function.java

非常棒的java数据库

            v0 = v0.convertScale(mode.convertOnlyToSmallerScale, scale);
            v0 = v0.convertPrecision(getPrecision());
            result = v0;
            break;
        }
        case MEMORY_FREE:
            session.getUser().checkAdmin();
            result = ValueInt.get(MemoryUtils.getMemoryFree());
            break;
        case MEMORY_USED:
            session.getUser().checkAdmin();
            result = ValueInt.get(MemoryUtils.getMemoryUsed());
            break;
        case LOCK_MODE:
            result = ValueInt.get(database.getLockMode());
            break;
        case SCHEMA:
            result = ValueString.get(session.getCurrentSchemaName());
            break;
        case SESSION_ID:
            result = ValueInt.get(session.getId());
            break;
        case IFNULL: {
            result = v0 == ValueNull.INSTANCE ? args[1].getValue(session) : v0;
            break;
        }
        case CASEWHEN: {
            Expression expr;
            if (v0 == ValueNull.INSTANCE || !v0.getBoolean().booleanValue()) {
                expr = args[2];
            } else {
                expr = args[1];
            }
            Value v = expr.getValue(session);
            result = v.convertTo(dataType);
            break;
        }
        case COALESCE: {
            result = v0;
            for (int i = 0; i < args.length; i++) {
                Value v = i == 0 ? v0 : args[i].getValue(session);
                if (!(v == ValueNull.INSTANCE)) {
                    result = v.convertTo(dataType);
                    break;
                }
            }
            break;
        }
        case GREATEST:
        case LEAST: {
            result = ValueNull.INSTANCE;
            for (int i = 0; i < args.length; i++) {
                Value v = i == 0 ? v0 : args[i].getValue(session);
                if (!(v == ValueNull.INSTANCE)) {
                    v = v.convertTo(dataType);
                    if (result == ValueNull.INSTANCE) {
                        result = v;
                    } else {
                        int comp = database.compareTypeSave(result, v);
                        if (info.type == GREATEST && comp < 0) {
                            result = v;
                        } else if (info.type == LEAST && comp > 0) {
                            result = v;
                        }
                    }
                }
            }
            break;
        }
        case CASE: {
            result = null;
            int i = 0;
            for (; i < args.length; i++) {
                Value when = args[i++].getValue(session);
                if (Boolean.TRUE.equals(when)) {
                    result = args[i].getValue(session);
                    break;
                }
            }
            if (result == null) {
                result = i < args.length ? args[i].getValue(session) : ValueNull.INSTANCE;
            }
            break;
        }
        case ARRAY_GET: {
            if (v0.getType() == Value.ARRAY) {
                Value v1 = args[1].getValue(session);
                int element = v1.getInt();
                Value[] list = ((ValueArray) v0).getList();
                if (element < 1 || element > list.length) {
                    result = ValueNull.INSTANCE;
                } else {
                    result = list[element - 1];
                }
            } else {
                result = ValueNull.INSTANCE;
            }
            break;
        }
        case ARRAY_LENGTH: {
            if (v0.getType() == Value.ARRAY) {
                Value[] list = ((ValueArray) v0).getList();
                result = ValueInt.get(list.length);
            } else {
                result = ValueNull.INSTANCE;
            }
            break;
        }
        case CANCEL_SESSION: {
            result = ValueBoolean.get(cancelStatement(session, v0.getInt()));
            break;
        }
        default:
            result = null;
        }
        return result;
    }

    private boolean cancelStatement(Session session, int targetSessionId) throws SQLException {
        session.getUser().checkAdmin();
        Session[] sessions = session.getDatabase().getSessions();
        for (int i = 0; i < sessions.length; i++) {
            Session s = sessions[i];
            if (s.getId() == targetSessionId) {
                Command c = s.getCurrentCommand();
                if (c == null) {
                    return false;
                } else {
                    c.cancel();
                    return true;
                }
            }
        }
        return false;
    }

    public Value getValueWithArgs(Session session, Expression[] args) throws SQLException {
        if (info.nullIfParameterIsNull) {
            for (int i = 0; i < args.length; i++) {
                if (getNullOrValue(session, args, i) == ValueNull.INSTANCE) {
                    return ValueNull.INSTANCE;
                }
            }
        }
        Value v0 = getNullOrValue(session, args, 0);
        Value resultSimple = getSimpleValue(session, v0, args);
        if (resultSimple != null) {
            return resultSimple;
        }
        Value v1 = getNullOrValue(session, args, 1);
        Value v2 = getNullOrValue(session, args, 2);
        Value v3 = getNullOrValue(session, args, 3);
        Value v4 = getNullOrValue(session, args, 4);
        Value v5 = getNullOrValue(session, args, 5);
        Value result;
        switch (info.type) {
        case ATAN2:
            result = ValueDouble.get(Math.atan2(v0.getDouble(), v1.getDouble()));
            break;
        case BITAND:
            result = ValueInt.get(v0.getInt() & v1.getInt());
            break;
        case BITOR:
            result = ValueInt.get(v0.getInt() | v1.getInt());
            break;
        case BITXOR:
            result = ValueInt.get(v0.getInt() ^ v1.getInt());
            break;
        case MOD: {
            int x = v1.getInt();
            if (x == 0.0) {
                throw Message.getSQLException(ErrorCode.DIVISION_BY_ZERO_1, getSQL());
            }
            result = ValueInt.get(v0.getInt() % x);
            break;
        }
        case POWER:
            result = ValueDouble.get(Math.pow(v0.getDouble(), v1.getDouble()));
            break;
        case ROUND: {
            double f = Math.pow(10., v1.getDouble());
            result = ValueDouble.get(Math.round(v0.getDouble() * f) / f);
            break;
        }
        case TRUNCATE: {
            double d = v0.getDouble();
            int p = v1.getInt();
            double f = Math.pow(10., p);
            double g = d * f;
            result = ValueDouble.get(((d < 0) ? Math.ceil(g) : Math.floor(g)) / f);
            break;
        }
        case HASH:
            result = ValueBytes.getNoCopy(getHash(v0.getString(), v1.getBytesNoCopy(), v2.getInt()));
            break;
        case ENCRYPT:
            result = ValueBytes.getNoCopy(encrypt(v0.getString(), v1.getBytesNoCopy(), v2.getBytesNoCopy()));
            break;
        case DECRYPT:
            result = ValueBytes.getNoCopy(decrypt(v0.getString(), v1.getBytesNoCopy(), v2.getBytesNoCopy()));
            break;
        case COMPRESS: {
            String algorithm = null;
            if (v1 != null) {
                algorithm = v1.getString();
            }
            result = ValueBytes.getNoCopy(CompressTool.getInstance().compress(v0.getBytesNoCopy(), algorithm));
            break;
        }
        case DIFFERENCE:
            result = ValueInt.get(getDifference(v0.getString(), v1.getString()));
            break;
        case INSERT: {
            if (v1 == ValueNull.INSTANCE || v2 == ValueNull.INSTANCE) {
                result = v1;
            } else {
                result = ValueString.get(insert(v0.getString(), v1.getInt(), v2.getInt(), v3.getString()));
            }
            break;
        }
        case LEFT:
            result = ValueString.get(left(v0.getString(), v1.getInt()));
            break;
        case LOCATE: {
            int start = v2 == null ? 0 : v2.getInt();
            result = ValueInt.get(locate(v0.getString(), v1.getString(), start));
            break;
        }
        case INSTR: {
            int start = v2 == null ? 0 : v2.getInt();
            result = ValueInt.get(locate(v1.getString(), v0.getString(), start));
            break;
        }
        case REPEAT: {
            int count = Math.max(0, v1.getInt());
            result = ValueString.get(repeat(v0.getString(), count));
            break;
        }
        case REPLACE: {
            String s0 = v0 == ValueNull.INSTANCE ? "" : v0.getString();
            String s1 = v1 == ValueNull.INSTANCE ? "" : v1.getString();
            String s2 = (v2 == null || v2 == ValueNull.INSTANCE) ? "" : v2.getString();
            result = ValueString.get(replace(s0, s1, s2));
            break;
        }
        case RIGHT:
            result = ValueString.get(right(v0.getString(), v1.getInt()));
            break;
        case LTRIM:
            result = ValueString.get(trim(v0.getString(), true, false, v1 == null ? " " : v1.getString()));
            break;
        case TRIM:
            result = ValueString.get(trim(v0.getString(), true, true, v1 == null ? " " : v1.getString()));
            break;
        case RTRIM:
            result = ValueString.get(trim(v0.getString(), false, true, v1 == null ? " " : v1.getString()));
            break;
        case SUBSTR:
        case SUBSTRING: {
            String s = v0.getString();
            int length = v2 == null ? s.length() : v2.getInt();
            result = ValueString.get(substring(s, v1.getInt(), length));
            break;
        }
        case POSITION:
            result = ValueInt.get(locate(v0.getString(), v1.getString(), 0));
            break;
        case XMLATTR:
            result = ValueString.get(StringUtils.xmlAttr(v0.getString(), v1.getString()));
            break;
        case XMLNODE: {
            String attr = v1 == null ? null : v1 == ValueNull.INSTANCE ? null : v1.getString();
            String content = v2 == null ? null : v2 == ValueNull.INSTANCE ? null : v2.getString();
            result = ValueString.get(StringUtils.xmlNode(v0.getString(), attr, content));
            break;
        }
        case REGEXP_REPLACE: {
            String regexp = v1.getString();
            try {
                result = ValueString.get(v0.getString().replaceAll(regexp, v2.getString()));
            } catch (PatternSyntaxException e) {
                throw Message.getSQLException(ErrorCode.LIKE_ESCAPE_ERROR_1, new String[]{regexp}, e);
            }
            break;
        }
        case RPAD:
            result = ValueString.get(StringUtils.pad(v0.getString(), v1.getInt(), v2 == null ? null : v2.getString(), true));
            break;
        case LPAD:
            result = ValueString.get(StringUtils.pad(v0.getString(), v1.getInt(), v2 == null ? null : v2.getString(), false));
            break;
            // date
        case DATEADD:
            result = ValueTimestamp.getNoCopy(dateadd(v0.getString(), v1.getInt(), v2.getTimestampNoCopy()));
            break;
        case DATEDIFF:
            result = ValueLong.get(datediff(v0.getString(), v1.getTimestampNoCopy(), v2.getTimestampNoCopy()));
            break;
        case EXTRACT: {
            int field = getDatePart(v0.getString());
            result = ValueInt.get(getDatePart(v1.getTimestamp(), field));
            break;
        }
        case FORMATDATETIME: {
            if (v0 == ValueNull.INSTANCE || v1 == ValueNull.INSTANCE) {
                result = ValueNull.INSTANCE;
            } else {
                String locale = v2 == null ? null : v2 == ValueNull.INSTANCE ? null : v2.getString();
                String tz = v3 == null ? null : v3 == ValueNull.INSTANCE ? null : v3.getString();
                result = ValueString.get(StringUtils.formatDateTime(v0.getTimestamp(), v1.getString(), locale, tz));
            }
            break;
        }
        case PARSEDATETIME: {
            if (v0 == ValueNull.INSTANCE || v1 == ValueNull.INSTANCE) {
                result = ValueNull.INSTANCE;
            } else {
                String locale = v2 == null ? null : v2 == ValueNull.INSTANCE ? null : v2.getString();
                String tz = v3 == null ? null : v3 == ValueNull.INSTANCE ? null : v3.getString();
                java.util.Date d = StringUtils.parseDateTime(v0.getString(), v1.getString(), locale, tz);
                result = ValueTimestamp.getNoCopy(new Timestamp(d.getTime()));
            }
            break;
        }
        case NULLIF: