30x slower depending on the ttfunk v1.6.x or later than depending on the ttfunk v1.5.x

[hidakatsuya]

Problem

ttfunk is a font metrics parser for prawn. And prawn v2.2 depends on ttfunk ~> 1.5, so thinreports-generator that depend on prawn also depend on either ttfunk version v1.5.x or v1.6.x.

However, ttfunk v1.6.x is known to have the following performance issue:
prawnpdf/ttfunk#82

As a result, PDF generation performance will also be reduced in environments and applications where thinreports-generator depends on ttfunk version 1.6.

Solution

This problem can be solved by making the dependent ttfunk version explicit in 1.5.x:

# Gemfile
gem 'thinreports'
+ gem 'ttfunk', '~> 1.5.1`

[hidakatsuya]

Thinreports v0.12.0 was released yesterday, but this version has a note about the current status of this issue.

However, please note that there is no way to avoid this performance problem if you use prawn v2.3 or later, since prawn v2.3 or later depends on ttfunk v1.6 or later.

If you want to avoid this performance problem while using Thinreports v0.12.0, you can lock prawn with v2.2 in addition to ttfunk, as shown below:

# Gemfile
+ gem 'prawn', '~> 2.2.2'
gem 'ttfunk', '~> 1.5.1'

In addition, this performance issue is expected to be resolved in the pullrequest below.
prawnpdf/ttfunk#83

[hidakatsuya]

Great performance tuning on ttfunk has been merged: prawnpdf/ttfunk#90