From c4b7ce37168edf66ccf0a53131278d17600e1bd4 Mon Sep 17 00:00:00 2001
From: Arnon Keereena <arnon.keereena@allianz.com>
Date: Thu, 4 May 2017 09:33:14 +0200
Subject: [PATCH] Remove branch iterator caching Add support for sequencing to
 allow syntax for commit in repo.commits(in: branch)

---
 SwiftGit2/CommitIterator.swift      | 75 ++++++++++++++++++++++++++++-
 SwiftGit2/Repository.swift          | 14 +-----
 SwiftGit2Tests/RepositorySpec.swift |  4 +-
 3 files changed, 78 insertions(+), 15 deletions(-)

diff --git a/SwiftGit2/CommitIterator.swift b/SwiftGit2/CommitIterator.swift
index 3d84f0be..6ad5cd55 100644
--- a/SwiftGit2/CommitIterator.swift
+++ b/SwiftGit2/CommitIterator.swift
@@ -6,7 +6,8 @@
 import Result
 import libgit2
 
-public class CommitIterator: IteratorProtocol {
+public class CommitIterator: IteratorProtocol, Sequence {
+	public typealias Iterator = CommitIterator
 	public typealias Element = Result<Commit, NSError>
 	let repo: Repository
 	private var revisionWalker: OpaquePointer? = nil
@@ -64,4 +65,76 @@ public class CommitIterator: IteratorProtocol {
 		git_commit_free(unsafeCommit)
 		return result
 	}
+	
+	public func makeIterator() -> CommitIterator {
+		return self
+	}
+	
+	public private(set) var underestimatedCount: Int = 0
+	public func map<T>(_ transform: (Result<Commit, NSError>) throws -> T) rethrows -> [T] {
+		var new: [T] = []
+		for item in self {
+			new = new + [try transform(item)]
+		}
+		return new
+	}
+	
+	public func filter(_ isIncluded: (Result<Commit, NSError>) throws -> Bool) rethrows -> [Result<Commit, NSError>] {
+		var new: [Result<Commit, NSError>] = []
+		for item in self {
+			if try isIncluded(item) {
+				new = new + [item]
+			}
+		}
+		return new
+	}
+	
+	public func forEach(_ body: (Result<Commit, NSError>) throws -> Void) rethrows {
+		for item in self {
+			try body(item)
+		}
+	}
+	
+	private func notImplemented(functionName: Any) {
+		assert(false, "CommitIterator does not implement \(functionName)")
+	}
+	private init(repo: Repository) {
+		self.repo = repo
+	}
+	
+	public func dropFirst(_ n: Int) -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: self.dropFirst)
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func dropLast(_ n: Int) -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: self.dropLast)
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func drop(while predicate: (Result<Commit, NSError>) throws -> Bool) rethrows -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: self.drop)
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func prefix(_ maxLength: Int) -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: "prefix(_ maxLength:")
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func prefix(while predicate: (Result<Commit, NSError>) throws -> Bool) rethrows -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: "prefix(with predicate:")
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func suffix(_ maxLength: Int) -> AnySequence<Iterator.Element> {
+		notImplemented(functionName: self.suffix)
+		return AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }
+	}
+	
+	public func split(maxSplits: Int, omittingEmptySubsequences: Bool, whereSeparator isSeparator: (Result<Commit, NSError>) throws -> Bool) rethrows -> [AnySequence<Iterator.Element>] {
+		notImplemented(functionName: self.split)
+		return [AnySequence<Iterator.Element> { return CommitIterator(repo: self.repo) }]
+	}
+	
 }
diff --git a/SwiftGit2/Repository.swift b/SwiftGit2/Repository.swift
index a41d795c..0b0f65ab 100644
--- a/SwiftGit2/Repository.swift
+++ b/SwiftGit2/Repository.swift
@@ -510,22 +510,12 @@ final public class Repository {
 		return setHEAD(reference).flatMap { self.checkout(strategy: strategy, progress: progress) }
 	}
 	
-	/// Cache for commits(in: branch)
-	///
-	/// Specifically for allowing syntax "while let commit = repo.commits(in: branch).next() {}"
-	public var branchCommitIteratorMap: [Branch: CommitIterator] = [:]
-	
 	/// Load all commits in the specified branch in topological & time order descending
 	///
 	/// :param: branch The branch to get all commits from
 	/// :returns: Returns a result with array of branches or the error that occurred
 	public func commits(in branch: Branch) -> CommitIterator {
-		if let iterator = branchCommitIteratorMap[branch] {
-			return iterator
-		} else {
-			let iterator = CommitIterator(repo: self, root: branch.oid.oid)
-			branchCommitIteratorMap[branch] = iterator
-			return iterator
-		}
+		let iterator = CommitIterator(repo: self, root: branch.oid.oid)
+		return iterator
 	}
 }
diff --git a/SwiftGit2Tests/RepositorySpec.swift b/SwiftGit2Tests/RepositorySpec.swift
index 9019e7d8..0688dae7 100644
--- a/SwiftGit2Tests/RepositorySpec.swift
+++ b/SwiftGit2Tests/RepositorySpec.swift
@@ -619,10 +619,10 @@ class RepositorySpec: QuickSpec {
 				]
 				var commitMessages: [String] = []
 				for branch in branches {
-					while let commit = repo.commits(in: branch).next() {
+					for commit in repo.commits(in: branch) {
 						commitMessages.append(commit.value!.message)
 					}
-				}
+			}
 				expect(commitMessages.count).to(equal(expectedCount))
 				expect(commitMessages).to(equal(expectedMessages))
 			}