This commit replaces the multuple `bytes.Containts` and `bytes.Replace` with a custom replacer that does one pass through the document and exploits the fact that there are two common prefixes we search for, `src=` and `href=`.
This is both faster and consumes less memory. There may be even better algos to use here, but we must leave some room for improvements for future versions.
This should also make it possible to solve #816.
```
benchmark old ns/op new ns/op delta
BenchmarkAbsUrl 25795 22597 -12.40%
BenchmarkXmlAbsUrl 17187 11166 -35.03%
benchmark old allocs new allocs delta
BenchmarkAbsUrl 60 33 -45.00%
BenchmarkXmlAbsUrl 30 16 -46.67%
benchmark old bytes new bytes delta
BenchmarkAbsUrl 5844 4167 -28.70%
BenchmarkXmlAbsUrl 3754 2069 -44.89%
```
Fixes#894
Remove the hugo-nav since it relied on a slow library. The current
build reimplements the absurl functionality based on string replace.
Discovered that my prior implementation missed the requirement for
making absolute paths (/path) absolute with the host, whereas a relative
path is left untouched. Updated the test cases to support this if this
is reimplemented.
50% speedup. Fix#91
to run the benchmark:
go test -test.run=NONE -bench=".*" -test.benchmem=true ./transform/ > new.txt
to compare the results:
/usr/local/go/misc/benchcmp baseline.txt new.txt
Speedup and memory improvements
benchmark old ns/op new ns/op delta
BenchmarkChain 101219 50453 -50.15%
BenchmarkTransform 51625 45531 -11.80%
benchmark old allocs new allocs delta
BenchmarkChain 222 103 -53.60%
BenchmarkTransform 135 106 -21.48%
benchmark old bytes new bytes delta
BenchmarkChain 23919 10998 -54.02%
BenchmarkTransform 11858 10665 -10.06%
