From d81a46d7b50f272efc19fd30822be216412910f9 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@scylladb.com>
Date: Mon, 7 Dec 2015 17:04:51 +0100
Subject: [PATCH] column_family: Add schema setters

There is one current schema for given column_family. Entries in
memtables and cache can be at any of the previous schemas, but they're
always upgraded to current schema on access.
---
 database.cc  | 12 ++++++++++++
 database.hh  |  1 +
 memtable.cc  |  4 ++++
 memtable.hh  |  1 +
 row_cache.cc |  4 ++++
 row_cache.hh |  1 +
 6 files changed, 23 insertions(+)

diff --git a/database.cc b/database.cc
index 6c338916bd..0a8e56a545 100644
--- a/database.cc
+++ b/database.cc
@@ -2237,3 +2237,15 @@ std::ostream& operator<<(std::ostream& os, const keyspace_metadata& m) {
     os << "}";
     return os;
 }
+
+void column_family::set_schema(schema_ptr s) {
+    dblog.debug("Changing schema version of {}.{} ({}) from {} to {}",
+                _schema->ks_name(), _schema->cf_name(), _schema->id(), _schema->version(), s->version());
+
+    for (auto& m : *_memtables) {
+        m->set_schema(s);
+    }
+
+    _cache.set_schema(s);
+    _schema = std::move(s);
+}
diff --git a/database.hh b/database.hh
index 5ba9795ac3..4a1db3c3be 100644
--- a/database.hh
+++ b/database.hh
@@ -228,6 +228,7 @@ public:
     column_family(column_family&&) = delete; // 'this' is being captured during construction
     ~column_family();
     schema_ptr schema() const { return _schema; }
+    void set_schema(schema_ptr);
     db::commitlog* commitlog() { return _commitlog; }
     future<const_mutation_partition_ptr> find_partition(schema_ptr, const dht::decorated_key& key) const;
     future<const_mutation_partition_ptr> find_partition_slow(schema_ptr, const partition_key& key) const;
diff --git a/memtable.cc b/memtable.cc
index 8cefdca883..f0f5ed1b46 100644
--- a/memtable.cc
+++ b/memtable.cc
@@ -295,3 +295,7 @@ void memtable::upgrade_entry(partition_entry& e) {
         });
     }
 }
+
+void memtable::set_schema(schema_ptr new_schema) noexcept {
+    _schema = std::move(new_schema);
+}
diff --git a/memtable.hh b/memtable.hh
index 3f26a6d6c0..32f37753eb 100644
--- a/memtable.hh
+++ b/memtable.hh
@@ -114,6 +114,7 @@ public:
     explicit memtable(schema_ptr schema, logalloc::region_group* dirty_memory_region_group = nullptr);
     ~memtable();
     schema_ptr schema() const { return _schema; }
+    void set_schema(schema_ptr) noexcept;
     future<> apply(memtable&);
     // Applies mutation to this memtable.
     // The mutation is upgraded to current schema.
diff --git a/row_cache.cc b/row_cache.cc
index 91d32edf6e..b679d1fdef 100644
--- a/row_cache.cc
+++ b/row_cache.cc
@@ -549,6 +549,10 @@ cache_entry::cache_entry(cache_entry&& o) noexcept
     }
 }
 
+void row_cache::set_schema(schema_ptr new_schema) noexcept {
+    _schema = std::move(new_schema);
+}
+
 mutation cache_entry::read(const schema_ptr& s) {
     auto m = mutation(_schema, _key, _p);
     if (_schema != s) {
diff --git a/row_cache.hh b/row_cache.hh
index 730b5d2173..45f091f679 100644
--- a/row_cache.hh
+++ b/row_cache.hh
@@ -242,6 +242,7 @@ public:
         return _tracker;
     }
 
+    void set_schema(schema_ptr) noexcept;
     const schema_ptr& schema() const;
 
     friend class just_cache_scanning_reader;