Error handling with exceptions in multi-thread download

there are three  program fragments,all of them  have same problems,
all  of them  can run ,but when i downloaded  30% data,an error

ocurr
undefined local variable or method `web’ for Data:Class (NameError)
cthreaddown is an array which contains many web.
would you kind to tell me how to fix it?
p1
for page_to_fetch in cthreaddown threads<<Thread.new(page_to_fetch) do |web| datafile="/home/pt/stock/" open(datafile,'a+'){|refile| open(web){|webfile| refile.puts webfile.read puts "#{web} is over" }} end end threads.each {|thr| begin thr.join rescue Timeout::Error => e puts "#{web} failed" rescue NameError => e puts "#{web} failed" rescue => e puts "#{web} failed" end }
p2
for page_to_fetch in cthreaddown threads<<Thread.new(page_to_fetch) do |web| datafile="/home/pt/stock/" open(datafile,'a+'){|refile| begin open(web){|webfile| refile.puts webfile.read puts "#{web} is over" }} rescue NameError => e puts "#{web} failed" rescue => e puts "#{web} wrong" end end end threads.each {|thr| thr.join }

 p3
 [code]
 for page_to_fetch in cthreaddown
 threads<<Thread.new(page_to_fetch) do |web|
     datafile="/home/pt/stock/"
     open(datafile,'a+'){|refile|
     begin
    open(web){|webfile|
          refile.puts  webfile.read
          puts "#{web}  is over"
     }}
    rescue NameError => e
       puts    "#{web}  failed"
    rescue => e
       puts  "#{web}  wrong"
     end
   end
  end

threads.each {|thr|
begin
thr.join
rescue Timeout::Error => e
puts “#{web} failed”
rescue NameError => e
puts “#{web} failed”
rescue => e
puts “#{web} failed”
end
}

You probably have a TimeOut error. And the errors actually comes from:

    rescue Timeout::Error => e
      puts    "#{web}  failed"

because web is not defined there.

B

i have omitted many lines of code,no TimeOut error,
for page_to_fetch in cthreaddown
threads<<Thread.new(page_to_fetch) do |web|
i have got an array— cthreaddown before
it can run , can get 30% data ,and then stop,

undefined local variable or method `web’ for Data:Class (NameError)

2010/8/27 Pen T. [email protected]:

there are three program fragments,all of them have same problems,
all of them can run ,but when i downloaded 30% data,an error
ocurr
undefined local variable or method `web’ for Data:Class (NameError)

You need to look into class methods of class Data. Somewhere there
you will find usage of “web” which is undefined. Unfortunately you
did not post that class so we cannot tell you where your error is.

cthreaddown is an array which contains many web.
would you kind to tell me how to fix it?
p1
[code]
for page_to_fetch in cthreaddown
threads<<Thread.new(page_to_fetch) do |web|
datafile="/home/pt/stock/"
open(datafile,‘a+’){|refile|
open(web){|webfile|
refile.puts webfile.read

You should use #write with #read and not #puts, because #puts does not
write out arguments unmodified. Also note that if webfile is large
this approach will break. You should better use blocked reading.

buffer = “”
while webfile.read(1024, buffer)
refile.write buffer
end

      puts    "#{web}  failed"
    rescue => e
      puts    "#{web}  failed"
   end
  }
 [/code]

Cheers

robert

sorry for that: def self.getdaystock(fromdate)

require ‘rubygems’
require ‘open-uri’
require ‘nokogiri’
require ‘mysql’
require ‘date’

class Data
def self.getdaystock()
time0=Time.now
i=0
cdown=[]
threads=[]
cthreaddown=[]
open("/home/pt/usa/stocklist",“r”){|item|
while line=item.gets
cdown<<line
end}
a=(fromdate.split("-")[1].to_i-1).to_s
b=fromdate.split("-")[2].to_s
c=fromdate.split("-")[0].to_s
d=Time.now.mon.to_s
e=Time.now.day.to_s
f=Time.now.year.to_s
cdown=cdown.map {|item|
item=‘http://ichart.finance.yahoo.com/table.csv?s=’+item.to_s+’&a=’+a+’&b=’+b+’&c=’+c+
‘&d=’+d+’&e=’+e+’&f=’+f+’&g=d&ignore=.csv’}
cdown.each.with_index {|item,idx|
cthreaddown<< item
i=i+1
if i==100 or idx==cdown.size-1 then
cthreaddown=cthreaddown.uniq
for page_to_fetch in cthreaddown
threads<<Thread.new(page_to_fetch) do |web|
datafile="/home/pt/usa/stock/"+web.split("=")[1].to_s.gsub("&a","")
begin
open(datafile,‘a+’){|refile|
open(web){|webfile|
refile.puts webfile.read
puts “#{web} over” }}
rescue Timeout::Error => e
puts “#{web} failed”
rescue NameError => e
puts “#{web} failed”
rescue => e
puts “#{web} wrong”
end
end
end
threads.each {|thr|
begin
thr.join
rescue Timeout::Error => e
puts “#{web} failed”
rescue NameError => e
puts “#{web} failed”
rescue => e
puts “#{web} failed”
end }
i=0
cthreaddown=[]
threads = []
sleep 0.01
else
end
}
end
end

i have opened 100 threads. there are 6000 companies in
/home/pt/usa/stocklist .

On 27.08.2010 16:22, Pen T. wrote:

cdown=[]
e=Time.now.day.to_s
threads<<Thread.new(page_to_fetch) do |web|
rescue => e
puts “#{web} failed”
end
end

i have opened 100 threads. there are 6000 companies in
/home/pt/usa/stocklist .

Well, there you have it. The error is in your exception handling code.

Btw, the whole code could use a bit of commenting and also be simplified
in areas. For example: you store Time.now initially and then call it
over and over again to fetch individual fields. This is not only
inefficient but also error prone because you will not get all values
from the same point in time.

Also, it’s a bad die to hardcode the URL in the middle of the code.
It’s much better to pass this as parameter or at least store it in some
constant for easier reference and documentation purposes.

Cheers

robert

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