ExpressionJSON.java

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package org.hsqldb;

import org.hsqldb.error.Error;
import org.hsqldb.error.ErrorCode;
import org.hsqldb.lib.HsqlArrayList;
import org.hsqldb.lib.OrderedHashMap;
import org.hsqldb.lib.OrderedHashSet;
import org.hsqldb.lib.StringConverter;
import org.hsqldb.types.ArrayType;
import org.hsqldb.types.Type;

/**
 * JSON functions
 *
 * @author Fred Toussi (fredt@users dot sourceforge.net)
 * @version 2.7.0
 * @since 2.7.0
 */
public interface ExpressionJSON {

    class ExpressionJSONWrapper extends Expression {

        public ExpressionJSONWrapper(Expression expr) {
            super(OpTypes.JSON_FUNCTION);

            nodes = new Expression[]{ expr };
        }

        public void resolveTypes(Session session, Expression parent) {
            nodes[LEFT].resolveTypes(session, this);

            dataType = nodes[LEFT].dataType;
        }

        public Object getValue(Session session) {
            return nodes[LEFT].getValue(session);
        }

        public String getSQL() {
            return nodes[LEFT].getSQL();
        }

        public String describe(Session session, int blanks) {
            return nodes[LEFT].getSQL();
        }
    }

    class ExpressionJSONArrayFromQuery extends Expression {

        final Expression exprQuery;
        final boolean    nullOnNull;

        public ExpressionJSONArrayFromQuery(
                Expression expressionQuery,
                boolean nullOnNull,
                Type dataType) {

            super(OpTypes.JSON_FUNCTION);

            this.exprQuery  = expressionQuery;
            this.nullOnNull = nullOnNull;
            this.dataType   = dataType == null
                              ? Type.SQL_VARCHAR_LONG
                              : dataType;
            nodes           = new Expression[]{ expressionQuery };
        }

        public void resolveTypes(Session session, Expression parent) {
            nodes[LEFT].resolveTypes(session, this);
        }

        public Object getValue(Session session) {

            StringBuilder sb     = new StringBuilder();
            Object        values = nodes[LEFT].getValue(session);

            nodes[LEFT].dataType.convertToJSON(values, sb);

            if (sb.length() > dataType.precision) {
                throw Error.error(ErrorCode.X_22001);
            }

            return sb.toString();
        }

        public String getSQL() {
            return Tokens.T_JSON_ARRAY + "()";
        }

        public String describe(Session session, int blanks) {
            return Tokens.T_JSON_ARRAY + "()";
        }
    }

    class ExpressionJSONArrayFromValues extends Expression {

        final HsqlArrayList<Expression> exprList;
        final boolean                   nullOnNull;

        public ExpressionJSONArrayFromValues(
                HsqlArrayList<Expression> expressionList,
                boolean nullOnNull,
                Type dataType) {

            super(OpTypes.JSON_FUNCTION);

            this.exprList   = expressionList;
            this.nullOnNull = nullOnNull;
            this.dataType   = dataType == null
                              ? Type.SQL_VARCHAR_LONG
                              : dataType;
            nodes           = new Expression[expressionList.size()];

            expressionList.toArray(nodes);
        }

        public void resolveTypes(Session session, Expression parent) {

            for (int i = 0; i < nodes.length; i++) {
                if (nodes[i] != null) {
                    nodes[i].resolveTypes(session, this);
                }
            }
        }

        public Object getValue(Session session) {

            StringBuilder sb    = new StringBuilder();
            int           count = 0;

            sb.append('[');

            for (int i = 0; i < nodes.length; i++) {
                if (count > 0) {
                    sb.append(',');
                }

                Object value = nodes[i].getValue(session);

                if (nodes[i].opType == OpTypes.JSON_FUNCTION) {
                    sb.append((String) value);
                } else {
                    nodes[i].dataType.convertToJSON(value, sb);
                }

                count++;
            }

            sb.append(']');

            if (sb.length() > dataType.precision) {
                throw Error.error(ErrorCode.X_22001);
            }

            return sb.toString();
        }

        public String getSQL() {
            return Tokens.T_JSON_ARRAY + "()";
        }

        public String describe(Session session, int blanks) {
            return Tokens.T_JSON_ARRAY + "()";
        }
    }

    class ExpressionJSONArrayAgg extends Expression {

        final boolean isValueJSON;
        final boolean nullOnNull;

        public ExpressionJSONArrayAgg(
                ExpressionArrayAggregate valuesAgg,
                boolean nullOnNull,
                Type dataType) {

            super(OpTypes.JSON_FUNCTION);

            this.nullOnNull  = nullOnNull;
            this.dataType    = dataType == null
                               ? Type.SQL_VARCHAR_LONG
                               : dataType;
            this.isValueJSON = valuesAgg.exprOpType == OpTypes.JSON_FUNCTION;
            nodes            = new Expression[]{ valuesAgg };
        }

        public void resolveTypes(Session session, Expression parent) {
            nodes[LEFT].resolveTypes(session, this);
        }

        public Object getValue(Session session) {

            StringBuilder sb         = new StringBuilder();
            Object        values     = nodes[LEFT].getValue(session);
            ArrayType     valuesType = (ArrayType) nodes[LEFT].dataType;

            if (isValueJSON) {
                valuesType.convertToJSONsimple(values, sb);
            } else {
                valuesType.convertToJSON(values, sb);
            }

            if (sb.length() > dataType.precision) {
                throw Error.error(ErrorCode.X_22001);
            }

            return sb.toString();
        }

        public String getSQL() {
            return Tokens.T_JSON_ARRAYAGG + "()";
        }

        public String describe(Session session, int blanks) {
            return Tokens.T_JSON_ARRAYAGG + "()";
        }
    }

    class ExpressionJSONObject extends Expression {

        final OrderedHashMap<Expression, Expression> exprMap;
        final boolean                                nullOnNull;
        final boolean                                uniqueKeys;

        public ExpressionJSONObject(
                OrderedHashMap<Expression, Expression> exprMap,
                boolean nullOnNull,
                boolean uniqueKeys,
                Type dataType) {

            super(OpTypes.JSON_FUNCTION);

            this.exprMap    = exprMap;
            this.nullOnNull = nullOnNull;
            this.uniqueKeys = uniqueKeys;
            this.dataType   = dataType == null
                              ? Type.SQL_VARCHAR_LONG
                              : dataType;
            nodes           = new Expression[exprMap.size() * 2];

            for (int i = 0; i < exprMap.size(); i++) {
                nodes[i * 2]     = exprMap.getKeyAt(i);
                nodes[i * 2 + 1] = exprMap.get(i);
            }
        }

        public void resolveTypes(Session session, Expression parent) {

            for (int i = 0; i < nodes.length; i++) {
                if (nodes[i] != null) {
                    nodes[i].resolveTypes(session, this);
                }
            }
        }

        public Object getValue(Session session) {

            StringBuilder          sb     = new StringBuilder();
            int                    count  = 0;
            OrderedHashSet<String> keySet = new OrderedHashSet<>();

            sb.append('{');

            for (int i = 0; i < exprMap.size(); i++) {
                int j = i * 2;

                if (count > 0) {
                    sb.append(',');
                }

                Object name = nodes[j].getValue(session);

                if (uniqueKeys) {
                    String s = nodes[j].dataType.convertToString(name);

                    if (!keySet.add(s)) {
                        throw Error.error(ErrorCode.X_23505);
                    }
                }

                if (nodes[j].dataType.isCharacterType()) {
                    nodes[j].dataType.convertToJSON(name, sb);
                } else {
                    String s = nodes[j].dataType.convertToString(name);

                    s = StringConverter.toQuotedString(s, '"', false);

                    sb.append(s);
                }

                sb.append(':');

                Object value = nodes[j + 1].getValue(session);

                if (nodes[j + 1].opType == OpTypes.JSON_FUNCTION) {
                    sb.append((String) value);
                } else {
                    nodes[j + 1].dataType.convertToJSON(value, sb);
                }

                count++;
            }

            sb.append('}');

            if (sb.length() > dataType.precision) {
                throw Error.error(ErrorCode.X_22001);
            }

            return sb.toString();
        }

        public String getSQL() {
            return Tokens.T_JSON_OBJECT + "()";
        }

        public String describe(Session session, int blanks) {
            return Tokens.T_JSON_OBJECT + "()";
        }
    }

    class ExpressionJSONObjectAgg extends Expression {

        final ExpressionArrayAggregate namesAgg;
        final ExpressionArrayAggregate valuesAgg;
        final boolean                  nullOnNull;
        final boolean                  uniqueKeys;
        boolean                        isValueJSON;

        public ExpressionJSONObjectAgg(
                ExpressionArrayAggregate namesAgg,
                ExpressionArrayAggregate valuesAgg,
                boolean nullOnNull,
                boolean uniqueKeys,
                Type dataType) {

            super(OpTypes.JSON_FUNCTION);

            this.namesAgg    = namesAgg;
            this.valuesAgg   = valuesAgg;
            this.nullOnNull  = nullOnNull;
            this.uniqueKeys  = uniqueKeys;
            this.dataType    = dataType == null
                               ? Type.SQL_VARCHAR_LONG
                               : dataType;
            this.isValueJSON = valuesAgg.exprOpType == OpTypes.JSON_FUNCTION;
            nodes            = new Expression[]{ namesAgg, valuesAgg };
        }

        public void resolveTypes(Session session, Expression parent) {

            for (int i = 0; i < nodes.length; i++) {
                if (nodes[i] != null) {
                    nodes[i].resolveTypes(session, this);
                }
            }
        }

        public Object getValue(Session session) {

            int      count     = 0;
            Object[] names     = (Object[]) nodes[LEFT].getValue(session);
            Object[] values    = (Object[]) nodes[RIGHT].getValue(session);
            Type     nameType  = nodes[LEFT].dataType.collectionBaseType();
            Type     valueType = nodes[RIGHT].dataType.collectionBaseType();

            //
            OrderedHashSet<String> keySet = new OrderedHashSet<>();

            //
            StringBuilder sb = new StringBuilder();

            sb.append('{');

            for (int i = 0; i < names.length; i++) {
                String name  = (String) names[i];
                String value = (String) values[i];

                if (name == null) {
                    continue;
                }

                if (!nullOnNull && value == null) {
                    continue;
                }

                if (count > 0) {
                    sb.append(',');
                }

                if (uniqueKeys) {
                    String s = nameType.convertToString(name);

                    if (!keySet.add(s)) {
                        throw Error.error(ErrorCode.X_23505);
                    }
                }

                if (nameType.isCharacterType()) {
                    nameType.convertToJSON(name, sb);
                } else {
                    String s = nameType.convertToString(name);

                    s = StringConverter.toQuotedString(s, '"', false);

                    sb.append(s);
                }

                sb.append(':');

                if (isValueJSON) {
                    sb.append(value);
                } else {
                    valueType.convertToJSON(value, sb);
                }

                count++;
            }

            sb.append('}');

            if (sb.length() > dataType.precision) {
                throw Error.error(ErrorCode.X_22001);
            }

            return sb.toString();
        }

        public String getSQL() {
            return Tokens.T_JSON_OBJECTAGG + "()";
        }

        public String describe(Session session, int blanks) {
            return Tokens.T_JSON_OBJECTAGG + "()";
        }
    }
}