rxjs 合并 http 响应

Question

多个http请求是并发的，并发请求数可以控制。 完成所有请求后，可以合并数据（数据可以是有序的，也可以是无序的）

from([link, link, link]).pipe(
   merge(l => request.get(l)),
   // something...
)

return [linkdata, linkdata, linkdata]

Answer 1

考虑实现它，如下所示：

from([link1, link2, link3]).pipe(
  mergeMap(request.get, CONCURRENT_NUMBER), // <= limit the number of active inner subscriptions at a time
  toArray() // <= transform stream into array prior to completion 
)
.subscribe(([result1, result2, result3]) => { })

Answer 2

好像你需要使用forkJoin

const links = [link1, link2, link3]; // assump `links` is an array of string

forkJoin(
  from(links).pipe(
    mergeMap((link: string) => {
      return http.get(link); // returns an observable
    }),
    toArray()
  )
).pipe(
   map(array => array[0]) // data stream is in [[data]] format, you only need head
); // [link1data, link2data, link3data]

Answer 3

我想你正在寻找mergeAll

from([link1, link2, link3].map(link => request.get(link))).pipe(
  mergeAll(CONCURRENT_NUMBER),
  // something like reduce, toArray... to combine the results
).subscribe(console.log);