From 5dc467310ddebeae8dcb6262f5499f37382711ab Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Roman=20Smr=C5=BE?= <roman.smrz@seznam.cz>
Date: Wed, 17 Feb 2021 22:15:27 +0100
Subject: WatchedHead object allowing to stop watching Head

---
 src/storage.h | 22 ++++++++++++++++------
 1 file changed, 16 insertions(+), 6 deletions(-)

(limited to 'src/storage.h')

diff --git a/src/storage.h b/src/storage.h
index b8d769c..7ed8cf6 100644
--- a/src/storage.h
+++ b/src/storage.h
@@ -39,7 +39,8 @@ public:
 	virtual vector<tuple<UUID, Digest>> headRefs(UUID type) const = 0;
 	virtual UUID storeHead(UUID type, const Digest & dgst) = 0;
 	virtual bool replaceHead(UUID type, UUID id, const Digest & old, const Digest & dgst) = 0;
-	virtual void watchHead(UUID type, const function<void(UUID id, const Digest &)> &) = 0;
+	virtual int watchHead(UUID type, const function<void(UUID id, const Digest &)> &) = 0;
+	virtual void unwatchHead(UUID type, int watchId) = 0;
 
 	virtual optional<vector<uint8_t>> loadKey(const Digest &) const = 0;
 	virtual void storeKey(const Digest &, const vector<uint8_t> &) = 0;
@@ -60,7 +61,8 @@ public:
 	virtual vector<tuple<UUID, Digest>> headRefs(UUID type) const override;
 	virtual UUID storeHead(UUID type, const Digest & dgst) override;
 	virtual bool replaceHead(UUID type, UUID id, const Digest & old, const Digest & dgst) override;
-	virtual void watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual int watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual void unwatchHead(UUID type, int watchId) override;
 
 	virtual optional<vector<uint8_t>> loadKey(const Digest &) const override;
 	virtual void storeKey(const Digest &, const vector<uint8_t> &) override;
@@ -83,7 +85,8 @@ private:
 	std::thread watcherThread;
 	int inotify = -1;
 	int inotifyWakeup = -1;
-	unordered_multimap<UUID, function<void(UUID id, const Digest &)>> watchers;
+	int nextWatcherId = 1;
+	unordered_multimap<UUID, tuple<int, function<void(UUID id, const Digest &)>>> watchers;
 	unordered_map<int, UUID> watchMap;
 };
 
@@ -102,7 +105,8 @@ public:
 	virtual vector<tuple<UUID, Digest>> headRefs(UUID type) const override;
 	virtual UUID storeHead(UUID type, const Digest & dgst) override;
 	virtual bool replaceHead(UUID type, UUID id, const Digest & old, const Digest & dgst) override;
-	virtual void watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual int watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual void unwatchHead(UUID type, int watchId) override;
 
 	virtual optional<vector<uint8_t>> loadKey(const Digest &) const override;
 	virtual void storeKey(const Digest &, const vector<uint8_t> &) override;
@@ -113,7 +117,8 @@ private:
 	unordered_map<Digest, vector<uint8_t>> keys;
 
 	mutex watcherLock;
-	unordered_multimap<UUID, function<void(UUID id, const Digest &)>> watchers;
+	int nextWatcherId = 1;
+	unordered_multimap<UUID, tuple<int, function<void(UUID id, const Digest &)>>> watchers;
 };
 
 class ChainStorage : public StorageBackend
@@ -134,7 +139,8 @@ public:
 	virtual vector<tuple<UUID, Digest>> headRefs(UUID type) const override;
 	virtual UUID storeHead(UUID type, const Digest & dgst) override;
 	virtual bool replaceHead(UUID type, UUID id, const Digest & old, const Digest & dgst) override;
-	virtual void watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual int watchHead(UUID type, const function<void(UUID id, const Digest &)> &) override;
+	virtual void unwatchHead(UUID type, int watchId) override;
 
 	virtual optional<vector<uint8_t>> loadKey(const Digest &) const override;
 	virtual void storeKey(const Digest &, const vector<uint8_t> &) override;
@@ -142,6 +148,10 @@ public:
 private:
 	shared_ptr<StorageBackend> storage;
 	unique_ptr<ChainStorage> parent;
+
+	mutex watcherLock;
+	int nextWatcherId = 1;
+	unordered_map<int, tuple<int, int>> watchers;
 };
 
 struct PartialStorage::Priv
-- 
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