diff options
| -rw-r--r-- | cmd/lspipeline/main.go | 52 |
1 files changed, 21 insertions, 31 deletions
diff --git a/cmd/lspipeline/main.go b/cmd/lspipeline/main.go index bf19b52..8980c59 100644 --- a/cmd/lspipeline/main.go +++ b/cmd/lspipeline/main.go @@ -12,7 +12,6 @@ import ( "os/exec" "sort" "strings" - "sync" "time" "rescribe.xyz/bookpipeline" @@ -124,11 +123,10 @@ func getBookDetails(conn LsPipeliner, key string) (date time.Time, done bool, er return objs[0].Date, false, nil } -// getBookDetailsWg gets the details for a book putting it into either the -// done or inprogress channels as appropriate, and using a sync.WaitGroup Done -// signal so it can be tracked. On error it sends to the errc channel. -func getBookDetailsWg(conn LsPipeliner, key string, done chan bookpipeline.ObjMeta, inprogress chan bookpipeline.ObjMeta, errc chan error, wg *sync.WaitGroup) { - defer wg.Done() +// getBookDetailsChan gets the details for a book putting it into either the +// done or inprogress channels as appropriate, or sending an error to errc +// on failure. +func getBookDetailsChan(conn LsPipeliner, key string, done chan bookpipeline.ObjMeta, inprogress chan bookpipeline.ObjMeta, errc chan error) { date, isdone, err := getBookDetails(conn, key) if err != nil { errc <- err @@ -148,6 +146,8 @@ func getBookDetailsWg(conn LsPipeliner, key string, done chan bookpipeline.ObjMe // list), and those which do not (the inprogress list). They are // sorted according to the date of the graph.png file, or the date // of a random file with the prefix if no graph.png was found. +// It spins up many goroutines to do query the book status and +// dates, as it is far faster to do concurrently. func getBookStatus(conn LsPipeliner) (inprogress []string, done []string, err error) { prefixes, err := conn.ListObjectPrefixes(conn.WIPStorageId()) if err != nil { @@ -155,37 +155,27 @@ func getBookStatus(conn LsPipeliner) (inprogress []string, done []string, err er return } - // 100,000 size buffer is to ensure we never block, as we're using waitgroup - // rather than channel blocking to determine when to continue. Probably there - // is a better way to do this, though, like reading the done and inprogress - // channels in a goroutine and doing wg.Done() when each is read there instead. - donec := make(chan bookpipeline.ObjMeta, 100000) - inprogressc := make(chan bookpipeline.ObjMeta, 100000) - errc := make(chan error, 100000) + donec := make(chan bookpipeline.ObjMeta, 100) + inprogressc := make(chan bookpipeline.ObjMeta, 100) + errc := make(chan error) - var wg sync.WaitGroup for _, p := range prefixes { - wg.Add(1) - go getBookDetailsWg(conn, p, donec, inprogressc, errc, &wg) - } - wg.Wait() - close(donec) - close(inprogressc) - - select { - case err = <-errc: - return inprogress, done, err - default: - break + go getBookDetailsChan(conn, p, donec, inprogressc, errc) } var inprogressmeta, donemeta ObjMetas - for i := range donec { - donemeta = append(donemeta, i) - } - for i := range inprogressc { - inprogressmeta = append(inprogressmeta, i) + // there will be exactly as many sends to donec or inprogressc + // as there are prefixes + for range prefixes { + select { + case i := <-donec: + donemeta = append(donemeta, i) + case i := <-inprogressc: + inprogressmeta = append(inprogressmeta, i) + case err = <-errc: + return inprogress, done, err + } } sort.Sort(donemeta) |