stream

问题 I'm trying to use WindowFunction with DataStream, my goal is to have a Query like the following SELECT *, count(id) OVER(PARTITION BY country) AS c_country, count(id) OVER(PARTITION BY city) AS c_city, count(id) OVER(PARTITION BY city) AS c_addrs FROM fm ORDER BY country have helped me for the aggregation by the country field, but I need to do the aggregation by two fields in the same time window. I don't know if it is possible to have two or more keys in keyBy( ) for this case val parsed =

问题 My use case is reading a compressed file from disk, de-compressing it incrementally and using the resulting data. Currently I am reading file contents into a temporary buffer allocated by me, point the decompression API at this buffer, and so on. The question is about understanding whether the temporary buffer really is necessary or helpful in this case. In an experiment, I opened a stream to a text file and called get() once. In the debugger I can see that the filebuffer in the stream

问题 My use case is reading a compressed file from disk, de-compressing it incrementally and using the resulting data. Currently I am reading file contents into a temporary buffer allocated by me, point the decompression API at this buffer, and so on. The question is about understanding whether the temporary buffer really is necessary or helpful in this case. In an experiment, I opened a stream to a text file and called get() once. In the debugger I can see that the filebuffer in the stream

问题 I have two streams fetching from two different api. Stream<Month> get monthOutStream => monthOutController.stream; Stream<MySchedule> get resultOutStream => resultController.stream; I am fetching these data at two different state of the application, result at the begining and Months after some events from user. MyScheduleBloc(){ initialData(); } Future initialData() async { MySchedule mySchedule = await myScheduleViewModel.importMySchedule(now.id); resultController.add(mySchedule); } My

问题 I have two streams fetching from two different api. Stream<Month> get monthOutStream => monthOutController.stream; Stream<MySchedule> get resultOutStream => resultController.stream; I am fetching these data at two different state of the application, result at the begining and Months after some events from user. MyScheduleBloc(){ initialData(); } Future initialData() async { MySchedule mySchedule = await myScheduleViewModel.importMySchedule(now.id); resultController.add(mySchedule); } My

问题 I am trying to stream the data from a mongodb cursor into an s3 file using a nodejs lambda. Following is a snippet of my code. What i observe is that the lambda does not wait for the pipeline to complete and exists it, so the file is not written to s3. But the same works fine if I run it as a standalone node.js script. const logger = require('./logger').logger; let s3Client = require('aws-sdk/clients/s3'); const stream = require('stream'); const util = require('util'); const pipeline = util

问题 I'm trying to query a few documents from a collection, this query should listen to changes made in the queried documents, so I'd need a stream. I'm doing following (in Dart/Flutter) Stream<List<MatchRequest>> _getNewMatches() { return Collection<MatchRequest>(path: 'requests') .ref .where('status', isNull: true) .where('users', arrayContains: ['$currentUid']) .orderBy('last_activity') .snapshots() .map((list) => list.documents.map( (doc) => Global.models[MatchRequest](doc.data) as

问题 I'm trying to query a few documents from a collection, this query should listen to changes made in the queried documents, so I'd need a stream. I'm doing following (in Dart/Flutter) Stream<List<MatchRequest>> _getNewMatches() { return Collection<MatchRequest>(path: 'requests') .ref .where('status', isNull: true) .where('users', arrayContains: ['$currentUid']) .orderBy('last_activity') .snapshots() .map((list) => list.documents.map( (doc) => Global.models[MatchRequest](doc.data) as

问题 I'm trying to query a few documents from a collection, this query should listen to changes made in the queried documents, so I'd need a stream. I'm doing following (in Dart/Flutter) Stream<List<MatchRequest>> _getNewMatches() { return Collection<MatchRequest>(path: 'requests') .ref .where('status', isNull: true) .where('users', arrayContains: ['$currentUid']) .orderBy('last_activity') .snapshots() .map((list) => list.documents.map( (doc) => Global.models[MatchRequest](doc.data) as

问题 I'm trying to query a few documents from a collection, this query should listen to changes made in the queried documents, so I'd need a stream. I'm doing following (in Dart/Flutter) Stream<List<MatchRequest>> _getNewMatches() { return Collection<MatchRequest>(path: 'requests') .ref .where('status', isNull: true) .where('users', arrayContains: ['$currentUid']) .orderBy('last_activity') .snapshots() .map((list) => list.documents.map( (doc) => Global.models[MatchRequest](doc.data) as