panic: interface conversion: interface is int32, not float64

[Nikolai Derzhak]

I am getting this error when starting replay with recorded OUTPUT json and go 1.4.2:

panic: interface conversion: interface is int32, not float64

goroutine 113 [running]:
github.com/ParsePlatform/flashback.(*OpsExecutor).execQuery(0xc20866b2c0, 0xc2085d0120, 0xc208697530, 0x0, 0x0)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/ops_executor.go:50 +0x20e
github.com/ParsePlatform/flashback.*OpsExecutor.(github.com/ParsePlatform/flashback.execQuery)·fm(0xc2085d0120, 0xc208697530, 0x0, 0x0)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/ops_executor.go:35 +0x4d
github.com/ParsePlatform/flashback.func·004(0x0, 0x0)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/ops_executor.go:144 +0x2b5
github.com/ParsePlatform/flashback.retryOnSocketFailure(0xc208815e70, 0xc2086621a0, 0xc20803c420, 0x0, 0x0)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/ops_executor.go:116 +0x47
github.com/ParsePlatform/flashback.(*OpsExecutor).Execute(0xc20866b2c0, 0xc208608050, 0x0, 0x0)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/ops_executor.go:146 +0xc6
main.func·003(0xc20866b2c0, 0x68ab90, 0x7)
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/cmd/flashback/main.go:317 +0x6b
created by main.func·005
        /home/ubuntu/gocode/src/github.com/ParsePlatform/flashback/cmd/flashback/main.go:328 +0x725

[Nikolai Derzhak]

$ go version
go version go1.4.2 linux/amd64

[Nikolai Derzhak]

Fixed it with next patch:

diff --git a/ops_executor.go b/ops_executor.go
index 99d5160..71ee781 100644
--- a/ops_executor.go
+++ b/ops_executor.go
@@ -47,11 +47,11 @@ func (e *OpsExecutor) execQuery(
        query := coll.Find(content["query"])
        result := []Document{}
        if content["ntoreturn"] != nil {
-               ntoreturn := int(content["ntoreturn"].(float64))
+               ntoreturn := int(content["ntoreturn"].(int32))
                query.Limit(ntoreturn)
        }
        if content["ntoskip"] != nil {
-               ntoskip := int(content["ntoskip"].(float64))
+               ntoskip := int(content["ntoskip"].(int32))
                query.Skip(ntoskip)
        }
        err := query.All(&result)

Let me know if it is ok and I will create PR.

[Travis Cline]

Please guard this with either a two-value type assertion or a type switch (and handle both cases).

[Nikolai Derzhak]

Sorry I am not familiar with go lang. Could you show me proper fix ?

[Travis Cline]

@nikolaiderzhak http://play.golang.org/p/yJ9AHa35NI should help

[Nikolai Derzhak]

@tmc Thanks Travis. That is from stackoverflow I found too :).

Could you provide ready patch for our case ? I really have dull view of what need to be done with that tricky (for not familiar person) Go syntax.

I will use provided above patch meanwhile. Until I get some spare time to play with that improvement.

[Travis Redman]

I just pushed a patch. Can you try the latest master and see if it fixes your issue? 97ad7ab

[David Murphy]

Travis was I writing my own on this, and you pushed right to master :P Anyhow both ways work, but I worry that we should not set query.Limit vs settings it to 0. It could change the test output if its normally returning 10k or 100k and we ask it for 0.

Thoughts?

[Travis Redman]

@dbmurphy yeah you're right. How about bd3ffb0 ? We just return and log an error if ntoreturn or ntoskip are some type we don't recognize.

[David Murphy]

Yeah that looks good.

[Nikolai Derzhak]

Sorry for delay. I have back to my benchmarking tasks and tested latest master (bd3ffb0) .

Did not get exceptions. So can I assume that the tool replays recorded operations correctly now ?

[Travis Redman]

Yes, the unprotected type assertion is now fixed.