如何使用JGit找到提交距离？

huangapple
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英文:

How to find commit distance using JGit?

问题

我有一个小的 Kotlin 工具类，使用 JGit 查找以下信息：

  1. branch, latestCommit, lastTag, lastTagCommit, lastReleaseTag, lastReleaseTagCommit, commitDistance

其中 lastReleaseTag 通过匹配给定的前缀来找到。

所有这些都在工作，除了 commitDistance，它表示在 latestCommit 和一个标签之间的提交次数。我正在使用 RevWalkUtils.count，但它总是返回零。

  1. class GitRepo(dir: File) {
  2.     private val log = LoggerFactory.getLogger(GitRepo::class.java)
  4.     constructor(dir: String) : this(File(dir))
  6.     private val repository = FileRepositoryBuilder()
  7.         .setGitDir(File(dir, ".git"))
  8.         .readEnvironment()
  9.         .findGitDir()
  10.         .setMustExist(true)
  11.         .build()
  13.     @JvmOverloads
  14.     fun info(releaseTagPrefix: String = "release/"): RepoInfo {
  15.         repository.use { repo ->
  16.             RevWalk(repo).use { walk ->
  17.                 val latestCommit: RevCommit? = Git(repository).use {
  18.                     try {
  19.                         it.log().setMaxCount(1).call().iterator().next()
  20.                     } catch (ex: NoHeadException) {
  21.                         log.warn("Repository has no HEAD")
  22.                         null
  23.                     }
  24.                 }
  26.                 val tags = repo.refDatabase.getRefsByPrefix("refs/tags/")
  27.                     .groupBy { it.name.startsWith("refs/tags/$releaseTagPrefix") }
  28.                     .mapValues { entry ->
  29.                         entry.value.maxByOrNull { it.name }
  30.                     }
  31.                 val lastReleaseTag = tags[true]
  32.                 val lastTag = tags[false]
  33.                 val lastTagCommit = lastTag?.toRevCommit(walk)
  34.                 val commitDistance = if (latestCommit == null || lastTagCommit == null) 0
  35.                 else RevWalkUtils.count(walk, latestCommit, lastTagCommit)
  37.                 return RepoInfo(
  38.                     repo.branch,
  39.                     latestCommit?.toObjectId()?.shorten(),
  40.                     lastTag?.tagName(),
  41.                     lastTag?.objectId?.shorten(),
  42.                     lastReleaseTag?.tagName(),
  43.                     lastReleaseTag?.objectId?.shorten(),
  44.                     commitDistance
  45.                 )
  46.             }
  47.         }
  48.     }
  50.     private fun ObjectId.shorten(): String {
  51.         return name.take(8)
  52.     }
  54.     private fun Ref.tagName(): String? {
  55.         return "refs\\/tags\\/(.*)".toRegex().find(this.name)?.groupValues?.get(1)
  56.     }
  58.     private fun Ref.toRevCommit(revWalk: RevWalk): RevCommit? {
  59.         val id = repository.refDatabase.peel(this)?.peeledObjectId ?: objectId
  60.         return try {
  61.             revWalk.parseCommit(id)
  62.         } catch (ex: MissingObjectException) {
  63.             log.warn("Tag: {} points to a non-existing commit", tagName())
  64.             null
  65.         }
  66.     }
  67. }

通过命令行调用 git rev-list --count start...end 返回 33。

JGit 版本为 5.9.0.202009080501-r。

英文:

I've a little Kotlin utility class that uses JGit to find the following information:

  1. branch, latestCommit, lastTag, lastTagCommit, lastReleaseTag, lastReleaseTagCommit, commitDistance

where lastReleaseTag is found by matching a given prefix.

All that is working, except for commitDistance, which is the number of commits between the latestCommit and a tag. I'm using RevWalkUtils.count, but it always returns zero.

  1. class GitRepo(dir: File) {
  2. private val log = LoggerFactory.getLogger(GitRepo::class.java)
  3. constructor(dir: String) : this(File(dir))
  4. private val repository = FileRepositoryBuilder()
  5. .setGitDir(File(dir, ".git"))
  6. .readEnvironment()
  7. .findGitDir()
  8. .setMustExist(true)
  9. .build()
  10. @JvmOverloads
  11. fun info(releaseTagPrefix: String = "release/"): RepoInfo {
  12. repository.use { repo ->
  13. RevWalk(repo).use { walk ->
  14. val latestCommit: RevCommit? = Git(repository).use {
  15. try {
  16. it.log().setMaxCount(1).call().iterator().next()
  17. } catch (ex: NoHeadException) {
  18. log.warn("Repository has no HEAD")
  19. null
  20. }
  21. }
  22. val tags = repo.refDatabase.getRefsByPrefix("refs/tags/")
  23. .groupBy { it.name.startsWith("refs/tags/$releaseTagPrefix") }
  24. .mapValues { entry ->
  25. entry.value.maxByOrNull { it.name }
  26. }
  27. val lastReleaseTag = tags[true]
  28. val lastTag = tags[false]
  29. val lastTagCommit = lastTag?.toRevCommit(walk)
  30. val commitDistance = if (latestCommit == null || lastTagCommit == null) 0
  31. else RevWalkUtils.count(walk, latestCommit, lastTagCommit)
  32. return RepoInfo(
  33. repo.branch,
  34. latestCommit?.toObjectId()?.shorten(),
  35. lastTag?.tagName(),
  36. lastTag?.objectId?.shorten(),
  37. lastReleaseTag?.tagName(),
  38. lastReleaseTag?.objectId?.shorten(),
  39. commitDistance
  40. )
  41. }
  42. }
  43. }
  44. private fun ObjectId.shorten(): String {
  45. return name.take(8)
  46. }
  47. private fun Ref.tagName(): String? {
  48. return "refs\\/tags\\/(.*)".toRegex().find(this.name)?.groupValues?.get(1)
  49. }
  50. private fun Ref.toRevCommit(revWalk: RevWalk): RevCommit? {
  51. val id = repository.refDatabase.peel(this)?.peeledObjectId ?: objectId
  52. return try {
  53. revWalk.parseCommit(id)
  54. } catch (ex: MissingObjectException) {
  55. log.warn("Tag: {} points to a non-existing commit", tagName())
  56. null
  57. }
  58. }
  59. }

A command line invocation of git rev-list --count start...end returns 33.

JGit 5.9.0.202009080501-r.

答案1

得分: 2

感谢 @fredrik，只需简单地在对 RevWalkUtils.count 的调用中交换提交即可。然而，事实证明 RevWalkUtils.count 返回的数量比 git rev-list --count start...end 大，可能是因为这个原因：

计算从起始点到达一个从终点可达的提交之间的提交数量。

我最终按以下方式更改了我的实现：

  1. class GitRepo(dir: File) {
  2.     constructor(dir: String) : this(File(dir))
  4.     private val log = LoggerFactory.getLogger(GitRepo::class.java)
  5.     private val repository = FileRepositoryBuilder()
  6.         .setGitDir(File(dir, ".git"))
  7.         .readEnvironment()
  8.         .findGitDir()
  9.         .setMustExist(true)
  10.         .build()
  12.     @JvmOverloads
  13.     fun info(tagPrefix: String = ".*"): RepoInfo {
  14.         repository.use { repo ->
  15.             val lastTag: Ref? = repo.refDatabase.getRefsByPrefix("refs/tags/")
  16.                 .filter { it.name.matches("refs/tags/$tagPrefix".toRegex()) }
  17.                 .maxByOrNull { it.name }
  18.             var latestCommit: RevCommit? = null
  19.             var lastTagCommit: RevCommit?
  20.             var commitDistance = 0
  21.             Git(repo).use { git ->
  22.                 try {
  23.                     latestCommit = git.log().setMaxCount(1).call().firstOrNull()
  24.                     lastTagCommit = lastTag?.let {
  25.                         val id = repo.refDatabase.peel(it)?.peeledObjectId ?: it.objectId
  26.                         git.log().add(id).call().firstOrNull()
  27.                     }
  28.                     if (latestCommit != null && lastTagCommit != null) {
  29.                         commitDistance = git.log().addRange(lastTagCommit, latestCommit).call().count()
  30.                     }
  31.                 } catch (ex: NoHeadException) {
  32.                     log.warn("Repository has no HEAD")
  33.                 } catch (ex: MissingObjectException) {
  34.                     log.warn("Tag: {} points to a non-existing commit: ", lastTag?.tagName(), ex.objectId.shorten())
  35.                 }
  37.                 return RepoInfo(
  38.                     repo.branch,
  39.                     latestCommit?.toObjectId()?.shorten(),
  40.                     lastTag?.tagName(),
  41.                     lastTag?.objectId?.shorten(),
  42.                     commitDistance
  43.                 )
  44.             }
  45.         }
  46.     }
  48.     private fun ObjectId.shorten(): String {
  49.         return name.take(8)
  50.     }
  52.     private fun Ref.tagName(): String? {
  53.         return "refs\\/tags\\/(.*)".toRegex().find(name)?.groupValues?.get(1)
  54.     }
  55. }
英文:

Thanks to @fredrik, it's just a simple matter of swapping the commits in the call to RevWalkUtils.count. However, it turns out that RevWalkUtils.count is returning a greater number than git rev-list --count start...end, perhaps because of this:
> count the number of commits that are reachable from start until a commit that is reachable from end is encountered

I ended up changing my implementation as follows:

  1. class GitRepo(dir: File) {
  2. constructor(dir: String) : this(File(dir))
  3. private val log = LoggerFactory.getLogger(GitRepo::class.java)
  4. private val repository = FileRepositoryBuilder()
  5. .setGitDir(File(dir, ".git"))
  6. .readEnvironment()
  7. .findGitDir()
  8. .setMustExist(true)
  9. .build()
  10. @JvmOverloads
  11. fun info(tagPrefix: String = ".*"): RepoInfo {
  12. repository.use { repo ->
  13. val lastTag: Ref? = repo.refDatabase.getRefsByPrefix("refs/tags/")
  14. .filter { it.name.matches("refs/tags/$tagPrefix".toRegex()) }
  15. .maxByOrNull { it.name }
  16. var latestCommit: RevCommit? = null
  17. var lastTagCommit: RevCommit?
  18. var commitDistance = 0
  19. Git(repo).use { git ->
  20. try {
  21. latestCommit = git.log().setMaxCount(1).call().firstOrNull()
  22. lastTagCommit = lastTag?.let {
  23. val id = repo.refDatabase.peel(it)?.peeledObjectId ?: it.objectId
  24. git.log().add(id).call().firstOrNull()
  25. }
  26. if (latestCommit != null && lastTagCommit != null) {
  27. commitDistance = git.log().addRange(lastTagCommit, latestCommit).call().count()
  28. }
  29. } catch (ex: NoHeadException) {
  30. log.warn("Repository has no HEAD")
  31. } catch (ex: MissingObjectException) {
  32. log.warn("Tag: {} points to a non-existing commit: ", lastTag?.tagName(), ex.objectId.shorten())
  33. }
  34. return RepoInfo(
  35. repo.branch,
  36. latestCommit?.toObjectId()?.shorten(),
  37. lastTag?.tagName(),
  38. lastTag?.objectId?.shorten(),
  39. commitDistance
  40. )
  41. }
  42. }
  43. }
  44. private fun ObjectId.shorten(): String {
  45. return name.take(8)
  46. }
  47. private fun Ref.tagName(): String? {
  48. return "refs\\/tags\\/(.*)".toRegex().find(name)?.groupValues?.get(1)
  49. }
  50. }

huangapple
  • 本文由 发表于 2020年10月22日 16:53:09
  • 转载请务必保留本文链接：https://go.coder-hub.com/64478667.html
  • eclipse
  • git
  • java
  • jgit
  • kotlin
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