I was wondering how I could do this as well. I ended up creating a custom
logger that tracks the # of logs generated, and then attaching it to the
connection.
```
require 'logger'
# A custom logger that tracks the count of logs generated
class CountLogger < Logger
def initialize(...)
@log_counter = Hash.new(0)
start_counting
super
end
# Returns the # of logs generated by log type: log_count(Logger::WARN)
# If no severity is passed in, return the total # of logs generated
def log_count(severity = nil)
severity.nil? ? @log_counter.values.sum : @log_counter[severity]
end
def start_counting
@counter_flag = true
end
def stop_counting
@counter_flag = false
end
def clear_counts
@log_counter = Hash.new(0)
end
def counting?
@counter_flag ||= false
end
def add(severity, message = nil, progname = nil)
@log_counter[severity] += 1 if counting?
super
end
end
@logger = CountLogger.new(nil)
DB.logger = @logger
# example of how you could make this work.
def count_queries
@logger.clear_counts
yield
puts "# of DB queries executed: #{@logger.log_count}"
end
```
One thing I've been playing around with is hooking this into Roda as a
plugin so that I can track the # of queries run per request. I can share
the code for it if there's interest in it.
Hope this helps!
On Friday, August 12, 2022 at 12:35:46 PM UTC-7 [email protected] wrote:
> Hey Mark,
>
> I'm no Jeremy, but I recently did something similar to detect N+1 issues
> in tests.
>
> I wrote a module that I prepended to `Sequel::Postgres::Dataset` and kept
> a `Thread.current[:queries]` in the block
>
> This only counts selects, you can override the other methods if necessary.
>
> module DatasetInstrumentation
> def fetch_rows(*)
> if Thread.current.key?(:queries)
> Thread.current[:queries] += 1
> end
>
> super
> end
> end
>
> Sequel::Postgres::Dataset.prepend(DatasetInstrumentation)
>
> ...
>
> def count_queries
> Thread.current[:queries] ||= 0
>
> yield
>
> count = Thread.current[:queries]
>
> Thread.current[:queries] = nil
>
> count
> end
>
> ...
>
> count_queries { Model.first }
>
> Hope this helps!
>
> On Friday, June 24, 2022 at 3:35:42 PM UTC-5 Jeremy Evans wrote:
>
>> On Fri, Jun 24, 2022 at 1:25 PM Mark Allen <[email protected]> wrote:
>>
>>> Specifically, I'm trying to do this exact thing, but with Sequel instead
>>> of ActiveRecord
>>>
>>>
>>> https://github.com/rmosolgo/graphql-ruby/blob/master/guides/dataloader/testing.md#testing-dataloader-sources
>>>
>>> On Friday, June 24, 2022 at 4:22:29 PM UTC-4 Mark Allen wrote:
>>>
>>>> Hi, I want to count the number of DB operations within a block. Can't
>>>> find any documentation how to do this. Found DB.extend_datasets which
>>>> looks
>>>> promising but can't find a way to UN-extend_dataset after. Thoughts?
>>>>
>>>
>> The easiest way is probably using a Database logger, and seeing how many
>> queries are logged during the block. You can remove the logger when the
>> block exits.
>>
>> Thanks,
>> Jeremy
>>
>
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