Esempio n. 1
0
/*
** Return UTF-16 encoded English language explanation of the most recent
** error.
*/
const void *sqlite3_errmsg16(sqlite3 *db){
  /* Because all the characters in the string are in the unicode
  ** range 0x00-0xFF, if we pad the big-endian string with a
  ** zero byte, we can obtain the little-endian string with
  ** &big_endian[1].
  */
  static const char outOfMemBe[] = {
    0, 'o', 0, 'u', 0, 't', 0, ' ',
    0, 'o', 0, 'f', 0, ' ',
    0, 'm', 0, 'e', 0, 'm', 0, 'o', 0, 'r', 0, 'y', 0, 0, 0
  };
  static const char misuseBe [] = {
    0, 'l', 0, 'i', 0, 'b', 0, 'r', 0, 'a', 0, 'r', 0, 'y', 0, ' ',
    0, 'r', 0, 'o', 0, 'u', 0, 't', 0, 'i', 0, 'n', 0, 'e', 0, ' ',
    0, 'c', 0, 'a', 0, 'l', 0, 'l', 0, 'e', 0, 'd', 0, ' ',
    0, 'o', 0, 'u', 0, 't', 0, ' ',
    0, 'o', 0, 'f', 0, ' ',
    0, 's', 0, 'e', 0, 'q', 0, 'u', 0, 'e', 0, 'n', 0, 'c', 0, 'e', 0, 0, 0
  };

  const void *z;
  if( sqlite3_malloc_failed ){
    return (void *)(&outOfMemBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  if( sqlite3SafetyCheck(db) || db->errCode==SQLITE_MISUSE ){
    return (void *)(&misuseBe[SQLITE_UTF16NATIVE==SQLITE_UTF16LE?1:0]);
  }
  z = sqlite3_value_text16(db->pErr);
  if( z==0 ){
    sqlite3ValueSetStr(db->pErr, -1, sqlite3ErrStr(db->errCode),
         SQLITE_UTF8, SQLITE_STATIC);
    z = sqlite3_value_text16(db->pErr);
  }
  return z;
}
Esempio n. 2
0
/*
** 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);
}
Esempio n. 3
0
/*
** This function takes two arguments.  It performance UTF-8/16 type
** conversions on the first argument then returns a copy of the second
** argument.
**
** This function is used in cases such as the following:
**
**      SELECT test_isolation(x,x) FROM t1;
**
** We want to verify that the type conversions that occur on the
** first argument do not invalidate the second argument.
*/
static void test_isolation(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
#ifndef SQLITE_OMIT_UTF16
  sqlite3_value_text16(argv[0]);
  sqlite3_value_text(argv[0]);
  sqlite3_value_text16(argv[0]);
  sqlite3_value_text(argv[0]);
#endif
  sqlite3_result_value(pCtx, argv[1]);
}
Esempio n. 4
0
SQLValue SQLiteStatement::getColumnValue(int col)
{
    ASSERT(col >= 0);
    if (!m_statement)
        if (prepareAndStep() != SQLITE_ROW)
            return SQLValue();
    if (columnCount() <= col)
        return SQLValue();

    // SQLite is typed per value. optional column types are
    // "(mostly) ignored"
    sqlite3_value* value = sqlite3_column_value(m_statement, col);
    switch (sqlite3_value_type(value)) {
        case SQLITE_INTEGER:    // SQLValue and JS don't represent integers, so use FLOAT -case
        case SQLITE_FLOAT:
            return SQLValue(sqlite3_value_double(value));
        case SQLITE_BLOB:       // SQLValue and JS don't represent blobs, so use TEXT -case
        case SQLITE_TEXT: {
            const UChar* string = reinterpret_cast<const UChar*>(sqlite3_value_text16(value));
            unsigned length = WTF::lengthOfNullTerminatedString(string);
            return SQLValue(StringImpl::create8BitIfPossible(string, length));
        }
        case SQLITE_NULL:
            return SQLValue();
        default:
            break;
    }
    ASSERT_NOT_REACHED();
    return SQLValue();
}
Esempio n. 5
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') -> '\u131' (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;            /* Pointer to input string */
  UChar *zOutput = 0;             /* Pointer to output buffer */
  int nInput;                     /* Size of utf-16 input string in bytes */
  int nOut;                       /* Size of output buffer in bytes */
  int cnt;
  int bToUpper;                   /* True for toupper(), false for tolower() */
  UErrorCode status;
  const char *zLocale = 0;

  assert(nArg==1 || nArg==2);
  bToUpper = (sqlite3_user_data(p)!=0);
  if( nArg==2 ){
    zLocale = (const char *)sqlite3_value_text(apArg[1]);
  }

  zInput = sqlite3_value_text16(apArg[0]);
  if( !zInput ){
    return;
  }
  nOut = nInput = sqlite3_value_bytes16(apArg[0]);
  if( nOut==0 ){
    sqlite3_result_text16(p, "", 0, SQLITE_STATIC);
    return;
  }

  for(cnt=0; cnt<2; cnt++){
    UChar *zNew = sqlite3_realloc(zOutput, nOut);
    if( zNew==0 ){
      sqlite3_free(zOutput);
      sqlite3_result_error_nomem(p);
      return;
    }
    zOutput = zNew;
    status = U_ZERO_ERROR;
    if( bToUpper ){
      nOut = 2*u_strToUpper(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }else{
      nOut = 2*u_strToLower(zOutput,nOut/2,zInput,nInput/2,zLocale,&status);
    }

    if( U_SUCCESS(status) ){
      sqlite3_result_text16(p, zOutput, nOut, xFree);
    }else if( status==U_BUFFER_OVERFLOW_ERROR ){
      assert( cnt==0 );
      continue;
    }else{
      icuFunctionError(p, bToUpper ? "u_strToUpper" : "u_strToLower", status);
    }
    return;
  }
  assert( 0 );     /* Unreachable */
}
ikptr
ik_sqlite3_value_text16 (ikptr s_value, ikpcb * pcb)
{
#ifdef HAVE_SQLITE3_VALUE_TEXT16
  sqlite3_value *	value = IK_SQLITE_VALUE(s_value);
  const void *		data;
  int			bytes;
  bytes = sqlite3_value_bytes16(value);
  data  = sqlite3_value_text16(value);
  return ika_bytevector_from_memory_block(pcb, data, bytes);
#else
  feature_failure(__func__);
#endif
}
Esempio n. 7
0
static void getUnicodeResult(const RtlFieldInfo *field, sqlite3_value *val, size32_t &chars, UChar * &result)
{
    assertex(val);
    if (isNull(val))
    {
        NullFieldProcessor p(field);
        rtlUnicodeToUnicodeX(chars, result, p.resultChars, p.unicodeResult);
        return;
    }
    if (sqlite3_value_type(val) != SQLITE_TEXT)
        typeError("string", field);
    const UChar *text = (const UChar *) sqlite3_value_text16(val);
    int bytes = sqlite3_value_bytes16(val);
    unsigned numchars = bytes / sizeof(UChar);
    rtlUnicodeToUnicodeX(chars, result, numchars, text);
}
Esempio n. 8
0
/*
** UTF-16 implementation of the substr()
*/
void sqlite3utf16Substr(
  sqlite3_context *context,
  int argc,
  sqlite3_value **argv
){
  int y, z;
  unsigned char const *zStr;
  unsigned char const *zStrEnd;
  unsigned char const *zStart;
  unsigned char const *zEnd;
  int i;

  zStr = (unsigned char const *)sqlite3_value_text16(argv[0]);
  zStrEnd = &zStr[sqlite3_value_bytes16(argv[0])];
  y = sqlite3_value_int(argv[1]);
  z = sqlite3_value_int(argv[2]);

  if( y>0 ){
    y = y-1;
    zStart = zStr;
    if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
      for(i=0; i<y && zStart<zStrEnd; i++) SKIP_UTF16BE(zStart);
    }else{
      for(i=0; i<y && zStart<zStrEnd; i++) SKIP_UTF16LE(zStart);
    }
  }else{
    zStart = zStrEnd;
    if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
      for(i=y; i<0 && zStart>zStr; i++) RSKIP_UTF16BE(zStart);
    }else{
      for(i=y; i<0 && zStart>zStr; i++) RSKIP_UTF16LE(zStart);
    }
    for(; i<0; i++) z -= 1;
  }

  zEnd = zStart;
  if( SQLITE_UTF16BE==SQLITE_UTF16NATIVE ){
    for(i=0; i<z && zEnd<zStrEnd; i++) SKIP_UTF16BE(zEnd);
  }else{
    for(i=0; i<z && zEnd<zStrEnd; i++) SKIP_UTF16LE(zEnd);
  }

  sqlite3_result_text16(context, zStart, zEnd-zStart, SQLITE_TRANSIENT);
}
// Called each time a custom function is evaluated.
static void sqliteCustomFunctionCallback(sqlite3_context *context,
        int argc, sqlite3_value **argv) {
    JNIEnv* env = AndroidRuntime::getJNIEnv();

    // Get the callback function object.
    // Create a new local reference to it in case the callback tries to do something
    // dumb like unregister the function (thereby destroying the global ref) while it is running.
    jobject functionObjGlobal = reinterpret_cast<jobject>(sqlite3_user_data(context));
    jobject functionObj = env->NewLocalRef(functionObjGlobal);

    jobjectArray argsArray = env->NewObjectArray(argc, gStringClassInfo.clazz, NULL);
    if (argsArray) {
        for (int i = 0; i < argc; i++) {
            const jchar* arg = static_cast<const jchar*>(sqlite3_value_text16(argv[i]));
            if (!arg) {
                ALOGW("NULL argument in custom_function_callback.  This should not happen.");
            } else {
                size_t argLen = sqlite3_value_bytes16(argv[i]) / sizeof(jchar);
                jstring argStr = env->NewString(arg, argLen);
                if (!argStr) {
                    goto error; // out of memory error
                }
                env->SetObjectArrayElement(argsArray, i, argStr);
                env->DeleteLocalRef(argStr);
            }
        }

        // TODO: Support functions that return values.
        env->CallVoidMethod(functionObj,
                gSQLiteCustomFunctionClassInfo.dispatchCallback, argsArray);

error:
        env->DeleteLocalRef(argsArray);
    }

    env->DeleteLocalRef(functionObj);

    if (env->ExceptionCheck()) {
        ALOGE("An exception was thrown by custom SQLite function.");
        LOGE_EX(env);
        env->ExceptionClear();
    }
}
Esempio n. 10
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);
}
Esempio n. 11
0
static void test_destructor16(
  sqlite3_context *pCtx, 
  int nArg,
  sqlite3_value **argv
){
  char *zVal;
  int len;
  
  test_destructor_count_var++;
  assert( nArg==1 );
  if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
  len = sqlite3_value_bytes16(argv[0]); 
  zVal = testContextMalloc(pCtx, len+3);
  if( !zVal ){
    return;
  }
  zVal[len+1] = 0;
  zVal[len+2] = 0;
  zVal++;
  memcpy(zVal, sqlite3_value_text16(argv[0]), len);
  sqlite3_result_text16(pCtx, zVal, -1, destructor);
}
Esempio n. 12
0
const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
  const void *val = sqlite3_value_text16( columnMem(pStmt,i) );
  columnMallocFailure(pStmt);
  return val;
}
/**
 * This function is invoked as:
 *
 *  _TOKENIZE('<token_table>', <data_row_id>, <data>, <delimiter>,
 *             <use_token_index>, <data_tag>)
 *
 * If <use_token_index> is omitted, it is treated as 0.
 * If <data_tag> is omitted, it is treated as NULL.
 *
 * It will split <data> on each instance of <delimiter> and insert each token
 * into <token_table>. The following columns in <token_table> are used:
 * token TEXT, source INTEGER, token_index INTEGER, tag (any type)
 * The token_index column is not required if <use_token_index> is 0.
 * The tag column is not required if <data_tag> is NULL.
 *
 * One row is inserted for each token in <data>.
 * In each inserted row, 'source' is <data_row_id>.
 * In the first inserted row, 'token' is the hex collation key of
 * the entire <data> string, and 'token_index' is 0.
 * In each row I (where 1 <= I < N, and N is the number of tokens in <data>)
 * 'token' will be set to the hex collation key of the I:th token (0-based).
 * If <use_token_index> != 0, 'token_index' is set to I.
 * If <data_tag> is not NULL, 'tag' is set to <data_tag>.
 *
 * In other words, there will be one row for the entire string,
 * and one row for each token except the first one.
 *
 * The function returns the number of tokens generated.
 */
static void tokenize(sqlite3_context * context, int argc, sqlite3_value ** argv)
{
    //ALOGD("enter tokenize");
    int err;
    int useTokenIndex = 0;
    int useDataTag = 0;

    if (!(argc >= 4 || argc <= 6)) {
        ALOGE("Tokenize requires 4 to 6 arguments");
        sqlite3_result_null(context);
        return;
    }

    if (argc > 4) {
        useTokenIndex = sqlite3_value_int(argv[4]);
    }

    if (argc > 5) {
        useDataTag = (sqlite3_value_type(argv[5]) != SQLITE_NULL);
    }

    sqlite3 * handle = sqlite3_context_db_handle(context);
    UCollator* collator = (UCollator*)sqlite3_user_data(context);
    char const * tokenTable = (char const *)sqlite3_value_text(argv[0]);
    if (tokenTable == NULL) {
        ALOGE("tokenTable null");
        sqlite3_result_null(context);
        return;
    }

    // Get or create the prepared statement for the insertions
    sqlite3_stmt * statement = (sqlite3_stmt *)sqlite3_get_auxdata(context, 0);
    if (!statement) {
        char const * tokenIndexCol = useTokenIndex ? ", token_index" : "";
        char const * tokenIndexParam = useTokenIndex ? ", ?" : "";
        char const * dataTagCol = useDataTag ? ", tag" : "";
        char const * dataTagParam = useDataTag ? ", ?" : "";
        char * sql = sqlite3_mprintf("INSERT INTO %s (token, source%s%s) VALUES (?, ?%s%s);",
                tokenTable, tokenIndexCol, dataTagCol, tokenIndexParam, dataTagParam);
        err = sqlite3_prepare_v2(handle, sql, -1, &statement, NULL);
        sqlite3_free(sql);
        if (err) {
            ALOGE("prepare failed");
            sqlite3_result_null(context);
            return;
        }
        // This binds the statement to the table it was compiled against, which is argv[0].
        // If this function is ever called with a different table the finalizer will be called
        // and sqlite3_get_auxdata() will return null above, forcing a recompile for the new table.
        sqlite3_set_auxdata(context, 0, statement, tokenize_auxdata_delete);
    } else {
        // Reset the cached statement so that binding the row ID will work properly
        sqlite3_reset(statement);
    }

    // Bind the row ID of the source row
    int64_t rowID = sqlite3_value_int64(argv[1]);
    err = sqlite3_bind_int64(statement, 2, rowID);
    if (err != SQLITE_OK) {
        ALOGE("bind failed");
        sqlite3_result_null(context);
        return;
    }

    // Bind <data_tag> to the tag column
    if (useDataTag) {
        int dataTagParamIndex = useTokenIndex ? 4 : 3;
        err = sqlite3_bind_value(statement, dataTagParamIndex, argv[5]);
        if (err != SQLITE_OK) {
            ALOGE("bind failed");
            sqlite3_result_null(context);
            return;
        }
    }

    // Get the raw bytes for the string to tokenize
    // the string will be modified by following code
    // however, sqlite did not reuse the string, so it is safe to not dup it
    UChar * origData = (UChar *)sqlite3_value_text16(argv[2]);
    if (origData == NULL) {
        sqlite3_result_null(context);
        return;
    }

    // Get the raw bytes for the delimiter
    const UChar * delim = (const UChar *)sqlite3_value_text16(argv[3]);
    if (delim == NULL) {
        ALOGE("can't get delimiter");
        sqlite3_result_null(context);
        return;
    }

    UChar * token = NULL;
    UChar *state;
    int numTokens = 0;

    do {
        if (numTokens == 0) {
            token = origData;
        }

        // Reset the program so we can use it to perform the insert
        sqlite3_reset(statement);
        UErrorCode status = U_ZERO_ERROR;
        char keybuf[1024];
        uint32_t result = ucol_getSortKey(collator, token, -1, (uint8_t*)keybuf, sizeof(keybuf)-1);
        if (result > sizeof(keybuf)) {
            // TODO allocate memory for this super big string
            ALOGE("ucol_getSortKey needs bigger buffer %d", result);
            break;
        }
        uint32_t keysize = result-1;
        uint32_t base16Size = keysize*2;
        char *base16buf = (char*)malloc(base16Size);
        base16Encode(base16buf, keybuf, keysize);
        err = sqlite3_bind_text(statement, 1, base16buf, base16Size, SQLITE_STATIC);

        if (err != SQLITE_OK) {
            ALOGE(" sqlite3_bind_text16 error %d", err);
            free(base16buf);
            break;
        }

        if (useTokenIndex) {
            err = sqlite3_bind_int(statement, 3, numTokens);
            if (err != SQLITE_OK) {
                ALOGE(" sqlite3_bind_int error %d", err);
                free(base16buf);
                break;
            }
        }

        err = sqlite3_step(statement);
        free(base16buf);

        if (err != SQLITE_DONE) {
            ALOGE(" sqlite3_step error %d", err);
            break;
        }
        numTokens++;
        if (numTokens == 1) {
            // first call
            u_strtok_r(origData, delim, &state);
        }
    } while ((token = u_strtok_r(NULL, delim, &state)) != NULL);
    sqlite3_result_int(context, numTokens);
}
Esempio n. 14
0
__declspec(dllexport) const void * WINAPI sqlite3_value_text16_interop(sqlite3_value *val, int *plen)
{
  const void *pval = sqlite3_value_text16(val);
  *plen = (pval != 0) ? wcslen((wchar_t *)pval) * sizeof(wchar_t) : 0;
  return pval;
}
Esempio n. 15
0
const void *sqlite3_column_text16(sqlite3_stmt *pStmt, int i){
  return sqlite3_value_text16( columnMem(pStmt,i) );
}
Esempio n. 16
0
static void mmenc_func(sqlite3_context *db, int argc, sqlite3_value **argv)
{
    mm_cipher_context_t *ctx;
    const UChar *src;
    int32_t src_len;
    char buf[1024];
    char *dst = buf;
    int32_t dst_len;
    UErrorCode status = U_ZERO_ERROR;
    int arg_type;

    // only accept 1 argument.
    if (argc != 1)
        goto error_misuse;

    // encoding BLOB data type is not supported.
    arg_type = sqlite3_value_type(argv[0]);
    if (arg_type == SQLITE_BLOB)
        goto error_misuse;

    // for data types other than TEXT, just return them.
    if (arg_type != SQLITE_TEXT) {
        sqlite3_result_value(db, argv[0]);
        return;
    }

    ctx = (mm_cipher_context_t *) sqlite3_user_data(db);
    src_len = sqlite3_value_bytes16(argv[0]) / 2;
    src = (const UChar *) sqlite3_value_text16(argv[0]);

    // transform input string to BOCU-1 encoding.
    // try stack buffer first, if it doesn't fit, malloc a new buffer.
    dst_len =
        ucnv_fromUChars(ctx->cnv, dst, sizeof(buf), src, src_len, &status);
    if (status == U_BUFFER_OVERFLOW_ERROR) {
        status = U_ZERO_ERROR;
        dst = (char *) sqlite3_malloc(dst_len);
        dst_len =
            ucnv_fromUChars(ctx->cnv, dst, dst_len, src, src_len, &status);
    }
    if (U_FAILURE(status) && status != U_STRING_NOT_TERMINATED_WARNING) {
        sqlite3_mm_set_last_error(
            "Failed transforming text to internal encoding.");
        goto error_error;
    }

    // encrypt transformed BOCU-1 string.
    do_rc4(ctx, dst, dst_len);

    // return
    sqlite3_result_blob(db, dst, dst_len, SQLITE_TRANSIENT);
    if (dst != buf)
        sqlite3_free(dst);
    return;

error_error:
    if (dst != buf)
        sqlite3_free(dst);
    sqlite3_result_error_code(db, SQLITE_ERROR);
    return;

error_misuse:
    if (dst != buf)
        sqlite3_free(dst);
    sqlite3_result_error_code(db, SQLITE_MISUSE);
    return;
}