1 files changed, 55 insertions, 0 deletions
diff --git a/app/src/main/java/dev/msfjarvis/aps/util/git/GitLogModel.kt b/app/src/main/java/dev/msfjarvis/aps/util/git/GitLogModel.kt
new file mode 100644
index 00000000..f6bbd55d
--- /dev/null
+++ b/app/src/main/java/dev/msfjarvis/aps/util/git/GitLogModel.kt
@@ -0,0 +1,55 @@
+/*
+ * Copyright © 2014-2020 The Android Password Store Authors. All Rights Reserved.
+ * SPDX-License-Identifier: GPL-3.0-only
+ */
+
+package dev.msfjarvis.aps.util.git
+
+import com.github.ajalt.timberkt.e
+import com.github.michaelbull.result.getOrElse
+import com.github.michaelbull.result.runCatching
+import dev.msfjarvis.aps.data.repo.PasswordRepository
+import dev.msfjarvis.aps.util.extensions.hash
+import dev.msfjarvis.aps.util.extensions.time
+import org.eclipse.jgit.api.Git
+import org.eclipse.jgit.revwalk.RevCommit
+
+private fun commits(): Iterable<RevCommit> {
+    val repo = PasswordRepository.getRepository(null)
+    if (repo == null) {
+        e { "Could not access git repository" }
+        return listOf()
+    }
+    return runCatching {
+        Git(repo).log().call()
+    }.getOrElse { e ->
+        e(e) { "Failed to obtain git commits" }
+        listOf()
+    }
+}
+
+/**
+ * Provides [GitCommit]s from a git-log of the password git repository.
+ *
+ * All commits are acquired on the first request to this object.
+ */
+class GitLogModel {
+
+    // All commits are acquired here at once. Acquiring the commits in batches would not have been
+    // entirely sensible because the amount of computation required to obtain commit number n from
+    // the log includes the amount of computation required to obtain commit number n-1 from the log.
+    // This is because the commit graph is walked from HEAD to the last commit to obtain.
+    // Additionally, tests with 1000 commits in the log have not produced a significant delay in the
+    // user experience.
+    private val cache: MutableList<GitCommit> by lazy(LazyThreadSafetyMode.NONE) {
+        commits().map {
+            GitCommit(it.hash, it.shortMessage, it.authorIdent.name, it.time)
+        }.toMutableList()
+    }
+    val size = cache.size
+
+    fun get(index: Int): GitCommit? {
+        if (index >= size) e { "Cannot get git commit with index $index. There are only $size." }
+        return cache.getOrNull(index)
+    }
+}