319636 - Provide convenience function for consuming an entire nsIInputStream

Status: RESOLVED FIXED

(Core :: XPCOM, enhancement)

Description

[Darin Fisher]

Provide convenience function for consuming an entire nsIInputStream

Comment 1

[Darin Fisher]

Attachment: v1 patch

Simple patch.  This is something the places project wants to use.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 205355 [details] [diff] [review]
v1 patch

>Index: io/nsStreamUtils.h
>Index: io/nsStreamUtils.cpp
>+NS_ConsumeStream(nsIInputStream *stream, nsACString &result)
>+        char *buf = result.BeginWriting();

Shouldn't you add |length| here?  Otherwise you're always reading into the beginning of the string...

sr=bzbarsky with that fixed.

Comment 3

[Darin Fisher]

Yes, indeed.  My testcase was apparently not comprehensive enough :-(

Comment 4

[Boris Zbarsky [:bzbarsky]]

The stream in the testcase just handed back all the data in a single chunk is all... ;)

Comment 5

[Christian :Biesinger (don't email me, ping me on IRC)]

Comment on attachment 205355 [details] [diff] [review]
v1 patch

heh, the other day I was thinking that a function like this would be useful :)

should the comments say that the stream needs to be blocking for reasonable behaviour? (at least I think that's the case...)

shouldn't you truncate the string at the beginning of this function?

Comment 6

[Darin Fisher]

I decided to let this function work with non-blocking streams as well.  The comments say that the function will append to the buffer and return a failure if it encountered an error at some point, but any data in the buffer will remain in the buffer.  This allows the function to be used with either type of stream.

I can make the function Truncate up front I suppose.  That makes the function a little less useful, but it perhaps makes its behavior a bit more predictable.  Hmm...

Comment 7

[Darin Fisher]

Attachment: v1.1 patch

Here's the version of the patch that I checked in.

Comment 8

[David G King]

This patch is giving me the following error on WinXP/cygwin/Mingw

e:/mozilla/source/mozilla/xpcom/build/dlldeps.cpp: In function `void XXXNeverCal
led()':
e:/mozilla/source/mozilla/xpcom/build/dlldeps.cpp:122: error: cannot convert `ns
CString' to `PRUint32' for argument `2' to `nsresult NS_ConsumeStream(nsIInputSt
ream*, PRUint32, nsACString_internal&)'

Comment 9

[Darin Fisher]

> CString' to `PRUint32' for argument `2' to `nsresult
> NS_ConsumeStream(nsIInputSt

crap, the line in dlldeps.cpp needs to have a "0" in the second parameter to NS_ConsumeStream.  It looks like the CVS servers are down for the count, so I won't be able to fix this until they come back online.

Comment 10

[Stefan Sitter [:ssitter]]

(In reply to comment #9)
> crap, the line in dlldeps.cpp needs to have a "0" in the second parameter to
> NS_ConsumeStream.  It looks like the CVS servers are down for the count, so I
> won't be able to fix this until they come back online.

I tried to build Sunbird from trunk today (dlldeps.cpp,v1.137 with "0") and get the following error: 

c:/dev/moz_build/mozilla/xpcom/build/dlldeps.cpp: 
   In function `void XXXNeverCalled()':

c:/dev/moz_build/mozilla/xpcom/build/dlldeps.cpp:122: 
   error: invalid initialization of non-const reference of type 
   'nsACString_internal&' from a temporary of type 'nsCString'

c:/dev/moz_build/mozilla/xpcom/build/../io/nsStreamUtils.h:136: 
   error: in passing argument 3 of `nsresult NS_ConsumeStream(nsIInputStream*, 
   PRUint32, nsACString_internal&)'

Comment 11

[Darin Fisher]

I applied a fix for this.  Please update dlldeps.cpp

Comment 12

[Brian Ryner (not reading)]

marking dependency for branch landing