(0, 0, nKey2, zB); + int rc; + UNUSED_PARAMETER(notUsed); + if( pA==0 || pB==0 ){ + rc = 0; + }else{ + rc = decimal_cmp(pA, pB); + } + decimal_free(pA); + decimal_free(pB); + return rc; +} + + +/* +** SQL Function: decimal_add(X, Y) +** decimal_sub(X, Y) +** +** Return the sum or difference of X and Y. +*/ +static void decimalAddFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *pA = decimal_new(context, argv[0], 0, 0); + Decimal *pB = decimal_new(context, argv[1], 0, 0); + UNUSED_PARAMETER(argc); + decimal_add(pA, pB); + decimal_result(context, pA); + decimal_free(pA); + decimal_free(pB); +} +static void decimalSubFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *pA = decimal_new(context, argv[0], 0, 0); + Decimal *pB = decimal_new(context, argv[1], 0, 0); + UNUSED_PARAMETER(argc); + if( pB ){ + pB->sign = !pB->sign; + decimal_add(pA, pB); + decimal_result(context, pA); + } + decimal_free(pA); + decimal_free(pB); +} + +/* Aggregate funcion: decimal_sum(X) +** +** Works like sum() except that it uses decimal arithmetic for unlimited +** precision. +*/ +static void decimalSumStep( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *p; + Decimal *pArg; + UNUSED_PARAMETER(argc); + p = sqlite3_aggregate_context(context, sizeof(*p)); + if( p==0 ) return; + if( !p->isInit ){ + p->isInit = 1; + p->a = sqlite3_malloc(2); + if( p->a==0 ){ + p->oom = 1; + }else{ + p->a[0] = 0; + } + p->nDigit = 1; + p->nFrac = 0; + } + if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return; + pArg = decimal_new(context, argv[0], 0, 0); + decimal_add(p, pArg); + decimal_free(pArg); +} +static void decimalSumInverse( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *p; + Decimal *pArg; + UNUSED_PARAMETER(argc); + p = sqlite3_aggregate_context(context, sizeof(*p)); + if( p==0 ) return; + if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return; + pArg = decimal_new(context, argv[0], 0, 0); + if( pArg ) pArg->sign = !pArg->sign; + decimal_add(p, pArg); + decimal_free(pArg); +} +static void decimalSumValue(sqlite3_context *context){ + Decimal *p = sqlite3_aggregate_context(context, 0); + if( p==0 ) return; + decimal_result(context, p); +} +static void decimalSumFinalize(sqlite3_context *context){ + Decimal *p = sqlite3_aggregate_context(context, 0); + if( p==0 ) return; + decimal_result(context, p); + decimal_clear(p); +} + +/* +** SQL Function: decimal_mul(X, Y) +** +** Return the product of X and Y. +** +** All significant digits after the decimal point are retained. +** Trailing zeros after the decimal point are omitted as long as +** the number of digits after the decimal point is no less than +** either the number of digits in either input. +*/ +static void decimalMulFunc( + sqlite3_context *context, + int argc, + sqlite3_value **argv +){ + Decimal *pA = decimal_new(context, argv[0], 0, 0); + Decimal *pB = decimal_new(context, argv[1], 0, 0); + signed char *acc = 0; + int i, j, k; + int minFrac; + UNUSED_PARAMETER(argc); + if( pA==0 || pA->oom || pA->isNull + || pB==0 || pB->oom || pB->isNull + ){ + goto mul_end; + } + acc = sqlite3_malloc64( pA->nDigit + pB->nDigit + 2 ); + if( acc==0 ){ + sqlite3_result_error_nomem(context); + goto mul_end; + } + memset(acc, 0, pA->nDigit + pB->nDigit + 2); + minFrac = pA->nFrac; + if( pB->nFrac<minFrac ) minFrac = pB->nFrac; + for(i=pA->nDigit-1; i>=0; i--){ + signed char f = pA->a[i]; + int carry = 0, x; + for(j=pB->nDigit-1, k=i+j+3; j>=0; j--, k--){ + x = acc[k] + f*pB->a[j] + carry; + acc[k] = x%10; + carry = x/10; + } + x = acc[k] + carry; + acc[k] = x%10; + acc[k-1] += x/10; + } + sqlite3_free(pA->a); + pA->a = acc; + acc = 0; + pA->nDigit += pB->nDigit + 2; + pA->nFrac += pB->nFrac; + pA->sign ^= pB->sign; + while( pA->nFrac>minFrac && pA->a[pA->nDigit-1]==0 ){ + pA->nFrac--; + pA->nDigit--; + } + decimal_result(context, pA); + +mul_end: + sqlite3_free(acc); + decimal_free(pA); + decimal_free(pB); +} + +#ifdef _WIN32 +__declspec(dllexport) +#endif +int sqlite3_decimal_init( + sqlite3 *db, + char **pzErrMsg, + const sqlite3_api_routines *pApi +){ + int rc = SQLITE_OK; + static const struct { + const char *zFuncName; + int nArg; + void (*xFunc)(sqlite3_context*,int,sqlite3_value**); + } aFunc[] = { + { "decimal", 1, decimalFunc }, + { "decimal_cmp", 2, decimalCmpFunc }, + { "decimal_add", 2, decimalAddFunc }, + { "decimal_sub", 2, decimalSubFunc }, + { "decimal_mul", 2, decimalMulFunc }, + }; + unsigned int i; + (void)pzErrMsg; /* Unused parameter */ + + SQLITE_EXTENSION_INIT2(pApi); + + for(i=0; i<sizeof(aFunc)/sizeof(aFunc[0]) && rc==SQLITE_OK; i++){ + rc = sqlite3_create_function(db, aFunc[i].zFuncName, aFunc[i].nArg, + SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC, + 0, aFunc[i].xFunc, 0, 0); + } + if( rc==SQLITE_OK ){ + rc = sqlite3_create_window_function(db, "decimal_sum", 1, + SQLITE_UTF8|SQLITE_INNOCUOUS|SQLITE_DETERMINISTIC, 0, + decimalSumStep, decimalSumFinalize, + decimalSumValue, decimalSumInverse, 0); + } + if( rc==SQLITE_OK ){ + rc = sqlite3_create_collation(db, "decimal", SQLITE_UTF8, + 0, decimalCollFunc); + } + return rc; +} |