12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970
import { executionCtx } from '../utils.ts';import { Types } from '../datatypes/index.ts';import { FunctionDefinition, QueryError } from '../interfaces.ts';import { asSeq, RegClass, _ISequence } from '../interfaces-private.ts';
// https://www.postgresql.org/docs/8.1/functions-sequence.html
function getSeq(id: RegClass) {    const { transaction, schema } = executionCtx();    if (!transaction) {        throw new QueryError('cannot query sequence value in this context');    }    return {        t: transaction,        seq: asSeq(schema.getObjectByRegOrName(id)),    };}const lastVal = Symbol();export const sequenceFunctions: FunctionDefinition[] = [
    {        name: 'nextval',        args: [Types.regclass],        returns: Types.integer,        implementation: (seqId: RegClass) => {            const { seq, t } = getSeq(seqId);            const ret = seq.nextValue(t);            t.set(lastVal, ret);            return ret;        },        impure: true,    },    {        name: 'currval',        args: [Types.regclass],        returns: Types.integer,        implementation: (seqId: RegClass) => {            const { seq, t } = getSeq(seqId);            return seq.currentValue(t);        },        impure: true,    },    {        name: 'lastval',        returns: Types.integer,        implementation: (seqId: RegClass) => {            const { transaction } = executionCtx();            if (!transaction) {                throw new QueryError('cannot query lastval in this context');            }            return transaction.get<number>(lastVal);        },        impure: true,    },    {        name: 'setval',        args: [Types.regclass, Types.integer],        returns: Types.integer,        implementation: (seqId: RegClass, val: number) => {            const { seq, t } = getSeq(seqId);            if (typeof val !== 'number') {                throw new QueryError('Invalid setval() value');            }            seq.setValue(t, val);            return val;        },        impure: true,    },]