# PDF::Writer running out of memory

**URL:** <https://www.ruby-forum.com/t/pdf-writer-running-out-of-memory/99803>\
**Category:** Ruby\
**Created:** [February 1, 2006, 7:01pm UTC](https://www.ruby-forum.com/t/pdf-writer-running-out-of-memory/99803 "2006-02-01T19:01:10Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [February 1, 2006, 7:01pm UTC](https://www.ruby-forum.com/t/pdf-writer-running-out-of-memory/99803/1 "2006-02-01T19:01:10Z")

</div>

I have a bunch of XML files containing specifications and I want to  
create a PDF file with an overview of the description element from those  
XML files.  
I parse the XML and convert it into a Spec object than I create the PDF  
using some attributes.  
Now, the following code runs out of memory at about 53 out of 87 of  
those specs.  
header and footer add a line and a bit of text (it’s actually code  
adapted from the PDF::Writer Manual Techbook 🙂 )

def create  
#creation time  
@time=Time.now.strftime(“%d/%m/%Y - %H:%M”)  
#main title/front page  
title  
#page header  
header  
#page footer  
footer  
@pdf.start\_new\_page  
@pdf.start\_page\_numbering(@pdf.absolute\_right\_margin, 36, 6,:right)  
specifications.each do |s|  
puts “doing #{s.name}”  
spec\_table(s).render\_on(@pdf)  
end  
return  
end

def spec\_table spec  
table=PDF::SimpleTable.new  
table.column\_order=[“row”]  
table.title=spec.title  
table.data=[{“row”=\>spec.description}]  
table.show\_headings=false  
table.width=@pdf.margin\_width  
table.header\_gap=20  
return table  
end

Below is the backtrace.  
Now before you all scream, I did reuse the SimpleTable object to avoid  
instantiating it for every spec. This did not make much difference,  
since the script run out of memory at exactly the same place.  
Is there a solution to this problem or do I need to work around it?  
Is there a workaround that gives me a single PDF at the end?  
All I can think about now is breaking the overview doc in several  
pieces.  
Keep in mind that the number of specs is only going to grow in the  
future.  
Cheers,  
V.-

* * *

## d:/dev/ruby/lib/ruby/gems/1.8/gems/transaction-simple-1.3.0/lib/transaction/simple.rb:370:in `dump': failed to allocate memory (NoMemoryError) from d:/dev/ruby/lib/ruby/gems/1.8/gems/transaction-simple-1.3.0/lib/transaction/simple.rb:370:in `start\_transaction’from d:/dev/ruby/lib/ruby/gems/1.8/gems/transaction-simple-1.3.0/lib/transaction/simple/group.rb:89:in `start_transaction'from d:/dev/ruby/lib/ruby/gems/1.8/gems/transaction-simple-1.3.0/lib/transaction/simple/group.rb:89:in `each’from d:/dev/ruby/lib/ruby/gems/1.8/gems/transaction-simple-1.3.0/lib/transaction/simple/group.rb:89:in `start_transaction' from d:/dev/ruby/lib/ruby/gems/1.8/gems/pdf-writer-1.1.3/lib/pdf/simpletable.rb:497:in `render\_on’ from d:/dev/ruby/lib/ruby/gems/1.8/gems/pdf-writer-1.1.3/lib/pdf/simpletable.rb:488:in `each' from d:/dev/ruby/lib/ruby/gems/1.8/gems/pdf-writer-1.1.3/lib/pdf/simpletable.rb:488:in `render\_on’ from d:/dev/ruby/lib/ruby/gems/1.8/gems/pdf-writer-1.1.3/lib/pdf/simpletable.rb:401:in `loop' from d:/dev/ruby/lib/ruby/gems/1.8/gems/pdf-writer-1.1.3/lib/pdf/simpletable.rb:401:in `render\_on’ from ./test.rb:524:in `create' from ./test.rb:522:in `each’ from d:/dev/ruby/lib/ruby/gems/1.8/gems/rake-0.7.0/lib/rake.rb:844:in `send' from d:/dev/ruby/lib/ruby/gems/1.8/gems/rake-0.7.0/lib/rake.rb:844:in `each’ from ./test.rb:522:in `create' from ./test.rb:493:in `overview’ from overview.rb:72

[http://www.braveworld.net/riva](http://www.braveworld.net/riva)

---

<div class="post-metadata">

**Author:** ![casper\_the\_ghost](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/c/58956e/32.png) [@casper\_the\_ghost](https://www.ruby-forum.com/u/casper_the_ghost)\
**Post date:** [February 1, 2006, 7:58pm UTC](https://www.ruby-forum.com/t/pdf-writer-running-out-of-memory/99803/2 "2006-02-01T19:58:38Z")

</div>

On 01/02/06, Damphyr [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote:

> I have a bunch of XML files containing specifications and I want to  
> create a PDF file with an overview of the description element from  
> those XML files. I parse the XML and convert it into a Spec object  
> than I create the PDF using some attributes. Now, the following code  
> runs out of memory at about 53 out of 87 of those specs. header and  
> footer add a line and a bit of text (it’s actually code adapted from  
> the PDF::Writer Manual Techbook 🙂 )

I have had someone else report this and provide me with a customized  
SimpleTable that drastically reduces the memory usage but drops  
some…recoverability; it does not surprise me that this is happening,  
but I have had no time to investigate exactly what can be done. It does  
not surprise me that this is happening, and there may be several ways to  
solve this.

The problem is best shown with code:

require ‘transaction/simple’

class Parent  
include Transaction::Simple

```
attr_accessor :children
def add_children(*children)
  children.each { |x|
    x.parent = self
    @children << x
  }
end
def initialize
  @children = []
end

```

end

class Child  
attr\_accessor :parent  
end

def show\_ids(parent)  
puts \<\<-EOS  
self \<#{parent.object\_id}\> [ #{parent.children.map do |el|  
el.parent.object\_id end.join(', ') } ]  
EOS  
end

a = Parent.new  
a.add\_children Child.new ; nil  
show\_ids(a) # self\<24875792\> [24875792]  
a.start\_transaction ; nil  
a.add\_children Child.new, Child.new ; nil  
show\_ids(a) # self\<24875792\> [24875792, 24875792, 24875792]  
a.rewind\_transaction ; nil  
a.add\_children Child.new, Child.new ; nil  
show\_ids(a) # self\<24875792\> [24852044, 24875792, 24875792]

That last one is the source of the memory leak. It’s also the source of  
a much more subtle bug in the making it impossible to set certain things  
“late” in the process.

-austin