git-fast-reword

Dependencies

• libgit2

macOS

brew install libgit2

Setup

$ go install

Usage

➜  git-fast-reword git:(master) ✗ make test
go build
cd utilite/testdata/django-like-queryset ; git reset --hard
HEAD сейчас на be51798 Update README.md
go test ./...
?       git-fast-reword [no test files]
ok      git-fast-reword/utilite 0.454s

➜  git-fast-reword git:(master) ✗ cd intellij-community 
➜  intellij-community git:(master) git-fast-reword -h
NAME:
   git-fast-reword - git-fast-reword hash new_message

USAGE:
   git-fast-reword [global options] command [command options] [arguments...]

COMMANDS:
   from-file, ff  
   help, h        Shows a list of commands or help for one command

GLOBAL OPTIONS:
   --help, -h  show help (default: false)
 
➜  intellij-community git:(master) cat test.json 
{
  "HEAD~31": "renamed HEAD~31",
  "HEAD~53": "renamed HEAD~53",
  "HEAD~173": "renamed HEAD~173"
}

➜  intellij-community git:(master) ✗ time git-fast-reword ff test.json
New hashes:
{
  "HEAD~173": "5d4cf25f2a99cd0fda742e206b109a9d19b2fe54",
  "HEAD~31": "24970821f817f3e2a36e9f6215b3a4e037244e0b",
  "HEAD~53": "f8eac669e619493ad7026d64151a127c90102d44"
}
git-fast-reword ff test.json  0,02s user 0,02s system 17% cpu 0,201 total

➜  intellij-community git:(master) git cat-file -p HEAD~31
tree 9876e6a8a3d9eb076d5787b4e54478409662ad7d
parent 77a3848975d4cbf80f54e356570c2a20c9f44683
author Yuriy Artamonov <[email protected]> 1588258011 +0300
committer intellij-monorepo-bot <[email protected]> 1588326021 +0000

renamed HEAD~31

➜  intellij-community git:(master) git cat-file -p HEAD~53
tree c6d98eaac03c46a1824b578876165f68ae155aa5
parent e24ba542c515b53320853e5ba4f724e790442186
author Vladislav.Soroka <[email protected]> 1588258289 +0300
committer intellij-monorepo-bot <[email protected]> 1588326021 +0000

renamed HEAD~53

➜  intellij-community git:(master) git cat-file -p HEAD~173
tree 7a035ec1c133f15d8850da4362324d93f38354d5
parent 222aad0c9aa95fb671000476c035f384a1de39a2
author Semyon Proshev <[email protected]> 1587481536 +0300
committer intellij-monorepo-bot <[email protected]> 1588197868 +0000

renamed HEAD~173

# bad case described below
➜  intellij-community git:(master) ✗ time git-fast-reword 13b78e06c18e2da98674b688e56df0b53b9fed76 "s bogom"
New hashes:
{
  "13b78e06c18e2da98674b688e56df0b53b9fed76": "8abaf5f64dee96bf5f1256daff3b3f6d32b1c070"
}
git-fast-reword 13b78e06c18e2da98674b688e56df0b53b9fed76 "s bogom"  6,52s user 0,73s system 92% cpu 7,818 total

➜  intellij-community git:(master) ✗ git cat-file -p 8abaf5f64dee96bf5f1256daff3b3f6d32b1c070
tree 60210d988e0eeb730544264e77a20b7cdda3ceb5
parent 28adfdb1e958083068562aa9909437d4db51f312
author Ivan Chirkov <[email protected]> 1587490014 +0200
committer intellij-monorepo-bot <[email protected]> 1587540666 +0000

s bogom

Algorithm

The utility traverses commits by doing DFS and updates them as needed. Recursion stops as soon as all commits with new messages are visited, therefore, in most cases, the utility will traverse only a small part of the graph. Since there may be a path between any two commits, then also this situation is possible:

Suppose we want to rename the commit 2. The search will go in the following order: 0-> 1-> 2 - here we saw that we’ve visited all commits with new messages (in this branch) and the recursion is stopped. Further, the search will go to 3 and since we do not know in advance whether there is a path to 2, then we have to traverse the entire graph to the very bottom. Looking at commit time (both commiter and author) is not an option, since it could have been changed before using rebase command. Since even in the worst case the utility runs within 10-13 seconds on the IntelliJ IDEA Community Edition repository, I did not bother and left everything as it is.