From dad2de7ba2323ff0f5c229968ec95f05b10b6f45 Mon Sep 17 00:00:00 2001
From: Nicolas Werner <nicolas.werner@hotmail.de>
Date: Sat, 2 May 2020 16:44:50 +0200
Subject: Add support for db migrations

---
 src/Cache.cpp | 36 ++++++++++++++++++++++++------------
 1 file changed, 24 insertions(+), 12 deletions(-)

(limited to 'src/Cache.cpp')

diff --git a/src/Cache.cpp b/src/Cache.cpp
index eb5c93aa..1a097cff 100644
--- a/src/Cache.cpp
+++ b/src/Cache.cpp
@@ -665,8 +665,15 @@ Cache::deleteData()
         }
 }
 
+//! migrates db to the current format
 bool
-Cache::isFormatValid()
+Cache::runMigrations()
+{
+        return true;
+}
+
+cache::CacheVersion
+Cache::formatVersion()
 {
         auto txn = lmdb::txn::begin(env_, nullptr, MDB_RDONLY);
 
@@ -676,18 +683,16 @@ Cache::isFormatValid()
         txn.commit();
 
         if (!res)
-                return false;
+                return cache::CacheVersion::Older;
 
         std::string stored_version(current_version.data(), current_version.size());
 
-        if (stored_version != CURRENT_CACHE_FORMAT_VERSION) {
-                nhlog::db()->warn("breaking changes in the cache format. stored: {}, current: {}",
-                                  stored_version,
-                                  CURRENT_CACHE_FORMAT_VERSION);
-                return false;
-        }
-
-        return true;
+        if (stored_version < CURRENT_CACHE_FORMAT_VERSION)
+                return cache::CacheVersion::Older;
+        else if (stored_version > CURRENT_CACHE_FORMAT_VERSION)
+                return cache::CacheVersion::Older;
+        else
+                return cache::CacheVersion::Current;
 }
 
 void
@@ -2468,10 +2473,17 @@ setup()
 }
 
 bool
-isFormatValid()
+runMigrations()
+{
+        return instance_->runMigrations();
+}
+
+cache::CacheVersion
+formatVersion()
 {
-        return instance_->isFormatValid();
+        return instance_->formatVersion();
 }
+
 void
 setCurrentFormat()
 {
-- 
cgit 1.5.1


From d6685e8d61baf7ac90daffa7457422daead55426 Mon Sep 17 00:00:00 2001
From: Nicolas Werner <nicolas.werner@hotmail.de>
Date: Sat, 2 May 2020 17:24:45 +0200
Subject: Add delete pending_receipts migration

---
 src/Cache.cpp | 43 ++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 42 insertions(+), 1 deletion(-)

(limited to 'src/Cache.cpp')

diff --git a/src/Cache.cpp b/src/Cache.cpp
index 1a097cff..1ae7a846 100644
--- a/src/Cache.cpp
+++ b/src/Cache.cpp
@@ -36,7 +36,7 @@
 
 //! Should be changed when a breaking change occurs in the cache format.
 //! This will reset client's data.
-static const std::string CURRENT_CACHE_FORMAT_VERSION("2018.09.21");
+static const std::string CURRENT_CACHE_FORMAT_VERSION("2020.05.01");
 static const std::string SECRET("secret");
 
 static lmdb::val NEXT_BATCH_KEY("next_batch");
@@ -669,6 +669,47 @@ Cache::deleteData()
 bool
 Cache::runMigrations()
 {
+        auto txn = lmdb::txn::begin(env_, nullptr, MDB_RDONLY);
+
+        lmdb::val current_version;
+        bool res = lmdb::dbi_get(txn, syncStateDb_, CACHE_FORMAT_VERSION_KEY, current_version);
+
+        txn.commit();
+
+        if (!res)
+                return false;
+
+        std::string stored_version(current_version.data(), current_version.size());
+
+        std::vector<std::pair<std::string, std::function<bool()>>> migrations{
+          {"2020.05.01",
+           [this]() {
+                   try {
+                           auto txn = lmdb::txn::begin(env_, nullptr);
+                           auto pending_receipts =
+                             lmdb::dbi::open(txn, "pending_receipts", MDB_CREATE);
+                           lmdb::dbi_drop(txn, pending_receipts, true);
+                           txn.commit();
+                   } catch (const lmdb::error &) {
+                           nhlog::db()->critical(
+                             "Failed to delete pending_receipts database in migration!");
+                           return false;
+                   }
+
+                   nhlog::db()->info("Successfully deleted pending receipts database.");
+                   return true;
+           }},
+        };
+
+        for (const auto &[target_version, migration] : migrations) {
+                if (target_version > stored_version)
+                        if (!migration()) {
+                                nhlog::db()->critical("migration failure!");
+                                return false;
+                        }
+        }
+
+        setCurrentFormat();
         return true;
 }
 
-- 
cgit 1.5.1