Hi Dave, On Fri, Nov 17, 2017 at 2:42 PM, Dave Page <dp...@pgadmin.org> wrote:
> > > On Fri, Nov 17, 2017 at 8:45 AM, Neel Patel <neel.pa...@enterprisedb.com> > wrote: > >> Hi Dave, >> >> On Thu, Nov 16, 2017 at 8:13 PM, Dave Page <dp...@pgadmin.org> wrote: >> >>> Hi >>> >>> On Thu, Nov 16, 2017 at 1:47 PM, Neel Patel <neel.pa...@enterprisedb.com >>> > wrote: >>> >>>> Hi, >>>> >>>> Adding information. >>>> >>>> With this patch, RM#2715 should also be resolved. >>>> >>>> Thanks, >>>> Neel Patel >>>> >>>> On Thu, Nov 16, 2017 at 7:01 PM, Neel Patel < >>>> neel.pa...@enterprisedb.com> wrote: >>>> >>>>> Hi, >>>>> >>>>> I am able to reproduce the crash while downloading and save data in >>>>> CSV file from query tool. >>>>> >>>>> Please find attached updated patch with below changes after reading Qt >>>>> documentation. >>>>> >>>>> - Added new signal "readyRead". As per the Qt documentation, this >>>>> signal will be emitted when data is ready from IO channel for large >>>>> amount >>>>> of data transfer between server and client. >>>>> - Ready read and DownloadInProgress signal is very quick in call >>>>> so we should not do large operation inside that slot because for >>>>> downloading big data it may possible of frequent call of those signals >>>>> which may cause the crash or missing data to write inside the file so >>>>> removed unnecessary logic from that slot. >>>>> - Fixed the crash while opening IODevice with NULL handle. >>>>> >>>>> With above changes, I have tested with same data as earlier and it is >>>>> working as expected without crashing the application. >>>>> >>>>> Do review it and let me know for comments. >>>>> >>>> >>> My first test was on Mac using Qt 5.8 with webkit, and when I attempted >>> to download the results from a 300K row query, it basically hung showing >>> the Downloading File progress indicator. It let me cancel it and carried on >>> working, but hung again the next time I tried the CSV download. Each time >>> it seems to download some data - from the same query I've seen 2.8MB, 5.1MB >>> and 1.5MB. >>> >> >> We are using "*downloadProgress*" signal to update the progress bar and >> here we are getting "readData" as bytes but "totalData" is unknown so we >> received "totalData" as -1 because Qt doesn't know the total size of the >> file we are getting from server but when we open "pgAdmin4" website in >> another link and try to download some binary or source at that time we are >> getting "totalData" as known size and we are displaying the progress bar >> correctly. >> >> Here, Qt sending the signal "downloadProgress" with unknown totalData >> size as -1 so we update the progress bar with 100% so from user point of >> view it looks like hang but it is downloading and writing to file at back >> ground. if we apply the same patch in windows then it display running >> progress bar so user can know something happening at back end side. >> >> I think it is same as browser - if we download big size file from server >> then it keep on downloading the file without displaying total size. What >> should we do here ? Should we create one custom progress bar dialog with >> moving cursor or something other so that user can know that activity is >> doing at backend ? Thoughts ? >> > > It is misleading, but it *is* also hanging. 10+ minutes to download a few > megs of data from a server on the same machine is not just a misleading > progress indicator :-) > Can you please share some table definition with no of rows with ~table size ? I have tried but not able to reproduce the issue. > > > -- > Dave Page > Blog: http://pgsnake.blogspot.com > Twitter: @pgsnake > > EnterpriseDB UK: http://www.enterprisedb.com > The Enterprise PostgreSQL Company >
