Merge "server.go cleanups"
diff --git a/polygerrit-ui/server.go b/polygerrit-ui/server.go
index 3844b5b..124b924 100644
--- a/polygerrit-ui/server.go
+++ b/polygerrit-ui/server.go
@@ -526,16 +526,23 @@
waitForNextChangeInterval = 1 * time.Second
)
+// typescriptLogWriter implements Writer interface and receives output
+// (stdout and stderr) from the typescript compiler. It reads incoming
+// data line-by-line, analyzes each line and updates compilationDoneWaiter
+// according to the current compiler state. Additionally, the
+// typescriptLogWriter passes all incoming lines to the underlying logger.
type typescriptLogWriter struct {
+ // unfinishedLine stores the portion of line which was partially received
+ // (i.e. all text received after the last EOL (\n) mark.
unfinishedLine string
- logger *log.Logger
+ // logger is used to pass-through all received strings
+ logger *log.Logger
// when WaitGroup counter is 0 the compilation is complete
compilationDoneWaiter *sync.WaitGroup
}
func newTypescriptLogWriter(compilationCompleteWaiter *sync.WaitGroup) *typescriptLogWriter {
return &typescriptLogWriter{
- unfinishedLine: "",
logger: log.New(log.Writer(), "TSC - ", log.Flags()),
compilationDoneWaiter: compilationCompleteWaiter,
}
@@ -572,7 +579,7 @@
// again until it finishes.
go func() {
time.Sleep(waitForNextChangeInterval)
- lw.compilationDoneWaiter.Add(-1)
+ lw.compilationDoneWaiter.Done()
}()
}
lw.logger.Print(text)
@@ -596,6 +603,20 @@
compilationCompleteWaiter := &sync.WaitGroup{}
logWriter := newTypescriptLogWriter(compilationCompleteWaiter)
+ // Note 1: (from https://golang.org/pkg/os/exec/#Cmd)
+ // If Stdout and Stderr are the same writer, and have a type that can
+ // be compared with ==, at most one goroutine at a time will call Write.
+ //
+ // Note 2: The typescript compiler reports all compilation errors to
+ // stdout by design (see https://github.com/microsoft/TypeScript/issues/615)
+ // It writes to stderr only when something unexpected happens (like internal
+ // exceptions). To print such errors in the same way as standard typescript
+ // error, the same logWriter is used both for Stdout and Stderr.
+ //
+ // If Stderr arrives in the middle of ordinary typescript output (i.e.
+ // something unexpected happens), the server.go can stop respond to http
+ // requests. However, this is not a problem for us: typescript compiler and
+ // server.go must be restarted anyway.
cmd.Stdout = logWriter
cmd.Stderr = logWriter
