Diff 2.0 (#515)
Diff 2.0 (#515)

* impl bingenerate

* fix

* improve: when index exist, use GetApproximateMidBySize, if not, use GetApproximateMid

* fix

* add example

* fix

* add example

* fix

* fix

* fix

* fix

* fix

* impl config hash

* impl conifg hash

* fix

* fix

* fix

* remove redundent log

* fix

* fix

* fix

* fix

* add todo

* fix chunk id

* fix

* impl report

* fix

* fix

* fix bounds is empty bug

* fix

* add test

* fix

* fix summary

* fix

* fix

* fix

* fix

* fix

* fix unit_test

* fix unit_test and remove some redundant code

* fix bingenerate bug

* fix

* async produce chunkIter

* impl produceChunkIter

* fix

* fix

* fix

* fix

* fix

* fix

* fix

* fix

* fix

* fix checkpoint

* fix checkpoint

* fix unit test

* fix

* fix checkpoint

* fix checkpoint

* fix checkpoint
pingcap/tidb-tools,pingcap/tidb-tools