mirror of
https://github.com/berkeleydb/libdb.git
synced 2024-11-17 01:26:25 +00:00
501 lines
14 KiB
C
501 lines
14 KiB
C
/*
|
||
** 2007 May 6
|
||
**
|
||
** 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.
|
||
**
|
||
*************************************************************************
|
||
** $Id: icu.c,v 1.7 2007/12/13 21:54:11 drh Exp $
|
||
**
|
||
** This file implements an integration between the ICU library
|
||
** ("International Components for Unicode", an open-source library
|
||
** for handling unicode data) and SQLite. The integration uses
|
||
** ICU to provide the following to SQLite:
|
||
**
|
||
** * An implementation of the SQL regexp() function (and hence REGEXP
|
||
** operator) using the ICU uregex_XX() APIs.
|
||
**
|
||
** * Implementations of the SQL scalar upper() and lower() functions
|
||
** for case mapping.
|
||
**
|
||
** * Integration of ICU and SQLite collation seqences.
|
||
**
|
||
** * An implementation of the LIKE operator that uses ICU to
|
||
** provide case-independent matching.
|
||
*/
|
||
|
||
#if !defined(SQLITE_CORE) || defined(SQLITE_ENABLE_ICU)
|
||
|
||
/* Include ICU headers */
|
||
#include <unicode/utypes.h>
|
||
#include <unicode/uregex.h>
|
||
#include <unicode/ustring.h>
|
||
#include <unicode/ucol.h>
|
||
|
||
#include <assert.h>
|
||
|
||
#ifndef SQLITE_CORE
|
||
#include "sqlite3ext.h"
|
||
SQLITE_EXTENSION_INIT1
|
||
#else
|
||
#include "sqlite3.h"
|
||
#endif
|
||
|
||
/*
|
||
** Maximum length (in bytes) of the pattern in a LIKE or GLOB
|
||
** operator.
|
||
*/
|
||
#ifndef SQLITE_MAX_LIKE_PATTERN_LENGTH
|
||
# define SQLITE_MAX_LIKE_PATTERN_LENGTH 50000
|
||
#endif
|
||
|
||
/*
|
||
** Version of sqlite3_free() that is always a function, never a macro.
|
||
*/
|
||
static void xFree(void *p){
|
||
sqlite3_free(p);
|
||
}
|
||
|
||
/*
|
||
** Compare two UTF-8 strings for equality where the first string is
|
||
** a "LIKE" expression. Return true (1) if they are the same and
|
||
** false (0) if they are different.
|
||
*/
|
||
static int icuLikeCompare(
|
||
const uint8_t *zPattern, /* LIKE pattern */
|
||
const uint8_t *zString, /* The UTF-8 string to compare against */
|
||
const UChar32 uEsc /* The escape character */
|
||
){
|
||
static const int MATCH_ONE = (UChar32)'_';
|
||
static const int MATCH_ALL = (UChar32)'%';
|
||
|
||
int iPattern = 0; /* Current byte index in zPattern */
|
||
int iString = 0; /* Current byte index in zString */
|
||
|
||
int prevEscape = 0; /* True if the previous character was uEsc */
|
||
|
||
while( zPattern[iPattern]!=0 ){
|
||
|
||
/* Read (and consume) the next character from the input pattern. */
|
||
UChar32 uPattern;
|
||
U8_NEXT_UNSAFE(zPattern, iPattern, uPattern);
|
||
assert(uPattern!=0);
|
||
|
||
/* There are now 4 possibilities:
|
||
**
|
||
** 1. uPattern is an unescaped match-all character "%",
|
||
** 2. uPattern is an unescaped match-one character "_",
|
||
** 3. uPattern is an unescaped escape character, or
|
||
** 4. uPattern is to be handled as an ordinary character
|
||
*/
|
||
if( !prevEscape && uPattern==MATCH_ALL ){
|
||
/* Case 1. */
|
||
uint8_t c;
|
||
|
||
/* Skip any MATCH_ALL or MATCH_ONE characters that follow a
|
||
** MATCH_ALL. For each MATCH_ONE, skip one character in the
|
||
** test string.
|
||
*/
|
||
while( (c=zPattern[iPattern]) == MATCH_ALL || c == MATCH_ONE ){
|
||
if( c==MATCH_ONE ){
|
||
if( zString[iString]==0 ) return 0;
|
||
U8_FWD_1_UNSAFE(zString, iString);
|
||
}
|
||
iPattern++;
|
||
}
|
||
|
||
if( zPattern[iPattern]==0 ) return 1;
|
||
|
||
while( zString[iString] ){
|
||
if( icuLikeCompare(&zPattern[iPattern], &zString[iString], uEsc) ){
|
||
return 1;
|
||
}
|
||
U8_FWD_1_UNSAFE(zString, iString);
|
||
}
|
||
return 0;
|
||
|
||
}else if( !prevEscape && uPattern==MATCH_ONE ){
|
||
/* Case 2. */
|
||
if( zString[iString]==0 ) return 0;
|
||
U8_FWD_1_UNSAFE(zString, iString);
|
||
|
||
}else if( !prevEscape && uPattern==uEsc){
|
||
/* Case 3. */
|
||
prevEscape = 1;
|
||
|
||
}else{
|
||
/* Case 4. */
|
||
UChar32 uString;
|
||
U8_NEXT_UNSAFE(zString, iString, uString);
|
||
uString = u_foldCase(uString, U_FOLD_CASE_DEFAULT);
|
||
uPattern = u_foldCase(uPattern, U_FOLD_CASE_DEFAULT);
|
||
if( uString!=uPattern ){
|
||
return 0;
|
||
}
|
||
prevEscape = 0;
|
||
}
|
||
}
|
||
|
||
return zString[iString]==0;
|
||
}
|
||
|
||
/*
|
||
** Implementation of the like() SQL function. This function implements
|
||
** the build-in LIKE operator. The first argument to the function is the
|
||
** pattern and the second argument is the string. So, the SQL statements:
|
||
**
|
||
** A LIKE B
|
||
**
|
||
** is implemented as like(B, A). If there is an escape character E,
|
||
**
|
||
** A LIKE B ESCAPE E
|
||
**
|
||
** is mapped to like(B, A, E).
|
||
*/
|
||
static void icuLikeFunc(
|
||
sqlite3_context *context,
|
||
int argc,
|
||
sqlite3_value **argv
|
||
){
|
||
const unsigned char *zA = sqlite3_value_text(argv[0]);
|
||
const unsigned char *zB = sqlite3_value_text(argv[1]);
|
||
UChar32 uEsc = 0;
|
||
|
||
/* Limit the length of the LIKE or GLOB pattern to avoid problems
|
||
** of deep recursion and N*N behavior in patternCompare().
|
||
*/
|
||
if( sqlite3_value_bytes(argv[0])>SQLITE_MAX_LIKE_PATTERN_LENGTH ){
|
||
sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
|
||
return;
|
||
}
|
||
|
||
|
||
if( argc==3 ){
|
||
/* The escape character string must consist of a single UTF-8 character.
|
||
** Otherwise, return an error.
|
||
*/
|
||
int nE= sqlite3_value_bytes(argv[2]);
|
||
const unsigned char *zE = sqlite3_value_text(argv[2]);
|
||
int i = 0;
|
||
if( zE==0 ) return;
|
||
U8_NEXT(zE, i, nE, uEsc);
|
||
if( i!=nE){
|
||
sqlite3_result_error(context,
|
||
"ESCAPE expression must be a single character", -1);
|
||
return;
|
||
}
|
||
}
|
||
|
||
if( zA && zB ){
|
||
sqlite3_result_int(context, icuLikeCompare(zA, zB, uEsc));
|
||
}
|
||
}
|
||
|
||
/*
|
||
** This function is called when an ICU function called from within
|
||
** the implementation of an SQL scalar function returns an error.
|
||
**
|
||
** The scalar function context passed as the first argument is
|
||
** loaded with an error message based on the following two args.
|
||
*/
|
||
static void icuFunctionError(
|
||
sqlite3_context *pCtx, /* SQLite scalar function context */
|
||
const char *zName, /* Name of ICU function that failed */
|
||
UErrorCode e /* Error code returned by ICU function */
|
||
){
|
||
char zBuf[128];
|
||
sqlite3_snprintf(128, zBuf, "ICU error: %s(): %s", zName, u_errorName(e));
|
||
zBuf[127] = '\0';
|
||
sqlite3_result_error(pCtx, zBuf, -1);
|
||
}
|
||
|
||
/*
|
||
** Function to delete compiled regexp objects. Registered as
|
||
** a destructor function with sqlite3_set_auxdata().
|
||
*/
|
||
static void icuRegexpDelete(void *p){
|
||
URegularExpression *pExpr = (URegularExpression *)p;
|
||
uregex_close(pExpr);
|
||
}
|
||
|
||
/*
|
||
** Implementation of SQLite REGEXP operator. This scalar function takes
|
||
** two arguments. The first is a regular expression pattern to compile
|
||
** the second is a string to match against that pattern. If either
|
||
** argument is an SQL NULL, then NULL Is returned. Otherwise, the result
|
||
** is 1 if the string matches the pattern, or 0 otherwise.
|
||
**
|
||
** SQLite maps the regexp() function to the regexp() operator such
|
||
** that the following two are equivalent:
|
||
**
|
||
** zString REGEXP zPattern
|
||
** regexp(zPattern, zString)
|
||
**
|
||
** Uses the following ICU regexp APIs:
|
||
**
|
||
** uregex_open()
|
||
** uregex_matches()
|
||
** uregex_close()
|
||
*/
|
||
static void icuRegexpFunc(sqlite3_context *p, int nArg, sqlite3_value **apArg){
|
||
UErrorCode status = U_ZERO_ERROR;
|
||
URegularExpression *pExpr;
|
||
UBool res;
|
||
const UChar *zString = sqlite3_value_text16(apArg[1]);
|
||
|
||
(void)nArg; /* Unused parameter */
|
||
|
||
/* If the left hand side of the regexp operator is NULL,
|
||
** then the result is also NULL.
|
||
*/
|
||
if( !zString ){
|
||
return;
|
||
}
|
||
|
||
pExpr = sqlite3_get_auxdata(p, 0);
|
||
if( !pExpr ){
|
||
const UChar *zPattern = sqlite3_value_text16(apArg[0]);
|
||
if( !zPattern ){
|
||
return;
|
||
}
|
||
pExpr = uregex_open(zPattern, -1, 0, 0, &status);
|
||
|
||
if( U_SUCCESS(status) ){
|
||
sqlite3_set_auxdata(p, 0, pExpr, icuRegexpDelete);
|
||
}else{
|
||
assert(!pExpr);
|
||
icuFunctionError(p, "uregex_open", status);
|
||
return;
|
||
}
|
||
}
|
||
|
||
/* Configure the text that the regular expression operates on. */
|
||
uregex_setText(pExpr, zString, -1, &status);
|
||
if( !U_SUCCESS(status) ){
|
||
icuFunctionError(p, "uregex_setText", status);
|
||
return;
|
||
}
|
||
|
||
/* Attempt the match */
|
||
res = uregex_matches(pExpr, 0, &status);
|
||
if( !U_SUCCESS(status) ){
|
||
icuFunctionError(p, "uregex_matches", status);
|
||
return;
|
||
}
|
||
|
||
/* Set the text that the regular expression operates on to a NULL
|
||
** pointer. This is not really necessary, but it is tidier than
|
||
** leaving the regular expression object configured with an invalid
|
||
** pointer after this function returns.
|
||
*/
|
||
uregex_setText(pExpr, 0, 0, &status);
|
||
|
||
/* Return 1 or 0. */
|
||
sqlite3_result_int(p, res ? 1 : 0);
|
||
}
|
||
|
||
/*
|
||
** Implementations of scalar functions for case mapping - upper() and
|
||
** lower(). Function upper() converts its input to upper-case (ABC).
|
||
** Function lower() converts to lower-case (abc).
|
||
**
|
||
** ICU provides two types of case mapping, "general" case mapping and
|
||
** "language specific". Refer to ICU documentation for the differences
|
||
** between the two.
|
||
**
|
||
** To utilise "general" case mapping, the upper() or lower() scalar
|
||
** functions are invoked with one argument:
|
||
**
|
||
** upper('ABC') -> 'abc'
|
||
** lower('abc') -> 'ABC'
|
||
**
|
||
** To access ICU "language specific" case mapping, upper() or lower()
|
||
** should be invoked with two arguments. The second argument is the name
|
||
** of the locale to use. Passing an empty string ("") or SQL NULL value
|
||
** as the second argument is the same as invoking the 1 argument version
|
||
** of upper() or lower().
|
||
**
|
||
** lower('I', 'en_us') -> 'i'
|
||
** lower('I', 'tr_tr') -> 'ı' (small dotless i)
|
||
**
|
||
** http://www.icu-project.org/userguide/posix.html#case_mappings
|
||
*/
|
||
static void icuCaseFunc16(sqlite3_context *p, int nArg, sqlite3_value **apArg){
|
||
const UChar *zInput;
|
||
UChar *zOutput;
|
||
int nInput;
|
||
int nOutput;
|
||
|
||
UErrorCode status = U_ZERO_ERROR;
|
||
const char *zLocale = 0;
|
||
|
||
assert(nArg==1 || nArg==2);
|
||
if( nArg==2 ){
|
||
zLocale = (const char *)sqlite3_value_text(apArg[1]);
|
||
}
|
||
|
||
zInput = sqlite3_value_text16(apArg[0]);
|
||
if( !zInput ){
|
||
return;
|
||
}
|
||
nInput = sqlite3_value_bytes16(apArg[0]);
|
||
|
||
nOutput = nInput * 2 + 2;
|
||
zOutput = sqlite3_malloc(nOutput);
|
||
if( !zOutput ){
|
||
return;
|
||
}
|
||
|
||
if( sqlite3_user_data(p) ){
|
||
u_strToUpper(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
|
||
}else{
|
||
u_strToLower(zOutput, nOutput/2, zInput, nInput/2, zLocale, &status);
|
||
}
|
||
|
||
if( !U_SUCCESS(status) ){
|
||
icuFunctionError(p, "u_strToLower()/u_strToUpper", status);
|
||
return;
|
||
}
|
||
|
||
sqlite3_result_text16(p, zOutput, -1, xFree);
|
||
}
|
||
|
||
/*
|
||
** Collation sequence destructor function. The pCtx argument points to
|
||
** a UCollator structure previously allocated using ucol_open().
|
||
*/
|
||
static void icuCollationDel(void *pCtx){
|
||
UCollator *p = (UCollator *)pCtx;
|
||
ucol_close(p);
|
||
}
|
||
|
||
/*
|
||
** Collation sequence comparison function. The pCtx argument points to
|
||
** a UCollator structure previously allocated using ucol_open().
|
||
*/
|
||
static int icuCollationColl(
|
||
void *pCtx,
|
||
int nLeft,
|
||
const void *zLeft,
|
||
int nRight,
|
||
const void *zRight
|
||
){
|
||
UCollationResult res;
|
||
UCollator *p = (UCollator *)pCtx;
|
||
res = ucol_strcoll(p, (UChar *)zLeft, nLeft/2, (UChar *)zRight, nRight/2);
|
||
switch( res ){
|
||
case UCOL_LESS: return -1;
|
||
case UCOL_GREATER: return +1;
|
||
case UCOL_EQUAL: return 0;
|
||
}
|
||
assert(!"Unexpected return value from ucol_strcoll()");
|
||
return 0;
|
||
}
|
||
|
||
/*
|
||
** Implementation of the scalar function icu_load_collation().
|
||
**
|
||
** This scalar function is used to add ICU collation based collation
|
||
** types to an SQLite database connection. It is intended to be called
|
||
** as follows:
|
||
**
|
||
** SELECT icu_load_collation(<locale>, <collation-name>);
|
||
**
|
||
** Where <locale> is a string containing an ICU locale identifier (i.e.
|
||
** "en_AU", "tr_TR" etc.) and <collation-name> is the name of the
|
||
** collation sequence to create.
|
||
*/
|
||
static void icuLoadCollation(
|
||
sqlite3_context *p,
|
||
int nArg,
|
||
sqlite3_value **apArg
|
||
){
|
||
sqlite3 *db = (sqlite3 *)sqlite3_user_data(p);
|
||
UErrorCode status = U_ZERO_ERROR;
|
||
const char *zLocale; /* Locale identifier - (eg. "jp_JP") */
|
||
const char *zName; /* SQL Collation sequence name (eg. "japanese") */
|
||
UCollator *pUCollator; /* ICU library collation object */
|
||
int rc; /* Return code from sqlite3_create_collation_x() */
|
||
|
||
assert(nArg==2);
|
||
zLocale = (const char *)sqlite3_value_text(apArg[0]);
|
||
zName = (const char *)sqlite3_value_text(apArg[1]);
|
||
|
||
if( !zLocale || !zName ){
|
||
return;
|
||
}
|
||
|
||
pUCollator = ucol_open(zLocale, &status);
|
||
if( !U_SUCCESS(status) ){
|
||
icuFunctionError(p, "ucol_open", status);
|
||
return;
|
||
}
|
||
assert(p);
|
||
|
||
rc = sqlite3_create_collation_v2(db, zName, SQLITE_UTF16, (void *)pUCollator,
|
||
icuCollationColl, icuCollationDel
|
||
);
|
||
if( rc!=SQLITE_OK ){
|
||
ucol_close(pUCollator);
|
||
sqlite3_result_error(p, "Error registering collation function", -1);
|
||
}
|
||
}
|
||
|
||
/*
|
||
** Register the ICU extension functions with database db.
|
||
*/
|
||
int sqlite3IcuInit(sqlite3 *db){
|
||
struct IcuScalar {
|
||
const char *zName; /* Function name */
|
||
int nArg; /* Number of arguments */
|
||
int enc; /* Optimal text encoding */
|
||
void *pContext; /* sqlite3_user_data() context */
|
||
void (*xFunc)(sqlite3_context*,int,sqlite3_value**);
|
||
} scalars[] = {
|
||
{"regexp", 2, SQLITE_ANY, 0, icuRegexpFunc},
|
||
|
||
{"lower", 1, SQLITE_UTF16, 0, icuCaseFunc16},
|
||
{"lower", 2, SQLITE_UTF16, 0, icuCaseFunc16},
|
||
{"upper", 1, SQLITE_UTF16, (void*)1, icuCaseFunc16},
|
||
{"upper", 2, SQLITE_UTF16, (void*)1, icuCaseFunc16},
|
||
|
||
{"lower", 1, SQLITE_UTF8, 0, icuCaseFunc16},
|
||
{"lower", 2, SQLITE_UTF8, 0, icuCaseFunc16},
|
||
{"upper", 1, SQLITE_UTF8, (void*)1, icuCaseFunc16},
|
||
{"upper", 2, SQLITE_UTF8, (void*)1, icuCaseFunc16},
|
||
|
||
{"like", 2, SQLITE_UTF8, 0, icuLikeFunc},
|
||
{"like", 3, SQLITE_UTF8, 0, icuLikeFunc},
|
||
|
||
{"icu_load_collation", 2, SQLITE_UTF8, (void*)db, icuLoadCollation},
|
||
};
|
||
|
||
int rc = SQLITE_OK;
|
||
int i;
|
||
|
||
for(i=0; rc==SQLITE_OK && i<(int)(sizeof(scalars)/sizeof(scalars[0])); i++){
|
||
struct IcuScalar *p = &scalars[i];
|
||
rc = sqlite3_create_function(
|
||
db, p->zName, p->nArg, p->enc, p->pContext, p->xFunc, 0, 0
|
||
);
|
||
}
|
||
|
||
return rc;
|
||
}
|
||
|
||
#if !SQLITE_CORE
|
||
int sqlite3_extension_init(
|
||
sqlite3 *db,
|
||
char **pzErrMsg,
|
||
const sqlite3_api_routines *pApi
|
||
){
|
||
SQLITE_EXTENSION_INIT2(pApi)
|
||
return sqlite3IcuInit(db);
|
||
}
|
||
#endif
|
||
|
||
#endif
|