Simplify Jbig2Image.decodeInteger()

[fkaelberer]

The nested braches look a little bit strange, but the new code is actually easier to compare to the spec.

[timvandermeij]

/botio test

[pdfjsbot]

From: Bot.io (Windows)

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Received

Command cmd_test from @timvandermeij received. Current queue size: 0

Live output at: http://107.22.172.223:8877/3f14d18f9ea041f/output.txt

[pdfjsbot]

From: Bot.io (Linux)

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Received

Command cmd_test from @timvandermeij received. Current queue size: 0

Live output at: http://107.21.233.14:8877/8d0f2858890fce6/output.txt

[pdfjsbot]

From: Bot.io (Windows)

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Success

Full output at http://107.22.172.223:8877/3f14d18f9ea041f/output.txt

Total script time: 23.64 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[pdfjsbot]

From: Bot.io (Linux)

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Success

Full output at http://107.21.233.14:8877/8d0f2858890fce6/output.txt

Total script time: 26.01 mins

• Font tests: Passed
• Unit tests: Passed
• Regression tests: Passed

[fkaelberer]

If I pulled readBits() out of the scope of decodeInteger(), I'd have to make decoder, contexts, and prev global, which I'd prefer to avoid.

Whichever version I use (old, inlined readBits(), 'global' readBits()), the speed difference between any of the versions neglectible. Most calls are made by decodeTextRegion() which, among other things, calls decodeInteger() 6000 times and takes 35-37ms no matter which version I use.
For comparison, decoder.readBit() is called 13M times on the same page.

So since speed doesn't really matter here, I'd rather keep the simplest version and leave it like it is.

[yurydelendik]

Let's go for simpler version. Thank you for the patch.

[p01]

That sounds reasonable. Good job on making this code easier to read/maintain!