@vulcan-sql/serve
Version:
VulcanSQL package for serving projects
72 lines • 2.85 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.JsonFormatter = void 0;
const tslib_1 = require("tslib");
const Stream = require("stream");
const core_1 = require("@vulcan-sql/core");
const responseFormatter_1 = require("../../models/extensions/responseFormatter");
const lodash_1 = require("lodash");
const logger = (0, core_1.getLogger)({ scopeName: 'SERVE' });
class JsonStringTransformer extends Stream.Transform {
constructor(options) {
/**
* make the json stream source (writable stream) is object mode to get data row directly from data readable stream.
* make the json stream transformed destination (readable stream) is not object mode
*/
options = options || {
writableObjectMode: true,
readableObjectMode: false,
};
if ((0, lodash_1.isUndefined)(options.readableObjectMode))
options.readableObjectMode = false;
if ((0, lodash_1.isUndefined)(options.writableObjectMode))
options.writableObjectMode = true;
super(options);
this.first = true;
}
_transform(chunk, _encoding, callback) {
if (this.first) {
this.push((0, responseFormatter_1.toBuffer)('['));
this.first = false;
}
else {
this.push((0, responseFormatter_1.toBuffer)(','));
}
this.push((0, responseFormatter_1.toBuffer)(JSON.stringify(chunk)));
callback(null);
}
_final(callback) {
// if first is still true, means no data.
if (this.first)
this.push((0, responseFormatter_1.toBuffer)('['));
this.push((0, responseFormatter_1.toBuffer)(']'));
callback(null);
}
}
let JsonFormatter = class JsonFormatter extends responseFormatter_1.BaseResponseFormatter {
format(data) {
const jsonStream = new JsonStringTransformer();
// Read data stream and convert the format to json format stream.
data
.pipe(jsonStream)
.on('error', (err) => {
logger.warn(`read stream failed, detail error ${err}`);
throw new core_1.InternalError(`read data in the stream for formatting to json failed.`);
})
.on('end', () => {
logger.debug('convert to json format stream > done.');
});
return jsonStream;
}
toResponse(stream, ctx) {
// set json stream to response in context ( data is json stream, no need to convert. )
ctx.response.body = stream;
ctx.response.set('Content-type', 'application/json');
}
};
JsonFormatter = tslib_1.__decorate([
(0, core_1.VulcanInternalExtension)(),
(0, core_1.VulcanExtensionId)('json')
], JsonFormatter);
exports.JsonFormatter = JsonFormatter;
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